DOM:element.dispatchEvent

From MDC

« Gecko DOM Reference

Contents 1 Summary 2 Syntax 3 Example 4 Notes 5 Specification

[edit] Summary

Dispatches an event into the event system. The event is still subject to the same capturing and bubbling behavior as directly dispatched events.

[edit] Syntax

bool = element.dispatchEvent(event)

• element is the target of the event.
• event is an event object to be dispatched.
• The return value is false, if at least one of the event handlers which handled this event, called preventDefault. Otherwise it returns true.

[edit] Example

This example demonstrates simulating a click on a checkbox using DOM methods. You can view the example in action here.

function simulateClick() {
  var evt = document.createEvent("MouseEvents");
  evt.initMouseEvent("click", true, true, window,
    0, 0, 0, 0, 0, false, false, false, false, 0, null);
  var cb = document.getElementById("checkbox"); 
  var canceled = !cb.dispatchEvent(evt);
  if(canceled) {
    // A handler called preventDefault
    alert("canceled");
  } else {
    // None of the handlers called preventDefault
    alert("not canceled");
  }
}

[edit] Notes

As demonstrated in the above example, dispatchEvent is the last step of the create-init-dispatch process, which is used for manually dispatching events into the implementation's event model.

The event can be created using document.createEvent method and initialized using initEvent or other, more specific, initialization methods, such as initMouseEvent or initUIEvent.

See also the Event object reference.

[edit] Specification

DOM Level 2 Events: dispatchEvent