Dynamically add properties/function to a service/factory - javascript

I wrote a small Angular1 app which has a Database service that is using LokiJS.
I was wondering if there is a way to dynamically add properties/functions to a Service/Factory.
I'm trying to add dynamic getter for every collection that is created via this Service.
Here my example:
Database.js
angular.module('MyApp')
.factory('Database', ['$log', '$q', 'Loki',
function Database($log, $q, Loki)
{
var _db,
dbInitialized = false;
function init(config)
{
// some logic here
}
function addCollection(name, cfg) {
// some logic here
_db.addCollection(name, cfg);
// this doesnt work, but is desired ->
/*this['get'+name] = this.getCollection.bind(this, name);*/
}
function getCollection(collectionName) {
// some logic here
return something;
}
return {
init: init,
addCollection: addCollection,
getCollection: getCollection
};
}
]
);
app.js
angular
.module('MyApp', ['lokijs'])
.run(['Database',
function (Database) {
Database.init();
Database.addCollection("MyCollection", {});
// then fill collection, afterwards ->
var collection = Database.getCollection("MyCollection");
// I would like to use Database.getMyCollection()
}]);;
Is there a way to modify a initialized Service/Factory?

The most appropriate place for that is decorator
app.decorator('Database', ['$delegate', function ($delegate) {
var Database = $delegate;
Database.init();
Database.addCollection("MyCollection", {});
...
return Database;
}]);
The recipe doesn't really differs from run block, but it guarantees that service will be initialized on injection, while run blocks depend on their order.

Related

How javascript select remote-data.service

I bought an app. I'm new with Javascript and AngularJS. I'm trying to following the code but I don't understand how the function on homeService.js knows that has to use remote-data.service.js
This is the home.controller.js
...
(function activate() {
...
loadCategories();
...
})();
...
// ...............................
function loadCategories() {
debugger;
homeService.getFeaturedCategories()
.then(function(categories) {
vm.categories = categories;
});
}
The function call homeService.getFeaturedCategories(). So....
home.service.js
function getFeaturedCategories() {
return dataService.getFeaturedCategories();
}
The function call to dataService.getFeaturedCategories()
Here is when data.service.js call to a remoteDataService.js and this file make the hhtp.get (I paste the full code of data.service.js):
(function() {
'use strict';
angular
.module('restaurant.common')
.factory('dataService', dataService);
dataService.$inject = ['ENV', '$injector'];
/* #ngInject */
function dataService(ENV, $injector) {
switch(ENV.dataProvider) {
case 'LOCAL':
return $injector.get('localDataService');
case 'REMOTE':
return $injector.get('remoteDataService');
case 'FIREBASE':
return $injector.get('firebaseDataService');
}
throw new Error('Data provider is not valid');
}
})();
I wanna know:
How the function returns remoteDataService.
Also I wanna know how make that only the function dataService.getFeaturedCategories() in the home.service.js make that dataservice return a localDataService. Because I wanna load a local JSON (not make a http.get)
Thanks!
Don't understand question. Your data service read ENV.dataProvider once, and return proper service. It's unable to return different services for different calls in current implementation.
you should use "localDataService" in home.service instead of "dataService". Just change names.
In your Home.service you should have lines like:
homeService.$inject = ['dataService'];
function homeService(dataService){
...
}
change it to: (order of $inject and arguments should be same.)
homeService.$inject = ['dataService', 'localDataService'];
function homeService(dataService, localDataService){
...
}
and use localDataService in your fn.

