So. I have simple controller and service:
angular
.module('field', [])
.controller('FieldController', function(FieldService) {
var vm = this;
vm.name = FieldService.getName();
})
.service('FieldService', function() {
var name = 'John'
this.getName = function() {
return name;
};
this.setName = function(newName) {
name = newName;
};
})
;
Then i have some $interval in anotherService, that getting data every 1 second and calling FieldService.setName:
.service('UpdateService', function($http, FieldService) {
$interval(function() {
$http.get('/somUrl')
.then(function(response) {
FieldService.setName(response.name);
});
});
})
But it won't change my HTML.
If i switch from primitive to object in returning value getName, then it's working.
Is there another approach? I personally think, that this structure i created is bad, but can't understand how it should be done.
JavaScript is always pass-by-value, but when your variable is an object, the 'value' is actually a reference to the object. So in your case, you are getting a reference to the object, not the value. So when the object changes, that change isn't propagated like a primitive would be.
Your code seems a bit incorrect, too. You are setting the value of response.name to FieldService.setName, which is actually a function.
If you want to use the getter/setter approach you have listed, then you could use events to let the controller know that name has changed.
.service('UpdateService', function($http, FieldService, $rootScope) {
$interval(function() {
$http.get('/somUrl')
.then(function(response) {
FieldService.setName(response.name);
$rootScope.$broadcast('nameChanged', {
name : response.name
});
});
});
})
.controller('FieldController', function(FieldService, $scope) {
var vm = this;
vm.name = FieldService.getName();
$scope.$on('nameChanged', function (evt, params) {
vm.name = params.name;
});
})
Another way to accomplish this is to use a $scope.$watch on the service variable in the controller:
.controller('FieldController', function($scope, FieldService) {
$scope.name = FieldService.getName();
$scope.$watch(function () {
return FieldService.getName();
}, function (newVal, oldVal) {
if (newVal !== oldVal) {
$scope.name = newVal;
}
});
})
I would move my $interval function inside a controller and then just update a $scope attribute every second. Then Angular will take care of the rendering.. Or you must also use an $interval function in your controller which gets the service content (ie FieldService.getName) every second.
I would use it this way:
angular
.module('field', [])
.controller('FieldController', function($scope, FieldService) {
$scope.name = function(){
FieldService.getName();
};
})
.service('FieldService', function() {
var name = 'John'
this.getName = function() {
return name;
};
this.setName = function(newName) {
name = newName;
};
});
Use name() in your html to see the update value.And your other service:
.service('UpdateService', function($http, FieldService) {
$interval(function() {
$http.get('/somUrl')
.then(function(response) {
FieldService.setName(response.name);
});
}, 1000);
})
There are numerous ways in which you can achieve this. No way is the best way. Depends on person to person.
Hope this helps.
There are several ways to solve that problem.
1) Move the $interval to controller.Then you will have a variable, which holds that data and you can bind it in view
2) You can use AngularJs Events.$rootScope will help you to send signal and catch it wherever you want.
If you want more info about this solutions, you can see it here:
http://www.w3docs.com/snippets/angularjs/bind-value-between-service-and-controller-directive.html
Related
I have a function inside a controller and I'm confused as to how to update a $scope variable from inside a .then function.
Heres my function:
searchSpotify(query, $scope) {
this.Spotify.search(query,'track').then(function (data) {
console.log(data.tracks.items); // this is working
$scope.result = data;
});
}
In the console log I receive this error:
TypeError: Cannot set property 'result' of undefined
Do I use $scope.$apply somehow?
