3.4. PREFIX-change

   [PREFIX-change][condition] ... [/condition] TEXT [/PREFIX-change]

Sets up a breaking sequence that occurs when the contents of [condition] [/condition] change. The most common one is a category break to nest or place headers.

The region is only output when a field or other repeating value between [condition] and [/condition] changes its value. This allows indented lists similar to database reports to be easily formatted. The repeating value must be a tag interpolated in the search process, such as [PREFIX-field] or [PREFIX-field database field]. If you need access to ITL tags, you can use [PREFIX-calc] with a $Tag-foo()> call.

Of course, this will only work as you expect when the search results are properly sorted.

The value to be tested is contained within a [condition]value[/condition] tag pair. The [PREFIX-change] tag also processes an [else] [/else] pair for output when the value does not change.

Here is a simple example for a search list that has a field category and subcategory associated with each item:

 <TABLE>
 <TR><TH>Category</TH><TH>Subcategory</TH><TH>Product</TH></TR>
 [search-list]
 <TR>
    <TD>
         [item-change cat]

         [condition][item-field category][/condition]

                 [item-field category]
         [else]
                 &nbsp;
         [/else]
         [/item-change cat]
    </TD>
    <TD>
         [item-change sub]

         [condition][item-field subcategory][/condition]

                 [item-field subcategory]
         [else]
                 &nbsp;
         [/else]
         [/item-change sub]
    </TD>
    <TD> [item-field name] </TD>
 [/search-list]
 </TABLE>

The above should put out a table that only shows the category and subcategory once, while showing the name for every product. (The &nbsp; will prevent blanked table cells if you use a border.)