AngularJs allow digest only current scope - javascript

Question: I have two controllers Dog and Cat. If I change dog name then $digest cycle runs and Cat also update here view because of method {{ctrl.getTime()}} usage. This is a big problem for big applications which loads all controllers and don't use ng-if or state. In our current app we have a lot of places where we use methods inside templates and what is event worse we load and initialise all application controllers and don't use states or ng-if, we only use ng-show. I know what better solution is to use properties, but I wonder is it possible tell angular to $digest only DogCtrl scope instead of all app scopes?
HTML
<div ng-app="myApp">
<div ng-controller="DogCtrl as ctrl">
<h3>DogCtrl</h3>
Dog name: <input ng-model="ctrl.name" />{{ctrl.name}}
</div>
<hr />
<div ng-controller="CatCtrl as ctrl">
<h3>CatCtrl</h3>
Cat getTime: {{ctrl.getTime()}} {{ctrl.random}}
</div>
</div>
Javascript
var myApp = angular.module('myApp',[]);
myApp.controller('DogCtrl', DogCtrl);
myApp.controller('CatCtrl', CatCtrl);
function DogCtrl() {
this.name = 'Doggy';
}
function CatCtrl() {
this.getTime = function() {
return new Date().getTime();
}
}
Fiddle: http://jsfiddle.net/nvgofo46/1/

Change your html to this:
<div ng-controller="CatCtrl as ctrl">
<h3>CatCtrl</h3>
Cat getTime: {{ctrl.currentTime}} {{ctrl.random}}
</div>
And change your controller to this:
function CatCtrl() {
this.getTime = function() {
return new Date().getTime();
}
this.currentTime = this.getTime();
}
As a rule of thumb, try not to have functions in your view. Because the functions will execute on every digest.
It's more efficient to bind to a model and update the model accordingly.
I could have remove the function and simply set this.currentTime = new Date().getTime(), but that's not the point of this exercise.

Related

AngularJS: Communication between dynamically added controllers

This is my first post/question here on StackOverflow so if you see any improvement I can made - please give me an advice :).
Now let me dive into the issue.
For the sake of simplicity I removed any irrelevant portions of code and presented only necessary files.
//app.modules.js
if (typeof window.app == "undefined") {
window.app = angular.module("AppModule", []);
}
//app.services.js
window.app
.service("settingsOverlaySvc", function($rootScope) {
this.broadcastToggle = function() {
$rootScope.$broadcast("toggle-conf");
};
});
//settings-ctrl.js
window.app.controller("SettingsController", ["$scope", "$window", "$sce", "settingsOverlaySvc",
function($scope, $window, $sce, settingsOverlaySvc) {
$scope.visible = false;
$scope.open = false;
$scope.toggleSettings = function() {
$scope.open = !$scope.open;
};
$scope.broadcastToggle = function() {
settingsOverlaySvc.broadcastToggle();
};
$scope.$on("toggle-conf", function() {
console.log("toggle-conf received");
$scope.visible = !$scope.visible;
});
}
]);
angular.bootstrap($("div[ng-controller='SettingsController']").parent(":not(.ng-scope)"), ["AppModule"]);
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<!-- Appended by JS - control1.html -->
<div>
<div ng-controller="SettingsController" ng-init="visible=true">
<span class="glyphicon glyphicon-cog" ng-class="{'settings-open': open}" ng-click="broadcastToggle();toggleSettings()">COG</span>
</div>
</div>
<!-- Appended by JS - control2.html-->
<div>
<div ng-controller="SettingsController" ng-cloak>
<div ng-if="visible">
<span class="glyphicon glyphicon-cog" ng-class="{'settings-open': open}" ng-click="toggleSettings()">COG</span>
<div ng-if="open">
<div class="divControl_2">Content_2</div>
</div>
</div>
</div>
</div>
The above snippet works as I expected - the $broadcast is called, all controllers receive the message and reacts. In my application the broadcast is received only by controller sending it. I think the problem is caused by dynamic HTML insertions.
The requirement is to render controls dynamically on page load. I'm using the following approach to generate content.
AddWidgets: function () {
var controlContainer1 = $("<section>", {
class: "sidebar-section",
id: "ctrl1-container"
});
var controlContainer2 = $("<section>", {
class: "sidebar-section",
id: "ctrl2-container"
});
$("aside.sidebar").append(controlContainer1);
$("aside.sidebar").append(controlContainer2);
$("#ctrl1-container").load("..\\assets\\ctrls\\control1.html");
$("#ctrl2-container").load("..\\assets\\ctrls\\control2.html");
}
I'm using the same controller because it shares the same logic for all controls.
I've read a lot materials about $broadcast and $emit functionality, guides on creating controllers, defining modules and services (that one gives me idea about creating service with $rootScope injected).
Now I'm thinking that generating angular content outside angular framework (AddWidgets function) can cause the problem (#stackoverflow/a/15676135/6710729).
What raised my spider sense alarm is when I've checked the JSFiddle example for the similar situation (http://jsfiddle.net/XqDxG/2342/) - no parent-child relation of controllers. When I peek at angulat scope of the controllers I can see that $$nextSibling and $$prevSibling properties are filled. In my case these are nulled [here].
Can you give me some guidelines how can I resolve my issue? I'm fairly new to AngularJS and learning as I'm developing the application.

