Interchange Databases

Table of Contents

1. Databases and Interchange

Interchange is database-independent, perhaps more so than almost any other powerful content management system.

Interchange can use GDBM, DB_File, SQL, LDAP, or in-memory databases. In most cases, these different database formats should operate the same when called by Interchange's access methods.

Also, most all of Interchange's core functions do not use hard-coded field names; virtually every field can have a configurable name.

Interchange does not require an external SQL database. If you have a small data set and do not want to integrate your own tool set, you cound use Interchange's internal database. However, the order management functions of Interchange will be slower and not as robust without an SQL database. SQL is strongly recommended for at least the state, country, orderline, transactions, and userdb tables. Any other tables that will have programmatic updates, such as inventory, will be best placed in SQL.

If you plan on using Interchange Admin UI, you should make the move to SQL. It provides easy import routines for text files that should replace text-file uploads.

Keeping a database in an SQL manager makes it easier to integrate Interchange with other tools. Interchange can be used to maintain a spreadsheet containing product information through modifying the file products.txt as needed. References to SQL, DBI, and DBD can be ignored.

1.1. Text Source Files

Interchange reads delimited text files to obtain its initial data. However, the text files are not the database. They are the source information for the database tables.

By default, all database source files are located in the products subdirectory of the catalog directory. The main products database is in the products/products.txt file in the supplied demo catalog.

Note: If you are using one of the internal database methods, any changes made to the ASCII source file will be reflected in the database in the next user session. If the product database contains less than a thousand records, updates will be instantaneous. If the product database is larger, updates will take longer. Use the NoImport reference tag to stop auto updating.

In the following configuration directive:

   Database  products  products.txt   TAB

the products table will obtain its source information from the file products.txt. What is done with it depends on the type of underlying database being used. The different types and their behavior are described below:


            NoImport  products
            Database products IMPORT_ONCE 1


           Database  products  DB_FILE   1



           Database   products   MEMORY   1

1.2. Interchange Database Conventions

This section describes naming and file usage conventions used with Interchange.

Note: Throughout the documentation, the following terms and their definitions are used interchangeably:

key, code

field, column

table, database

If necessary, Interchange can read the data to be placed in tables from a standard ASCII-delimited file. All of the ASCII source files are kept in the products directory, which is normally in the catalog directory (where catalog.cfg is located). The ASCII files can have ^M (carriage return) characters, but must have a new line character at the end of the line to work. NOTE: Mac users uploading files must use ASCII mode, not binary mode.

Interchange's default ASCII delimiter is TAB.

Note: The items must be separated by a single delimiter. The items in this document are lined up for reading convenience.


            code    description             price   image
            SH543   Men's fine cotton shirt 14.95   shirts.jpg


            SH543|Men's fine cotton shirt|14.95|shirts.jpg


            "SH543","Men's fine cotton shirt","14.95","shirts.jpg"

Note: Using the default TAB delimiter is recommended if you plan on searching the ASCII source file of the database. PIPE works fairly well, but CSV delimiter schemes might cause problems with searching.

IMPORTANT NOTE: Field names are usually case-sensitive. Use consistency when naming or you might encounter problems. All lower or all upper case names are recommended.

1.3. The Product Database

Each product being sold should be given a product code, usually referred to as SKU, a short code that identifies the product on the ordering page and in the catalog. The products.txt file is a ASCII-delimited list of all the product codes, along with an arbitrary number of fields which must contain at least the fields description and price (or however the PriceField and DescriptionField directives have been set). Any additional information needed in the catalog can be placed in any arbitrary field. See Interchange Database Capability for details on the format.

Field names can be case-sensitive depending on the underlying database type. Unless there are fields with the names "description" and "price" field, set the PriceField and DescriptionField directives to use the [item-price] and [item-description] tags.

The product code, or SKU, must be the first field in the line, and must be unique. Product codes can contain the characters A-Za-z0-9, along with hyphen (-), underscore (_), pound sign/hash mark (#), slash (/), and period (.). Note that slash (/) will interfere with on-the-fly page references. Avoid if at all possible.

The words should be separated by one of the approved delimiting schemes (TAB, PIPE, or CSV), and are case-sensitive in some cases. If the case of the "description" or "price" fields have been modified, the PriceField and DescriptionField directives must be appropriately set.

Note: CSV is not recommended as the scheme for the products database. It is much slower than TAB- or PIPE-delimited, and dramatically reduces search engine functionality. No field-specific searches are possible. Using CSV for any small database that will not be searched is fine.

IMPORTANT NOTE: The field names must be on the first line of the products.txt file. These field names must match exactly the field names of the [item-field] tags in the catalog pages, or the Interchange server will not access them properly. Field names can contain the characters A-Za-z0-9 and underscore (_).

More than one database may be used as a products database. If the catalog directive, ProductFiles, is set to a space-separated list of valid Interchange database identifiers, those databases will be searched (in the order specified) for any items that are ordered, or for product information (as in the [price code] and [field code] tags).

When the database table source file (i.e., products.txt) changes after import or edit, a DBM database is re-built upon the next user access. No restart of the server is necessary.

If changing the database on-the-fly, it is recommended that the file be locked while it is being modified. Interchange's supplied import routines do this.

1.4. Multiple Database Tables

Interchange can manage an unlimited number of arbitrary database tables. They use the TAB delimiter by default, but several flexible delimiter schemes are available. These are defined by default:

   Type 1      DEFAULT - uses default TAB delimiter
   Type 2      LINE
               Each field on its own line, a blank line
               separates the record. Watch those carriage
               returns! Also has a special format when CONTINUE
               is set to be NOTES.
   Type 3      %%
               Fields separated by a \n%%\n combination, records by
               \n%%%\n (where \n is a newline). Watch those carriage
   Type 4      CSV
   Type 5      PIPE
   Type 6      TAB
   Type 7      reserved
   Type 8      SQL
   Type 9      LDAP

The databases are specified in Database directives, as:

   Database    arbitrary arbitrary.csv CSV

This specifies a Type 4 database, the ASCII version of which is located in the file arbitrary.csv, and the identifier it will be accessed under in Interchange is "arbitrary." The DBM file, if any, will be created in the same directory if the ASCII file is newer, or if the DBM file does not exist. The files will be created as arbitrary.db or arbitrary.gdbm, depending on DBM type.

The identifier is case sensitive, and can only contain characters in the class [A-Za-z0-9_]. Fields are accessed with the [item_data identifier field] or [data identifier field key] elements. NOTE: Use of lower-case letters is strongly recommended.

If one of the first six types is specified, the database will automatically be built in the default Interchange DB style. The type can be specified with DB_FILE, GDBM, or MEMORY, if the type varies from that default. They will coexist with an unlimited number of DBI databases of different types.

In addition to the database, the session files will be kept in the default format, and are affected by the following actions.

The order of preference is:


            perl -e 'require GDBM_File and print "I have GDBM.\n"'

DB_File (Berkeley DB)

            perl -e 'require DB_File and print "I have Berkeley DB.\n"'
            # csh or tcsh
            setenv MINIVEND_DBFILE 1
            # sh, bash, or ksh
            Database arbitrary  DB_FILE  1


            Database arbitrary  MEMORY  1

Note: The use of memory databases is not recommended.

1.5. Character Usage Restrictions

To review, database identifiers, field names, and product codes (database keys) are restricted in the characters they may use. The following table shows the restrictions:

                                  Legal characters
 Database identifiers             A-Z a-z 0-9 _
 Field names                      A-Z a-z 0-9 _
 Database keys (product code/SKU) A-Z a-z 0-9 _ # - . /
 Database values                  Any (subject to field/record delimiter)

Some SQL databases have reserved words which cannot be used as field names; Interchange databases do not have this restriction.

For easy HTML compatibility, it is not recommended that a / be used in a part number if using the flypage capability. It can still be called [page href=flypage arg="S/KU"].

1.6. Database Attributes

Especially in SQL databases, there are certain functions that can be set with additional database attributes. For text import, the CONTINUE extended database import attribute allows additional control over the format of imported text.

Note: CONTINUE applies to all types except CSV. (Do not use NOTES unless using type LINE.)


          Database products products.txt  TAB
          Database products CONTINUE      DITTO
          code     price     description
          00-0011  500000    The Mona Lisa, one of the worlds great masterpieces.
                             Now at a reduced price!

Note: Fields are separated by tabs, formatted for reading convenience.

          Database products products.txt  LINE
          Database products CONTINUE      LINE
            The Mona Lisa, one of the worlds great masterpieces.
            Now at a reduced price!
            A special frame for the Mona Lisa.
          Database products products.txt  LINE
          Database products CONTINUE      NOTES
            description ~
            title: Mona Lisa
            price: 500000
            code: 00-0011
            image: 00-0011.jpg
            The Mona Lisa, one of the worlds great masterpieces.
            Now at a reduced price!
            title: The Art Store T-Shirt
            code: 99-102
            size: Medium, Large*, XL=Extra Large
            color: Green, Blue, Red, White*, Black
            price: 2000
            Extra large 1.00 extra.


            Database products EXCEL 1


        Database transactions LARGE 1

1.7. Dictionary Indexing With INDEX

Interchange will automatically build index files for a fast binary search of an individual field. This type of search is useful for looking up the author of a book based on the beginning of their last name, a book title based on its beginning, or other similar situations.

Such a search requires a dictionary ordered index with the field to be searched contained in the first field and the database key (product code) in the second field. If the INDEX field modifier is specified, Interchange will build the index upon database import:

  Database  products  products.txt   TAB
  Database  products  INDEX          title

If the title field is the fourth column in the products database table, a file products.txt.4 will be built, containing two tab-separated fields something like:

   American Gothic   19-202
   Mona Lisa         00-0011
   Sunflowers        00-342
   The Starry Night  00-343

Options can be appended to the field name after a colon (:). The most useful will be f, which does a case-insensitive sort. The mv_dict_fold option must be added to the search in this case.

Another option is c, which stands for "comma index." To index on comma-separated sub-fields within a field, use the :c option:

  Database  products  products.txt   TAB
  Database  products  INDEX          category:c

This can get slow for larger databases and fields. Interchange will split the field on a comma (stripping surrounding whitespace) and make index entries for each one. This allows multiple categories in one field while retaining the fast category search mechanism. It might also be useful for a keywords field.

The fast binary search is described in greater detail in THE SEARCH ENGINE below.

