194587 - Synthetic (Trigger) Event via dispatchEvent() method generates exception

Status: RESOLVED FIXED

(Documentation Graveyard :: Web Developer, defect)

Description

[leonard]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.3b) Gecko/20030221
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.3b) Gecko/20030221

I took some code directly adapted from the Gecko DOM Reference
(http://www.mozilla.org/docs/dom/domref/dom_el_ref36.html) but when trying to
implement it, I get the following exception generated:

Error: uncaught exception: [Exception... "Could not convert JavaScript argument
arg 0 [nsIDOMEventTarget.dispatchEvent]"  nsresult: "0x80570009
(NS_ERROR_XPC_BAD_CONVERT_JS)"  location: "JS frame ::
http://randomfoo.net/sandbox/mozilla/dispatchEvent/ref.html :: <TOP_LEVEL> ::
line 6"  data: no]

As a secondary issue, there does not seem to be any documentation for the names
of the Event Interface types that Gecko uses.  Is this available anywhere (and
if it's just in the source, mind giving a pointer to where I might want to start
looking?)

Reproducible: Always

Steps to Reproduce:

Comment 1

[Boris Zbarsky [:bzbarsky]]

This documentation is totally wrong.  

1) The boolean return value has nothing to do with whether the event is successful
2) dispatchEvent takes an event object, not a string.

I suggest looking at
http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html# for
something like correct documentation.

Comment 2

[leonard]

OK, it works when passing an actual event object (although it barfs up an
exception if I try to predeclare an 'new Event', it works fine handling a
createEvent()): http://randomfoo.net/sandbox/mozilla/dispatchEvent/dom.html

One thing that's curious, is that the MouseEvent click doesn't seem to actually
simulate a mouseclick in the interface.  It'll trigger the onclick listener, but
it won't for example, cause say a select form element to expand.  Is it supposed
to? (and if it's not can anyone point me in a direction of how/if to do it [ie,
a different event type I should be specifying in initEvent()?])

Comment 3

[Daniel Wang]

-> Ian

Comment 4

[Ian Oeschger (gone)]

moving stuff over to an outside-the-firewall email for the time being, looking
for people to pick these Help and doc bugs up for me.

Comment 5

[Daniel Wang]

taking over some of Ian's bugs

Comment 6

[Daniel Wang]

-> Doron

Comment 7

[Chad Skeeters]

I'm pretty sure something has changed recently because I have code that used to
work and I've had to modify it to get it to work correctly again.  I have
commented out what used to work.  Now I have to create a new event otherwise I
get this error.

Error: uncaught exception: [Exception... "Component returned failure code:
0x80070057 (NS_ERROR_ILLEGAL_VALUE) [nsIDOMEventTarget.dispatchEvent]" 
nsresult: "0x80070057 (NS_ERROR_ILLEGAL_VALUE)"  location: "JS frame ::
http://u-web-dev.karta.com/interface/pages/author/v2/includes/page/UiPopupMenuItem.js
:: anonymous :: line 46"  data: no]


UiPopupMenuItem.prototype.handleClick = function(mouseEvent) {
  var i = UiUtil.childIterator(this.pTd);
  if (i.hasNext()) {
    if (mouseEvent.target == this.pTd) {
      var firstChild = i.next();
      if (firstChild.nodeType == UiUtil.ELEMENT_NODE) {
        if (firstChild.dispatchEvent) {

          var e = document.createEvent("MouseEvents");
          e.initEvent("click", true, false);
          firstChild.dispatchEvent(e);
          //firstChild.dispatchEvent(mouseEvent);
        }
      }
    }
  }
}

I don't know if that makes it a bug or not.  Maybe it was never supposed to work
in the first place.  If you want me to pair this down to a working example that
doesn't function I can.

Comment 8

[Boris Zbarsky [:bzbarsky]]

Redispatch of an event that is currently being dispatch was disabled for
security reasons.

Comment 9

[Yuh-Ruey Chen]

documentation is already fixed:
http://developer.mozilla.org/en/docs/DOM:element.dispatchEvent