Defining the XREF

The Define XREF screen (the following figure) is where you specify which source layout library members are to be used for formatting the data records of your file.

The scrollable area in the lower half of the screen is where you enter line commands and member names (or patterns).

Define XREF Screen. Requesting a Pattern Member List.

The optional Beginning Data-Name field is provided for cases when the referenced source layout library member contains multiple 01-level data structures, or is a source language program (COBOL or PL/I) containing an embedded data structure that you want to use for formatting your data records.

File-AID examines the source code for the data-name and extracts the data structure at the level of the data-name specified, stopping when an equal or lower level data structure or other non-data declarative source statement is encountered.

If you do not specify a value in the Beginning Data-Name field for a source member with multiple 01-level data structures, File-AID displays a list of structures from which you can select.

Whenever File-AID is unable to clearly determine the structure to use (for example the layout member is a source program), the Source Statement Selection screen is displayed to capture the starting and ending data names or line numbers of the source statements which define the data structure you want to use.

The EX (Extract) layout line command is provided to give you direct access to the Source Statement Selection screen to enable source data structure extraction from within a program when starting-data-name or line-number is not adequate for isolating the data structure to use for formatting.

Use the Description field to document your comments to help you identify each of the layout usage conditions you define for each layout member.

Fields at the top half of the screen capture information about this XREF to help with future identification. One of these fields is the Generated filler length field, which can be used to request that File-AID automatically generate a filler field before each of the layouts when presenting formatted data displays.