EDIT:
Here's the entire controller for context
(function() {
class SelectionController {
constructor(User, groupService, selectionService, songService, $scope, $routeParams, Spotify) {
this.groupId = $routeParams.groupId;
this.selectionId = $routeParams.selectionId;
this.groupService = groupService;
this.selectionService = selectionService
//this.selections = this.selectionService.getSelections();
this.songService = songService;
this.searchResults;
this.$scope = $scope;
this.Spotify = Spotify
}
searchSpotify(query) {
this.Spotify.search(query, 'track').then(function(data) {
console.log(data.tracks.items);
$scope.result = data;
});
}
addSong(name, artist, album) {
alert('called from selection controller');
this.songService.addSong(this.selectionId, name, artist, album);
}
createSelection(name, description) {
this.selectionService.createSelection(this.groupId, name, description);
}
deleteSelection(selection) {
this.selectionService.deleteSelection(selection);
}
}
angular.module('songSelectionApp')
.controller('SelectionController', SelectionController);
})();
Save reference to $scope:
searchSpotify(query) {
var $scope = this.$scope;
this.Spotify.search(query, 'track').then(function(data) {
console.log(data.tracks.items);
$scope.result = data;
});
}
Or use arrow functions:
searchSpotify(query) {
this.Spotify.search(query, 'track').then((data) => {
console.log(data.tracks.items);
this.$scope.result = data;
});
}
.bind(this) should also work, as another answers suggest.
Regarding $scope.$apply: you need it only when you want to change a $scope outside of a $digest, for example when you use external (non-angular) libraries/functions, like WebSocket, or jquery event listeners. Untill Spotify is an angular service/factory - you don't need $scope.$apply
From docs:
$apply() is used to execute an expression in angular from outside of the angular framework. (For example from browser DOM events, setTimeout, XHR or third party libraries).
this.Spotify.search(query,'track').then(function (data) {
console.log(data.tracks.items); // this is working
this.result = data;
}.bind($scope));
Should be all you need really. You are basically telling the internal scope what this should really be
You should use
this.Spotify.search(query,'track').then(function (data) {
console.log(data.tracks.items); // this is working
this.$scope.result = data;
}.bind(this));
This is a relatively simple piece of code that calls a service and returns some data. I need to set the $scope with the result of the data. Is there an easy way to set this data to the scope without resorting to to binding the scope to the function in the then clause?
Angular Code
(function () {
var app = angular.module('reports', []);
var reportService = function($http, $q) {
var service = {};
service.getMenuData = function() {
var deffered = $q.defer();
$http.get('/Report/MenuData').success(function(data) {
deffered.resolve(data);
}).error(function(data) {
deferred.reject("Error getting data");
});
return deffered.promise;
}
return service;
};
reportService.$inject = ['$http', '$q'];
app.factory('reportService', reportService);
var reportMenuController =
function ($scope, $http, reportService) {
$scope.getMenuData = function(e) {
reportService.getMenuData().then(function(data) {
// Need to set the $scope in here
// However, the '$scope' is out of scope
});
}
};
reportMenuController.$inject = ['$scope', '$http', 'reportService'];
app.controller('ReportMenuController', reportMenuController);
})();
Markup
<div>
<div ng-controller="ReportMenuController">
<button ng-click="getMenuData()">Load Data</button>
</div>
</div>
There is absolutely no problem to set the $scope from within the function passed to then(). The variable is available from the enclosing scope and you can set your menu data to one of its fields.
By the way: You should consider to use then() instead of success() for your http request. The code looks much nicer because then() returns a promise:
service.getMenuData = function() {
return $http.get('/Report/MenuData').then(function(response) {
return response.data;
}, function(response) {
deferred.reject("Error getting data");
});
}
success() is deprecated by now.
I didn't notice the small detail missing in the plunker where my code was different.
(function () {
...
var reportMenuController =
function ($scope, $http, reportService) {
$scope.getMenuData = getMenuData;
function getMenuData(e) {
reportService.getMenuData().then(function(data) {
// Now I have access to $scope
});
}
};
...
})();
Notice the changes to the two lines as below:
$scope.getMenuData = getMenuData;
function getMenuData(e) {
This also begs a small question which is, "Why is it okay to set getMenuData to the $scope before it is declared?
