How can I trigger a JavaScript event click

Question

I have a hyperlink in my page. I am trying to automate a number of clicks on the hyperlink for testing purposes. Is there any way you can simulate 50 clicks on the hyperlink using JavaScript?

<a href="#" target="_blank" onclick="javascript:Test("Test");">MSDN</a>

I'm looking for onClick event trigger from the JavaScript.

Answer 1

Use a testing framework

This might be helpful - http://seleniumhq.org/ - Selenium is a web application automated testing system.

You can create tests using the Firefox plugin Selenium IDE

Manual firing of events

To manually fire events the correct way you will need to use different methods for different browsers - either el.dispatchEvent or el.fireEvent where el will be your Anchor element. I believe both of these will require constructing an Event object to pass in.

The alternative, not entirely correct, quick-and-dirty way would be this:

var el = document.getElementById('anchorelementid');
el.onclick(); // Not entirely correct because your event handler will be called
              // without an Event object parameter.

Answer 2

I would recommend using an automated UI testing framework like Selenium

Answer 3

Add an ID to your link

<a href="#" target="_blank" id="my-link" onclick="javascript:Test("Test");">MSDN</a>

and call it in your javascript code:

var l = document.getElementById('my-link');
for(var i=0; i<50; i++)
   l.onclick();

Answer 4

Using JQuery, you do this:

$('your selector').trigger('click');

If you're curious about how that is done, you could look at the JQuery source.

Answer 5

Here is what I use:

/**
 * Fire an event handler to the specified node. Event handlers can detect that the event was fired programatically
 * by testing for a 'synthetic=true' property on the event object
 * @param {HTMLNode} node The node to fire the event handler on.
 * @param {String} eventName The name of the event without the "on" (e.g., "focus")
 */
function fireEvent(node, eventName) {
  // Make sure we use the ownerDocument from the provided node to avoid cross-window problems
  var doc;
  if (node.ownerDocument) {
    doc = node.ownerDocument;
  } else if (node.nodeType == JSUtil.NodeTypes.DOCUMENT_NODE){
    // the node may be the document itself
    doc = node;
  } else {
    throw new Error("Invalid node passed to JSUtil.fireEvent: " + node.id);
  }

  if (node.fireEvent) {
    // IE-style
    var event = doc.createEventObject();
    event.synthetic = true; // allow detection of synthetic events
    node.fireEvent("on" + eventName, event);
  } else if (node.dispatchEvent) {
    // Gecko-style approach is much more difficult.
    var eventClass = "";

    // Different events have different event classes.
    // If this switch statement can't map an eventName to an eventClass,
    // the event firing is going to fail.
    switch (eventName) {
      case "click": // Dispatching of 'click' appears to not work correctly in Safari. Use 'mousedown' or 'mouseup' instead.
      case "mousedown":
      case "mouseup":
        eventClass = "MouseEvents";
        break;

      case "focus":
      case "change":
      case "blur":
      case "select":
        eventClass = "HTMLEvents";
        break;

      default:
        throw "JSUtil.fireEvent: Couldn't find an event class for event '" + eventName + "'.";
        break;
    }
    var event = doc.createEvent(eventClass);
    var bubbles = eventName == "change" ? false : true;  
    event.initEvent(eventName, bubbles, true); // All events created as bubbling and cancelable.

    event.synthetic = true; // allow detection of synthetic events
    node.dispatchEvent(event);
  }
};