BREW Extensions Demystified - Part I

The BREW extensions are nothing but custom BREW interfaces developed for a specific purpose. Every BREW extension will have its own folder in the brew directory with its mod, mif, sig and bar files.

Difference between Applets and Extensions
The basic difference BREW applets and extensions are

1. Applets are stand-alone BREW applications, whereas extensions are used by one or more applets for a specific functionality.
2. Applets must provide the IApplet interface to the BREW for reference counting and handling of events. Extensions can have its own interface.
3. Applets can be launched from BREW App Manager or ISHELL_StartApplet() or equivalent API's. Extensions are instantiated with ISHELL_CreateInstance().

Note: An extensions privileges are same as the privileges of the applet in which the extension in instantiated. For example if you are using IFile API's in your extenstion, the applet which will be using your extension should have the File Persmisson.

Now that you have the basic understanding of what are applets and extensions, In the following posts we will convert the McbXML by Martyn Brown as a IMCBXML BREW interface.