Access Global javascript variables inside AngularJS

I'm working on a site, and I started building it before I realized I needed some dynamic framework. After learning about AngularJS, I decided to use it, where I needed (not the whole site).
I have a very long script in JS, and I want to be able to get and set the variables from within AngularJS directives and controllers.
I found this answer, and it was quite good - I was able to get the variable from within the function. But when the variable changed outside the function, AngularJS' variable won't update.
My code looked something like this:
JS:
var app = angular.module('someName', []);
var currentPage = 'Menu';
app.controller('PageController', ['$window','$scope', function($window,$scope){
this.currentPage = $window.currentPage;
this.isPage = function(page){
return (page == this.currentPage);
};
}]);
function button1onClick(){
currentPage = 'Game';
}
HTML:
<div ng-controller="PageController">
<div id="Game" ng-show="page.isPage('Game')">
...
</div>
<div id="Menu" ng-show="page.isPage('Menu')">
...
</div>
</div>
(button1onClick was called when I clicked some button on the page)
The idea is that I have two dives I want to switch between, using a globle variable. 'Menu' page was visible at first but upon clicking I was supposed to see only the 'Game' div.
The variable inside the controller didn't upadte, but was only given the initial value of currentPage.
I decided to use the $window service inside the isPage function, but this didn't work either. Only when I called a function that tested the $window.currentPage variable, the pages switched - like I wanted:
JS:
var app = angular.module('someName', []);
var currentPage = 'Menu';
app.controller('PageController', ['$window','$scope', function($window,$scope){
this.isPage = function(page){
return (page == $window.currentPage);
};
this.button2onClick = function() {
$window.alert($window.currentPage);
}
}]);
function button1onClick(){
currentPage = 'Game';
}
HTML:
<button onclick="button1onClick()">CLICK ME</button> //Button 1
<div ng-controller="PageController">
<button ng-click="page.button2onClick">CLICK ME</button> //Button 2
<div id="Game" ng-show="page.isPage('Game')">
...
</div>
<div id="Menu" ng-show="page.isPage('Menu')">
...
</div>
</div>
So the only way I was able to update the pages is to call a function that tests the variable, thus updating the variable in AngularJS.
Is there a way to access a global variable without needing to test it to update it?
Am I doing something wrong? I don't want to convert my whole site to AngularJS-style, I like the code the way it is. Is AngularJS not the framework for me?
EDIT:
some things to clear out:
I'm new to AngularJS, so if you could explain what your answer does it would be great.
The whole reason why I do this instead of redirecting to another page is not to shut down socket.io 's connection
OP, take a look at UI Router.
var app = angular.module("app", ['ui.router']);
app.config(['$urlRouterProvider', '$stateProvider', function($urlRouterProvider, $stateProvider) {
$urlRouterProvider.otherwise('/main');
$stateProvider.state('main', {
controller: 'MainCtrl',
templateUrl: 'main.html',
url: '/main/'
}).state('game', {
controller: 'GameCtrl',
url: '/game/',
templateUrl: 'game.html'
});
}]);
HTML links:
<a ui-sref="main">Go to Main</a>
<a ui-sref="game">Go to Game</a>
View injection
<div ui-view="">
</div>
You should not use $window as a map object.
You should probably create a PageService:
angular.module('someName')
.factory('Page', [function(){
var currentPage = 'Menu';
return {
getPage: function() {
return currentPage;
},
isPage: function(page) {
return page === currentPage;
},
setPage: function(page) {
currentPage = page;
}
}
}]);
app.controller('PageController', ['Page','$scope', function(Page,$scope){
this.currentPage = Page.getPage();
this.isPage = Page.isPage;
this.button10Click = function(){
Page.setPage('Game');
}
}]);
HTML
<div class="button" ng-click="page.button10Click()">Game</div>
After reading malix's answer and KKKKKKKK's answer, and after researching a bit, I was able to solve my problem, and even write a better looking code.
To switch divs as I wanted in the example, I used ui-router, almost exactly the way KKKKKKKK did. The only difference is that I change state programmaticly - $state.go('menu')
To access global variables in other places in my code, I had to re-structure my whole code to fit AngularJS's structure, and used a Service, similarly to malix's answer:
app.factory('Data', function(){
var Data = {};
//DEFINE DATA
Data.stateChange = function(){};
Data.menuData = {};
Data.randomColors = ['#35cd96', '#6bcbef', '#E8E1DA', '#91ab01'];
/RETURN DATA
return Data;
});
It can be done using $rootScope. Variable initialize once can be accessible in other controllers.
function Ctrl1($scope, $rootScope) {
$rootScope.GlobalJSVariableA= window.GlobalJSVariable; }
Any controller & any view can access it now
function CtrlN($scope, $rootScope) {
$scope.GlobalJSVariableA= $rootScope.GlobalJSVariableA;
}

