Modifying Angular Factory Object from inside a function - javascript

This is the function that I am working with to call my factory
var myService = function($http) {
return {
bf: null,
initialize: function() {
this.promise = $http.get(this.server + "/requestkey").success(function(data) {
myService.bf = new Blowfish(data.key);
});
}
}
And I am creating this object using
TicTacTorrent.service('AService', ['$http', myService]);
However, when calling AService.initialize() it creates the promise object like it should, but it doesn't update the BF object. I'm confused as to how to update the bf object to be the new value. How would I reference myService.bf since this.bf would create a local instance for .success function?

Try this:
var myService = function($http) {
this.bf = null;
return {
bf: this.bf,
initialize: function() {
this.promise = $http.get(this.server + "/requestkey").success(function(data) {
myService.bf = new Blowfish(data.key);
});
}
}

Where do you want to initialize?
Have you seen the $provider example code?
Search for "provider(name, provider)" and check if it suits your need.
Otherwise I'm unsure what the code you'vew written will run like.
I usually write factories like this:
angular.module('app').factory('myService', ['$http', function($http) {
var publicObj = {};
publicObj.bf = ""; // Just to make sure its initialized correctly.
publicObj.initialize = function() {snip/snap... myService.bf = new Blowfish(data.key);};
return publicObj;
}]);
The difference might be that you previous code returned an inline anonymous object which might have a hard time referring to itself. But by that logic it should work by just making myService return a predeclared var and returning that.

Related

Angular service inheritance using Object.create()

I'm trying to use inheritance in angular services, as explained here:
http://blog.mgechev.com/2013/12/18/inheritance-services-controllers-in-angularjs/, I want to use the "Inject the parent" method.
However, it doesn't seem to work, and I can't see why.
var myApp = angular.module('myApp',[]);
angular.module('myApp').controller('MyCtrl', MyCtrl);
angular.module('myApp').factory('BaseModel', BaseModel);
angular.module('myApp').factory('ThreadModel', ThreadModel);
angular.module('myApp').factory('PostModel', PostModel);
function MyCtrl($scope, ThreadModel, PostModel) {
$scope.tableNameForThreads = ThreadModel.getTableName();
$scope.tableNameForPosts = PostModel.getTableName();
}
function BaseModel() {
var tableName = "";
var service = {
init: init,
getTableName: getTableName
};
return service;
function getTableName() {
return tableName;
}
function init(theTableName) {
tableName = theTableName;
}
}
function ThreadModel(BaseModel) {
var service = Object.create(BaseModel);
service.init("threads");
return service;
}
function PostModel(BaseModel) {
var service = Object.create(BaseModel);
service.init("posts");
return service;
}
The result is that ThreadModel.getTableName() returns "posts" in stead of "threads".
I tried both Object.create(...) and angular.copy(BaseModel, this), but both don't seem to make a deep copy.
JSFIDDLE: http://jsfiddle.net/dirkpostma/Lvc0u55v/3989/
What am I doing wrong here?
The problem is that with this set up using Object.create you produce services with the tableName variable stored in the same common closure (BaseModel function). To put it simply, init method modifies the same local tableName variable.
You could fix it like this:
function BaseModel() {
var service = {
init: init,
getTableName: getTableName
};
return service;
function getTableName() {
return this._tableName;
}
function init(theTableName) {
this._tableName = theTableName;
}
}
Note, that getTableName and init methods now work with instance property this._tableName which is not shared between TableModel and PostModel instances.
Demo: http://jsfiddle.net/Lvc0u55v/3991/
#dfsq has already well explained and given a simple solution. I put here what I am thinking about this issue.
In your code Object.create(BaseModel) creates a new object whose prototype is a returned value of BaseModel function. In those children models init method modifies tableName within the local scope of BaseModel function. If you replace tableName with this.tableName, that will work as you expected: both init and getTableName methods will actually modify/call tableName property of service variable within ThreadModel or PostModel functions. But it looks complicated.
In your case I would like suggest the following service inheritance solution, which would be clearer. There is an other post that can be interesting.
var myApp = angular.module('myApp', []);
angular.module('myApp').controller('MyCtrl', MyCtrl);
angular.module('myApp').service('BaseModel', BaseModel);
angular.module('myApp').service('ThreadModel', ['BaseModel', ThreadModel]);
angular.module('myApp').service('PostModel', ['BaseModel', PostModel]);
function MyCtrl($scope, ThreadModel, PostModel) {
$scope.tableNameForThreads = ThreadModel.getTableName();
$scope.tableNameForPosts = PostModel.getTableName();
}
function BaseModel() {
this.tableName = "";
this.getTableName = function() {
return this.tableName;
}
this.init = function(theTableName) {
this.tableName = theTableName;
}
}
function ThreadModel(BaseModel) {
angular.extend(ThreadModel.prototype, BaseModel);
this.tableName = "threads";
}
function PostModel(BaseModel) {
angular.extend(PostModel.prototype, BaseModel);
this.tableName = "posts";
}
JSFiddle: http://jsfiddle.net/Lvc0u55v/3993/

