What Is an Application?

An application is a platform-independent repository for a group of related components, such as procedures, Master and Access Files, data files, HTML files, PDF files, and image files. It provides a way to confer a unique identity on the application components and facilitates the sharing of components across applications in an organized manner. This construct also simplifies the process of moving a user application from one platform to another.

These components are physically grouped together on an application-by-application basis for run-time execution. This physical grouping can be within an application under a common root or a mapping to an application anywhere in the file system. The physical application or mapped name is referred to as the application name in this document. A comprehensive set of application (APP) commands are provided to control/manipulate the application components, as well as to facilitate applications that can be written and deployed to any platform.

The physical location of an application and its components is determined by a configuration parameter called approot. This parameter is set at installation time and stored in the configuration file, edaserve.cfg. On z/OS, the EDASERVE configuration file must be a member in a PDS allocated to DDNAME ERRORS. The default value is dependent on the platform, relative to the install ID home directory, where applicable.

Application directories can be nested, except on z/OS. A nested application directory is an application created within a higher-level application. For more information. see Nested Application Directories.

On z/OS, data sets are created for each component type using the approot value as the high-level qualifier.

On z/OS, the following is a list of all application data sets automatically created for an application, where approot is USERID.APPS and the application name is BASEAPP:

APP CREATE BASEAPP
USERID.APPS.BASEAPP.ACCESS.DATA
USERID.APPS.BASEAPP.ETG.DATA
USERID.APPS.BASEAPP.FOCCOMP.DATA
USERID.APPS.BASEAPP.FOCEXEC.DATA
USERID.APPS.BASEAPP.FOCSTYLE.DATA
USERID.APPS.BASEAPP.GIF.DATA
USERID.APPS.BASEAPP.HTML.DATA
USERID.APPS.BASEAPP.MAINTAIN.DATA
USERID.APPS.BASEAPP.MASTER.DATA
USERID.APPS.BASEAPP.SQL.DATA
USERID.APPS.BASEAPP.WINFORMS.DATA

To reference an application file in a FOCUS command, use the syntax appname/filename if the file is not first in the application path. For example:

TABLE FILE baseapp/GGSALES
...

No allocation or definition is needed for referencing the standard file types. Other types of files that you may create within an application must be allocated or defined before being used. FOCUS files can be defined with a USE command.