ng-include doesn't render partial view everytime using $scope

inside view I'm conditionally rendering html using ng-include and ng-if
<div ng-controller="myController">
<div ng-if="myProperty == 1">
<div ng-include="'view1.html'"></div>
</div>
<div ng-if="myProperty == 2">
<div ng-include="'view2.html'"></div>
</div>
</div>
and inside controller I have $scope.myProperty which receive value inside controller using $scope injection from other js object. On this controller I have also callback function which updates $scope.myProperty every x seconds.
app.controller('myController', function ($scope) {
...
$scope.myProperty = 0; //init value
function callback() {
$scope.$apply(); // force update view
// correctly write myProperty value on every data change
console.log($scope.myProperty);
}
var otherJsObject= new myObject($scope, callback);
otherJsObject.work();
...
}
callback function correctly change myProperty value but it doesn't update inside view every time.
update:
$scope.bindUIProp = { a: $scope.myProperty};
function callback() {
$scope.$apply();
$scope.bindUIProp.a = $scope.myProperty;
console.log('Callback ' + $scope.myProperty);
console.log('drawstage ' + $scope.bindUIProp.a);
}
var otherJsObject= new myObject($scope, callback);
otherJsObject.work();
and inside view I used object property
<div ng-controller="myController">
<div ng-if="bindUIProp.a == 1">
<div ng-include="'view1.html'"></div>
</div>
<div ng-if="bindUIProp.a == 2">
<div ng-include="'view2.html'"></div>
</div>
</div>
this approach work every time when page is refreshed, parial view is not updated from view1 to view2 when scope.bindUIProp.a is changed to 2.
Instead of writing to property at root level. Write one level below.
Instead of $scope.myProperty,
use $scope.mp.myProperty
Both ng-if and ng-include create child scopes.
You are having problems due to using a primitive in your main scope. Primitives don't have inheritance so the binding is getting broken in the nested child scopes.
change it to an object:
$scope.myProperty = { someProp: 0};
Personally I rarely use ng-include because of the child scope it creates. I prefer having my own directive if all I want is to include a template.

