Combining multiple jquery files

Question

For some reason I can't combine my javascript files in one single file through php, like I can with css.

Basicly I wish to combine all of my javascript files into one. However that breaks my code somehow. It's like the $-value which jQuery generates isn't available through the rest of the code (such as jquery ui).

Does the jQuery need to be loaded in it's own <script type="text/javascript" src=""></script> for some reason? And what is that reason then?

I include them in the same order that they work in the browser.

jQuery -> jQuery UI -> jQuery custom functions -> my own script

Answer 1

You might want to put a new-line and/or semicolon between the single scripts.
Eg the minified jquery ui script you get from https://ajax.googleapis.com/ajax/libs/jqueryui/1.8.18/jquery-ui.min.js ends with

return this}})}(jQuery)

If you now append another script right behind that you will most likely get a syntax error.
Lets take a crude scripts.php

<?php
header('Content-type: Application/javascript');
readfile('http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js');
readfile('http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.18/jquery-ui.min.js');

echo '$(document).ready(function() {
    alert("hello");
    $( "#dialog" ).dialog( "open" );
});
';

this won't work, but

<?php
header('Content-type: Application/javascript');
readfile('http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js');
echo "\r\n;";
readfile('http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.18/jquery-ui.min.js');
echo "\r\n;";    
echo '$(document).ready(function() {
    alert("hello");
    $( "#dialog" ).dialog( "open" );
});
';

will.

Other things to consider:

• this is probably not a silver bullet. I chose "\\r\\n;" to a) escape from a // comment in the last line and b) to close an "open" statement with the semi-colon. But the missing-semicolon behaviour of javascript (and the implementations of it) can be rather odd (it's a bad feature) and I'd rather "fix" each individual script manually than adding a fixed "repair string".
• I'm stronlgy in the "let a cdn like google host those javascript libraries and rely on the client's cache" camp ...but without good evidence at hand to support that position.