Automatic Editing and Error Handling › Error Handling at Runtime

Error Handling at Runtime

When is a Field in Error?

A field is identified as being in error when automatic editing detects an error in that field on mapin. User-written edit modules, CA ADS dialogs, and application programs can perform their own editing and validation and specify whether a field is in error.

Defining Attributes for Redisplay

The CA ADS dialog or application program that uses a map can redisplay a map that contains fields in error.

Attributes can be defined for the redisplay of correct and incorrect fields. Such error-handling attributes can be used to draw the operator's attention to input errors. Error messages can be specified for fields in error. Additionally, the terminal alarm can be sounded when a map contains input errors. Specifications for the redisplay of maps with input errors are made as follows:

• The mapping facility can be used to make error-handling specifications for a map when the map is defined
• The CA ADS dialog or application program that issues the mapout can modify error-handling specifications for the map

Error-handling attributes defined by the mapping facility are available for use when automatic editing and error-handling are enabled for the map (regardless of the individual field settings).

Note: For information about how to enable automatic editing and error-handling for a map, see Enabling Automatic Editing and Error Handling.

The ways in which CA ADS dialogs and application programs redisplay maps are contrasted in the following figure. Dialogs and programs can be set up to handle input errors as follows.

• A CA ADS dialog EXECUTE ON EDIT ERRORS YES/NO specification determines how the dialog executes if fields are in error:
  • YES specifies that control passes to the appropriate response process. The response process can include statements to determine if errors have been detected on mapin, to set additional fields in error, and so forth.

    A DISPLAY command must be used to redisplay the map for the operator. The map is redisplayed according to current error-handling specifications.

  • NO specifies that control is not passed to the response process. The map is redisplayed according to current error-handling specifications. The terminal operator must correct all map fields that are in error before control passes to the appropriate response process.

  Note: For more information about the CA ADS features and syntax, see the CA ADS Reference Guide.

• An application program includes Data Manipulation Language (DML) statements to determine if errors have been detected on mapin, to set additional fields in error, and so forth. A DML statement can issue a mapout to redisplay the map according to current error-handling specifications.

Dialogs, Programs, and Input Errors

An application program should not issue mapout requests with the NEWPAGE (ERASE) specification during error-handling; NEWPAGE (ERASE) maps out all map fields, including literal fields, and changes MDT settings.

Note: For more information about the development of application programs that interact with maps, see the appropriate CA IDMS DML Reference Guide.

Steps Performed by Runtime Mapping

When a CA ADS dialog or application program redisplays a map for which automatic editing and error-handling are enabled, current error-handling attributes are automatically used for the field.

The list and diagram that follow illustrate the steps performed by runtime mapping:

• Modified data tags are set for correct fields.
• Correct-field attributes (if any) take effect for fields that are not in error or that were not edited.
• Incorrect-field attributes (if any) take effect only for fields that are in error.
• The cursor is displayed at the first map field in error.
• Blank required fields or any edited field for which data was not transmitted are redisplayed with a question mark (?) character.
• Data that is not in error is moved from the I/O buffer to program variable storage on a mapin operation if DATA is Y (YES) on mapin for the field.
• Data that is in error is not moved from the I/O buffer to protected variable storage on a mapin operation.
• On an initial display of a map by a CA ADS dialog, all literals and data fields are transmitted even if a field is in error. However, in all other cases, during a mapout operation, if any field is flagged as being in error, then, for all fields (both correct and incorrect), only attribute bytes are transmitted back to the screen; no data is moved from program variable storage to the screen.

Error Handling at Runtime