Can't access variable inside angular.js controller

This is my controller:
app.controller("PlaceController", ['$http', function($http){
this.places = shops;
var hotels = this;
hotels.objects = [];
this.spots = new Array;
this.newPlace = {};
this.city = new String();
this.addPlace = function() {
this.places.push(this.newPlace);
this.newPlace = {};
var request = *some query syntax, sorry for hiding*
$http.get(request).success(function(data) {
hotels.objects = data;
console.log(hotels.objects.elements);
});
for (each in hotels.objects.elements) {
this.spots.push(each.tags.name);
};
console.log(this.spots);
}}] );
I get an empty array when I log this.spots to the console. The http request etc work perfectly because the console.log(hotels.objects.elements) statement works perfectly.
Because of this problem, I can't output it into my HTML either. What should I do?
You are issuing an asynchronous request to get the spots, but you're logging them before they complete.
Change this.addPlace to log / act on the spots array inside the promise callback:
this.addPlace = function() {
this.places.push(this.newPlace);
this.newPlace = {};
var request = *some query syntax, sorry for hiding*
$http.get(request).success(function(data) {
hotels.objects = data;
console.log(hotels.objects.elements);
for (each in hotels.objects.elements) {
this.spots.push(each.tags.name);
};
console.log(this.spots);
});
You're adding to the spots array before the ajax request is done, move your calls to push inside the callback:
$http.get(request).success(function(data) {
hotels.objects = data;
console.log(hotels.objects.elements);
angular.forEach(hotels.objects.elements, function(value) {
hotels.spots.push(value.tags.name);
});
});
Also, you should really be using $scope instead of references to this. This would simplify your code a bit, without needing to rename this to hotels
full controller code using $scope
app.controller("PlaceController", ['$scope', '$http', function($scope, $http){
$scope.places = shops;
$scope.objects = [];
$scope.spots = new Array;
$scope.newPlace = {};
$scope.city = new String();
$scope.addPlace = function() {
$scope.places.push($scope.newPlace);
$scope.newPlace = {};
var request = *some query syntax, sorry for hiding*
$http.get(request).success(function(data) {
$scope.objects = data;
console.log($scope.objects.elements);
angular.forEach($scope.objects.elements, function(value, key) {
$scope.spots.push(value.tags.name);
});
// spots is ready, log it, do whatever
console.log($scope.spots);
});
}}] );
NOTE: Using $scope means you won't need to call this from your html to reference the objects and functions defined in your controller.
An example:
<div ng-controller="PlaceController">
<!-- no need to call places.city, if you use $scope just write city -->
{{city}}
</div>
EDIT: You probably shouldn't use JavaScript's for-in, the problem with it is that it iterates on the names or indexes of your objects/arrays.
An example:
var someArray = ['a', 'b', 'c'];
for (i in someArray) {
console.log(i); // prints 0, 1, 2
console.log(someArray[i]); // prints 'a', 'b', 'c'
}
This is different from any for-in/for-each implementation in other popular languages.
Anyway, in this case I've edited the code above to use Angular's forEach, which is a more appropriate solution (many libraries implement custom for-each functions to fix JS's weird for-in)
You can read more in Angular's docs
Another option, in plain javascript is, if $scope.objects.elements is an array, using the map() function, like this:
$scope.spots = $scope.objects.elements.map(function(value) {
return value.tags.name; // value is an item in object.elements
});
try this ..
due to your async call you need to perform task inside success
$http.get(request).success(function(data) {
hotels.objects = data;
console.log(hotels.objects.elements);
for (each in hotels.objects.elements) {
hotels.spots.push(each.tags.name);
};
console.log(this.spots);
});

