After installing Gaia to my phone. In most apps buttons are not working. I have to debug that. Is there any documents which will explain by each app by app basis. I have solved all HTML and CSS problem but not able to find the code in .js files. Is it documented any where that in which .js file button events are handled.
Thanks for the help.
From Firefox 33 (this is not in the stable release) you should have a little 'ev' flag next to an element when it has events attached. You can then use this to attach to an event handler. See this blogpost.
Otherwise go to the Debugger with the App manager attached. Click on 'Expand panes' (next to the search box), and you can then choose the Events pane. All registered event listeners are located here. If you toggle the checkbox the code will automatically break when the event happens and you can debug it.