1.8. MEMORY for Memory-Only Databases

Interchange's memory-based databases are the fastest possible way to organize and store frequently used data. To force a database to be built in memory instead of DBM, use the MEMORY modifier:

  Database  country  country.asc   TAB
  Database  country  MEMORY        1

Obviously, large tables will use a great deal of memory, and the data will need to be re-imported from the ASCII source file at every catalog reconfiguration or Interchange restart. The big advantage of using MEMORY is that the database remains open at all times and does not need to be reinitialized at every connect. Use it for smaller tables that will be frequently accessed.

Memory tables are read only -- the MEMORY modifier forces IMPORT_ONCE.


The IMPORT_ONCE modifier tells Interchange not to re-import the database from the ASCII file every time it changes. Normally, Interchange does a comparison of the database file modification time with the ASCII source every time it is accessed, and if the ASCII source is newer it will re-import the file.

IMPORT_ONCE tells it only to import on a server restart or catalog reconfiguration:

  Database  products  products.txt   TAB
  Database  products  IMPORT_ONCE    1

SQL databases don't normally need this. They will only be imported once in normal operation. Also see NoImport for a way to guarantee that the table will never be imported.

IMPORT_ONCE is always in effect for MEMORY databases. A catalog reconfiguration is required to force a change.

1.10. MIRROR

Additionally, you can have two tables, the regular table and the memory table by adding to the definition files:

        Database country_memory country_memory.txt TAB
        Database country_memory MIRROR          country
        Database country_memory MEMORY          1

1.11. SQL/DBI parameters


Tells Interchange to use a SQL sequence to number new database items inserted into the database.

If you have Interchange create the table, then you need to do:

  Database foo foo.txt dbi:mysql:test
  Database foo AUTO_SEQUENCE foo_seq

Then on MySQL, Pg, or Oracle, Interchange will create an integer key type and a sequence (or AUTO_INCREMENT in MySQL) to maintain the count.


Sets the MAXVAL to have in an AUTO_SEQUENCE counter:

  Database foo AUTO_SEQUENCE_MAXVAL  1000000


Sets the MINVAL to have in an AUTO_SEQUENCE counter:

  Database foo AUTO_SEQUENCE_MINVAL  10


Sets the starting value for an AUTO_SEQUENCE counter:

  Database foo AUTO_SEQUENCE_START  1000


If you are using a DBI table with composite keys, where two or more fields combine to make the unique identifier for a record, you must tell Interchange so it can request data in the right way. To do this, set:

  Database  product_spec product_spec.asc dbi:mysql:foobase
  Database  product_spec COMPOSITE_KEY sku feature
  Database  product_spec COLUMN_DEF    "sku=varchar(32)"
  Database  product_spec COLUMN_DEF    "feature=varchar(128)"

If you want to create a custom index for the table, do so. If you don't specify a POSTCREATE or INDEX parameter for the table, Interchange will create a unique index with all composite key elements at table creation time.

1.11.6. DSN

The data source name (DSN) for the database. It is beyond the scope of this document to describe this in detail.

Normally this is set as the type in the initial Database configuration line, i.e.

  Database  foo  foo.txt  dbi:mysql:foobase

This has the same effect:

  Database  foo  foo.txt  SQL
  Database  foo  DSN      dbi:mysql:foobase

Some other examples of DSN specs:

 Database  foo  DSN;database=foobase
 Database  foo  DSN  dbi:Pg:dbname=foobase
 Database  foo  DSN;sid=ORCL


Informs Interchange that the SQL database in use has commit() and rollback() for transactions. For PostgreSQL and Oracle this should be set properly to 1 -- for MySQL and other databases you have to set it.

1.11.8. HAS_LIMIT

Informs Interchange that the SQL database in use has as the LIMIT extension to SQL to limit return from queries. Should be set properly by default for MySQL, PostgreSQL, and Oracle.


One or more SQL statements that should be performed after Interchange creates a table.

 Database foo POSTCREATE "create unique index foo_idx on foo(key1,key2)"
 Database foo POSTCREATE "create index mulkey_idx on foo(mulkey)"

1.11.10. PRECREATE

One or more SQL statements that should be performed before Interchange creates a table.

 Database foo POSTCREATE "drop table foobackup"
 Database foo POSTCREATE "alter table foo rename to foobackup"

1.11.11. REAL_NAME

Sometimes it may be convenient to have a table named a consistent value in Interchange despite its name in the underlying database. For instance, two divisions of a company may share orders but have different products tables. You can tell Interchange to name the table products for its purposes, but use the products_a table for SQL statements:

 Database products REAL_NAME products_a

Of course if you have SQL queries that are passed verbatim to Interchange (i.e. the [query ...] tag) you must use the REAL_NAME in those.

1.12. Importing in a Page

To add a data record to a database as a result of an order or other operation, use Interchange's [import ...] tag.

[import table type*] RECORD [/import]

         [import table=table_name

Import one or more records into a database. The type is any of the valid Interchange delimiter types, with the default being TAB. The table must already be a defined Interchange database table. It cannot be created on-the-fly. If on-the-fly functionality is need, it is time to use SQL.

The import type selected need not match the type the database was specified. Different delimiters may be used.

The type of LINE and continue setting of NOTES is particularly useful, for it allows fields to be named and not have to be in any particular order of appearance in the database. The following two imports are identical in effect:

   [import table=orders]
            code: [value mv_order_number]
   shipping_mode: [shipping-description]
          status: pending

   [import table=orders]
   shipping_mode: [shipping-description]
   status:        pending
   code:          [value mv_order_number]

The code or key must always be present, and is always named code. If NOTES mode is not used, the fields must be imported in the same order as they appear in the ASCII source file.

The file option overrides the container text and imports directly from a named file based in the catalog directory. To import from products.txt, specify file="products/products.txt". If the NoAbsolute directive is set to Yes in interchange.cfg, only relative path names will be allowed.

The [import ....] TEXT [/import] region may contain multiple records. If using NOTES mode, a separator must be used, which, by default, is a form-feed character (^L). See Import Attributes for more information.

1.13. Exporting from a Database

To export an existing database to a file to its text file, suitable for full-text search by Interchange, use Interchange's UI create a page that contains a [export table=TABLENAME] ITL tag (ExportTag).

1.14. Write Control

Interchange databases can be written in the normal course of events, either using the [import ...] tag or with a tag like [data table=table column=field key=code value=new-value]. To control writing of a global database, or to a certain catalog within a series of subcatalogs, or make one read only, see the following:

To enable write control:

   Database   products  WRITE_CONTROL  1

Once this is done, to make a database read only, which won't allow writing even if [tag flag write]products[/tag] is specified:

   Database   products  READ_ONLY  1

To have control with [tag flag write]products[/tag]:

   Database   products  WRITE_TAGGED  1

To limit write to certain catalogs, set:

   Database   products  WRITE_CATALOG  simple=0, sample=1

The "simple" catalog will not be able to write, while "sample" will if [tag flag write]products[/tag] is enabled. If a database is to always be writable, without having to specify [tag flag write] ... [/tag], then define:

   Database   products  WRITE_ALWAYS  1

The default behavior of SQL databases is equivalent to WRITE_ALWAYS, while the default for GDBM_File, DB_File, and Memory databases is equivalent to:

   Database   products  WRITE_CONTROL 1
   Database   products  WRITE_TAGGED  1

1.15. Global Databases

If a database is to be available to all catalogs on the Interchange server, it may be defined in interchange.cfg. Any catalog running under that server will be able to use it. It is writable by any catalog unless WRITE_CONTROL is used.

2. SQL Support

Interchange can use any of a number of SQL databases through the powerful Perl DBI/DBD access methods. This allows transparent access to any database engine that is supported by a DBD module. The current list includes mSQL, MySQL, Solid, PostgreSQL, Oracle, Sybase, Informix, Ingres, Dbase, DB2, Fulcrum, and others. Any ODBC (with appropriate driver) should also be supported.

No SQL database is included with Interchange, but there are a number widely available on the Internet. Most commonly used with Interchange are PostgreSQL, MySQL, and Oracle. It is beyond the scope of this document to describe SQL or DBI/DBD. Sufficient familiarity is assumed.

In most cases, Interchange cannot perform administrative functions, like creating a database or setting access permissions. This must be done with the tools provided with a SQL distribution. But, if given a blank database and the permission to read and write it, Interchange can import ASCII files and bootstrap from there.

2.1. SQL Support via DBI

The configuration of the DBI database is accomplished by setting attributes in additional Database directives after the initial defining line as described above. For example, the following defines the database arbitrary as a DBI database, sets the data source (DSN) to an appropriate value for an mSQL database named minivend on port 1114 of the local machine:

   Database arbitrary arbitrary.asc SQL
   Database arbitrary DSN           dbi:mSQL:minivend:localhost:1114

As a shorthand method, include the DSN as the type:

   Database arbitrary arbitrary.asc dbi:mSQL:minivend:localhost:1114

Supported configuration attributes include (but are not limited to):











ChopBlanks, LongReadLen, LongTruncOK, RaiseError, etc.


Here is an example of a completely set up DBI database on MySQL, using a comma-separated value input, setting the DBI attribute LongReadLen to retrieve an entire field, and changing some field definitions from the default char(128):

 Database   products  products.csv  dbi:mysql:minivend
 Database   products  USER          minivend
 Database   products  PASS          nevairbe
 Database   products  DELIMITER     CSV

 # Set a DBI attribute
 Database   products  LongReadLen   128

 # change some fields from the default field type of char(128)
 # Only applies if Interchange is importing from ASCII file
 # If you set a field to a numeric type, you must set the
 # NUMERIC attribute
 Database   products  COLUMN_DEF    "code=char(20) NOT NULL primary key"
 Database   products  COLUMN_DEF    price=float, discount=float
 Database   products  COLUMN_DEF    author=char(40), title=char(64)
 Database   products  COLUMN_DEF    nontaxable=char(3)
 Database   products  NUMERIC       price
 Database   products  NUMERIC       discount

MySQL, DBI, and DBD::mysql must be completely installed and tested, and have created the database minivend, for this to work. Permissions are difficult on MySQL. if having trouble, try starting the MySQL daemon with safe_mysqld --skip-grant-tables & for testing purposes.

To change to ODBC, the only changes required might be:

   Database products  DSN         dbi:ODBC:TCP/IP localhost 1313
   Database products  ChopBlanks  1

The DSN setting is specific to a ODBC setup. The ChopBlanks setting takes care of the space-padding in Solid and some other databases. It is not specific to ODBC. Once again, DBI, DBD::ODBC, and the appropriate ODBC driver must be installed and tested.

