Deprecated collection functionality
This topic describes features and functionality that are only supported by deprecated collection instances.
Run time behavior
A collection runs in two phases.
In the first phase, the system creates a list of candidate steps to be executed, resolving
any rows of the Collection tab with Another
Collection
or List View
as the Execute
field. Rules of these types can cause additional rules to be appended to the bottom of the
list of candidate rules.
Steps execute from top to bottom to assemble this list. For steps with Another
Collection
in the Execute field, preconditions are
evaluated. Rules for the called collection are included in the list only for steps with no
precondition, or steps with preconditions that evaluate to true. Preconditions for other
steps are ignored during this phase.
At the end of this phase, no candidate step contains Another Collection
or List View
in the Execute field; all such rows are
expanded.
In the second phase, steps assembled in the first phase are evaluated in sequence, subject to preconditions and stop conditions. Preconditions are tested, and rules are executed only for rows that contain no precondition or a precondition that evaluates to true. Stop conditions (on the Preamble and Stop tab) are re-executed again for each row; any stop condition that evaluates to true causes the Collect instruction to end.
When all candidate steps are evaluated, the Collect instruction ends.
During execution of a collection rule, the page on which the collection rule operates
becomes the primary page. The page keyword PRIMARY
and the results of the
tools.getPrimaryPage() PublicAPI method reflect this change. When the
collection rule completes, the primary page of the calling activity resumes as primary.
Circumstances
Typically, the Circumstance Property and Circumstance Date Property field, if not blank, identify a property with no page name, starting with a period. When executing a collection rule, such references cause rule resolution to search the current primary page for the property and value. Other pages are not searched.
Logging
When the Save Execution Information? box on the Preamble
and Stop tab is selected, execution of the Collect instruction causes
execution details to be saved in a clipboard page named pxTraceCollection
,
an instance of the Log-Collection class. This page is saved, but not
immediately committed to the PegaRULES database. Normal workflow processing typically
provides the Commit operation later.
The key to a Log-Collection instance is formed from three properties:
- Date and time of execution (property pxCreateDateTime ).
- Purpose — second key part — of the collection rule ( pyPurpose ).
- Handle of the rule on which the collection was applied ( pzInsKey ).
The pyTop property on this page identifies the top-level collection rule that executed. Embedded pages (of property pyAction ) identify the steps for rules that executed, in sequence. This page helps you identify steps not executed or executed more often than intended.
To present the page as a tree structure, run the standard activity Log-Collection.ShowCollectionSteps. The resulting chart identifies the elements of the collection.