createElement proxy

gistfile1.js

(function (docInstance) {
    var Monitor = function () {
        return this.init.apply(this, arguments);
    };

    Monitor.prototype = {
        Resources: {
            img: true,
            script: true
        },

        init: function (tagName) {
            var el = this.create(tagName);

            if (this.Resources[tagName.toLowerCase()]) {
                el.__defineSetter__(
                    'src', this.setSource
                );
            }

            return el;
        },

        create: (function () {
            var doc = docInstance.constructor.prototype,
                create = doc.createElement;

            doc.createElement = function (tagName) {
                return new Monitor(tagName);
            };

            return (function (tagName) {
                return create.call(
                    docInstance, tagName
                );
            });
        })(),

        /* NB: the setter is called in the context of a DOM-element. */
        setSource: function (src) {
            console.warn('Setting the source property of %o to %s.', this, src);

            delete this['src'];

            this.src = src;

            this.__defineSetter__(
                'src', Monitor.prototype.setSource
            );
        }
    };
})(document);