Document.ready in external files?

Question

I am referencing JavaScript as follows on an HTML page:

<script type="text/javascript" src="http://code.jquery.com/jquery-1.6.1.min.js"></script>
<script type="text/javascript" src="http://code.jquery.com/mobile/1.0b1/jquery.mobile-1.0b1.min.js"></script>
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false&amp;region=GB"></script>
<script type="text/javascript" src="js/shared.js"></script>
<script type="text/javascript">
$('document').ready(function() {   
    // In-page code: call some functions in shared.js
});
</script>

The functions defined in shared.js are not wrapped inside $('document').ready. So:

1. Is it safe to assume that functions defined in shared.js are available to the "in-page code"?

2. If I pull out the in-page code into a separate file called local.js (keeping it wrapped in $('document').ready), is it still safe to assume that functions defined in shared.js are available?

3. Finally, is the fact that I'm not wrapping shared.js inside $('document').ready a problem? I'm finding that if I do wrap it, its functions are no longer available to the in-page code.

The reason for question 3 is that I'm hitting this problem: Uncaught TypeError: Property ... is not a function - after page has loaded

and wondering if it is something to do with how I've organised my code.

UPDATE: Thanks for the answers. It's now clear that using $('document').ready in shared.js would remove those functions from global scope. However, I just want to clarify the original question in point 3.

Can I assume that if I do the following:

• inside my in-page code, loaded inside $('document').ready, call a function from shared.js
• have the function in shared.js refer to jQuery, Google Maps, or elements on my page

there will be no problems?

In other words, is it safe to assume that the page will have loaded by the time the functions inside shared.js are called, even if I'm not wrapping everything in that file inside $('document').ready?

Answer 1

Is it safe to assume that functions defined in shared.js are available to the "in-page code"?

Yes, As long as those functions are injected into global scope

If I pull out the in-page code into a separate file called local.js (keeping it wrapped in $('document').ready), is it still safe to assume that functions defined in shared.js are available?

Yes, As long as local.js is included after shared.js AND shared.js injects functions into global scope.

Finally, is the fact that I'm not wrapping shared.js inside $('document').ready a problem? I'm finding that if I do wrap it, its functions are no longer available to the in-page code.

Wrapping functions in document.ready takes them outside of global scope.

var foo = 4; // global
$(function() {
  var bar = 5; // local
});
foo = bar; // error

You need to inject variables in global scope, this is as easy as doing

$(function() {
  /* all your code */

  window["SomeGlobalVariable"] = someFunctionIWantGlobal;
});