Re: DWR, Dojo, and AJAX issue

Discovered from the dojo-list that when using "eval" in Firefox, the 
script is always evaluated in the scope of the window object, but in 
IE7, the script is evaluated in the scope of the function in which it is 
called.  Since I'm using dojo to evaluate the DWR scripts, they were all 
being evaluated in the context of dojo's "dj_eval" function, ala the bug 
documented here: http://trac.dojotoolkit.org/ticket/744  Thus, the 
DWREngine and services I was including weren't available globally.

On the DWR side, the way DWR generates JavaScript could be changed to 
prepend "window." to the functions/objects it creates -- this would 
declare the DWR stuff in the window scope so it could be modularly 
included/imported as I'm doing.

If you're using dojo, an easier workaround in the meantime is to change 
the dj_eval function as suggested in the above link.

Thanks!
Jim


Jim wrote:
> Hello all,
>
> I'm working on a relatively simple dojo module that allows for 
> lazily-loading DWR services.  Reason: if I have a widget that requires 
> a DWR service, I don't want to have to make sure the enclosing HTML 
> page has the appropriate script tags -- I want to say inside my dojo 
> module: mycompany.dwr.loadDWRService("WidgetDWRService");
>
> My solution so far works great in FF2.0, but I'm having trouble 
> getting it to work in IE7 -- I think the DWR JavaScript files aren't 
> evaluating correctly in IE7.
>
> Here is my module; hoping someone familiar with dojo (I'm using 0.4.1) 
> and DWR (I'm using 1.1.3) can help me figure out the issue and/or a 
> workaround:
> ================================
> dojo.provide("mycompany.dwr.common");
>
> mycompany.dwr.loadDWREngine = function() {
>  if (! dj_undef("DWREngine")) {
>    dojo.debug("Engine already loaded");
>    return;
>  }
>
>  dojo.debug("Result of load: " + 
> dojo.hostenv.loadPath("../../dwr/engine.js"));
>  if (dj_undef("DWREngine")) {
>    dojo.debug("DWREngine doesn't exist -- loading failed");
>  } else {
>    dojo.debug("DWREngine successfully loaded");
>  }
> };
>
> mycompany.dwr.loadDWRService = function(/*String*/dwrName) {
>  // First trying to load the DWREngine
>  mycompany.dwr.loadDWREngine();
>
>  if (! dj_undef(dwrName)) {
>    dojo.debug(dwrName + " already loaded");
>    return;
>  }
>
>  dojo.debug("Result of service load: "
>      + dojo.hostenv.loadPath("../../dwr/interface/" + dwrName + ".js"));
>  if (dj_undef(dwrName)) {
>    dojo.debug(dwrName + " doesn't exist -- loading failed");
>  } else {
>    dojo.debug(dwrName + " successfully loaded");
>  }
> };
> ================================
>
> In my dojo widget, I'm making the following call:  
> mycompany.dwr.loadDWRService("WidgetDWRService");
>
> In Firefox 2.0.0.1, this is the dojo.debug output from above:
> Result of load: true
> DWREngine successfully loaded
> Result of service load: true
> WidgetDWRService successfully loaded
> Engine already loaded
>
> In Internet Explorer 7.0.5730.11, this is the dojo.debug output from 
> above:
> Result of load: true
> DWREngine doesn't exist -- loading failed
> Result of service load: true
> WidgetDWRService doesn't exist -- loading failed
>
>
> Anyone have any ideas why this would work perfectly in Firefox but not 
> in IE7, and how I could go about debugging it?  I know IE7 is a little 
> awkward with AJAX support with its ActiveX and native XMLHttpRequest 
> objects each being a little different, but I don't know enough about 
> that to know if it's what the issue is here.
>
> Thanks much,
> Jim