Mapping Facility

Information about the capabilities of CA IDMS Mapping Facility.
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This section describes the capabilities of the CA IDMS Mapping Facility and serves as a reference tool for the CA IDMS applications developer in designing maps.
It also provides an overview of the interactions between the mapping facility, the Integrated Data Dictionary (IDD), user-written programs, and CA ADS for CA IDMS dialogs. This section also describes the online and batch methods of map-definition.
A
map
is a formatted terminal screen that is used to communicate between an application and a terminal operator. The CA IDMS mapping facility is used to define the layout of maps. The mapping facility simplifies the development, storage, and use of input/output (I/O) displays and fields.
  • Development -- The mapping facility enables the map developer to:
    • Use commands or screen prompts to simplify the definition of maps
    • Take advantage of consistent procedures to establish fields on a map
    • Predefine the characteristics of the data that is transmitted between the I/O device and program variable storage
    • Use the mapping facility to specify links between a map and records
    • Generate an automatic screen layout from a record definition
  • Storage -- The mapping facility handles the storage and retrieval of map-related entity occurrences and map load modules
  • Use -- The mapping facility creates maps that can be integrated easily with dialogs and programs.
    • Dialogs that are generated by the application development system, CA ADS, use CA IDMS maps exclusively for screen I/O operations.
    • Programs that are written in COBOL, PL/I, and Assembler can use maps for I/O transactions when appropriate Data Manipulation Language (DML) statements are included in the code.
References to user-written programs apply equally to CA ADS dialogs and host language programs unless otherwise noted.
Online and Batch Capabilities
The map developer can use the mapping facility to create and maintain maps in either an online or batch environment.
The
online mapping compiler
is a convenient online tool for generating and maintaining map-related entity occurrences and map load modules. A map developer using the online compiler does not need to write code or execute JCL routines. The mapping facility is integrated with other CA online systems.
The
batch compiler and utility
are the batch equivalent to the online compiler. The developer generates and maintains map-related entity occurrences by submitting statements to the batch compiler. Map load modules are generated and maintained by statements that are submitted to the batch utility.
The online compiler can be used to modify most map-related entity occurrences and load modules that are created by using the batch compiler and utility. The batch compiler and utility can be used to modify any map entity occurrence or load module generated by the online compiler.
Input/Output Operations
At runtime, stored records that are associated with the map are bound to areas of program variable storage that are defined by the CA ADS dialog or application program that uses the map. Values are transmitted on output and input operations:
  • On output (mapout) operations
    , values in record elements that are used by the map can be transmitted to the map with any fixed character strings (that is, literal fields) that are defined for the map. The amount of data that is transmitted is determined by the runtime application and by specifications that are made for the map during map-definition time.
  • On input (mapin) operations
    , values that a user supplies and that the map is prepared to receive are transmitted to program variable storage.
For more information about CA IDMS I/O modes and for programming considerations that affect modes of I/O, see the DML Reference for COBOL,
DML Reference for Assembler
, or the DML Reference for PL/I.
Terminals Supported by the Mapping Facility
The following terminals are supported by the CA IDMS mapping facility:
Terminal
Mapping Consideration
3270-type
Runtime mapping uses attribute bytes to establish individual fields on the screen. Fields are displayed on the screen with the attributes available on the terminal. Attributes such as color and underscoring are not available on a 3270-type terminal.
3279-type
Runtime mapping uses attribute bytes to establish fields on the screen. Fields are displayed on the screen with the attributes available on the terminal. Display attributes such as color and underscoring are available on 3279-type terminals.
Glass TTY-type
The screen is processed as a single wraparound data line; however, runtime mapping displays data so that it appears to the operator that fields are posted to the map as on 3270-type terminals. Fields are displayed according to the default display options for the screen; most 3270- and 3279-type display attributes are unavailable.
For more information about attributes and attribute bytes, see Attributes for Fields in Designing Map Fields.