AngularJS automatically updating controller data by service

I'm having some basic problems with angular at the moment. I just wrote a service that reads the temperature of an external device in an interval of five seconds. The service saves the new temperature into a variable and exposes it via a return statement. This looks kind of this (simplified code):
angular.service("tempService", ["$interval", function ($interval) {
//revealing module pattern
var m_temp = 0,
requestTemp = function() {//some logic here},
onResponseTemp = function (temp) {
m_temp = temp;
},
//some other private functions and vars ...
foo = bar;
//request new temperture every 5s, calls onResponseTemp after new data got received
$interval(requestTemp, 5000);
return {
getTemp = function(){return m_temp;}
}
}]);
I use a controller to fetch the data from the service like this:
angular.controller("tempCtrl", ["$scope", "tempService", function ($scope, tempService) {
$scope.temp = tempService.getTemp();
}]);
In my view I access it like this:
<div ng-controller="tempCtrl">
<p>{{temp}}</p>
</div>
But I only get 0 and the value never changes. I have tried to implement a custom Pub/Sub pattern so that on a new temperature my service fires an event that my controller is waiting for to update the temperature on the scope. This approach works just fine but I'm not sure if this is the way to go as angular brings data-binding and I thought something this easy had to work by itself ;)
Help is really appreciated.
Please see here http://jsbin.com/wesucefofuyo/1/edit
var app = angular.module('app',[]);
app.service("tempService", ["$interval", function ($interval) {
//revealing module pattern
var m_temp = {
temp:0,
time:null
};
var requestTemp = function() {
m_temp.temp++;
m_temp.time = new Date();
};
var startTemp = function() {
$interval(requestTemp, 3000);
};
return {
startTemp :startTemp,
m_temp:m_temp
};
}]);
app.controller('fCtrl', function($scope,tempService){
$scope.temp = tempService;
$scope.temp.startTemp();
});
You are returning a primitive from your service, if you want to update an primative you need to reftech it. You should return an object, as on object is passed by reference, you get the actual values in your controller.
do this in your service:
return m_temp;
And this in your controller:
$scope.temp = tempService;
and your view will update as soon as the service gets updated.
Does this help you?
i think you should use $interval in controller ot in service
$interval(tempService.getTemp(), 5000);

AngularJS: Reassigning an object vs. replacing it in a controller

I am building a subscriber/observer pattern for displaying data in realtime for my angular app.
The observer is built with a factory injected into the angular controller and whose role is to fetch data and update it. The basic code structure can he found in this fiddle: http://jsfiddle.net/ctrager/67QR7/3/
var myApp = angular.module('myApp', [])
.factory('MyFactory', [function () {
var Collection = {};
Collection.isLoaded = 0;
Collection.data = [1, 2];
Collection.username = "corey and eric";
Collection.update = function () {
Collection.data.push(new Date())
}
Collection.replace = function () {
// If you do Collection.data = []
// here you are doing the same thing
// as the empty collection bug. I can't
// tell you EXACTLY why this confuses angular
// but I'm 99% sure it's the same phenomenon
Collection.data = [new Date()]
}
Collection.replace_fixed = function () {
// This works
Collection.data.length = 0
Collection.data.push(new Date())
}
return Collection;
}])
function MyCtrl($scope, MyFactory) {
$scope.name = 'Eric';
$scope.items = MyFactory.data;
$scope.replace = function(){
console.log("replace")
MyFactory.replace()
//$scope.items = MyFactor.data;
}
$scope.replace_fixed = function(){
console.log("replace_fixed")
MyFactory.replace_fixed()
//$scope.items = MyFactor.data;
}
$scope.update = function(){
console.log("update")
MyFactory.update()
}
}
The factory (MyFactory) contains a collection (Collection.data). Any push (/splice) to that collection is reflected in the scope, but if I replace the entire collection (Collection.replace()) the change is no longer reflected in $scope. Any idea why?
This works:
http://jsfiddle.net/67QR7/4/
changed the thing stored on scope to be the factory instead of data. then the html repeat to do items.data.
So it looks like this is because you replaced the reference inside collection, but that doesn't change where $scope.items was pointing to.
So you are creating a reference to MyFactory.data from $scope.items. Angular puts a $watch on $scope.items and looks for changes. When you call MyFactory.replace, you change MyFactory.data, but $scope.items remains the same. So as far as your watch is concerned, nothing has happened.
You can fix this by using replace_fixed, or watch for changes to MyFactory.data. http://jsfiddle.net/KtB93/
$scope.MyFactory = MyFactory;
$scope.$watch("MyFactory.data", function(newData) {
console.log('myFactory.data changed');
$scope.items = newData;
});
Or alternatively (probably better), you can use a function as the watch expression so you don't have to plop MyFactory on the scope (http://jsfiddle.net/XAW54/1/):
$scope.$watch(function() {
return MyFactory.data;
}, function(newData) {
$scope.items = newData;
});

