Programming with the wftk: list XML

Programmer's Guide to the wftk: list XML

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Lists

Lists, and by extension queries, are represented rather simply in the wftk: they consist of an XML element of type "list" which contains any number of arbitrary elements as contents. A query is performed by creating a list structure (using xml_create), possibly setting some attributes to restrict the search, and passing it to the appropriate wftk function. The library will perform your query (for example, for the tasks active in a given process) and will add elements to the list which represent the result set.

The list structure is thus very much like a RecordSet in the Microsoft world.

To read the contents of a list structure, iterate along it using xml_firstelem and xml_nextelem.

Example

A typical list is a list of tasks returned by wftk_task_list. It might look like this (except that I've indented it conveniently, which the wftk won't do):

<list process="proc104">
  <task id="4" user="bob" label="Process application" role="Tech Support"/>
  <task id="6" user="sue" label="Check consistency" role="Purchasing"/>
</list>

Simple.