Loading view configuration

I would like to do something like this:
app.config(function($routeProvider){
$routeProvider.when('products/list', {
controller: 'ProductListCtrl',
templateUrl : 'products/list/view.html',
resolve : { data : function(){
...
},
loadingTemplateUrl : 'general/loader.html'
}
});
I would like to have the loading page in a different view.
This would make the code in the view and controller of every page cleaner, (no <...ng-include ng-show="loading"...>). This would also mean that I don't have to $scope.$watch the data for changes. Is there a clean solution to do something similar (not necessarily in the .config method) or an alternative library to do this?
Assuming you want to show some general template for all state transitions while the data is resolved, my suggestion is to listen to the events fired by the routing library. This allows to use one central point to handle all state transitions instead of polluting the routing config (which I think will not be that easy to do).
Please see the docs for $routeChangeStart, $routeChangeSuccess and of course $routeChangeError at the angular router docs
Maybe someone could be interested in what I did: I created a new service and a new view directive. It could seem like a lot of work, but doing this was much easier than I had expected. The new service enables me to separate the main view from the loading view, that I could reuse in all pages of the application. I also provided the possibility to configure an error template url and error controller, for when the loading failed.
The Angular $injector, $templateRequest and $controller services do most of the work. I just had to connect a directive, that depends on these services, to the right event ($locationChangeSuccess), and to the promise, retrieved (using $q.all) from the resolve object's functions. This connection was done in the route service. The service selects the right template url and comtroller, and passes it on for the directive to handle.
A shortened version (with the getCurrentConfig method left out):
RouteService:
(function () {
'use strict';
// provider:
angular.module('pikcachu')
.provider('pikaRouteService', [function () {
var routeConfigArray;
var otherwiseRouteConfig;
//configuration methods
this.when = function (url, routeConfig){
routeConfigArray.push({url: url, routeConfig: routeConfig});
return this;
}
this.otherwise = function(routeConfig){
otherwiseRouteConfig = routeConfig;
return this;
}
// service factory:
this.$get = ['$rootScope', '$location', '$q', '$injector', '$templateRequest',
function ($rootScope, $location, $q, $injector, $templateRequest) {
function RouteService() {
this.setViewDirectiveUpdateFn = function(){ /*...*/ }
function init(){
$rootScope.$on('$locationChangeSuccess', onLocationChangeSuccess);
}
function onLocationChangeSuccess(){
// get the configuration based on the current url
// getCurrentConfig is a long function, because it involves parsing the templateUrl string parameters, so it's left out for brevity
var currentConfig = getCurrentConfig($location.url());
if(currentConfig.resolve !== undefined){
// update view directive to display loading view
viewDirectiveUpdateFn(currentConfig.loadingTemplateUrl, currentConfig.loadingController);
// resolve
var promises = [];
var resolveKeys = [];
for(var resolveKey in currentConfig.resolve){
resolveKeys.push(resolveKey);
promises.push($injector.invoke(resolve[resolveKey]));
}
$q.all(promises).then(resolveSuccess, resolveError);
function resolveSucces(resolutionArray){
// put resolve results in an object
var resolutionObject = {};
for(var i = 0; i< promises.length;++i){
resolved[resolveKeys[i]] = resolutionArray[i];
}
viewDirectiveUpdateFn(currentConfig.errorTemplateUrl, currentConfig.errorController);
}
function resolveError(){
viewDirectiveUpdateFn(currentConfig.errorTemplateUrl, currentConfig.errorController);
}
}
}
init();
}
return new RouteService();
}]
})();
View directive
(function () {
'use strict';
angular.module('pikachu')
.directive('pikaView', ['$templateRequest', '$compile', '$controller', 'pikaRouteService', function ($templateRequest, $compile, $controller, pikaRouteService) {
return function (scope, jQdirective, attrs) {
var viewScope;
function init() {
pikaRouteService.listen(updateView);
}
function updateView(templateUrl, controllerName, resolved) {
if(viewScope!== undefined){
viewScope.$destroy();
}
viewScope = scope.$new();
viewScope.resolved = resolved;
var controller = $controller(controllerName, { $scope: viewScope });
$templateRequest(templateUrl).then(onTemplateLoaded);
function onTemplateLoaded(template, newScope) {
jQdirective.empty();
var compiledTemplate = $compile(template)(newScope);
jQdirective.append(compiledTemplate);
}
}
init();
};
}
]);
})();

What's the proper way to use this extension in AngularJS code?