How to setup a service from a base module to call a function on a service in a module that uses the base module in angularjs

I an writing a service that is to be used in multiple independent websites. However, at some points it needs to trigger different code depending on what website it is used in. I want to keep this per website code separate from the base service.
Here is some example code demonstrating the design I want (although it isn't working):
var baseModule = angular.module('baseModule', []);
baseModule.service('baseService', function() {
this.func = function() {
return ["first",
/* TODO somehow get from appropriate
service in website module */
"FIXME",
"end"];
};
});
var website1 = angular.module('website1', ['baseModule']);
website1.service('website1Service', function() {
this.someCustomValue = function() {
// Note that while this is a constant value, in
// the real app it will be more complex,
// so replacing this service with a constant provider won't work.
return "someValue";
}
});
// TODO : somehow link website1Service.someCustomValue to baseService
var website2 = angular.module('website2', ['baseModule']);
website2.service('website2Service', function() {
this.anotherValue = function() { return "anotherValue"; }
});
// TODO : somehow link website2Service.anotherValue to baseService
// Testing code:
function makeTestController(expected) {
return ['$scope', 'baseService', function($scope, baseService) {
var result = baseService.func();
if (angular.equals(result, expected)) {
$scope.outcome = "Test Passed!";
} else {
$scope.outcome = 'Test failed...\n' +
"Expected: " + angular.toJson(expected) + '\n' +
"But got : " + angular.toJson(result);
}
}];
}
website1.controller('TestController1',
makeTestController(['first', 'someValue', 'end']));
website2.controller('TestController2',
makeTestController(['first', 'anotherValue', 'end']));
// since this test uses multiple angular apps, bootstrap them manually.
angular.bootstrap(document.getElementById('website1'), ['website1']);
angular.bootstrap(document.getElementById('website2'), ['website2']);
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<h3>Website 1</h3>
<div id='website1'>
<div ng-controller='TestController1'>
<pre>{{outcome}}</pre>
</div>
</div>
<div id='website2'>
<h3>Website 2</h3>
<div ng-controller='TestController2'>
<pre>{{outcome}}</pre>
</div>
</div>
I've thought of a few solutions to this, but none seem optimal.
The most obvious way would be to replace the baseService service with a provider, and allow it to be configured in each module. This seems to be the standard way of configuring services in other modules. However, I cannot access the website1Service and website2Service in in the provider functions, as services cannot be accessed in provider functions. This is noted in the docs:
During application bootstrap, before Angular goes off creating all services, it configures and instantiates all providers. We call this the configuration phase of the application life-cycle. During this phase, services aren't accessible because they haven't been created yet.
Another solution to work around this is use angular.injector to find the right service. However, the docs for angular.injector imply that you really only need this for interacting with third party libraries. So it appears there is a better way.
Finally, I could add a dependency to a nonexistant service (eg "baseServiceActions") in baseModule, and require a service with that name be implemented in website1 and website2. The dependency injection should then bind it all together when baseService is used. However, this is a pretty weird way of working, and would result in poor error messages if the baseServiceActions module wasn't implemented in a new website that used the baseModule module.
Is there a better way of doing this? If so, is it possible to change the example code I posted to get all the tests passing? Ideally none of the testing code should be changed.
I eventually worked out a fairly good solution to this. I created a service named "<serviceName>Settings", and added a setup function to it. I then call that setup function in a module run block in the module I want to use it in. Finally I have a validate method that is called in the service that uses the settings to ensure it is setup, and throws a nice error message if it isn't. This solved all the problems I had with the other solutions.
This is how my example problem would look with this solution:
var baseModule = angular.module('baseModule', []);
baseModule.service('baseService', ['baseServiceSettings', function(baseServiceSettings) {
baseServiceSettings.validate();
this.func = function() {
return ["first",
baseServiceSettings.getValue(),
"end"];
};
}]);
baseModule.service('baseServiceSettings', function() {
this.setup = function(getter) {
this.getValue = getter;
};
this.validate = function() {
if (!this.getValue) {
throw "baseServiceSettings not setup! Run baseServiceSettings.setup in a module run block to fix";
}
};
});
var website1 = angular.module('website1', ['baseModule']);
website1.run(['baseServiceSettings', 'website1Service', function(baseServiceSettings, website1Service) {
baseServiceSettings.setup(website1Service.someCustomValue);
}]);
website1.service('website1Service', function() {
this.someCustomValue = function() {
// Note that while this is a constant value, in
// the real app it will be more complex,
// so replacing this service with a constant provider won't work.
return "someValue";
}
});
var website2 = angular.module('website2', ['baseModule']);
website2.service('website2Service', function() {
this.anotherValue = function() { return "anotherValue"; }
});
website2.run(['baseServiceSettings', 'website2Service', function(baseServiceSettings, website2Service) {
baseServiceSettings.setup(website2Service.anotherValue);
}]);
// Testing code:
function makeTestController(expected) {
return ['$scope', 'baseService', function($scope, baseService) {
var result = baseService.func();
if (angular.equals(result, expected)) {
$scope.outcome = "Test Passed!";
} else {
$scope.outcome = 'Test failed...\n' +
"Expected: " + angular.toJson(expected) + '\n' +
"But got : " + angular.toJson(result);
}
}];
}
website1.controller('TestController1',
makeTestController(['first', 'someValue', 'end']));
website2.controller('TestController2',
makeTestController(['first', 'anotherValue', 'end']));
// since this test uses multiple angular apps, bootstrap them manually.
angular.bootstrap(document.getElementById('website1'), ['website1']);
angular.bootstrap(document.getElementById('website2'), ['website2']);
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<h3>Website 1</h3>
<div id='website1'>
<div ng-controller='TestController1'>
<pre>{{outcome}}</pre>
</div>
</div>
<div id='website2'>
<h3>Website 2</h3>
<div ng-controller='TestController2'>
<pre>{{outcome}}</pre>
</div>
</div>

