dojo.parser is used even if we import dojox.mobile.parser

[Ming Zhe Huang]

Please see the attached HTML.
The test HTML only uses dojo mobile components. However, if you imports "dijit/Dialog" (but not use it), you'll find that dojo.parser will be used, which will cause error message "Uncaught Error: Tried to register widget with id==list but that id is already registered".

[Ming Zhe Huang]

test case

[bill]

The practical solution/workaround is to stop setting parseOnLoad: true, and instead call the parser you want manually, ex:

dojo.ready(100, dojo.parser, "parse");

[ykami]

Archer, did Bill's suggestion solve your problem?

[bill]

For a fix, how about modifying dojox/mobile/parser to defer to dojo/parser if it is loaded too? Code like this:

if(config.parseOnLoad){
	ready(100, function(){
		// Now that all the modules are loaded, check if the app loaded dojo/parser too.
		// If it did, let dojo/parser handle the parseOnLoad flag instead of me.
		if(!require("dojo/parser")){
			parser.parse();
		}
	});
}

(By "fix" I mean a way to stop both parsers from running.)

[bill]

PS: Or vice-versa: you could add code to dojo/parser.js to defer to dojox/mobile/parser.js. When both parsers are loaded does it usually mean that the user wants to use dojox/mobile/parser?

[ykami]

Bill, it doesn't look like the problem is caused by parseOnLoad:true.

dojo/html.js has dojo/parser in its deps list, which seems to be pulling dojo.parser in this case.

In dojo-1.6, I had been doing like this in dojox.mobile.parser so as not to accidentally load dojo.parser, and it was working well.

dojo.provide("dojo.parser"); // not to load dojo.parser unexpectedly

Isn't there any equivalent technique available for AMD loader?

[bill]

AMD has an ​alias modules feature but I don't think it's appropriate here. I don't see an easy way to prevent both parsers from being loaded.

So, the question (to me) becomes how to prevent parseOnLoad:true from running both parsers... hence my suggestion above.

Also, I don't think it's safe to replace dojo/parser with dojox/mobile/parser in the above example, because Dialog (based on ContentPane) depends on the stopParser feature, only in dojo/parser. Maybe other reasons too.

[ykami]

I don't think parseOnLoad:true would be a problem, because the automatic dojo.parser loading is guarded by an existence check code as below. And dojox.mobile.parser defines dojo.parser. (The original intention was to allow user apps to call the parser like dojo.parser.parse() instead of dojox.mobile.parser.parse(), but fortunately that also prevents the parseOnLoad:true from loading dojo.parser.)

if(has("dojo-sync-loader") && dojo.config.parseOnLoad && !dojo.isAsync){
    ready(99, function(){
        if(!dojo.parser){
            dojo.deprecated("Add explicit require(['dojo/parser']);", "", "2.0");
            require(["dojo/parser"]);
        }
    });
}

[ykami]

Bill, now I understood what you meant. I was thinking about how to prevent 'loading' of the two parsers, but you were actually talking about how to prevent 'running' both of them. Let me consider your suggested code.

[ykami]

In [27164]:

Fixes #14243 !strict. If both dojo.parser and dojox.mobile.parser are loaded, always use dojo.parser, because dojox.mobile.parser is a pure subset of dojo.parser without any extensions. There is no point in using the subset one.

[ykami]

Bill, this code does not seem to work on IE6. parser.parse() is never called for some reason. Too bad..
Although mobile does not officially support IE6, NONE of the test cases work on IE6 due to this problem.
I guess non-mobile dojo/dijit/dojox, where IE6 is still supported, have the same problem?

try{
	require("dojo/parser");
}catch(e){
	parser.parse();
}

[bill]

In [27303]:

workaround IE6 bug where thrown exceptions are ignored (see ​http://support.microsoft.com/kb/944397), refs #14243 !strict.

[ykami]

Thank you for the fix!
I personally think contextRequire should not throw exceptions, though.