I'm using a framework called Radiant UI, which is a way to get HTML5 UI into Unreal Engine 4. I'm trying to pick up some modern Javascript while I do that, so I'm building the UI in AngularJS.
My understanding of Angular is still pretty weak though, and I'm a bit confused about what the best practice is here. The extension injects the following Javascript when it sets up.
var RadiantUI;
if (!RadiantUI)
RadiantUI = {};
(function() {
RadiantUI.TriggerEvent = function() {
native function TriggerEvent();
return TriggerEvent(Array.prototype.slice.call(arguments));
};
RadiantUI.SetCallback = function(name, callback) {
native function SetHook();
return SetHook(name, callback);
};
RadiantUI.RemoveCallback = function(name) {
native function RemoveHook();
return RemoveHook(name);
};
})();;
So this is simply pushing RadiantUI into the global namespace. That would be fine if the extension was always there, but it isn't. In the test environment (Chrome), it's not there. It's only there when running in the game engine. That, combined with the fact that globals suck, means I want to encapsulate it.
In the previous iteration of this, I had it wrapped in an AMD module, and it worked well. Like this:
define([], function()
{
if ("RadiantUI" in window)
{
console.log("RadiantUI in global scope already!");
return window.RadiantUI;
}
var RadiantUI;
if (!RadiantUI) {
RadiantUI = {};
RadiantUI.TriggerEvent = function() {}
RadiantUI.SetCallback = function() {}
RadiantUI.RemoveCallback = function() {}
}
console.log("Using fake RadiantUI bindings");
return RadiantUI;
});
So here's what I want to do:
I want to include radiant as a dependency to my app/stateProvider and have it injected, much the same way it would be in AMD. With the stub methods in place if the extension isn't present. What's the proper approach to this? A module? A service provider?
UPDATE: This is the working code using the answer given.
var myapp = angular.module('bsgcProtoApp', ['ui.router' ]);
myapp.value('radiant', window.RadiantUI || {
TriggerEvent: function()
{
console.log("TriggerEvent called");
},
SetCallback: function(name, callback)
{
console.log("Setcallback called");
},
RemoveCallback: function(name)
{
console.log("RemoveCallback called");
}
});
myapp.config(['$stateProvider', '$urlRouterProvider', function($stateProvider, $urlRouterProvider )
{
$urlRouterProvider.otherwise("/mainmenu");
$stateProvider.state('mainmenu',
{
name: "mainmenu",
url: "/mainmenu",
templateUrl: 'templates/mainmenu.html',
controller: ['$scope', 'radiant', function($scope, radiant)
{
$scope.tester = function()
{
radiant.TriggerEvent("DuderDude");
console.log("Duder!");
}
}],
});
}]);
You presumably have an Angular module or app. For the sake of this answer, let's call it MyApp.
Now you can do
MyApp.value("RadiantUI", window.RadiantUI || {
TriggerEvent = function(){},
//... more properties
});
Now to access this value as a dependency in a controller for example, you'd do this
MyApp.controller(["$scope", "RadiantUI", function($scope, RadiantUI){
// ... controller code ...
}]);

