TRANSFER Programming Manual

Dividing Application Tasks
Developing TRANSFER Applications
40970 Tandem Computers Incorporated 8–7
Carefully integrate the use of function keys with the screen displays. An operator will
use these keys either to signal completion of an operator function or to specify a
choice, such as adding an item or deleting an item. To avoid errors and confusion:
Use the keys consistently on all screens.
Lay out the references to the keys distinctly on the screen.
Limit the number of function keys needed on each screen.
Avoid using multiple keys for the same function.
Confine screen entries to similar, related choices.
Consider using shifted keys for functions that might produce irreversible results.
Provide a series of help screens and menu screens to help the user to progress
through the application.
Distinguish various kinds of fields in the screen layout. You might use
underlining or reverse video for entry fields, dim display for special prompts, and
blinking or brightened display for error messages.
Use default values and protect crucial screen fields to help prevent errors. You
can use SCREEN COBOL field characteristic clauses to specify integrity
constraints.
If you are adding the TRANSFER delivery system to an existing application, decide
how to integrate the new functions, screens, and keys into the existing application.
Dividing Application
Tasks
Consider how the work performed by the application should be divided among
clients, agents, and other application programs. In making these decisions, refer to the
discussions of clients and agents in this manual and to the PATHWAY manuals
referenced in the preface. Note the following restrictions:
A process can read or update only those profile records associated with the
correspondent that the process presently represents.
A process can create distribution lists or folders only for the correspondent that
the process presently represents.
A process can handle profile records for other correspondents at a node only if the
process represents a correspondent with system administrator capability at that
same node.
A process can add, delete, and alter folders and distribution lists owned by other
correspondents at a node only if the process represents a correspondent with
system administrator capability. Note that this privilege does not include listing
the contents of another correspondent's folders.