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Dealing With JQuery ParseHTML() And Html() When Using Google Closure Compiler,,,

I have a simple set of statements that actually work (I have run that code and it does what I expect of it) that looks as follow:

result_xml = result.jqxhr.responseXML;
a = jQuery("data[name='calendar']", result_xml).text();
new_calendar = jQuery.parseHTML(a);
jQuery("div.calendar").html(jQuery("div.calendar table.calendar-table", new_calendar));

result comes from an AJAX reply, you should recognize the jqxhr field.

I expect a to be a string since I get a block of data with text(). The data is an HTML string that I saved in the XML document. So I can cast it this way:

a = /** @type {string} */ jQuery("data[name='calendar']", result_xml).text();

Now I convert that string to an HTML DOM thinking it would be an Element:

new_calendar = /** @type {Element} */ jQuery.parseHTML(a);

And that's where I get this weird error:

WARNING - invalid cast - must be a subtype or supertype
from: (Array.<(Element|null)>|null)
to : (Element|null)

So parseHTML() would be returning an array of elements (or null)?

Then I was trying to use the output of the parseHTML() in the html() function and there too, I have a hard time to understand what is going on.

WARNING - invalid cast - must be a subtype or supertype found : (Array.<(Element|null)>|null)
required: (Document|Element|Object.|jQuery|null|undefined)

Frankly, I do not see why the Google compiler makes it such that the output of one function cannot be the input of another, even if it works just fine in the real world.

Would an array of Element be considered a Document?

Then finally (yeah! all of that for 3 lines of JavaScript!) I get another error in regard to the input of the html() function:

WARNING - actual parameter 1 of jQuery.prototype.html does not match formal parameter found : jQuery
required: (function (number, string): ?|string|undefined)
jQuery("div.calendar").html(jQuery("div.calendar table.calendar-table", new_calendar));

Here too, it works in the real world... will the jQuery object automatically be converted to a string and then re-transformed to a set of tags to be added in my calendar?

Are all of these normal limitations of the closure compiler?


Based on Chad answer, I changed my code this way:

result_xml = result.jqxhr.responseXML;
a = /** @type {string} */ (jQuery("data[name='calendar']", result_xml).text());
new_calendar = jQuery.parseHTML(a);
jQuery("div.calendar").empty().append(jQuery("div.calendar table.calendar-table", new_calendar[0]));
  1. I cast the text() output to string in closure;
  2. I use element 0 of new_calendar instead of directly new_calendar.
  3. I changed the html() with empty().append() since the append() function accepts a jQuery object as input

This makes the closure compiler happy.

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Answer

Yes Absolutely this is expected behavior. There are many things that "work" in JavaScript. Closure-compiler attempts to force good behavior when asked.

As for jQuery - these are the normal limitations of the published jQuery API. With jQuery the code often supports undocumented behaviors (like you are listing). However the jQuery team is free to change behaviors that are not documented at any time.

Closure-compiler warns you if you are not matching what is listed as the API spec (and that definition is community maintained - so not always 100% right).

Here's the relevant specifications:

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source: stackoverflow.com
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