Passing parameters to JavaScript files

Question

Often I will have a JavaScript file that I want to use which requires certain variables be defined in my web page.

So the code is something like this:

<script type="text/javascript" src="file.js"></script>
<script type="text/javascript">
   var obj1 = "somevalue";
</script>

But what I want to do is:

<script type="text/javascript" 
     src="file.js?obj1=somevalue&obj2=someothervalue"></script>

I tried different methods and the best one yet is to parse the query string like this:

var scriptSrc = document.getElementById("myscript").src.toLowerCase();

And then search for my values.

I wonder if there is another way to do this without building a function to parse my string.

Do you all know other methods?

Answer 1

I'd recommend not using global variables if possible. Use a namespace and OOP to pass your arguments through to an object.

This code belongs in file.js:

var MYLIBRARY = MYLIBRARY || (function(){
    var _args = {}; // private

    return {
        init : function(Args) {
            _args = Args;
            // some other initialising
        },
        helloWorld : function() {
            alert('Hello World! -' + _args[0]);
        }
    };
}());

And in your html file:

<script type="text/javascript" src="file.js"></script>
<script type="text/javascript">
   MYLIBRARY.init(["somevalue", 1, "controlId"]);
   MYLIBRARY.helloWorld();
</script>