event-handling

I'm writing a Chrome extension that places a button next to the "reply" button of each email. And elsewhere on the page is the main React component. When the component loads, i add listeners to a custom event: componentDidMount: function() { this.listenForFileEmailEvent(); }, listenForFileEmailEvent: function() { window.addEventListener("fileThisEmail", this.handleFileEmail, false); }, I place the button in each email and setup the event: $(document).on("click", ".file-this-email", function(e) { var email = $(e.target).parents(".gs").find('.gD').first().attr("email"); var name = $(e.target)

I have a GridView with dynamically created image buttons that should fire command events when clicked. The event handling basically works, except for the very first time a button is clicked. Then, the postback is processed, but the event is not fired. I have tried to debug this, and it seems to me, that the code executed before and after the first click is exactly the same as for any other clicks. (With the exception that in the first click, the event handler is not called.) There is some peculiarity in that: The buttons which fire the event are created dynamically through databinding, i.e.

What is the difference between var events = require('events'), emitter = new events.EventEmitter(); and var emitter = require('events').EventEmitter; or EventEmitter is pretty forgiving in using/not using new and () ? Your second example doesn't call EventEmitter at all. emitter ends up being a reference to the function, not an object created by calling it. If you meant to have () on that: var events = require('events'), emitter = new events.EventEmitter(); vs var emitter = require('events').EventEmitter(); // Note ------------------------------------^^ Then there are two differences: You have

If you subscribe the .net event with the same subscribe more then once, then your subscribed method will be called the same times as subscribed. And if you unsubscribe just once, then it will be just one minus to the call. Meaning you have to unsubscribe same no of times as subscribed, otherwise u will be keep informed. Somtimes you don't want to do it. In order to to prevent an event Handler to be hooked twice, we can implement event as following. private EventHandler foo; public event EventHandler Foo { add { if( foo == null || !foo.GetInvocationList().Contains(value) ) { foo += value; } }

How do you add an event listener or handler to widgets in GWT 1.7? I know there are some questions alreayd about this on SO but it seems they are outdated. For example (ignoring the fact that there is a :hover in CSS) how do I add a Hover listener to a FlexTable for example? If you want to add a MouseOverHandler to a FlexTable try this: public class MyFlexTable extends FlexTable implements MouseOverHandler, HasMouseOverHandler { public MyFlexTable() { this.addMouseOverHandler(this); } public void onMouseOver(MouseOverEvent event) { //do something } public HandlerRegistration