Backbone Application Console Logging (uses underscore.js)

gistfile1.js

App.Log = {
  level: 0,
	_ie: (
		function(){
			var undef, v = 3,
			div = document.createElement('div'),
			all = div.getElementsByTagName('i');

			while (div.innerHTML = '<!--[if gt IE ' + (++v) + ']><i></i><![endif]-->', all[0] );
			return v > 4 ? v : undef;
		}()
	),
	_av_funcs: ['error','info','log','log','log'],
	_log: function() {
		if(!console) return;
		var args = Array.prototype.slice.call(arguments),
			func=args.shift(), level=args.shift();
		if(typeof console[func] === 'function' && level<=this.level) {
			if(this._ie) {
				for(var i = 1, len = args.length; i < len; i++) {
					console[func].apply(console, [args[0], " ", args[i]]);
				}
			} else {
				console[func].apply(console, args);
			}
		}
		return;
	},
	init: function(level) {
		if(level) this.level = level;
		if (Function.prototype.bind && console && typeof console.log == "object") {
			(function () {
				_.each(["log","info","error"],
					function (method) {
						if(console[method]) {
							console[method] = Function.prototype.call.bind(console[method], console);
						} else {
							var i=-1;
							while((i = _.indexOf(this._av_funcs, method)) !== -1) {
								this._av_funcs[i] = 'log';
							}
						}
					},
					this
				);
			})();
		}
		return;
	},
	_call: function(caller, args, type) {
		args = Array.prototype.slice.call(args);
		if(typeof type !== 'undefined') {
			try {args = type.concat(args);} catch (e) {}
		}
		return caller.apply(this, args);
	},
	verb: function() {
		return this._call(this._log, arguments, [this._av_funcs[4], 5,'VERB']);
	},
	xhr: function() {
		return this._call(this._log, arguments, [this._av_funcs[3], 4,'XHR']);
	},
	debug: function() {
		return this._call(this._log, arguments, [this._av_funcs[2], 3,'DEBUG']);
	},
	info: function() {
		return this._call(this._log, arguments, [this._av_funcs[1], 2,'INFO']);
	},
	error: function() {
		return this._call(this._log, arguments, [this._av_funcs[0], 1,'ERROR']);
	}
};

App.Log.init(4);