Best practices for multiple Add-Ins?

[AdamBecker]

Meta Question: Is there a tutorial on add-ins which gets into Best Practices, and talks about the interactions of multiple add-ins? That's rather than just the nuts and bolts of creating and loading single Add-Ins.

With the Add-Ins I write: Should an Add-In include other Add-Ins? Or should I make a larger set of small add-ins, and load each as they are needed?

I'm working a large number of related, smallish projects. I have a lot of code, in both class and regular modules, which I re-use from project to project. Many of these projects are delivered to other users to use on their (changing) data sets - although sometimes they just want the analysis from me. Currently, most of my reusable code is in one big Add-In. I'm thinking of splitting into separate Add-Ins so I don't have to load 30+ modules just to use a single function. But I'm not sure how that works. If Top.xlsm is using the Bottom.xlam add-in, then when I save Top as top.xlsm, does it carry the functionality of bottom along with it? Should it? When I create a new .xlsm file, should I add just the Top add-in, or load both of them separately?

I'm primarily asking for Excel 2007, under Windows 7.

[JosephP]

you can set a reference to an add-in project from a macro workbook then use the code (mostly) as if it were in the macro workbook. the only thing saved with the workbook is the reference

[AdamBecker]

@JosephP: thanks, but if I have two Add-Ins, Top and Bottom, and Top uses functions from Bottom, and Bottom is loaded when I save Top as an .xlam, then does the user have to separately load both add-ins? Or does Top drag Bottom along with it?

As a larger question, what's the right way to organize these dependent Add-Ins in a way that's both easy on the user and the maintainer?

[JosephP]

if you have a reference set in Top to Bottom then Bottom will be opened when Top is loaded

you could also simply use code in the primary add-in that loads other add-ins as required