2.2. SQL Access Methods

An Interchange SQL database can be accessed with the same tags as any of the other databases can. Arbitrary SQL queries can be passed with the [query sql="SQL STATEMENT"] ITL tag.

            SELECT  sku, description
            FROM    products
            WHERE   somecol
                                        BETWEEN '[filter sql][cgi from][/filter]'
                                        AND '[filter sql][cgi to][/filter]'
            AND     someothercol = '[filter sql][cgi whatever][/filter]'
            ORDER BY sku
            sku=[sql-code] - desc=[sql-param description]<br>
            Something was found<br>
            Nothing was found<br>

Not the filter for [cgi foo] values, which prevent single quotes (') from destroying the query.

2.3. Importing from an ASCII File

When importing a file for SQL, Interchange by default uses the first column of the ASCII file as the primary key, with a char(16) type, and assigns all other columns a char (128) definition. These definitions can be changed by placing the proper definitions in COLUMN_DEF Database directive attribute:

 Database  products  COLUMN_DEF  price=char(20), nontaxable=char(3)

This can be set as many times as desired, if it will not fit on the line.

 Database  products  COLUMN_DEF  price=char(20), nontaxable=char(3)
 Database  products  COLUMN_DEF  description=char(254)

To create an index automatically, append the information when the value is in quotes:

 Database  products  COLUMN_DEF  "code=char(14) primary key"

The field delimiter to use is TAB by default, but can be changed with the Database DELIMITER directive:

 Database  products products.csv dbi:mSQL:minivend:localhost:1114
 Database  products DELIMITER  CSV

To create other secondary keys to speed sorts and searches, do so in the COLUMN_DEF:

 Database  products COLUMN_DEF  "author=char(64) secondary key"

Or use external database tools. NOTE: Not all SQL databases use the same index commands.

To use an existing SQL database instead of importing, set the NoImport directive in catalog.cfg to include any database identifiers not to be imported:

   NoImport  products inventory

WARNING: If Interchange has write permission on the products database, be careful to set the NoImport directive or create the proper .sql file. If that is not done, and the database source file is changed, the SQL database could be overwritten. In any case, always back up the database before enabling it for use by Interchange.

3. Managing DBM Databases

3.1. Making the Database

The DBM databases can be built offline with the offline command. The directory to be used for output is specified either on the command line with the -d option, or is taken from the catalog.cfg directive OfflineDir -- offline in the catalog directory by default. The directory must exist. The source ASCII files should be present in that directory, and the DBM files are created there. Existing files will be overwritten.

   offline -c catalog [-d offline_dir]

Do a perldoc VENDROOT/bin/offline for full documentation.

3.2. Updating Individual Records

If it takes a long time to build a very large DBM database, consider using the bin/update script to change just one field in a record, or to add from a corrections list.

The database is specified with the -n option, or is 'products' by default.

The following updates the products database price field for item 19-202 with the new value 25.00:

   update -c catalog -f price 25.00

More than one field can be updated on a single command line.

   update -c catalog -f price -f comment 25.00 "That pitchfork couple"

The following takes input from file, which must be formatted exactly like the original database, and adds/corrects any records contained therein.

   update -c catalog -i file

Invoke the command without any arguments for a usage message describing the options.

4. Other Database Capabilities

Interchange has a number of other options that can affect operation of or operations on a defined database.

4.1. Search Modification

Normally, Interchange can search any database and will return all records that match the search specification. Some attributes affect this.


When set to a field name, i.e.:

   Database  sometable  HIDE_FIELD  inactive

Interchange will not return records that have that field (in the example, c<inactive>) set to a true (non-blank, non-zero) value.

4.1.2. NO_SEARCH

An indication that the database should not be searchable by default. Used to determine the default search files for a product searc.

   Database  sometable  NO_SEARCH  1

In the foundation demo, this is used to prevent the options table from being searched for products.

4.2. Indexing

You can indicate that a database should be indexed on a field with the INDEX modifier:

        Database sometable  INDEX  category

This will create an ASCII index on every import, and will also create an index on the field at SQL creation time.

If you wish to create SQL indices at table creation time without creating an ASCII index, use the NO_ASCII_INDEX parameter:

        Database sometable  NO_ASCII_INDEX  1

Of course you can create a SQL index manually at any time via your SQL toolset.

5. The Search Engine

Interchange implements a search engine which will search the product database (or any other file) for items based on customer input. It uses either forms or link-based searches that are called with the special page name scan. The search engine uses many special Interchange tags and variables.

If the search is implemented in a link or a form, it will always display formatted results on the results page, an Interchange page that uses some combination of the [search-region], [search-list], [more-list], [more], and other Interchange tags to format and display the results. The search results are usually a series of product codes/SKUs or other database keys, which are then iterated over similar to the [item-list].

Note: Examples of search forms and result pages are included in the demos.

Two search engine interfaces are provided, and five types of searching are available. The default is a text-based search of the first products database source file (i.e., products.txt). A binary search of a dictionary-ordered file can be specified. An optional Glimpse search is enabled by placing the command specification for Glimpse in the catalog.cfg directive Glimpse. There is a range-based search, used in combination with one of the above. And finally, there is a fully-coordinated search with grouping.

The default, a text based search, sequentially scans the lines in the target file. By default it returns the first field (delineated by the delimiter for that database) for every line matching the search specification. This corresponds to the product code, which is then used to key specific accesses to the database.

The text-based search is capable of sophisticated field-specific searches with fully-independent case-sensitivity, substring, and negated matching.

5.1. The Search Form

A number of variables can be set on search forms to determine which search will be used, what fields in the database it will search, and what search behavior will be.

Here is a simple search form:

 <FORM ACTION="[area search]" METHOD=POST>
 <INPUT TYPE="text" SIZE="30" NAME="mv_searchspec">
 <INPUT TYPE="submit" VALUE="Search">

When the "Search" submit button is pressed (or <ENTER> is pressed), Interchange will search the products.txt file for the string entered into the text field mv_searchspec, and return the product code pertaining to that line.

The same search for a fixed string, say "shirt," could be performed with the use of a hot link, using the special scan URL:

 [page search="se=shirt"]See our shirt collection!</a>

The default is to search every field on the line. To match on the string "shirt" in the product database field "description," modify the search:

 <INPUT TYPE="hidden" NAME="mv_search_field" VALUE="description">

In the hot-linked URL search:

 [page search="
           "]See our shirt collection!</a>

To let the user decide on the search parameters, use checkboxes or radiobox fields to set the fields:

   Search by author
      <INPUT TYPE="checkbox" NAME="mv_search_field" VALUE="author">
   Search by title
       <INPUT TYPE="checkbox" NAME="mv_search_field" VALUE="title">

Fields can be stacked. If more than one is checked, all checked fields will be searched.

5.2. Glimpse

To use the Glimpse search, the Glimpse index must be built based on files in the ProductDir, or wherever the files to be searched will be located. If the catalog is in /var/lib/interchange/foundation, the command line to build the index for the products file would be:

   chdir /var/lib/interchange/foundation/products
   glimpseindex -b -H . products.txt

There are several ways to improve search speed for large catalogs. One method that works well for large products.txt files is to split the products.txt file into small index files (in the example, 100 lines) with the split(1) UNIX/POSIX command. Then, index it with Glimpse:

   split -100 products.txt index.txt.
   glimpseindex -H /var/lib/interchange/foundation/products index.txt.*

This will dramatically increase search speeds for large catalogs, at least if the search term is relatively unique. If it is a common string, in a category search, for example, it is better to use the text-based search.

To search for numbers, add the -n option to the Glimpse command line.

Note: A large catalog is one of more than several thousand items; smaller ones have acceptable speed in any of the search modes.

If the Glimpse executable is not found at Interchange startup, the Glimpse search will be disabled and the regular text-based search used instead.

There are several things to watch for while using Glimpse, and a liberal dose of the Glimpse documentation is suggested. In particular, the spelling error capability will not work in combination with the field-specific search. Glimpse selects the line, but Interchange's text-based search routines disqualify it when checking to see if the search string is within one of the specified fields.

To use field-specific searching on Glimpse, tell it what the field names are. If the search is on the products database (file), nothing is needed for the default is to use the field names from the products database. If it is some other field layout, specify the file to get the field names from with mv_field_file (ff).

5.3. Fast Binary Search

Fast binary searching is useful for scanning large databases for strings that match the beginning of a line. They use the standard Perl module Search::Dict, and are enabled through use of the mv_dict_look, mv_dict_end, mv_dict_limit, mv_dict_fold, and mv_dict_order variables.

The field to search is the first field in the file, the product code should be in the second field, delimited by TAB. Set the mv_return_fields=1 to return the product code in the search.

The search must be done on a dictionary-ordered pre-built index, which can be produced with the database INDEX modifier. See Dictionary indexing with INDEX.

If using the mv_dict_look parameter by itself, and the proper index file is present, Interchange will set the options:


This will make the search behave much like the simple search described above, except it will be much faster on large files and will match only from the beginning of the field. Here is an example. A title index has been built by including in catalog.cfg:

   Database   products   INDEX    title

Note: The ASCII source file must be "touched" to rebuild the index and the database.

Now, specify in a form:

   <FORM ACTION="[process href=search]" METHOD=POST>
   <INPUT TYPE=hidden NAME=mv_dict_limit VALUE=title>
   <INPUT NAME=mv_dict_look>

or in a URL:

   [page search="dl=Van Gogh/di=title"]

This search is case-sensitive. To do the same thing case-insensitively:

   Database   products   INDEX    title:f

   <FORM ACTION="[process href=search]" METHOD=POST>
   <INPUT TYPE=hidden NAME=mv_dict_limit VALUE=title>
   <INPUT TYPE=hidden NAME=mv_dict_fold  VALUE=1>
   <INPUT NAME=mv_dict_look>

   [page search="dl=Van Gogh/di=title/df=1"]

5.4. Coordinated and Joined Searching

Interchange will do a complete range of tests on individual columns in the database. To use this function, set mv_coordinate to Yes (co=yes in the one-click syntax). In order to use coordinated searching, the number of search fields must equal the number of search strings.

To make sure that is the case, use the mv_search_map variable. It allows variables to be mapped to others in the search specification. For example:

   <INPUT TYPE=hidden NAME=mv_search_map VALUE="
   <INPUT TYPE=hidden NAME=mv_search_field VALUE=title>
   <INPUT TYPE=hidden NAME=mv_search_field VALUE=artist>
   <INPUT TYPE=hidden NAME=mv_search_field VALUE=category>
   Artist: <INPUT NAME=search1 VALUE="">
   Title:  <INPUT NAME=search2 VALUE="">
   Genre:  <INPUT NAME=search3 VALUE="">

Even if the user leaves one blank, the search will work.

