General Information

The DO SET statement allows for the extraction of information from reports, assigning that information to internal variables, and the manipulation of those variables (such as concatenation and sub-string extraction). Additionally, strings can extracted from XML documents and environment variables such as JOBNAME and EXTWTR.

DO SET Placement

The following are rules for placement of the DO SET parameter:

• DO SET can be placed after an ON statement before the first WHEN statement.
• DO SET can be placed after a WHEN statement or between other DO statements.
• WHEN can be used with a list of DO SET statements without other DO statements.

Using Variables with the WHEN Statement

You can use variables with the WHEN LINE and WHEN VAR variants of the WHEN statement. For an example of using variables with WHEN VAR and WHEN LINE, see Example 2 in Examples. For more information on the WHEN statement, see WHEN: Decollating Parameter.

Using Variables with DO Statements

Certain DO statements can contain variables, including the system variables JOBNAME, EXTWTR, USERID, FILE, DSNLLQ, or a substring of the variable, using the following format:

DO parameter [=] {reg_syntax | %%var1[(startpos,length)]}

where

• reg_syntax is the regular syntax for the DO statement.
• var1 is the variable name.
• startpos is the starting position of the substring to be extracted.
• length is the length of the substring to be extracted.

The following are the DO parameters that support variables, and their formats:

• DO USER=%%<var1>
• DO NAME=%%<var1>
• DO REMARK=%%<var1>
• DO REMARK2=%%<var1>
• DO REMARK3=%%<var1>
• DO PRINT=%%<var1> %%<var2> ...
• DO BACKUP=%%<var1> %%<var2> ...
• DO MIGRATE=%%<var1> (Control-V only)
• DO MASKRUL=%%<var1>

For an example of using variables with DO statements, see Example 3 in Examples.

DO SET and Decollation Subtasks

In decollation subtasks, for each page that is processed, the following steps are performed:

1. All DO SET statements that are placed before the WHEN statement are executed.
2. WHEN statements, including WHEN VAR, are checked.
3. DO statements, including DO SET, from their matching WHEN statements, are executed.

The values assigned by DO SET for the current page may be used in DO statements that appear later in the same page. These values can also be used in the WHEN statements that begin on the next page.

Note: If a variable is used before it is assigned, it has a NULL value.

Extracting a Value from a Decollated Report

When using this option for setting a value for DO SET, do the following:

1. In the varvalue field, type * (asterisk), and press Enter. The LINE and COL fields are displayed. The length of the varvalue field is reduced to 1 character.

   Note: To switch back to the regular varvalue field, replace the * in the varvalue field with any character other than a blank or * (asterisk), and press Enter. The LINE and COL fields are hidden, and the length of the varvalue field is restored to its normal default.

2. Enter the line and column numbers for the report field you want to extract, in the following format:

   LINE[n] COL [k–m]

   where

   • n is the line number
   • k is the first column from which the value is extracted
   • m is the last column from which the value is extracted

   For an example using of extracting a value using this method, see Example 1 in Examples.

Extracting a Value from the XML List of Node Tag Names

When using this option for setting a value for DO SET, use the following format for the XML path (Xpath):

<{/[/] {* | node}/.../{* | source_node}}>

where

• node is the tag name of the XML node containing the needed element, in the form

  tag[index]

  where

  • tag is the tag name.
  • index is the tag number (starting at 1) in the tag collection. It is specified as a sequential child number in the collection of tags with the specified name under some parent. All tag names are separated by a slash (/).
• source_node is the last element of the list (the source node tag name) in the form

  {@attribute_name | text()[[index]]}

  where

  • attribute_name is the attribute name of the source node tag name, which is used as the variable value.
  • text() is the text node, with or without an index, which is used as the variable value.
  • index is the tag number (starting at 1) in the tag collection. The index is enclosed in [ ] (square brackets).

Searches for source tag names are performed using the following rules:

1. The search of source tag is implemented through the node tags from the parent level through the child level.
2. If node is an * (asterisk), this indicates that any next level tag matches the search.
3. If Xpath begins with double slashes (//), the first tag is searched on all levels.

XML Considerations

Because decollation sub-tasks process documents page-by-page, XML documents that are referenced can contain one or more pages. The number of pages is determined by setting an appropriate value for the LINECT CDAM control parameter. For more information on the LINCECT parameter, see CDAM Control Parameters.

You can split an XML report (EDCDIC only) into pages by setting the PRINT/CDAM XMLSEP parameter to tagname. For more information on the XMLSEP parameter, see CDAM Control Parameters.

Because XML documents do not have fixed line and column positions, you cannot reference data from an XML document with any statement that contains the LINE and COL parameters. Strings from the XML document must first be assigned to variables using DO SET statements, after which they may be used in other WHEN and DO statements.

For an example of extracting strings from an XML document, see Example 4 in Examples.