Obj-List-View method

Use the Obj-List-View method to execute the retrieval and sorting operations, but not the formatting and display processing, of a list view rule.

Obj-List-View processing can return a smaller set of columns and a more precisely selected set of rows than the similar Obj-List method, and so can require less memory and less network traffic than an Obj-List method.

Parameters

Specify all three key parts of a list view rule.

Results

The system uses rule resolution to find the list view rule and executes it, but does not produce any HTML output display. The selection criteria of the list view rule and the sorting requirements (recorded on the Content tab) are converted to an SQL query that is sent to the PegaRULES database.

The database results are organized into a results page of class Code-Pega-List. The name of this page is determined by the Content Page Name field on the Content tab of the List View form, (The Step Page field on the step is ignored.)

Each embedded pages contains the properties listed on the Content tab. If any of these properties is not exposed as a column in the database, the entire Storage Stream (blob) column is accessed. If the Maximum Value field on the Content tab is not blank, the method returns at most the number of embedded pages specified in the Maximum Value field.

Most information in the Organize, Display Field, and Format tabs is not used. However, if report paging is enabled on the Organize tab, only rows for a single page are returned.

Properties of Code-Pega-List

Expand this node to review the main properties of Code-Pega-List.

This table identifies some of the main properties of the Code-Pega-List class, which is output from various methods. Properties marked with a yellow diamond can hold input parameters for the search. Other properties specified as read-only contain outputs from the search.

Property	Purpose
pyCacheFile	For list view reports that save results as an XML file in the lookup list cache, identifies the file name.
pyCondition	A Page List. Identifies the parameters that define search comparisons, for the Obj-List method: pyConditionFieldName — A property reference resulting in a single text value pyConditionOperation — A comparison operator, such as "<" pyConditionValue1 — An expression for the comparison value
pyDetailsAction	For list view and summary view rules, identifies the value of the pyAction parameter to the ShowView activity, such as PREPARE or SHOW.
pyDetailsWindow	For list view and summary view rules, identifies the name of the window that is to hold the resulting display.
pxElapsedTime	Elapsed time in seconds to process the RDB-List operation. Read-only.
pxMore	Indicates whether there are more instances not returned. Values are true or false. Read-only.
pyMaxRecords	Optional input to limit the number of rows returned.
pxNextKey	Indicates the key of the first row (instance) not returned, if pxMore is true. Read-only.
pyObjClass	Identifies the class containing the instances that are to be searched. This property is different from pxObjClass, the class of this page, which always has the value Code-Pega-List.
pyPageSize	For list view or summary view rules that support report paging, the maximum number of results to presented on a page.
pyQueryTimeStamp	A DateTime value recording the start of the operation. Read-only.
pxResults	A Page List containing pages with individual search results. each of the class defined in the pxObjClass property. (Not used for Obj-List methods that specify the lightweight results format.) Read-only.
pxResultCount	Number of rows of data returned by the search. Read-only.
pyReturnLightweightResults	For the Obj-List method, indicates that the results are in a special format rather than in pxResults pages. Read-only.
pxSelectStatement	For the Obj-List method, the SQL statement sent to the database before substitution. Read-only.
pxSQLStatementPost	For the RDB-List method, SQL statements as sent to the SQL database. Appears only when requested through the {SQLPage} syntax. Read-only.
pxSQLStatementPre	For the RDB-List method, SQL statements before substitution. Appears only when requested through the {SQLPage} syntax. Read-only.
pxTimeElapsed	For the Obj-List method, elapsed seconds taken for the method. Read-only.
pxTotalResultCount	For the RDB-List method, the total number of results returned by the query. This is set only if pyReturnTotalResultCount is true. (If pyReturnTotalResultCount is false, then this is zero.) Read-only.
pyUseAlternateDb	Set to true if an alternate database, not the primary PegaRULES database, was the source of data for a list view or summary view report.

Performance

This method can return thousands of database rows and create large clipboard pages. Use care to retrieve only the rows (instances) and columns (properties) you truly need.

Execution of this method may cause an alert to be added to the Alert log, of type PEGA004-PEGA007, PEGA0025, PEGA0027. or PEGA0028. Review the Alert log to understand the frequency and sources of such alerts, and for best performance, alter your application or database to eliminate those that occur frequently. For example, if execution of an Obj-List-View method accesses properties within the Storage Stream column, a PEGA0025 alert occurs. The alert indicates that exposing one or more columns in the PegaRULES database table that holds instances of the class is likely to improve performance.

Checking the method status

This method updates the pxMethodStatus property. See How to test method results using a transition.

See the PDN article Comparing the Obj-List-View, Obj-Browse and Obj-List methods.

Methods and instructions by function

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