Leading/trailing whitespace is stripped from all lines in the mv_search_map variable, so it can be positioned as shown for convenience.

Coordinated searches may be joined with the output of another table if set one of the mv_search_field values is set to a table:column pair. Note that this will slow down large searches considerably unless there is another search specification, as the database must be accessed for every search line If there is a search field that qualifies for a regular expression search function, or conducting a binary search with mv_dict_look, or are not doing an OR search, the penalty should not be too great as only matching lines will cause an access to the database.

Individual field operations can then be specified with the mv_column_op (or op) parameter. The operations include:

   operation            string     numeric   equivalent
   equal to               eq         ==           =
   not equal              ne         !=           <>
   greater than           gt         >
   less than              lt         <
   less than/equal to     le         <=
   greater than/equal to  ge         >=
   regular expression     rm                       =~ , LIKE
   regular expression NOT rn                       !~
   exact match            em
   Text::Query::Advanced  aq
   Text::Query::Simple    tq

An example:

   [page search="
           se=Van Gogh
   "] Sunflowers, Van Gogh </a>

   [page search="


           se=Van Gogh

   "] Any in stock except Sunflowers, Van Gogh </a>

Note that in the second example, nu=0 must be specified even though that is the default. This is to set the proper correspondence. To avoid having to do this, use Interchange's option array feature:

   [page search.0="
                   se=Van Gogh
       ] Any in stock except Sunflowers, Van Gogh </a>

The co=yes is assumed when specifying a multiple search.

The second search will check the stock status of the painting provided there is an inventory table as in some of the Interchange demo catalogs. If the qty field is greater than or equal to 1, the product will be picked. If out of stock, it will not be found.

It always helps to have an rm type included in the search. This is used to pre-screen records so that database accesses only need be made for already-matching entries. If accesses must be made for every record, large searches can get quite slow.

The special aq and tq query types only operate if the Text::Query CPAN module is installed. This allows Altavista-style searches on the field, using AND, OR, NOT, and NEAR with arbitrarily complex parentheses.

A useful form for the aq type would be:

  <form action="[area search]" method=POST>
  <input type=hidden name=mv_session_id value="[data session id]">
  <input type=hidden name=mv_column_op VALUE="aq">
  <input type=hidden name=mv_coordinate VALUE=1>
  <input type=hidden name=mv_min_string value=2>
  <input type=hidden name=mv_search_field VALUE=":sku:description:comment:category">
  <input type=hidden name=mv_searchtype VALUE=db>
  <input name=mv_searchspec type=text size=12>
  <input type=submit value="SEARCH">

This searches the sku, description, comment, and category fields in the default products file with Text::Query syntax. Try the term "painters NEAR set" in the default foundation example.

5.5. Custom search operators

You can write your own search operator with Interchange's CodeDef. In interchange.cfg, or in the code directory tree, you can put:

 CodeDef find_mirrored SearchOp
 CodeDef find_mirrored Routine <<EOR
 sub {
       my ($self, $i, $pat) = @_;
       $pat = reverse $pat;
       return sub {
               my $string = shift;
               $string =~ /$pat/io;

Now you can do:

   [loop search="
   [loop-code] [loop-param description]<br>

The passed parameters are:

Must return a sub which receives the data to match and returns 1 if it matches. DOES NOT HONOR mv_negate UNLESS you tell it to.

See Vend::Search::create_text_query for an example of how to return a proper routine and look in search object for the associated params.

5.6. Specifying a Text-Based Search with SQL Syntax

If the Perl SQL::Statement module is installed, SQL syntax can be specified for the text-based search. This is not the same as the external SQL database search, treated below separately. This works on the ASCII text source file, not on the actual database.

This syntax allows this form setup:

   Artist: <INPUT NAME="artist">
   Title:  <INPUT NAME="title">
   <INPUT TYPE=hidden NAME="mv_sql_query"
               SELECT code FROM products
               WHERE artist LIKE artist
               AND    title LIKE title">

If the right hand side of an expression looks like a column, i.e., is not quoted, the appropriate form variable is substituted. (If used in a one-click, the corresponding scratch variable is used instead.) The assumption is reversed for the left-hand side. If it is a quoted string, the column name is read from the passed values. Otherwise, the column name is literal.

   Search for: <INPUT NAME="searchstring"><BR>
   Search in   <INPUT TYPE="radio" NAME="column" VALUE="title"> title
       <INPUT TYPE="radio" NAME="column" VALUE="artist"> artist
       <INPUT TYPE=hidden NAME="mv_sql_query"
         VALUE="SELECT code FROM products WHERE 'column' LIKE searchstring">

Once again, this does not conduct a search on an SQL database, but formats a corresponding text-based search. Parentheses will have no effect, and an OR condition will cause all conditions to be OR. The searches above would be similar to:

   [page search="
               se=[value artist]
               se=[value title]
           "  ]
       Search for [value artist], [value title]

   [page search="
               sf=[value column]
               se=[value searchstring]
           "  ]
   Search for [value searchstring]
          in  [value column]

5.7. One-Click Searches

Interchange allows a search to be passed in a URL, as shown above. Just specify the search with the special page parameter search or special page scan. Here is an example:

    [page search="
       Impressionist Paintings

This is the same:

    [page scan se=Impressionists/sf=category]
       Impressionist Paintings

Here is the same thing from a home page (assuming /cgi-bin/vlink is the CGI path for Interchange's vlink):

    <A HREF="/cgi-bin/vlink/scan/se=Impressionists/sf=category">
       Impressionist Paintings

The two-letter abbreviations are mapped with these letters:

 ac  mv_all_chars
 bd  mv_base_directory
 bs  mv_begin_string
 ck  mv_cache_key
 co  mv_coordinate
 cs  mv_case
 cv  mv_verbatim_columns
 de  mv_dict_end
 df  mv_dict_fold
 di  mv_dict_limit
 dl  mv_dict_look
 DL  mv_raw_dict_look
 do  mv_dict_order
 dr  mv_record_delim
 em  mv_exact_match
 er  mv_spelling_errors
 ff  mv_field_file
 fi  mv_search_file
 fm  mv_first_match
 fn  mv_field_names
 hs  mv_head_skip
 ix  mv_index_delim
 lb  mv_search_label
 lf  mv_like_field
 lo  mv_list_only
 lr  mv_search_line_return
 ls  mv_like_spec
 ma  mv_more_alpha
 mc  mv_more_alpha_chars
 md  mv_more_decade
 ml  mv_matchlimit
 mm  mv_max_matches
 MM  mv_more_matches
 mp  mv_profile
 ms  mv_min_string
 ne  mv_negate
 ng  mv_negate
 np  mv_nextpage
 nu  mv_numeric
 op  mv_column_op
 os  mv_orsearch
 pf  prefix
 ra  mv_return_all
 rd  mv_return_delim
 rf  mv_return_fields
 rn  mv_return_file_name
 rr  mv_return_reference
 rs  mv_return_spec
 se  mv_searchspec
 sf  mv_search_field
 sg  mv_search_group
 si  mv_search_immediate
 sm  mv_start_match
 sp  mv_search_page
 sq  mv_sql_query
 sr  mv_search_relate
 st  mv_searchtype
 su  mv_substring_match
 tf  mv_sort_field
 to  mv_sort_option
 un  mv_unique
 va  mv_value

These can be treated just the same as form variables on the page, except that they can't contain a new line. If using the multi-line method of specification, the characters will automatically be escaped for a URL.

IMPORTANT NOTE: An incompatibility in earlier Interchange catalogs is specifying [page scan/se=searchstring]. This is interpreted by the parser as [page scan/se="searchstring"] and will cause a bad URL. Change this to [page scan se=searchstring], or perhaps better yet:

   [page search="

A one-click search may be specified in three different ways.


         [page scan se=Surreal/se=Gogh/os=yes/su=yes/sf=artist/sf=category]
            Van Gogh -- compare to surrealists


            [page scan
                se="Van Gogh"
            ] Van Gogh -- compare to surrealists </a>


         [page href=scan se="Van Gogh"&sp=lists/surreal&os=yes&su=yes&sf=artist]
            Van Gogh -- compare to surrealists

5.8. Setting Display Options with mv_value

A value can be specified that will be set in the link with the mv_value parameter. It takes an argument of var=value, just as setting a normal variable in an Interchange profile. Actually mv_value is a misnomer, it will almost never be used in a form where variable values can be set. Always specify it in a one-click search with va=var=value. Example:

   [page href=scan
              va=category_name=Renaissance and Impressionist Paintings
              os=yes"]Renaissance and Impressionist Paintings</a>

Display the appropriate category on the search results page with [value category_name].

5.9. In-Page Searches

To specify a search inside a page with the [search-region parameters*] tag. The parameters are the same as the one-click search, and the output is always a newline-separated list of the return objects, by default, a series of item codes.

The [loop ...] tag directly accepts a search parameter. To search for all products in the categories "Americana" and "Contemporary," do:

   [loop search="
   Artist: [loop-field artist]<BR>
   Title: [loop-field title]<P>

The advantage of the in-page search is that searches can be embedded within searches, and there can be straight unchanging links from static HTML pages.

To place an in-page search with the full range of display in a normal results page, use the [search-region] tag the same as above, except that [search-list], [more-list], and [more] tags can be placed within it. Use them to display and format the results, including paging. For example:

   [search-region  more=1
   [page [item-code]]
       [item-field title]<A>, by [item-field artist]
       Sorry, no matches for [value mv_searchspec].

Note: The [item-code] above does not need to be quoted because it is replaced before the [page ...] tag is interpolated. If building large lists, this is worth doing because unquoted tags are twice as fast to parse.

To use the same page for search paging, make sure to set the sp=page parameter.

5.10. Search Profiles

An unlimited number of search profiles can be predefined that reside in a file or files. To use this, make up a series of lines like:


These correspond to the Interchange search variables that can be set on a form. Set it right on the page that contains the search.

[set artist_profile]

This is the same:

[set artist_profile]

Then, in the search form, set a variable with the name of the profile:

   <INPUT TYPE=hidden NAME=mv_profile VALUE=artist_profile>

In a one-click search, use the mp modifier:

[page scan se=Leonardo/mp=artist_profile]A left-handed artist</a>

They can also be placed in a file. Define the file name in the SearchProfile directive. The catalog must be reconfigured for Interchange to read it. The profile is named by placing a name following a __NAME__ pragma:

 __NAME__ title_search

The __NAME__ must begin the line, and be followed by whitespace and the name.

