FileMaker Extra: Creating a Custom Function Library

If you or your organization uses custom functions across several solutions, you'll likely want to develop some sort of centralized library of the functions you've developed. That way, when you find yourself in need of a particular function, you won't have to rack your brain remembering where it was used before. Also, centralizing the function library is a way of creating a knowledge base that can help your organization leverage its past work and can aid in the training of new developers.

Your library can take many forms. One option, of course, is to create a FileMaker Pro file for your function library. Minimally, you'll want to include fields for the function name , its parameters, its formula, and a brief description. You might also use a container field to store an example file for a particular function. Another "nice to have" would be a related table for storing information about where you've used the function.

As of the time of this writing, there's no way to move custom functions from one file to another. Cutting and pasting formulas to and from the library isn't terribly time consuming, though. Custom functions are, however, part of the Database Design Report (DDR) that can be produced by the FileMaker Developer 7. If you're handy with XML, or are looking for a fun first XML project, you might want to use the XML output of the DDR to create your function library.

Finally, if you always want to have a particular set of custom functions in your files, create a sparse template file that has them in it. Then, rather than create new files from scratch, you can just duplicate and develop on top of your template.