Trying to get this factory recognised in my other controllers so i can inject a result object into them.
myApp.factory('resultService', function(){
function SampleService() {
this.result = [];
}
});
This the the code in my controller with some removed that isn't purpose to the question.
myApp.controller('125Zero', ['$scope','ngAudio', function($scope, ngAudio, SampleService){
$scope.buttonPressed= function() {
var tempObj = {};
tempObj.title = $scope.title;
tempObj.frequency = $scope.frequency;
console.log(tempObj);
SampleService.result.push($scope.tempObj);
}
}]);
I keep receiving TypeError: Cannot read property 'result' of undefined.
i understand its probably something silly i've missed.
myApp.controller('125Zero', ['$scope','ngAudio', function($scope, ngAudio, SampleService){
You've nt injected SampleService in the array notation of dependencies.
myApp.controller('125Zero', ['$scope','ngAudio', 'resultService', function($scope, ngAudio, resultService){
Also you need to return an object from the factory. Currently you're not returning anything.
you need to do somethin like this:
myApp.factory('SampleService', function() {
return {
result: []
}
});
Maybe you are confused
This is your service
myApp.factory('resultService', function(){
this.result = [];
return this;
});
And you can use it in this way
myApp.controller('125Zero', ['$scope','ngAudio', 'resultService', function($scope, ngAudio, SampleService, resultService){
$scope.buttonPressed= function() {
var tempObj = {};
tempObj.title = $scope.title;
tempObj.frequency = $scope.frequency;
console.log(tempObj);
resultService.result.push($scope.tempObj);
}
}]);
I need a Factory object that can be applied with a $scope.property to get a result. I also need to know if either the modifier in the factory instance, or the $scope.property changes to update the result. How I am seeing this pattern might be wrong of course.
app.factory('MyFactory',
function () {
var MyFactory = function (name, modifier) {
this.name = name;
this.result = 0;
this.modifier = modifier;
}
//I might want to call this when modifier or MyProperty changes
MyFactory.prototype.modifyingMethod = function () {
this.result = this.modifier * //externalProperty;
}
MyFactory.prototype.watcher = function () {
//no idea what I will do here or if I need this at all
// I need to recalculate the result like with $watch
this.modifyingMethod();
}
return MyFactory;
}
)
app.controller('MyCtrl'
function($scope, MyFactory) {
$scope.MyProperty = 42;
$scope.MyFactoryOptions = [
new MyFactory('Option1', 1),
new MyFactory('Option2', 2),
new MyFactory('Option3', 3),
new MyFactory('Option4', 4),
new MyFactory('Option5', 5)
];
}
So I have the problem that I need to $watch MyProperty and the modifier (it can be changed bu users) so I can change the result. If the Property is a value type passing it into the Factory constructor will not work. Perhaps I could pass a function in the returns MyProperty.
Can I set up internal $watch on the factory. If I would do this outside of the factory, in the controller, I would need to do it for each instance. Should I perhaps set up some sort of register method on my factory object?
Are there any suggestions, patterns or something I might want to use?
Basically you could understand your Factory as an interface to a collection of objects (either an array or associative array respectively pure javascript object).
I find your approach with Objects very appealing and I am sure you can achieve similar things. Still I put together a fiddle, that shows how I would solve the problem:
In a MVC pattern your Factory would be the model, the controller should be as simple as possible and your HTML with directives represents the view.
You controller watches for changes from the user ($scope.MyProperty with $watch). While the model is self aware of any depending external property changes. Note that the changes of the ExternalObject service/factory will only be recognizable, if those aren't primitive values. That is why in the ExternalObject factory I return the whole object.
In a perfect world you wouldn't need to listen for changes with an interval, but will receive a javascript event. If this is possible, do it! Note that object updates out of Angular's scope will need you to do a $scope.$apply(), if you want to see the changes in the view. $intervaland $timeout both call a $scope.apply(), so using them is best practice.