How to include/inject functions which use $scope into a controller in angularjs?

I am trying to include a library of functions, held in a factory, into a controller.
Similar to questions like this:
Creating common controller functions
My main controller looks like this:
recipeApp.controller('recipeController', function ($scope, groceryInterface, ...){
$scope.groceryList = [];
// ...etc...
/* trying to retrieve the functions here */
$scope.groceryFunc = groceryInterface; // would call ng-click="groceryFunc.addToList()" in main view
/* Also tried this:
$scope.addToList = groceryInterface.addToList();
$scope.clearList = groceryInterface.clearList();
$scope.add = groceryInterface.add();
$scope.addUp = groceryInterface.addUp(); */
}
Then, in another .js file, I have created the factory groceryInterface. I've injected this factory into the controller above.
Factory
recipeApp.factory('groceryInterface', function(){
var factory = {};
factory.addToList = function(recipe){
$scope.groceryList.push(recipe);
... etc....
}
factory.clearList = function() {
var last = $scope.prevIngredients.pop();
.... etc...
}
factory.add = function() {
$scope.ingredientsList[0].amount = $scope.ingredientsList[0].amount + 5;
}
factory.addUp = function(){
etc...
}
return factory;
});
But in my console I keep getting ReferenceError: $scope is not defined
at Object.factory.addToList, etc. Obviously I'm guessing this has to do with the fact that I'm using $scope in my functions within the factory. How do I resolve this? I notice that in many other examples I've looked at, nobody ever uses $scope within their external factory functions. I've tried injecting $scope as a parameter in my factory, but that plain out did not work. (e.g. recipeApp.factory('groceryInterface', function(){ )
Any help is truly appreciated!
Your factory can't access your $scope, since it's not in the same scope.
Try this instead:
recipeApp.controller('recipeController', function ($scope, groceryInterface) {
$scope.addToList = groceryInterface.addToList;
$scope.clearList = groceryInterface.clearList;
$scope.add = groceryInterface.add;
$scope.addUp = groceryInterface.addUp;
}
recipeApp.factory('groceryInterface', function () {
var factory = {};
factory.addToList = function (recipe) {
this.groceryList.push(recipe);
}
factory.clearList = function() {
var last = this.prevIngredients.pop();
}
});
Alternatively, you can try using a more object oriented approach:
recipeApp.controller('recipeController', function ($scope, groceryInterface) {
$scope.groceryFunc = new groceryInterface($scope);
}
recipeApp.factory('groceryInterface', function () {
function Factory ($scope) {
this.$scope = $scope;
}
Factory.prototype.addToList = function (recipe) {
this.$scope.groceryList.push(recipe);
}
Factory.prototype.clearList = function() {
var last = this.$scope.prevIngredients.pop();
}
return Factory;
});
You cannot use $scope in a factory as it is not defined. Instead, in your factory functions change the properties of the object the factory is returning, e.g.
factory.addToList = function (recipe) {
this.groceryList.push(recipe);
}
these will then get passed on to your $scope variable
$scope.addToList = groceryInterface.addToList;
// ... = groceryInterface.addToList(); would assign to `$scope.addToList` what is returned, instead of the function itself.
This isn't the exact answer for this question, but I had a similar issues that I solved by simply passing $scope as an argument to a function in my factory. So it won't be the normal $scope, but $scope at the time the function in the factory is called.
app.controller('AppController', function($scope, AppService) {
$scope.getList = function(){
$scope.url = '/someurl'
// call to service to make rest api call to get data
AppService.getList($scope).then(function(res) {
// do some stuff
});
}
});
app.factory('AppService', function($http, $q){
var AppService = {
getList: function($scope){
return $http.get($scope.url).then(function(res){
return res;
});
},
}
return AppService;
});

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