How to write extensions

Development Workflow:

• Download Brackets per Main Wiki
• Create a new folder in extensions/user with yourExtensionName, and a main.js file for your extension code. (You may want to copy an existing extension like InlineImageViewer - whatever is most similar to what you want to do.)
• Open up Brackets, and if it's not already opened, open the brackets/ folder.
• Open a new window (Debug->Experimental->New Window), which opens a new Brackets instance. You'll use this window for testing your extension. You generally don't want to use the same window, as you may end up breaking Brackets itself. (But you can if you want)
• In window #2, open a folder on your file system and create a new file for testing your extension (test.html). Write whatever code will help you test the extension.
• The development workflow is like this:
• In window #1, edit your extension code.
• In window #2, reload window (Ctrl/Command-R) to get extension changes and test.
• To debug problems, open the developer tools for window #2. You can use console.log from the extension code, set breakpoints, etc. (If you set a breakpoint, clear it before you close dev tools, otherwise Bracket will die. Bug)
• Repeat.

Extension Architecture:

Your extension consists of a main.js (your main module) and any other JS files (other modules). When you use Require in your main module to import your own modules, you get a private copy of modules, so they dont conflict with other modules. To access core modules, use bracket.getModules().

You often want an extension to integrate with the UI somehow. If your extension is doing something new from scratch, you can add new menu items or keyboard shortcuts for your new behavior -- see next section for how. Certain existing Brackets features are extensible in their own right; those features typically provide UI already that you plug into via a more "headless" API -- see the section after next.

Extending the UI generically

See Simple "Hello World" extension for a code sample.

For any new behavior, first register a Command that implements your behavior, via CommandManager.register(). This just maps a Command id (string) to your handler function.

Add a menu item: Get a top-level menu by calling Menus.getMenu() with one of the AppMenuBar constants. Then add a menu item via theMenu.addMenuItem(), linking it to your Command id. The menu item's label will be the string name you gave the Command when it was created.

As a convenience, addMenuItem() also lets you create a keyboard shortcut for your Command at the same time.

Add a keyboard shortcut: To add a keyboard shortcut without any related menu item, call KeyBindingManager.addBinding() directly, linking a shortcut to your Command id.

Extending specific Brackets functionality

Quick Edit: To create an extension that responds on CTRL+E (like the inline image viewer), use EditorManager.registerInlineEditProvider(). That manager works by iterating through all the possible inline edit providers on CTRL+E and finding which ones actually respond - it has no notion of priority now, so if your extension wants to respond in the same scenario as some other provider, you'll be out of luck.

Quick Open: To interface with the quick open (file open/jump to) interface, use QuickOpen.addQuickOpenPlugin().