Parent scope variables don't update in the view when child controllers modify them

The jsFiddle for this question can be found here: http://jsfiddle.net/Hsw9F/1/
JavaScript (console.log debug information available in the jsFiddle)
var app = angular.module('StackOverflow',[]);
function ParentController($scope) {
$scope.parentCounter = 5;
}
function ChildController($scope) {
$scope.childCounter = $scope.parentCounter;
$scope.increaseCounters = function() {
++$scope.parentCounter;
++$scope.childCounter;
};
}
In the example above I have a counter in the parent and the child controllers named parentCounter and childCounter respectively. I've also provided a function in the child controller named increaseCounters() that increases both counters by one.
Both of these counters are displayed on the page:
<div ng-app="StackOverflow">
<div ng-controller="ParentController">
Parent Counter: {{parentCounter}}<br />
<div ng-controller="ChildController">
Child Counter: {{childCounter}}<br />
<a href="javascript:void(0)"
ng-click="increaseCounters()">Increase Counters</a>
</div><!-- END ChildController -->
</div><!-- END ParentController -->
</div><!-- END StackOverflow app -->
The problem is that AngularJS doesn't seem to update the {{parentCounter}} on the page, and only updates the {{childCounter}} when the increase counters function is called. Is there anything I have overlooked?
++$scope.parentCounter; creates a child scope property with name parentCounter that hides/shadows the parent scope property of the same name.
Add console.log($scope); to your increaseCounters() function to see it.
One workaround: ++$scope.$parent.parentCounter;
The problem you are experiencing has to do with the way JavaScript prototypal inheritance works. I suggest reading What are the nuances of scope prototypal / prototypical inheritance in AngularJS? -- it has some nice pictures explaining what happens when primitives are created in child scopes.
Because the child controller gets a copy of the parent counter value. If you want to increase the parent controller counter value, you need to execute a function on the parent controller:
function ParentController($scope) {
$scope.parentCounter = 5;
$scope.increaseParent = function() {
++$scope.parentCounter;
};
}
function ChildController($scope) {
$scope.childCounter = $scope.parentCounter;
$scope.increaseCounters = function() {
console.log('-------------------------------------');
console.log('parent before: ' + $scope.parentCounter);
console.log('child before: ' + $scope.childCounter);
$scope.increaseParent();
++$scope.childCounter;
console.log('parent after: ' + $scope.parentCounter);
console.log('child after: ' + $scope.childCounter);
};
}

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