Tag: Lotus Notes

I use many lists in my programs. They are handy for keeping it tidy and configurable. I surely could put a constant in its own identificator and sometimes I do. But what if I need two or more similar constants? Lists are definitely the best choice for holding column numbers and for exchanging fields between Office and Notes documents.

Sometimes double lists would be better than normal lists. Example: an agent for importing some fields from an Excel book with many sheets into a Notes document using a double list for declaring the import structure. It should work this way:

With such a structure one could define the import as a simple forall loop:

Unfortunately double lists don’t exist in LotusScript, so there is no chance for that code to run in a Notes system.

Here is my implementation of double lists, in its own “DoubleLists” script library. Its use is very similar to the one described earlier, but this is working code.

The important thing here is the flexibility of this approach, something similar to the Prolog programming language. The import machine is known and fixed, but by means of a simple set of declarations it can import any book. And adding a new field to import is just a matter of copy and paste a declaration and adjust it, as well as stopping the import of a field is just a matter of commenting out a declaration. And the program gets self documented. These are the reasons why I use lists and double lists as much as possible.

The error_handling.lss file I described in a previous post needs to be available on any machine where the script using it will execute. This is due to a weird behavior of the Notes engine when processing the %Include instruction: The inclusion is done at execution time if executing on a client and at compilation time if executing on a server.

It is certainly possible to distribute a file to all the users, explaining in which folder to copy it, but it is much simpler to have the same database that use it to install it whenever needed.

The HelpAbout document is a good place for storing a file. After attaching it, a HideWhen formula will prevent it from showing up to the user. Then a simple (Install error_handling.lss) agent will extract the file to the proper folder (if the folder doesn’t already have one). And the formula @Command( [RunAgent]; "(Install error_handling.lss)" ) in the PostOpen event of the Database Script library will run the agent each time the user opens the database.

Here is the code for the agent:

In my apps I use many embedded views that show a single category. They are handy, but lack powerful features exposed views have. Sorting by a different column is one of them.

Clearly it’s not a problem for embedded views as it is for categorized views. Notes cannot properly sort a categorized view by a different column, because the feature is poorly implemented in that case.

So the hack should allow for a sorting that left the categorization in place. For backward compatibility, it could be a switchable feature, and the switch could be a special starting for the view comment, like “[1]”.