In the C/Base Tutorial manual, exact key sequences were given in order to duplicate the examples used in the text. If you were unable to perform certain of those sequences because your keyboard lacked one or more of the required keys, the termset(C-1) program may be used to define key sequences to 'replace' the missing keys. (For more information, see Chapter 11, Creating Terminal Definitions.) Wtrdef can also simulate editing functions which may not be supported directly by your monitor. For example, if your monitor does not have the ability to insert lines within a screen display, wtrdef simulates a line insertion by redrawing the screen with the new line included.
Obviously, when designing your own reports, you must make the decisions regarding their layout. The designing of visual reports is often a time-consuming 'trial and error' process which wtrdef attempts to expedite by displaying the report format 'as you go'. It is intended to help users generate reports without first having to learn how to program, use a text-editor, etc. As such, visual reportfiles are very basic, with only certain types of complex reporting.
Among its limitations is the fact that it only allows reporting on one file. You can do lookups from other RMSfiles, but the more advanced reports which access several RMSfiles are not possible with visual reportfiles.
All of the Demonstration System reports can be created as visual reportfiles. Certain types of reports, such as ones that perform an initial record selection to retrieve a value from one RMSfile, and then use that value to perform subsequent record selections from other RMSfiles, cannot be done as visual reports.
Other limitations worthy of note are the absence of any computations other than totals and the lack of any conditional statements other than those used in record selection.
The processing of records is also limited to the selection and sorting processes, as no capability is offered to add, update, or delete data file records.
Finally, no provision has been made for printing lines longer than the width of the terminal screen. If your terminal has 80 columns, you can lay-out reports with at most 80 columns. If your terminal is capable of displaying lines of 132 columns in length, you should be able to lay-out reports of this length. You may need to use the termset program in order to 'enable' these capabilities prior to 'using' them.
Although not all reports can be made to fit the model of a visual reportfile, they can still serve a very useful purpose in designing complex reports, even with the limitations previously mentioned. A visual reportfile can be created and used to design the overall layout of a report with no concern as to what values will actually be printed. The reportfile containing this 'rough draft' of the report can then be converted to a Report Writer reportfile using preport as described earlier. Once the reportfile is in this form, a programmer can modify the file by adding the Report Writer language statements necessary to complete the report. (Note: Once in this form, there is no way to convert a text reportfile containing Report Writer code back into a visual reportfile. Therefore, any modifications made to the Report Writer text reportfile could not be incorporated into a visual reportfile.)