Decorating $http service to support url interpolation

gistfile1.ts

function httpDecorator($delegate: ng.IHttpService) {
	var $http = $delegate;

	var wrapper = () => {
	  // interpolate the url
		var config = arguments[0];
		config.url = interpolateUrl(config.url, config.params, config.data);

		return $http.apply($http, arguments);
	};

	// $http has convenience methods such as $http.get() that we have
	// to pass through as well.
	Object.keys($http).filter(key => (typeof $http[key] === 'function')).forEach(key => {
		wrapper[key] = () => {
		  // interpolate the url
			arguments[0] = interpolateUrl(arguments[0], arguments[1].params, arguments[1].data);
			return $http[key].apply($http, arguments);
		};
	});

	// the $http service also has object properties that need to be copied (eg. defaults)
	Object.keys($http).filter(key => (typeof $http[key] === 'object')).forEach(key => {
		wrapper[key] =  $http[key];
	});

	return wrapper;
}

httpDecorator.$inject = ['$delegate'];

// register the decorator on the loaded module
mainModule.config([
	'$provide', $provide => {
		$provide.decorator('$http', httpDecorator);
	}
]);


// Code beyond this point adapted from: https://gist.github.com/bennadel/11178024/

// I move values from the params and data arguments into the URL where
// there is a match for labels. When the match occurs, the key-value
// pairs are removed from the parent object and merged into the string
// value of the URL.
function interpolateUrl(url, params, data) {

	// Make sure we have an object to work with - makes the rest of the
	// logic easier.
	params = (params || {});
	data = (data || {});

	// Strip out the delimiter fluff that is only there for readability
	// of the optional label paths.
	url = url.replace(/(\(\s*|\s*\)|\s*\|\s*)/g, "");

	// Replace each label in the URL (ex, :userID).
	url = url.replace(
		/:([a-z]\w*)/gi,
		($0, label) => {
			// NOTE: Giving "data" precedence over "params".
			var val = popFirstKey(data, params, label);
			return val !== null && val !== undefined ? val : '';
		}
	);

	// Strip out any repeating slashes (but NOT the http:// version).
	url = url.replace(/(^|[^:])[\/]{2,}/g, "$1/");

	// Strip out any trailing slash.
	url = url.replace(/\/+$/i, "");

	return (url);

}


// I take 1..N objects and a key and perform a popKey() action on the
// first object that contains the given key. If other objects in the list
// also have the key, they are ignored.
function popFirstKey(object1, object2, objectN) {
	// Convert the arguments list into a true array so we can easily
	// pluck values from either end.
	var objects = Array.prototype.slice.call(arguments);

	// The key will always be the last item in the argument collection.
	var key = objects.pop();
	var object = null;

	// Iterate over the arguments, looking for the first object that
	// contains a reference to the given key.
	while (object = objects.shift()) {
		if (object.hasOwnProperty(key)) {
			return (popKey(object, key));
		}
	}
}


// I delete the key from the given object and return the value.
function popKey(object, key) {
	var value = object[key];
	delete (object[key]);
	return (value);
}