Log all Ext events

extEventLogger.js

javascript:(
  function() {
    var o = Ext.util.Observable.prototype;
    o.fireEvent = o.fireEvent.createInterceptor(function(evt) {
      var a = arguments;
      console.log(this, ' fired event ', evt, ' with args ', Array.prototype.slice.call(a,1,a.length));
    });
  }
)();

Save as a bookmarklet and run it on a page that uses ExtJS. All Ext events will be logged to the javascript console.