DFDSEARCH{...} -- Perform a low-level XPath query on the DataFlowDiaPlugin data

• Parameters:

  Parameter	Description	Default
  query	The XPath query to perform on the data store (see below).	none, required parameter
  aggregate	If 0, apply "format" to each matching XML node. See below.	1
  atomempty	If 1, insert the empty value for individual (atomic) XPath subexpressions in format that have no results.	0
  separator	Specifies text to insert between each record of formatted output.	$n() (newline)
  newline	Text to insert in the output, if aggregate is 1, between aggregated matches.	<br/>
  format	Specifies the output format using an XPath expression.	none
  header	Specifies text to insert at the top of formatted output.	none
  footer	Specifies text to insert at the bottom of formatted output.	none
  empty	Text to insert into formatted output if an XPath expression matches nothing.
  zeroresults	Text to display if there are no matches to the query expression.	No results.$n
  label	Indicate how wiki links are labeled, with the Entity id, spec, aspec (abbreviated spec) or topic	name

The query option is where half the utility of this macro resides. Use this option to specify an XPath query that will match XML nodes in the data store that are of interest. Example:

/datacrossref/data[@deprecated='1' and @web='Extensions']

See DataFlowDiaPluginFormatting for details on formatted text output.

Some noteworthy comments:

• All entity nodes have an @id, @name, @web, @topic and @defined attribute.
• Entities other than group may have group child nodes.
• As a work-around for the fact that XPath 1.0 does not support querying node names, all nodes for searching have a @nodename attribute.
  • Aside: The nodename() function is supported by XPath 2.0 but libxml2 does not and apparently will not support XPath 2.0. DataFlowDiaPlugin is developed using a Perl wrapper for libxml2.
• Cross references defined in DFD macros are typically accessible to DFDSEARCH using the singular (non-plural) form of the name, e.g. inputs becomes multiple XML nodes called input.