The special variable mv_last stops interpretation of search variables. The following variables are always interpreted:


Other than that, if mv_last is set in a search profile, and there are other variables on the search form, they will not be interpreted.

To place multiple search profiles in the same file, separate them with __END__, which must be on a line by itself.

5.11. Search Reference

The supplied simple/srchform.html and simple/results.html pages show example search forms. Modify them to present the search in any way desired. Be careful to use the proper variable names for passing to Interchange. It is also necessary to copy the hidden variables as-is. They are required to interpret the request as a search.

Note: The following definitions frequently refer to field name and column and column number. All are the references to the columns of a searched text file as separated by delimiter characters.

The field names can be specified in several ways.


Other database files

Other files

Fields can also always be specified by an integer column number, with 0 as the first column.



            [set /directory/name]1[/set]





        !=              Not equal to
        !~              Not matching regular expression
        <               Less than
        <=              Less than or equal to
        <>              Not equal to
        =               Equal to
        ==              Equal to
        =~              Matching regular expression
        >               Greater than
        >=              Greater than or equal to
        em              Exact match
        eq              Equal to
        ge              Greater than or equal to
        gt              Greater than
        le              Less than or equal to
        lt              Less than
        ne              Not equal to
        rm              Matching regular expression
        rn              Not matching regular expression

Note that several of the operators are the same. They do either numeric or string comparisons based on the status of mv_numeric (alias nu) for that column.




Note: This is the reverse sense from mv_case.


Note: The order of this and the mv_dict_end variable is significant. Each will overwrite the other.

            <INPUT TYPE=hidden NAME=mv_dict_limit  VALUE=category>
            <INPUT TYPE=hidden NAME=mv_search_file VALUE="products.txt">
            <INPUT TYPE=hidden NAME=mv_dict_limit    VALUE="-1">
            <INPUT TYPE=hidden NAME=mv_search_file   VALUE="products.txt.category">
            <INPUT TYPE=hidden NAME=mv_return_fields VALUE="1">
            Search for
            <SELECT NAME=mv_dict_limit>
            <OPTION> author
            <OPTION> title
            </SELECT> beginning with <INPUT NAME=mv_dictlook>







Note: Use this on the product database only if planning on both pre-sorting with mv_sort_field and then post-sorting with [sort]field:opt[/sort].














As with SQL queries, you can use the '*' shortcut to return all fields. For example:

    [loop search="fi=nation/ra=yes/rf=*"]

when used with a hypothetical 'nation' table would be equivalent to:

    [loop search="

as well as:

    [loop search="fi=nation/ra=yes/rf=0,1,2,3,4"]


    [query sql="select * from nation"][/query]

However, you probably rarely need to use every single field in a row. For maximum maintainability and execution speed the best practice is to list by name only the fields you want returned.









Tells the search engine that there is a small amount of data in the file and that it should perform the search function on every line.

Normally, when Interchange can find a fixed search expression it produces a "screening" function which will allow records to be quickly rejected when they don't match. If there are less than 50 records in the file or database, this may be counterproductive.


Note: If specifying a sort for the product database, mv_field_names must be specified if doing a fieldname-addressed post-sort.






5.12. The Results Page

Once a search has been completed, there needs to be a way of presenting the output. By default, the SpecialPage search is used. It is set to results in the distribution demo, but any number of search pages can be specified by passing the value in the search form specified in the variable mv_search_page.

On the search page, some special Interchange tags are used to format the otherwise standard HTML. Each of the iterative tags is applied to every code returned from the search. This is normally the product code, but could be a key to any of the arbitrary databases. The value placed by the [item-code] tag is set to the first field returned from the search.

The basic structure looks like this:

    your iterating code, once for each match
    Text / tags to be output if no matches found (optional but recommended)
    More / paging area (optional)

Tip for catalogs upgraded from Minivend 3: A [search-list][/search-list] must always be surrounded by a [search-region][/search-region] pair. This is a change from Minivend 3.


            [search-region prefix=my]
                SKU:   [my-code]
                Title: [my-data products title]
         [item-alternate N] true [else] false [/else] [/item-alternate]
         [if-item-param named_field] true [else] false [/else] [/if-item-param]
         [item-param named_field]
         [if-item-pos N] true [else] false [/else] [/if-item-pos]
         [item-pos N]
         [if-item-field products_field] true [else] false [/else] [/if-item-field]
         [item-field products_column]
         [if-item-data table column] true [else] false [/else] [/if-item-data]
         [item-data table column]
         [item-price N* noformat=1*]
         [item-calc] [/item-calc]
         [item-change marker]
                [condition]variable text[/condition]
                [else] false [/else]
         [/item-change marker]
         [item-last] condition [/item-last]
         [item-next] condition [/item-next]

Note: those that reference the shopping cart do not apply, i.e., [item-quantity], [item-modifier ...] and friends.




[sort database:field:option* database:field:option*]

[item-change marker]

                 [item-change cat]
                 [condition][item-field category][/condition]
                         [item-field category]
                 [/item-change cat]
                 [item-change subcat]
                 [condition][item-field subcategory][/condition]
                         [item-field subcategory]
                 [/item-change subcat]
            <TD> [item-field name] </TD>

[/item-change marker]



[more-list next_img* prev_img* page_img* border* border_current*]

             Previous   <IMG SRC="prev.gif" Border=3>
             Page 1     <IMG SRC="/cgi-bin/page_num.cgi?1">
             Page 2     <IMG SRC="/cgi-bin/page_num.cgi?2">
             Next       <IMG SRC="next.gif" Border=3>
             Previous   <IMG SRC="prev.gif">
             Page 1     <IMG SRC="/cgi-bin/page_num.cgi?1">
             Page 2     <IMG SRC="/cgi-bin/page_num.cgi?2">
             Next       <IMG SRC="next.gif">
             Previous   <IMG SRC="prev.gif" Border=0>
             Page 1     <IMG SRC="/cgi-bin/page_num.cgi?1">
             Page 2     <IMG SRC="/cgi-bin/page_num.cgi?2">
             Next       <IMG SRC="next.gif" Border=0>
            [first-anchor] First [/first-anchor]
            [next-anchor] Forward | [/next-anchor]
            [prev-anchor] Back [/prev-anchor]
            [last-anchor] Last [/last-anchor]
            [page-anchor] Page $PAGE$ (matches $MINPAGE$-$MAXPAGE$) | [/page-anchor]
            $PAGE$       Page number
            $MINPAGE$    Minimum match on page
            $MAXPAGE$    Maximum match on page
          [link-template]<a href="$URL$" target="_top">$ANCHOR$</a>[/link-template]
            $URL$      The URL for the 'more' page in question
            $ANCHOR$   The page number or the word "Next" or "Previous"
                           for the link in question.
          Previous 1 2 3 4 5 6 7 8 9 10 [more>>] Next
          Previous [<<more] 11 12 13 14 15 16 17 18 19 20 [more>>] Next
          Previous (lower) 11 12 13 14 15 16 17 18 19 20 (higher) Next



            Previous 1 2 3 4 5 6 Next


6. Sorting

Interchange has standard sorting options for sorting the search lists, loop lists, and item lists based on the contents of database fields. In addition, it adds list slices for limiting the displayed entries based on a start value and chunk size (or start and end value, from which a chunk size is determined). All accept a standard format sort tag which must be directly after the list call:

   [loop 4 3 2 1]
   [sort -2 +2]

   [sort products:category:f]
       [item-price] [item-description]<BR>

   [sort products:price:rn]
       [item-price] [item-code]<BR>

   [loop search="ra=yes"]
   [sort products:category products:title]
   [loop-field category] [loop-field title] <BR>

All sort situations, [search list], [loop list], [tag each table], and [item-list], take options of the form:

 [sort database:field:option* -n +n =n-n ... ]




          f   case-insensitive sort (folded) (mutually exclusive of n)
          n   numeric order (mutually exclusive of f)
          r   reverse sort





Multiple levels of sort are supported, and database boundaries on different sort levels can be crossed. Cross-database sorts on the same level are not supported. If using multiple product databases, they must be sorted with embedded Perl. This is actually a feature in some cases, all items in a used database can be displayed before or after new ones in products.

Examples, all based on the simple demo:

Loop list

            [loop 00-0011 19-202 34-101 99-102]
            [sort products:title]
                [loop-code] [loop-field title]<BR>
            34-101 Family Portrait
            00-0011 Mona Lisa
            19-202 Radioactive Cats
            99-102 The Art Store T-Shirt
            [loop 00-0011 19-202 34-101 99-102]
            [sort products:title -3 +2]
                [loop-code] [loop-field title]<BR>
            19-202 Radioactive Cats
            99-102 The Art Store T-Shirt

Search list

            [sort products:artist products:title:rf]
                [item-field artist] [item-field title]<BR>
            Gilded Frame
            Grant Wood American Gothic
            Jean Langan Family Portrait
            Leonardo Da Vinci Mona Lisa
            Salvador Dali Persistence of Memory
            Sandy Skoglund Radioactive Cats
            The Art Store The Art Store T-Shirt
            Vincent Van Gogh The Starry Night
            Vincent Van Gogh Sunflowers
            [sort products:artist products:title:rf =6-10]
                [item-field artist] [item-field title]<BR>
            Sandy Skoglund Radioactive Cats
            The Art Store The Art Store T-Shirt
            Vincent Van Gogh The Starry Night
            Vincent Van Gogh Sunflowers

Shopping cart

            [sort products:price:rn]
                [item-price] [item-code]<BR>

Complete database contents

            [tag each products]
            [sort products:category products:title]
            [loop-field category] [loop-field title] <BR>

Note that large lists may take some time to sort. If a product database contains many thousands of items, using the [tag each products] sort is not recommended unless planning on caching or statically building pages.

7. Shipping

Interchange has a powerful custom shipping facility that performs UPS and other shipper lookups, as well as a flexible rule-based facility for figuring cost by other methods.

7.1. Shipping Cost Database

The shipping cost database (located in ProductDir/shipping.asc) is a tab-separated ASCII file with eight fields: code, text description, criteria (quantity or weight, for example), minimum number, maximum number, and cost, query, and options. None of the fields are case-sensitive.

To define the shipping database in a catalog configuration file, set the Variable MV_SHIPPING to what would be its contents.