Actually there still has to be a lot of cleanup to be done in this code, but it might give you a basic idea how to use an alternative structure:
var app = angular.module('yourApp', []);
window.yourGlobalObject = {};
setInterval(function () {
yourGlobalObject.externalProperty = Math.floor(Math.random() * 5000);
}, 1000);
app.factory('ExternalObject', ['$window', function ($window) {
return $window.yourGlobalObject;
}]);
app.factory('MyFactory', ['$interval', 'ExternalObject', function ($interval, ExternalObject) {
var options = [{
name: 'Option1',
modifier: 1
}, {
name: 'Option2',
modifier: 2
}, {
name: 'Option3',
modifier: 3
}],
cachedExternalProperty = 0,
cachedMyProperty = 0;
MyFactory = {
getOptions: function () {
return options;
},
addOption: function (name, modifier) {
options.push({
name: name,
modifier: modifier
});
},
setMyProperty: function (value) {
cachedMyProperty = value;
},
setResults: function (myProperty) {
angular.forEach(options, function (option, key) {
option.result = option.modifier * ExternalObject.externalProperty * myProperty;
});
console.log(options);
}
};
// let the service check for updates in the external property, if changed
$interval(function () {
if (cachedExternalProperty !== ExternalObject.externalProperty) {
cachedExternalProperty = ExternalObject.externalProperty;
MyFactory.setResults(cachedMyProperty);
}
}, 1000);
return MyFactory;
}]);
app.controller('MyCtrl', ['$scope', 'MyFactory', function ($scope, MyFactory) {
$scope.MyProperty = 42;
$scope.MyFactoryOptions = MyFactory.getOptions();
$scope.setResults = function () {
MyFactory.setResults($scope.MyProperty);
};
$scope.$watch('MyProperty', function (value) {
MyFactory.setMyProperty(value)
MyFactory.setResults(value);
});
}]);
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<body>
<section ng-app="yourApp" ng-controller="MyCtrl">
<button ng-click="setResults(MyProperty)">Update Results</button>
<div ng-repeat="factory in MyFactoryOptions">{{factory.name}} {{factory.result}}</div>
<input type="number" ng-model="MyProperty">
</section>
</body>
Suppose I have a service that depends on a value in $rootScope, as with the following (trivial) service:
angular.module('myServices', [])
.factory('rootValGetterService', function($rootScope) {
return {
getVal: function () {
return $rootScope.specialValue;
}
};
});
If I want to unit test this by putting a value in $rootScope, what is the best way to go about it?
...
var $rootScope;
beforeEach(inject(function(_$rootScope_) {
$rootScope = _$rootScope_;
}));
...
By using provide(), you can inject a new $rootScope:
describe('in rootValGetter', inject(function ($rootScope) {
var scope;
var testRootValGetter;
beforeEach(function () {
scope = $rootScope.$new();
module(function ($provide) {
$provide.value('$rootScope', scope);
});
inject(function ($injector) {
testRootValGetterService = $injector.get('rootValGetterService');
});
});
it('getVal returns the value from $rootScope', function() {
var value = 12345;
scope.specialValue = value;
expect(testRootValGetterService.getVal()).toBe(value);
}
}
Include angular-mocks.js, then use angular.mock.inject:
Instead of creating a new scope as you would if you were injecting $scope you can mock the properties you need directly into $rootScope.
Then $rootScope will be injected with those properties available in the code you are testing.
At least this is the way I solved the same problem.
The following code should work in your example.
beforeEach(inject(function($rootScope) {
$rootScope.specialValue = 'whatever';
}));
Just try to give a more detailed answer including the test case:
...
var $rootScope;
beforeEach(inject(function(_$rootScope_) {
$rootScope = _$rootScope_;
}));
...
it('getVal returns the value from $rootScope', function() {
var value = 12345;
$rootScope.specialValue = value;
expect(testRootValGetterService.getVal()).toBe(value);
}
Here's what I did:
it('some kind of wacky test', function($rootScope, Translate){
$rootScope.lang = 'en';
expect(Translate('overview').toBe('Overview');
}
Hope this helps others as this was the solution to a similar problem.
var rootValGetterService;
beforeEach(inject(function($rootScope,$injector) {
$rootScope.specialValue = "test";
rootValGetterService= $injector.get('rootValGetterService');
}));
it("Should have a service", function () {
expect(rootValGetterService).toBeDefined();
});