The missing JS utils

[morlandi]

Decide where to place these javascript utilities:

window.Utils = (function() {

    function getCookie(name) {
        var value = '; ' + document.cookie,
            parts = value.split('; ' + name + '=');
        if (parts.length == 2) return parts.pop().split(';').shift();
    }

    function lookup_queryset(qs, model, pk) {
    /*
        Find a specific record into serialized queryset;
    */
        var obj = null;
        $.each(qs, function(index, value) {
            if (value.pk == pk && value.model == model) {
                obj = value;
                return false;
            }
        });
        return obj;
    }

    // Speed up calls to hasOwnProperty
    var hasOwnProperty = Object.prototype.hasOwnProperty;

    // http://stackoverflow.com/questions/4994201/is-object-empty
    function isEmptyObject(obj) {

        // null and undefined are "empty"
        if (obj == null) return true;

        // Assume if it has a length property with a non-zero value
        // that that property is correct.
        if (obj.length > 0)    return false;
        if (obj.length === 0)  return true;

        // If it isn't an object at this point
        // it is empty, but it can't be anything *but* empty
        // Is it empty?  Depends on your application.
        if (typeof obj !== "object") return true;

        // Otherwise, does it have any properties of its own?
        // Note that this doesn't handle
        // toString and valueOf enumeration bugs in IE < 9
        for (var key in obj) {
            if (hasOwnProperty.call(obj, key)) return false;
        }

        return true;
    }


    // Find an Object by attribute in an Array
    // http://stackoverflow.com/questions/5579678/jquery-how-to-find-an-object-by-attribute-in-an-array#19154349
    function lookup(array, prop, value) {
        for (var i = 0, len = array.length; i < len; i++)
            if (array[i] && array[i][prop] === value) return array[i];
        return null;
    }

    return {
        getCookie: getCookie,
        lookup_queryset: lookup_queryset,
        isEmptyObject: isEmptyObject,
        lookup: lookup
    };

})();