To set the file to be something other than shipping.asc in the products directory, set the Special directive:

   Special  shipping.asc  /home/user/somewhere/shipping_defs

There are two styles of setting which can be mixed in the same file. The first is line-based and expects six or more TAB-separated fields. They would look like:

default No shipping weight  0   99999999    0

upsg    UPS Ground  weight  0   0   e Nothing to ship!
upsg    UPS Ground  weight  0   150 u Ground [default zip 98366] 3.00
upsg    UPS Ground  weight  150 999999  e @@TOTAL@@ lbs too heavy for UPS

The second is a freeform method with a mode: Description text introducing the mode line. The special encoding is called out by indented parameters. The below is identical to the above:

   upsg: UPS Ground
       criteria    weight
       min         0
       max         0
       cost        e Nothing to ship!

       min         0
       max         150
       cost        u
       table       2ndDayAir
       geo         zip
       default_geo 98366
       adder       3

       min         150
       max         999999
       cost        e @@TOTAL@@ lbs too heavy for UPS

The second format has several advantages. Multiple lines can be spanned with the <<HERE document format, like so:

   upsg: UPS Ground
       criteria    <<EOF
       return 'weight' if $Values->{country} eq 'US';
       return 'weight' if ! $Values->{country};
       # Return blank, don't want UPS
       return '';

The definable fields are, in order, for the tab-separated format:







           f       Formula (ITL tags OK, evaluated as Perl)
           x       Multiplied by a number
           [uA-Z]  UPS-style lookup
           m       Interchange chained cost lookup (all items summed together)
           i       Interchange chained cost lookup (items summed individually)








7.2. Criteria Determination

The criteria field varies according to whether it is the first field in the shipping file exactly matching the mode identifier. In that case, it is called the main criterion. If it is in subsidiary shipping lines matching the mode (with optional appended digits), it is called a qualifying criterion. The difference is that the main criterion returns the basis for the calculation (i.e., weight or quantity), while the qualifying criterion determines whether the individual line may match the conditions.

The return must be one of:


o <field name> or <table>::<field name>

o n.nn

IMPORTANT NOTE: The above only applies to the first field that matches the shipping mode exactly. Following criteria fields contain qualifier matching strings.

7.3. Shipping Calculation Modes

There are eight ways that shipping cost may be calculated. The method used depends on the first character of the cost field in the shipping database.

N.NN (digits)








7.4. How Shipping is Calculated

  1. The base code is selected by reading the value of mv_shipmode in the user session. If it has not been explicitly set, either by means of the DefaultShipping directive or by setting the variable on a form (or in an order profile), it will be default.
    The mv_shipmode must be in the character class [A-Za-z0-9_]. If there are spaces, commas, or nulls in the value, they will be read as multiple shipping modes.
      The criterion field is found. If it is quantity, it is the total quantity of items on the order form. If it is any other name, the criterion is calculated by multiplying the return value from the product database field for each item in the shopping cart, multiplied by its quantity. If the lookup fails due to the column or row not existing, a zero cost will be returned and an error is sent to the catalog error log. If a number is returned from an Interchange tag, that number is used directly.
      Entries in the shipping database that begin with the same string as the shipping mode are examined. If none is found, a zero cost is returned and an error is sent to the catalog error log.

Note: The same mode name may be used for all lines in the same group, but the first one will contain the main criteria.

  1. The value of the accumulated criteria is examined. If it falls within the minimum and maximum, the cost is applied.
  2. If the cost is fixed, it is simply added.
  3. If the cost field begins with an x, the cost is multiplied by the accumulated criterion, i.e., price, weight, etc.
  4. If the cost field begins with f, the formula following is applied. Use @@TOTAL@@ as the value of the accumulated criterion.
  5. If the cost field begins with u or a single letter from A-Z, a UPS-style lookup is done.
  6. If the cost field begins with s, a Perl subroutine call is made.
  7. If the cost field begins with e, zero cost is returned and an error placed in the session ship_message field, available as [data session ship_message].

Here is an example shipping file using all of the methods of determining shipping cost.

Note: The columns are lined up for reading convenience. The actual entries should have one tab between fields.

global Option   n/a               0   0  g PriceDivide

rpsg  RPS     quantity         0   0     R RPS products/rps.csv
rpsg  RPS     quantity         0   5     7.00
rpsg  RPS     quantity         6   10    10.00
rpsg  RPS     quantity         11  150   x .95

usps  US Post price            0   0     0
usps  US Post price            0   50    f 7 + (1 * @@TOTAL@@ / 10)
usps  US Post price            50  100   f 12 + (.90 * @@TOTAL@@ / 10)
usps  US Post price            100 99999 f @@TOTAL@@ * .05

upsg  UPS     weight [value state]  0   0   e Nothing to ship.
upsg  UPS     AK HI            0   150   u upsg [default zip 980] 12.00 round
upsg  UPS                      0   150   u Ground [default zip 980] 2.00 round
upsg  UPS                      150 9999  e @@TOTAL@@ lb too heavy for UPS

upsca UPS/CA  weight           0   0     c C UPS_Canada products/can.csv
upsca UPS/CA  weight           -1   -1   o PriceDivide=0
upsca UPS/CA  weight           0   150   C upsca [default zip A7G] 5.00
upsca UPS/CA  weight           150 99999 e @@TOTAL@@ lb too heavy for UPS





            1. Weight
            2. The zip/postal code of the recipient of which only
               the first three digits are used.
            3. A fixed amount to add to the cost found in the UPS
               tables (use 0 as a placeholder if specifying roundup)
            4. If set to 'round,' will round the cost up to the next
               integer monetary unit.
            UPSZoneFile  products/450.csv
            Database  Ground  Ground.csv  CSV

A simple shipping cost qualification can be appended to a UPS lookup. If any additional parameters are present after the five usual ones used for UPS lookup, they will be interpreted as a Perl subroutine call. The syntax is the same as if it was encased in the tag [perl] [/perl], but the following substitutions are made prior to the call:

            @@COST@@  is replaced with whatever the UPS lookup returned
            @@GEO@@   is replaced with the zip (or other geo code)
            @@ADDER@@ is replaced with the defined adder
            @@TYPE@@  is replaced with the UPS shipping type
            @@TOTAL@@ is replaced with the total weight


Up to 27 different lookup zones can be defined in the same fashion, allowing for multiple zone files. If one of the cost lines (the last field) in the shipping.asc file begins with a c, it configures another lookup zone which must be lettered from A to Z. It takes the format:

            c X name file* length* multiplier*
            c U UPS products/450.csv 3 1

7.5. More On UPS-Style Lookup

The UPS-style lookup uses two files for its purposes, both of which need to be in a format like UPS distributes for US shippers.

The zone file is a file that is usually specific to the originating location. For US shippers shipping to US locations, it is named for the first three digits of the originating zip code with a CSV extension. For example, 450.csv.

It has a format similar to:

   low - high, zone,zone,zone,zone

The low entry is the low bound of the geographic location; high is the high bound. (By geographic location, the zip code is meant.) If the first digits of the zip code, compared alphanumerically, fall between the low and high values, that zone is used as the column name for a lookup in the rate database. The weight is used as the row key.

The first operative row of the zone file (one without leading quotes) is used to determine the zone column name. In the US, it looks something like:

 Dest. ZIP,Ground,3 Day Select,2nd Day Air,2nd Day Air A.M.,\
  Next Day Air Saver,Next Day Air

Interchange strips all non-alpha characters and comes up with:


Therefore, the zone column (shipping type) that would be used for UPS ground would be "Ground," and that is what the database should be named. To support the above, use a shipping.asc line that reads:

   upsg  UPS Ground  weight  0  150  u Ground [default zip 983]

and a catalog.cfg database callout of:

   Database  Ground  Ground.csv  CSV

These column names can be changed as long as they correspond to the identifier of the rate database.

The rate database is a standard Interchange database. For U.S. shippers, UPS distributes their rates in a fairly standard comma-separated value format, with weight being the first (or key) column and the remainder of the columns corresponding to the zone which was obtained from the lookup in the zone file.

To adapt other shipper zone files to Interchange's lookup, they will need to fit the UPS US format. (Most of the UPS international files don't follow the U.S. format). For example, the 1998 Ohio-US to Canada file begins:

   Canada Standard Zone Charts from Ohio
   Locate the zone by cross-referencing the first three
   characters of the destination Postal Code in the Postal
   Range column.

   Postal Range  Zone
   A0A  A9Z      54
   B0A  B9Z      54
   C0A  C9Z      54
   E0A  E9Z      54
   G0A  G0A      51
   G0B  G0L      54
   G0M  G0S      51
   G0T  G0W      54

It will need to be changed to:

   A0A-A9Z, 54
   B0A-B9Z, 54
   C0A-C9Z, 54
   E0A-E9Z, 54
   G0A-G0A, 51
   G0B-G0L, 54
   G0M-G0S, 51
   G0T-G0W, 54

Match it with a canstnd CSV database that looks like this:


It is called out in catalog.cfg with:

   Database canstnd canstnd.csv CSV

With the above, a 4-pound shipment to postal code E5C 4TL would yield a cost of 13.20.

7.6. Geographic Qualification

If the return value in the main criterion includes whitespace, the remaining information in the field is used as a qualifier for the subsidiary shipping modes. This can be used to create geographic qualifications for shipping, as in:

upsg  UPS Ground  weight [value state]  0   0    e No items selected
upsg  UPS Ground  AK HI                 0   150  u Ground [value zip] 12.00
upsg  UPS Ground                        0   150  u Ground [value zip] 3.00

If upsg is the mode selected, the value of the user session variable state is examined to see if it matches the geographic qualification on a whole-word boundary. If it is AK or HI, UPS Ground with an adder of 12 will be selected. If it "falls through," UPS Ground with an adder of 3 will be selected.

7.7. Handling Charges

Additional handling charges can be defined in the shipping file by setting the form variable mv_handling to a space, comma, or null-separated set of valid shipping modes. The lookup and charges are created in the same fashion, and the additional charges are added to the order. (The user is responsible for displaying the charge on the order report or receipt with a [shipping handling] tag, or the like.) All of the shipping modes found in mv_handling will be applied. If multiple instances are found on a form, the accordingly null-separated values will all be applied. NOTE: This should not be done in an item-list unless the multiple setting of the variables is accounted for.

To only process a handling charge once, do the following:

   [if-item-field very_heavy]
   [perl values]
       return '' if $Values->{mv_handling} =~ /very_heavy/;
       return "<INPUT TYPE=hidden NAME=mv_handling VALUE=very_heavy>";

A non-blank/non-zero value in the database field will trigger Perl code which will only set mv_handling once.

