125318 - JavaScript Menu not working

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect, P2)

Description

[Volker Merschmann]

Hovering over top menu should show up pull-downs

Comment 1

[gavin long]

May be evangelism.  The browser sniffing feeds the browser either
http://www.volvooceanrace.org/scripts/menu/iemenu.js or nsmenu.js

The "NS" file is served to NN4 only.  Moz gets the "IE" file, which has calls to
both document.all and document.getElementById(), so it's possible that it's
intentional that Moz gets the IE file.

Unfortunately, both those JS files are deliberately obfuscated, so figuring out
what's happening isn't going to be easy.

Confirming.  I'm going to try and descramble iemenu.js a bit, and see what I can
find...

Comment 2

[gavin long]

Curiously, the iemenu.js file ALSO has document.layer calls.

I'm no JS whiz, but I managed to descramble the file a bit (I'll attach it in a
mo, so that any interested JS gurus can try to work out what's going on.

Mousing over the menubar gives "Error: mFrame has no properties
Source File: http://www.volvooceanrace.org/scripts/menu/iemenu.js
Line: 1"

Comment 3

[gavin long]

Attachment: slightly descrambled JS file

Comment 4

[Phil Schwartau]

Gavin, thank you for descrambling the JS file! Thanks to you,
I was able to debug it. I see two problems:


1. When you load the site, you see this error in the JS Console:

Error: setting a property that has only a getter
Source File: http://www.volvooceanrace.org/scripts/menu/iemenu.js
Line: 1

Note it says "Line:1" because the file is obfuscated: all on one line!
Thanks to Gavin, we find where the error is :


var BV=navigator.appVersion;
BV=parseFloat(BV.indexOf('MSIE')>0?
              BV.split(';')[1].split(' ')[2] : BV.split(' ')[0]);
var BN=window.navigator.appName;
var IsWin=(navigator.userAgent.indexOf('Windows')!=-1)?true:false;
var OP=(navigator.userAgent.indexOf('Opera')!=-1&&BV>=4)?true:false;
var SM=(BN.indexOf('Netscape')!=-1&&(BV>=5)||OP)?true:false;
var NS=(BN.indexOf('Netscape')!=-1&&!SM)?true:false;
var IE=(BN.indexOf('Explorer')!=-1&&(BV>=4)||SM)?true:false;

if((!IsWin&&IE)||SM)
{
  frames.self=window;   <<<<<<<<<<<<<<<<<<<<<<<<<<<<< ERROR OCCURS HERE
  frames.top=top;
}

Note: in Mozilla |SM| evaluates to true, so we DO hit this line -



2. The menu items at the top of the page are "HOME", "NEWS", etc.
   These are accessed in the code via

            mFrame.document.getElementById('Home');  etc.

   Now, |mFrame| is null as Gavin pointed out in Comment #2. 
   To make a long story short, |mFrame| is supposed to be the
   Window object, so this can be reduced to: 

               document.getElementById('Home');

   But: load the site and try this in the URL bar:

     javascript: alert(document.getElementById('Home') === null);


   In IE6, you get 'false', in Mozilla  you get 'true'
   So in Mozilla, none of the menu code is going to work.

Comment 5

[Phil Schwartau]

The |frames.self=window;| error above is the reason |mFrame| evaluates
to null in Mozilla, as far as I can see. The problem occurs here:


function SetUpEvents()
{
  onerror=errHandler;

  if(typeof(mFrame)=="undefined")
    mFrame=eval(frames['self']);   <<<<<<<<<<<<<< null BECAUSE OF ABOVE ERROR

  if(typeof(mFrame)=="undefined")  <<< typeof(mFrame)== typeof(null)== "object"
  {
    window.setTimeout("SetUpEvents()",10);  <<< so we don't fall into here
  }
  else 
  {
    if(NS)
    {
      mFrame.captureEvents(Event.MOUSEMOVE);
      mFrame.onmousemove=HideMenus;
      PrepareEvents();
    }

    if(IE)
    {
      document.onmousemove=HideMenus;
      mFrame.document.onmousemove=document.onmousemove;
    }
  }
}

Comment 6

[Phil Schwartau]

Reassigning to DOM Level 0, because these are DOM issues, not JS Engine.
As outlined in Comment #4 above, we have two separate problems:

1. Why does |frames.self = window| trigger an error in Mozilla
   but not in IE6? 

2. Why is document.getElementById('Home') === null in Mozilla,
   but not in IE6?


Problem 1 causes the variable |mFrame| to be null, which ruins
their whole menu DHTML. However, even if we set |mFrame = this|
in the JS Debugger, so that it is the global Window object it
is supposed to be, the DHTML menus fail because of Problem 2.

Comment 7

[Phil Schwartau]

*** Bug 103112 has been marked as a duplicate of this bug. ***

Comment 8

[Darren Hampton]

As you probably can see by now we're using the commercial DHTML MenuBuilder 
from xFX software (http://software.xfx.net/mainindex.htm) for this, and we've 
not seen many other problems before with their code.

I have been using build 2001031614 of Mozilla for testing (out-of-the-box RH7.1 
distribution) and haven't come up against any problems with the menu code. 
Interestingly they say that their code is compatible with Mozilla 0.6 on their 
product description.

While I can see there's a problem here not so much with our page/code but with 
the DOM, if anyone has a suggestion how we can keep our Mozilla fans happy I'd 
be happy to try and implement it.

Comment 9

[Phil Schwartau]

Darren: thanks. Using Mozilla binary 2002021413 on WinNT,

1. I went to that site, http://software.xfx.net/mainindex.htm.
2. I clicked on "Public Forum", which led me to:            
   http://software.xfx.net/uboards/indexp.php?forum=uboard_main.htm
3. I moused over the "DHTML Menu Builder" link
4. CRASH!!!

But that looks like a different issue than here. The stack trace
is almost identical to the one posted at Bugzilla bug 123803:
http://bugzilla.mozilla.org/attachment.cgi?id=68162&action=view

Comment 10

[Fabian Guisset]

frames.self=window fails in Mozilla because nsIDOMWindowInternal::Self is a
readonly attribute (which is why it says setting a property that only has a
getter). The MSDN library says it is also readonly in IE
(http://msdn.microsoft.com/library/default.asp?url=/nhp/Default.asp?contentid=28000441)

Not sure about the second error.

Comment 11

[Ian Neal]

Is this problem still occuring as I can't see any of the messages mentioned on
BuildID 2003020308 on WinXP SP1

Comment 12

[Volker Merschmann]

Ian: The site has been changed, the event is over for some months. There are no
pull-downs now.
Think we should close this or find a similar bug to track this. Johnny?

Comment 13

[Johnny Stenback (:jst)]

Attachment: Fix the window.self='...' problem.

Sounds like we can't do much more than fix the one problem we know about here
for now, this patch makes window.self (and thus also frames.self) settable.

Comment 14

[Johnny Stenback (:jst)]

Attachment: Adding comment about nsIDOMWindowInternal::self

Forgot this in the first diff, just adding a comment...

Comment 15

[Fabian Guisset]

Comment on attachment 114989 [details] [diff] [review]
Fix the window.self='...' problem.

how many non-settable properties are non-replaceable now? wouldn't it make
sense to implement a general mechanism that all non-settable properties are
replaceable?
If not, r=fabian.

Comment 16

[Johnny Stenback (:jst)]

Fabian, that's an idea to think about, but for now I'm not up for doing that.
Please feel free to file a bug on that though.

FIXED.