Vision Components

Vision uses the compiler and interpreter already in place as part of ABF. In this way, Vision functions in an Ingres environment as an extension of ABF, allowing you to combine the functions of the two tools, as described in Accessing Vision through ABF.

The following figure shows how the various Vision and Ingres components interact:

Each of Vision's components is used to create the 4GL source code and forms for an application. These components include:

• The application flow diagram that specifies the frames that your application uses and how those frames are called

• The visual query for each Append, Browse, and Update frame that provides basic information to generate the frame's form and database query

• Additional information--parameters, local variables, 4GL escape code and frame behavior specification--used to generate queries and forms or specify how the user interacts with a frame

Any 4GL escape code is included in the generated source code exactly as you have written it.

• The Reconcile utility to modify visual queries whose database tables have been changed (by adding a new column, for example)

See How the Vision Reconcile Utility Works for more information about the reconciliation process.

The code generator creates this file by combining a generic template for a frame type with information about a specific frame of that type. This information is provided by the visual query and other components discussed above.

– A copy of a standard user help file for each frame, based on the frame's type

See How Vision Generates Code for more information about how Vision generates source code and help files.

• The Vision form generation facility that creates a form for each generated frame

Vision determines the fields for the form based on the visual query and application flow diagram. Vision modifies the form when these specifications change.

• The application report that provides a summary of information about each frame in an application

The output from these components is processed through the ABF/4GL compiler and interpreter, as with any ABF/4GL application. After the application is compiled:

• Create an image file that contains the compiled code; this file is written to the object directory.

Ingres makes no distinction between the code that Vision generates and any other 4GL code that your application uses. You can edit Vision-generated source code as described in Modifying Vision Code.

• The frames and forms that you created through Vision are stored as database objects in the appropriate catalogs.

Ingres treats these objects the same as any other database objects, such as reports or join definitions, that you have used with frames for which Vision did not generate the 4GL code.