7.8. Default Shipping Mode

If a default shipping mode other than default is desired, enter it into the DefaultShipping directive:

   DefaultShipping     upsg

This will make the entry on the order form checked by default when the user starts the order process, if it is put in the form:

 <INPUT TYPE=RADIO NAME=mv_shipmode VALUE=upsg [checked mv_shipmode upsg]>

To force a choice by the user, make mv_shipmode a required form variable (with RequiredFields or in an order profile) and set DefaultShipping to zero.

8. User Database

Interchange has a user database function which allows customers to save any pertinent values from their session. It also allows the setting of database or file access control lists for use in controlling access to pages and databases on a user-by-user basis.

The database field names in the user database correspond with the form variable names in the user session. If there is a column named address, when the user logs in the contents of that field will be placed in the form variable address, and will be available for display with [value address]. Similarly, the database value is available with [data table=userdb column=address key=username].

The ASCII file for the database will not reflect changes unless the file is exported with [tag export userdb][/tag]. It is not advisable to edit the ASCII file, as it will overwrite the real data that is in the DBM table. User logins and changes would be lost. Note: This would not happen with SQL, but editing the ASCII file would have no effect. It is recommended that the NoImport configuration directive be set accordingly.

The field names to be used are not set in concrete. They may be changed with options. Fields may be added or subtracted at any time. Most users will choose to keep the default demo fields for simplicity sake, as they cover most common needs. As distributed in the demo, the fields are:


A few of those fields are special in naming, though all can be changed via an option. A couple of the fields are reserved for Interchange's use.

Note: If not running with PGP or other encryption for credit card numbers, which is never recommended, it is important that the mv_credit_card_info field be removed from the database.

The special database fields are:

   accounts         Storage for billing accounts book
   address_book     Storage for shipping address book
   b_nickname       Nickname of current billing account
   carts            Storage for shopping carts
   p_nickname       Nickname for current preferences
   preferences      Storage for preferences
   s_nickname       Nickname for current shipping address
   db_acl           Storage for database access control lists
   file_acl         Storage for file access control lists
   acl              Storage for simple integrated access control

If not defined, the corresponding capability is not available.

Note: The fields accounts, address_book, carts, and preferences should be defined as a BLOB type, if using SQL. This is also suggested for the acl fields if those lists could be large.

Reserved fields include:

   code        The username (key for the database)
   password    Password storage
   time        Last time of login

8.1. The [userdb ...] Tag

Interchange provides a [userdb ...] tag to access the UserDB functions.

       oldpass="old password"*
       shipping="fields for shipping save"
       billing="fields for billing save"
       preferences="fields for preferences save"

* Optional

It is normally called in an mv_click or mv_check setting, as in:

   [set Login]
   [userdb function=login]

   <FORM ACTION="[process]" METHOD=POST>
   <INPUT TYPE=hidden NAME=mv_click VALUE=Login>
   Username <INPUT NAME=mv_username SIZE=10>
   Password <INPUT NAME=mv_password SIZE=10>

There are several global parameters that apply to any use of the userdb functions. Most importantly, by default, the database table is set to be userdb. If another table name must be used, include a database=table parameter with any call to userdb. The global parameters (default in parentheses):

 database          Sets user database table (userdb)
 show              Show the return value of certain functions
                   or the error message, if any (0)
 force_lower       Force possibly upper-case database fields
                   to lower case session variable names (0)
 billing           Set the billing fields (see Accounts)
 shipping          Set the shipping fields (see Address Book)
 preferences       Set the preferences fields (see Preferences)
 bill_field        Set field name for accounts (accounts)
 addr_field        Set field name for address book (address_book)
 pref_field        Set field name for preferences (preferences)
 cart_field        Set field name for cart storage (carts)
 pass_field        Set field name for password (password)
 time_field        Set field for storing last login time (time)
 outboard          Set fields that live in another table
 outboard_key_col  Set field providing key for outboard tables
 expire_field      Set field for expiration date (expire_date)
 acl               Set field for simple access control storage (acl)
 file_acl          Set field for file access control storage (file_acl)
 db_acl            Set field for database access control storage (db_acl)
 indirect_login    Log in field if different than real username ('')

By default the system crypt() call will be used to compare the password. This is best for security, but the passwords in the user database will not be human readable.

If no critical information is kept and Interchange administration is not done via the UserDB capability, use the UserDB directive (described below) to set encryption off by default:

   UserDB   default   crypt   0

Encryption can still be set on by passing crypt=1 with any call to a new_account, change_pass, or login call.

If you are encrypting, and you wish to use MD5 to encrypt the passwords, set the md5 parameter:

UserDB default md5 1

8.2. Setting Defaults with the UserDB Directive

The UserDB directive provides a way to set defaults for the user database. For example, to save and recall the scratch variable tickets in the user database instead of the form variable tickets, set:

   UserDB   default   scratch  tickets

That makes every call to [userdb function=login] equivalent to [userdb function=login scratch=tickets].

To override that default for one call only, use [userdb function=login scratch="passes"].

To log failed access authorizations, set the UserDB profile parameter log_failed true:

   UserDB  default  log_failed 1

To disable logging of failed access authorizations (the default), set the UserDB profile parameter log_failed to 0:

   UserDB  default  log_failed 0

The UserDB directive uses the same key-value pair settings as the Locale and Route directives. If there are more than one set of defaults, set them in a hash structure:

   UserDB  crypt_case  <<EOF
       'scratch'        => 'tickets',
       'crypt'          => '1',
       'ignore_case'    => '0',

   UserDB  default  <<EOF
       'scratch'        => 'tickets',
       'crypt'          => '1',
       'ignore_case'    => '1',

Note: The usual here-document caveats apply. The "EOF" must be on a line by itself with no leading/trailing whitespace.

The last one to be set becomes the default.

The option profile selects the set to use. For usernames and passwords to be case sensitive with no encryption, pass this call:

   [userdb function=new_account profile=case_crypt]

The username and password will be stored as typed in, and the password will be encrypted in the database.

8.3. User Database Functions

The user database features are implemented as a series of functions attached to the userdb tag. The functions are:




            [userdb function=new_account
            [userdb function=new_account
                    username="[value mv_order_number]"
                    password="[value zip]"
                    verify="[value zip]"



            [userdb function=set_shipping nickname=Dad]


            [userdb function=get_shipping nickname=Dad]


            [set name=shipping_nicknames
              [userdb function=get_shipping_names show=1]


            [userdb function=set_billing nickname=discover]


            [userdb function=get_billing nickname=visa]



            [userdb function=set_cart nickname=christmas]


            [userdb function=get_cart nickname=mom_birthday]


            [userdb function=set_acl location=cartcfg/editcart]
            [userdb function=set_acl location=cartcfg/editcart delete=1]
            [userdb function=set_acl location=cartcf/editcart show=1]


            [if type=explicit
            [page cartcfg/editcart]Edit your cart configuration</a>

set_file_acl, set_db_acl

            [userdb function=set_file_acl

check_file_acl, check_db_acl

            [userdb function=check_db_acl
            [if type=explicit
            [userdb function=set_acl location=cartcfg/edit_inventory]
            [page cartcfg/edit_inventory]You may edit the inventory database</a>
            [userdb function=set_acl location=cartcfg/edit_inventory delete=1]
            Sorry, you can't edit inventory.

8.4. Address Book

Address_book is a shipping address book. The shipping address book saves information relevant to shipping the order. In its simplest form, this can be the only address book needed. By default these form values are included:


The first field is always the name of the form variable that contains the key for the entry. The values are saved with the [userdb function=set_shipping] tag call, and are recalled with [userdb function=get_shipping]. A list of the keys available is kept in the form value address_book, suitable for iteration in an HTML select box or in a set of links.

To get the names of the addresses, use the get_shipping_names function:

   [userdb function=get_shipping_names]

By default, they are placed in the variable address_book. Here is a little snippet that builds a select box:

   <FORM ACTION="[process]" METHOD=POST>
   [userdb function=get_shipping_names]
   [if value address_book]
   <SELECT NAME="s_nickname">
   [loop arg="[value address_book]"] <OPTION> [loop-code] [/loop]
   <INPUT TYPE=submit NAME=mv_check VALUE="Recall Shipping">

The same principle works with accounts, carts, and preferences.

To restore a cart based on the above, put in an mv_check routine:

   [set Recall Shipping]
   [userdb function=get_shipping nickname="[value s_nickname]"]

When the mv_check variable is encountered, the contents of the scratch variable Recall Shipping are processed and the shipping address information inserted into the user form values. This is destructive of any current values of those user session variables, of course.

To change the fields that are recalled or saved, use the shipping parameter:

   [userdb function=get_shipping
           shipping="city state"]

Only the values of the city and state variables will be replaced.

8.5. Accounts Book

The accounts book saves information relevant to billing the order. By default these form values are included:


The values are saved with the [userdb function=set_billing] tag call, and are recalled with [userdb function=get_billing]. A list of the keys available is kept in the form value accounts, suitable for iteration in an HTML select box or in a set of links.

8.6. Preferences

Preferences are miscellaneous session information. They include, by default, the following fields:


The field p_nickname acts as a key to select the preference set. To change the values that are included with the preferences parameter:

   [userdb function=set_preferences
           preferences="email_copy email fax_order fax"]

or in catalog.cfg:

   UserDB default preferences "mail_list email fax_order music_genre"

8.7. Carts

The contents of shopping carts may be saved or recalled in much the same fashion. See the Simple demo application ord/basket.html page for an example.

8.8. Controlling Page Access With UserDB

Interchange can implement a simple access control scheme with the user database. Controlled pages must reside in a directory which has a file named .access that is zero bytes in length. (If it is more than 0 bytes, only the RemoteUser or MasterHost may access files in that directory.)

Set the following variables in catalog.cfg:

   Variable   MV_USERDB_ACL_TABLE  userdb
   Variable   MV_USERDB_ACL_COLUMN acl

The MV_USERDB_ACL_TABLE is the table which controls access, and likewise the MV_USERDB_ACL_TABLE names the column in that database which will be checked for authorization.

The database entry should contain the complete Interchange-style page name of the page to be allowed. It will not match substrings.

