angular.js decorator for $templateCache to add callbacks for when templates become registered

template-cache-watch.js

angular.module('$template-cache-watch', [])

.decorator('$templateCache', function ($delegate) {
	var decorated = Object.create($delegate);

	var callbacks = Object.create(null);

	decorated.watch = function (key, callback) {
		if (!callbacks[key]) {
			callbacks[key] = [];
		}
		callbacks[key].push(callback);
	};

	decorated.put = function (key, value) {
		if ($delegate.put(key, value)) {
			if (callbacks[key]) {
				callbacks[key].forEach(function (callback) {
					callback(value);
				});
				delete callbacks[key];
			}
		}
	};

	decorated.remove = function (key) {
		delete callbacks[key];
		$delegate.remove(key);
	};

	decorated.removeAll = function (key) {
		callbacks = Object.create(null);
		$delegate.removeAll(key);
	};

	return decorated;
});