Add jQuery.parseJSON to jQuery 1.3

Question

Is it possible to extend jQuery 1.3 to include the parseJSON function from 1.4.1+, and have it function the same way as it does in jQuery 1.4.1+? How would I go about that?

I have some sites where I have to use jQuery 1.3, but I have a tool that requires parseJSON, which was only introduced in jQuery 1.4.1. I vaguely know that I should be taking parseJSON from 1.4.1+ and trying to make it a plugin, but I don't know how to do that.

Answer 1

You could make it a plugin like this:

$.extend({
    error: function( msg ) { throw msg; },
    parseJSON: function( data ) {
        if ( typeof data !== "string" || !data ) {
            return null;
        }    
        data = jQuery.trim( data );    
        if ( /^[\],:{}\s]*$/.test(data.replace(/\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g, "@")
            .replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g, "]")
            .replace(/(?:^|:|,)(?:\s*\[)+/g, "")) ) {    
            return window.JSON && window.JSON.parse ?
                window.JSON.parse( data ) :
                (new Function("return " + data))();    
        } else {
            jQuery.error( "Invalid JSON: " + data );
        }
    }
});

You can test it here.
This code's adopted from jQuery 1.4.4 - found here. After including the above with jQuery 1.3 as your question has, just use $.parseJSON() as you normally would...or in your case, just include the plugins after the above code and $.parseJSON() will be present for them to use.