For example, if the user flycat followed this link:

   <A HREF="[area cartcfg/master_edit]">Edit</A>

Access would be allowed if the contents of the userdb were:

   code    acl
   flycat  cartcfg/master_edit

and disallowed if it were:

   code    acl
   flycat  cartcfg/master_editor

Access can be enabled with:

   [userdb function=set_acl location="cartcfg/master_edit"]

Access can be disallowed with:

   [userdb function=set_acl

Of course, a pre-existing database with the ACL values will work as well. It need not be in the UserDB setup.

8.9. Using more than one table

You can save/retrieve userdb information from more than one table with the outboard specifier. It is a quoted key-value comma-separated series of field specifications. For instance, if the billing address is to be stored in a separate table named "billing", you would do:

        UserDB  default outboard  <<EOF

When the user logs in, Interchange will access the first_name field in table billing to get the value of b_fname. When the values are saved, it will be saved there as well. If you wish to make the fields read-only, just set UserDB default scratch "b_fname b_lname ..." and the values will be retrieved/saved from there. To initialize the values for a form, you could do a function after the user logs in:

        my @s_fields = grep /\S/, split /[\s,\0]+/, $Config->{UserDB}{scratch};
        for(@s_fields) {
                $Values->{$_} = $Scratch->{$_};

If the fields in the outboard table use another key besides username, you can specify the column in the userdb that contains the key value:

        UserDB  default  outboard_key_col   account_id

9. Tracking and Back-End Order Entry

Interchange allows the entry of orders into a system through one of several methods. Orders can be written to an ASCII file or formatted precisely for email-based systems. Or they can go directly into an SQL or DBM database. Finally, embedded Perl allows completely flexible order entry, including real-time credit card verification and settlement.

9.1. ASCII Backup Order Tracking

If AsciiTrack is set to a legal file name (based in VendRoot unless it has a leading "/"), a copy of the order is saved and sent in an email.

If the file name string begins with a pipe "|", a program will be run and the output "piped" to that program. This allows easy back-end entry of orders with an external program.

9.2. Database Tracking

Once the order report is processed, the order is complete. Therefore, it is the ideal place to put Interchange tags that make order entries in database tables.

A good model is to place a single record in a database summarizing the order and a series of lines that correspond to each line item in the order. This can be in the same database table. If the order number itself is the key for the summary, a line number can be appended to the order number to show each line of the order.

The following would summarize a sample order number S00001 for part number 00-0011 and 99-102:

   code     order_number part_number  quantity   price    shipping  tax
   S00001   S00001                    3          2010     12.72     100.50
   S00001-1 S00001       00-0011      2          1000     UPS       yes
   S00001-2 S00001       99-102       1          10       UPS       yes

Fields can be added where needed, perhaps with order status, shipping tracking number, address, customer number, or other information.

The above is accomplished with Interchange's [import ....] tag using the convenient NOTES format:

   [set import_status]
   [import table=orders type=LINE continue=NOTES]

   code: [value mv_order_number]
   order_number: [value mv_order_number]
   quantity: [nitems]
   price: [subtotal noformat=1]
   shipping: [shipping noformat=1]
   tax: [salestax noformat=1]


   [import table=orders type=LINE continue=NOTES]

   code: [value mv_order_number]-[item-increment]
   order_number: [value mv_order_number]
   quantity: [item-quantity]
   price: [item-price noformat=1]
   shipping: [shipping-description]
   tax: [if-item-field nontaxable]No[else]Yes[/else][/if]


9.3. Order Routing

Interchange can send order emails and perform custom credit card charges and/or logging for each item. The Route directive is used to control this behavior, along with the mv_order_route item attribute.

If no Route is in the catalog, Interchange uses a default "mail out the order and show a receipt" model.

Routes are established with the Route directive, which is similar to the Locale directive. Each route is like a locale, so that key-value pairs can be set. Here is an example setting:

   Route  mail  pgp_key         0x67798115
   Route  mail  email 
   Route  mail  reply 
   Route  mail  encrypt         1
   Route  mail  encrypt_program "/usr/bin/pgpe -fat -q -r %s"
   Route  mail  report          etc/report_mail

Note: Values with whitespace in them must be quoted.

You can also set the route in a valid Perl hash reference string:

   Route  mail <<EOR
        pgp_key         => '0x67798115',
        email           => '',
        reply           => '',
        encrypt         => 1,
        encrypt_program => q{/usr/bin/gpg -e -a -r '%s' --batch},
        report          => 'etc/report_mail',

This route would be used whenever the mail route was called by one of the three possible methods:

route called from master route

route set in item

route set in the form variable mv_order_route

The last route that is defined is the master route, by convention named main. Besides setting the global behavior of the routing, it provides some defaults for other routes. For example, if encrypt_program is set there, then the same value will be the default for all routes. Most settings do not fall through.

The attributes that can be set are:


A list of routes which should be pushed on the stack of routes to run, after all currently scheduled routes are done. NOTE: cascades can cause endless loops, so only one setting is recommended, that being the main route.








This should be set if neither attach or email is set.






        Route  main   extended    { email => '' }
        Route  main   email

The ultimate setting of email will be




   individual_track_ext     .pgp


   individual_track_mode    0444














   track_mode    0444


Individual item routing causes all items labeled with that route to be placed in a special sub-cart that will be used for the order report. This means that the [item-list] LIST [/item-list] will only contain those items, allowing operations to be performed on subsets of the complete order. The [subtotal], [salestax], [shipping], [handling], and [total-cost] tags are also affected.

Here is an example of an order routing:

   Route  HARD      pgp_key          0x67798115
   Route  HARD      email  
   Route  HARD      reply  
   Route  HARD      encrypt          1
   Route  HARD      report           etc/report_mail

   Route  SOFT      email            ""
   Route  SOFT      profile          create_download_link
   Route  SOFT      empty            1

   Route  mail      pgp_key          0x67798115
   Route  mail      email  
   Route  mail      reply  
   Route  mail      encrypt          1
   Route  mail      report           etc/report_all

   Route  user      error_ok         1
   Route  user      email            email
   Route  user      reply  
   Route  user      report           etc/user_copy

   Route  log       empty            1
   Route  log       report           etc/log_transaction
   Route  log       transactions     "transactions orderline inventory"
   Route  log       track            logs/log

   Route  main      supplant         1
   Route  main      receipt          etc/receipt.html
   Route  main      master           log mail user
   Route  main      cascade          log mail user
   Route  main      encrypt_program  "/usr/bin/gpg -e -a r '%s' --batch"

This will have the following behavior:




Encryption The mail order route and the HARD order route will be sent by email, and encrypted against different GPG key IDs. They will get their encrypt_program setting from the main route.

To set the order routing for individual items, some method of determining their status must be made and the mv_order_route attribute must be set. This could be set at the time of the item being placed in the basket, or have a database field called goods_type set to the appropriate value. The following example uses a Perl routine on the final order form:

  [perl table=products]
     my %route;
     my $item;
     foreach $item (@{$Items}) {
         my $code = $item->{code};
         my $keycode = $Tag->data('products', 'goods_type', $code);
         $item->{mv_order_route} = $keycode;

Now the individual items are labeled with a mv_order_route value which causes their inclusion in the appropriate order routing.

Upon submission of the order form, any item labeled HARD will be accumulated and sent to the e-mail address, where the item will be pulled from inventory and shipped.

Any item labeled SOFT will be passed to the order profile create_download_link, which will place it in a staging area for customer download. (This would be supported by a link on the receipt, possibly by reading a value set in the profile).

10. SSL Support

Interchange has several features that enable secure ordering via SSL (Secure Sockets Layer). Despite their mystique, SSL servers are actually quite easy to operate. The difference between the standard HTTP server and the SSL HTTPS server, from the standpoint of the user, is only in the encryption and the specification of the URL; https: is used for the URL protocol specification instead of the usual http: designation.

IMPORTANT NOTE: Interchange attempts to perform operations securely, but no guarantees or warranties of any kind are made! Since Interchange comes with source code, it is fairly easy to modify the program to create security problems. One way to minimize this possibility is to record digital signatures, using MD5 or PGP or GnuPG, of interchange, interchange.cfg, and all modules included in Interchange. Check them on a regular basis to ensure they have not been changed.

Interchange uses the SecureURL directive to set the base URL for secure transactions, and the VendURL directive for normal non-secure transactions. Secure URLs can be enabled for forms through a form action of [process secure=1]. An individual page can be displayed via SSL with [page href=mvstyle_pagename secure=1]. A certain page can be set to be always secure with the AlwaysSecure catalog.cfg directive.

Interchange incorporates additional security for credit card numbers. The field mv_credit_card_number will not ever be written to disk.

To enable automated encryption of the credit card information, the directive CreditCardAuto needs to be defined as Yes. EncryptProgram also needs to be defined with some value, one which will, hopefully, encrypt the number. PGP is now recommended above all other encryption program. The entries should look something like:

 CreditCardAuto   Yes
 EncryptProgram   /usr/bin/pgpe -fat -r

See CreditCardAuto for more information on how to set the form variables.

11. Frequently Asked Questions

11.1. I can't get SQL to work: Undefined subroutine &Vend::Table::DBI::create ...

This probably means one of the following:

No SQL database.


            perl -MCPAN -e 'install DBI'


            perl -MCPAN -e 'install DBD::XXXXX'
            use DBI;
            use DBD::XXXXX;

I don't like the column types that Interchange defines!

I change the ASCII file, but the table is not updated. Why?

Why do I even need an ASCII file?

            Database products products.txt dbi:mysql:test_minivend
            Database pricing pricing.txt dbi:mysql:test_minivend

Interchange overwrites my predefined table!

11.2. How can I use Interchange with Microsoft Access?

Though Interchange has ODBC capability, the Microsoft Access ODBC driver is not a network driver. You cannot access it on a PC from your ISP or UNIX system.

However, you can turn it around. Once you have created a MySQL or other SQL database on the UNIX machine, you may then obtain the Windows ODBC driver for the database (MySQL has a package called myODBC) and use the UNIX database as a data source for your PC-based database program.

Here is a quick procedure that might get you started:

            mysqladmin shutdown
            safe_mysqld --skip-grant-tables &
            mysqladmin create test_odbc
            mysql test_odbc
            mysql> create table test_me ( code char(20), testdata char(20) );
            Query OK, 0 rows affected (0.29 sec)
            mysql> insert into test_me VALUES ('key1', 'data1');
            Query OK, 1 rows affected (0.00 sec)
            mysql> insert into test_me VALUES ('key2', 'data2');
            Query OK, 1 rows affected (0.00 sec)

Copyright 2002-2004 Interchange Development Group. Copyright 2001-2002 Red Hat, Inc. Freely redistributable under terms of the GNU General Public License.