Dynamic List Values from a Macro Input Parameter
You can populate the list of valid values dynamically from another input parameter to the macro. For example, one input parameter is a document with results from an RSS web feed. A second parameter accepts one article title that users should select from the RSS results to use as a query to another mashable.
Thus one field in the repeating items from the first input parameter provides the dynamic list of valid values for a second macro input parameter. The first input parameter must be a document type that has at least one repeating node.
To provide a dynamic list of values for an input parameter based on a repeating node from another parameter, you add the following macro metadata elements to <parameter>:
<type> with a datatype of
enum<list> as a child of <type>
<xpath> as a child of <list>
You specify the path within the source input parameter to the repeating node that contains the values for this list in the
limitTo attribute in <xpath>
In this example, the <item> node in the RSS feed for the newsSource input parameter is repeating. The list of values to show for the newsItem input parameter is the article titles for each <item> in newsSource: