A New ``HELP Mechanism'' in KUIP
Nicole Cremel CN/ASD
As reported in the article ``The PAW Medium Term Plan for 1995/1996'' (section 5.2), one of the complaints made by PAW users resulting from the ``PAW Questionnaire'' concerned the ``on-line'' help, which, with the current implementation, requires that users know the exact name of a command in order to find some help information. The first step towards an improvement in that area has been to implement a new ``help mechanism'' based on keywords rather than exact command names. This new feature will be available in a new version of KUIP which will be put in the ``new'' area (usually /cern/new/lib/ on Unix) quickly after the release of the CERN Program Library (i.e. arround the 1st or 2nd week of April).
The major change is the introduction of a new directive in the KUIP ``Command Definition File'' (CDF):
>Keyword keyw1 keyw2 keyw3 ... ... keywnWhere keyw1, keyw2, ..., keywn are a list of (significant) keywords to be associated to a particular command. For instance, in the KUIP CDF itself, we have:
>Command PSVIEW >Parameters FNAME 'File name' C >Keyword PostScript display viewer >Guidance Invoke the PostScript viewer on the file. ... >Action kxpsview%CIn order to have a ``good'' (or functional) help interface it will be good if all the application programmers modify their existing CDF in order to introduce the appropriate keywords to be associated to each command; but it is also better to keep this list reasonably small otherwise the user may be lost with a list of possible commands which will be too large to be efficient.
One should note that the introduction of this new directive means that this new version of KUIP will be associated to a new version of the KUIP compiler which must be used in order to translate the CDF into a C file.
It has been decided that, instead of introducing a new command, this new ``help mechanism'' based on keywords will fully replace the existing ``HELP'' command currently available for any KUIP-based application. However, in case of a problem, users will still be able in a first instance to retrieve the usual ``help'' behavior with the new command ``CHELP'' (standing for ``Command-HELP''), which is just a renaming of the ``old'' help command. This command may be declared obsolete in a future release if, as we expect, the ``new'' help appears to be more powerful, and if there is no request from the users to keep it.
This important change will affect all applications based on KUIP, for example, those applications which are part of the CERN library, PAW (and Paw++), GEANT (and Geant++) or FATMEN. Application programmers who based their own application on KUIP, for the user interface, must not forget to re-compile their CDF as soon as they link their application with this new version.
Please note that more work will be done in this area in the future, in order to facilitate the ``navigation'' between related topics, and implement some hypertext capabilities. A new directive >Link followed by the information required to create an hypertext link has already been implemented in the CDF but is not yet operational.