I've been working on 2 projects which needs to be tied together using another feature.
A custom field type that is a Regular Expression Field. When configuring the RegEx field, you choose which Regular Expression you wish to enforce using a combo box. This combo box gets it data from an XML file. This is installed as a solution globally with no feature.
A global config document library. Installed directly to the SharePoint Central Administration Site. When installed it creates a document template, then document library based on new content type also created on install. Once installed the XML file required for project 1 is added. There is also a class created that is used in project 1 that can call the document library. This is installed as a solution for the Central Adminstration Site only.
How the class for accessing the XML file works is reading a config value in the web.config of the web site, which tells the site where the Central Administration site is, and what the Global Config Document Library is called. (This is all similar to Chris 'o Briens Local config store http://www.sharepointnutsandbolts.com/2008/05/config-store-faqs.html).
I've created a feature called ActivationForGlobalConfig, which upon activation will insert the correct appSetting values required in the web config to access the global configuration store. Due to the fact I'm using the Global config store with a custom field type, that will be visible in every site, I need to edit the web.config for every current web application, and every future web application created in the farm.
How to I create a feature that can be deployed to every current web application, and future application that will activate on default? I've tried using the features ActivateOnDefault="True" but it doesn't seem to do anything.