The EtToolsVendorExtensionsApp provides protocol for extending the configuration map, applications, classes, methods, and text browser menus in the form of the following twelve SubApplication class methods:

Each of these methods has two parameters: aMenu is the menu (an instance of CwMenu) that you are adding item(s) to, and aBrowser is the browser that the menu is being built for. You’ve probably already noticed that not all of these methods are applicable to every browser. The rule for applicability is pretty simple. Each of these methods contains the name of a browser menu bar item in its selector. If the browser you want to extend has a menu bar item with that name, then the method is applicable; otherwise it isn’t.

In many cases, you will want to point your callback to the browser, since it serves as a source of state information.

The simplest use of these methods is to add an item to the identified main menu. Let's look at a short example of doing this.

This method adds a new menu item labeled Inspect Browser to the end of aMenu owned by aBrowser.

Sometimes you want your tool to be installed on a submenu rather than the main menu. For this purpose, you can use the #menuItemWithValue: method to access submenus. Here's an example of how to use it:

This example is taken from the code for the three-way differences browser goodie supplied in the repository. We use #menuItemWithValue: because we want the menu item to appear on the Compare… submenu along with all other differencing options.