[OpenLayers-Trac] [OpenLayers] #3518: VirtualEarth sometimes broken in Mozilla

[OpenLayers]

#3518: VirtualEarth sometimes broken in Mozilla
--------------------------------+-------------------------------------------
 Reporter:  philipn             |       Owner:  ahocevar    
     Type:  feature             |      Status:  new         
 Priority:  major               |   Milestone:  2.12 Release
Component:  Layer.VirtualEarth  |     Version:  2.11 RC3    
 Keywords:                      |       State:              
--------------------------------+-------------------------------------------
 I've noticed that VirtualEarth layers don't always appear in Firefox.  In
 particular, they don't seem to always load correctly when there's other
 base layers in the mix.

 It looks like this is because the VirtualEarth JS incorrectly calls
 {{{window.attachEvent}}}, which doesn't exist in Firefox:

   From the VE Init() method, beautified:

 {{{
   ...
         graphicCanvas = GetGraphic(this);
         window.attachEvent("onresize", WindowResizeSVG);
         tileLayerManager.Active = true;
   ...
 }}}

 There are other instances in the VE js where {{{window.attachEvent}}} are
 called, but they don't appear to screw up OL, at least in my experiences.

 It looks like {{{Layer.VirtualEarth}}} tries to cover this up by using a
 {{{try/catch}}} block:

 {{{
         if (this.mapObject != null) {
             try { // this is to catch a Mozilla bug without falling apart
               ...
             } catch (e) { }
             ...
         }
 }}}

 This just stops OL from crashing -- the layer can remain unloaded.  My
 attached patch replaces this {{{try/catch}}} with a check for the
 existence of {{{window.attachEvent}}} and temporarily monkey-patches in a
 working {{{window.attachEvent}}} for the duration of the map load call.
 The patch fixes all issues I'm seeing with VE layer loading in FF.

 ------

 I've attached an example that reproduces this issue for me.  I'm using FF
 6.0.2 and, additionally, the olwidget OL wrapper.  It doesn't appear to
 have anything to do with the OL wrapper I'm using, but I didn't have time
 to come up with a new test case.  Toggling to the VE later produces the
 error {{{mapInstance.GetCurrentMode() is null}}}

-- 
Ticket URL: <http://trac.openlayers.org/ticket/3518>
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