Example Angular.js use of the simple-request-caching module

request-from-server.js

angular.module('requestFromServer', [ 'simpleRequestCaching' ]).factory('requestFromServer', function($http, simpleRequestCaching) {
	return new simpleRequestCaching({
		cacheMillis: 1000 * 60, // one minute cache
		request: function(params) {
			return $http.get('/api/data', params)
		}
	})
})

simple-request-caching.js

/*
The angularized version of: https://github.com/tobiaslabs/simple-request-caching
npm version: 0.0.7
Released under the VOL: http://veryopenlicense.com
*/
angular.module('simpleRequestCaching', []).factory('SimpleRequestCaching', function($timeout) {
	function SimpleRequestCaching(options) {
		if (!options || typeof options.cacheMillis !== 'number' || !options.request) {
			throw new Error('SimpleRequestCaching requires the options object: {cacheMillis, request}')
		}
		options.stringify = options.stringify || SimpleRequestCaching.stringifyForFlatObjects

		var previousRequests = {}
		return function makeRequest(request) {
			var requestString = options.stringify(request)
			var previousRequest = previousRequests[requestString]
			var promise
			if (!previousRequest || SimpleRequestCaching.hasExpired(previousRequest.requested, new Date(), options.cacheMillis)) {
				previousRequests[requestString] = {
					requested: new Date(),
					promise: options.request(request)
				}
				previousRequests[requestString].promise.then(function noop(){}, function errorHandler() {
					delete previousRequests[requestString]
				})
				previousRequest = previousRequests[requestString]
				if (options.cacheMillis >= 0) {
					$timeout(function destroyCachedRequest() {
						delete previousRequests[requestString]
					}, options.cacheMillis)
				}
			}
			return previousRequest.promise
		}
	}

	SimpleRequestCaching.stringifyForFlatObjects = function stringifyForFlatObjects(obj) {
		return JSON.stringify(Object.keys(obj).sort().reduce(function(ary, key) {
			return ary.concat([key, obj[key]])
		}, []))
	}

	SimpleRequestCaching.hasExpired = function hasExpired(previousRequestDate, now, millis) {
		if (millis < 0) {
			return false
		} else {
			var expireDate = new Date(previousRequestDate.getTime() + millis)
			return expireDate.getTime() < now.getTime()
		}
	}

	return SimpleRequestCaching	
})

some-controller.js

angular.module('someController', [ 'requestFromServer' ]).controller('SomeCtrl', function($scope, requestFromServer) {
	$scope.params = {}
	$scope.update = function(params) {
		$scope.loading = true
		requestFromServer($scope.params).then(function(data) {
			$scope.loading = false
			$scope.username = data.username
		})
	}
})