Update a module value or re-register a filter in AngularJS

Is it possible to have a filter that depends on a lazy-loaded value?
In my case, a language pack is loaded asynchronously and the filter should reflect the loaded values once values are loaded.
// setup the i18n filter
app.filter('i18n', ['localizedTexts', function(localizedTexts) {
return function(localeKey) {
console.log(localeKey, localizedTexts) // prints out nulls for the second argument
return localizedTexts && localizedTexts[localeKey];
};
}]);
// setup the defualt value
app.value('localizedTexts', null);
// load values
app.run(['$http', function($http) {
$http.get('values.json').success(function(response) {
// update the value -- DOES NOT INVALIDATE THE FILTER NOR THE VIEW
app.value('localizedTexts', response);
});
}]);
I've also prepared a Plunker example: http://plnkr.co/edit/THTD3UiYgegusCl54Qhp?p=preview
Thoughts?
You can use a factory instead of using a value.
Associated Plunker
app.factory('localizedTexts', ['$http', function($http) {
var localizedTexts = {};
$http.get('values.json').success(function(res) {
angular.extend(localizedTexts, res);
})
return localizedTexts;
}]);
UPDATE: if this seemed a bit dirty then you can alternatively use the $provide Provider during the configuration phase and use a decorator to change value of the localizedTexts value. Check this updated PLUNKER
app.value('localizedTexts', null);
app.config(['$provide', function($provide) {
$provide.decorator('localizedTexts', ['$delegate', '$http', function($delegate, $http) {
var localizedTexts = {};
$http.get('values.json').success(function(values) {
angular.extend(localizedTexts, values);
})
return localizedTexts;
}]);
}]);

Updating angular.js service object without extend/copy possible?

I have 2 services and would like to update a variable in the 1st service from the 2nd service.
In a controller, I am setting a scope variable to the getter of the 1st service.
The problem is, the view attached to the controller doesn't update when the service variable changes UNLESS I use angular.extend/copy. It seems like I should just be able to set selectedBuilding below without having to use extend/copy. Am I doing something wrong, or is this how you have to do it?
controller
app.controller('SelectedBuildingCtrl', function($scope, BuildingsService) {
$scope.building = BuildingsService.getSelectedBuilding();
});
service 1
app.factory('BuildingsService', function() {
var buildingsList = [];
var selectedBuilding = {};
// buildingsList populated up here
...
var setSelectedBuilding = function(buildingId) {
angular.extend(selectedBuilding, _.find(
buildingsList, {'building_id': buildingId})
);
};
var getSelectedBuilding = function() {
return selectedBuilding;
};
...
return {
setSelectedBuilding: setSelectedBuilding,
getSelectedBuilding: getSelectedBuilding
}
});
service 2
app.factory('AnotherService', function(BuildingsService) {
...
// something happens, gives me a building id
BuildingsService.setSelectedBuilding(building_id);
...
});
Thanks in advance!
When you execute this code:
$scope.building = BuildingsService.getSelectedBuilding();
$scope.building is copied a reference to the same object in memory as your service's selectedBuilding. When you assign another object to selectedBuilding, the $scope.building still references to the old object. That's why the view is not updated and you have to use angular.copy/extend.
You could try the following solution to avoid this problem if you need to assign new objects to your selectedBuilding:
app.factory('BuildingsService', function() {
var buildingsList = [];
var building = { //create another object to **hang** the reference
selectedBuilding : {}
}
// buildingsList populated up here
...
var setSelectedBuilding = function(buildingId) {
//just assign a new object to building.selectedBuilding
};
var getSelectedBuilding = function() {
return building; //return the building instead of selectedBuilding
};
...
return {
setSelectedBuilding: setSelectedBuilding,
getSelectedBuilding: getSelectedBuilding
}
});
With this solution, you have to update your views to replace $scope.building bindings to $scope.building.selectedBuilding.
In my opinion, I will stick to angular.copy/extend to avoid this unnecessary complexity.
I dont believe you need an extend in your service. You should be able to watch the service directly and respond to the changes:
app.controller('SelectedBuildingCtrl', function($scope, BuildingsService) {
// first function is evaluated on every $digest cycle
$scope.$watch(function(scope){
return BuildingsService.getSelectedBuilding();
// second function is a callback that provides the changes
}, function(newVal, oldVal, scope) {
scope.building = newVal;
}
});
More on $watch: https://code.angularjs.org/1.2.16/docs/api/ng/type/$rootScope.Scope

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