Here's a brief example here: http://plnkr.co/edit/x1sSw8?p=preview.
This is the HTML file:
<body ng-controller="MainCtrl as main">
<p>Hello {{main.name}}!
My current value for <code>main.value</code> is {{main.value}}.</p>
<button ng-click="main.doSomething()">Click Me</button>
</body>
Here is the app.js file:
var app = angular.module('plunker', []);
app.controller('MainCtrl', function() {
this.name = 'World';
this.value = 0;
this.doSomething = function(){
this.value += 5;
}
this.doSomethingElse = function(){
this.value -= 5;
}
});
When I click the button, I normally expect the counter to go up in increments of 5. When I inspect the button and change the ng-click function to doSomethingElse(), why does it still continue to increment?
I understand I'm not directly changing the event listeners, so I wonder how AngularJS is protecting the controllers from outside tampering (like in the example I described). My guess is that it builds event listeners up after it parses the DOM for the first time (reading ng-click attributes and all).
When I inspect the button and change the ng-click function to doSomethingElse(), why does it still continue to increment?
You should check out the compilation & linking processes in Angular. The short reason is that, angular goes over these elements once they are created, not every time you click it. Since it is scanned and parsed by angular when the element is created, manually changing it by hand does not change anything, because angular does not check out what's written in there.
More info: https://docs.angularjs.org/guide/compiler
Related
I would like to be able to select a button using querySelector and set an attribute of "ng-click=doSomething()"
I have tried selecting the button and then setAttribute("ng-click", "doSomething()") but its not working
my DOM:
<body>
<div ng-app="myApp" ng-controller="mainCtrl">
<button id="myBtn">click Me</button>
</div>
<script src="./js/app2.js"></script>
</body>
my javascript:
(function() {
"use strict";
angular.module("myApp", []).controller("mainCtrl", mainCtrl);
/** #ngInject */
function mainCtrl($scope) {
init();
function init() {
$scope.doSomething = () => {
console.log("doing something");
}
let btn = document.querySelector('#myBtn');
btn.setAttribute("ng-click", "doSomething()");
}
}
})();
when I click the button it should console log something.
Generally speaking, if you dynamically add "AngularJS-ified" stuff to a document after it's created - such as dynamically creating <button> elements and then adding ng-click attributes to them - those elements will neither be tracked by watchers, nor be part of the normal digest cycle. So, for example, consider the following simple example:
const myApp = angular.module('stuff', [])
.controller('stuff-cont', function($scope) {
const targ = document.querySelector('#target');
for (let i = 0; i < 10; i++) {
let newBtn = document.createElement('button');
newBtn.setAttribute('ng-click', 'sayRandNum()');
newBtn.innerText = `Button ${i}`
targ.append(newBtn);
}
$scope.sayRandNum = () =>{
alert('Your random number is '+Math.ceil(Math.random()*100));
}
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.7.5/angular.min.js"></script>
<div ng-app='stuff' ng-controller='stuff-cont'>
<div id='target'>
</div>
The buttons above are clickable, they have an appropriately "structured" ng-click, but they <i>don't trigger</i>!
</div>
Here, we're (for some reason...) creating 10 nearly-identical buttons. However, because of when we built these ng-click'ed buttons (namely, after the initial compilation phase), and specifically when we added the ng-click attributes (also after the initial compilation phase), the buttons are effectively not "known" to the AngularJS cycle".
Looked at another way, when AngularJS is first "loaded" on a page, it first walks through the HTML on that page, and looks for any databinds ({{likeThis}}; we'll ignore these for now) or directives. ng-click, ng-repeat, and other Babbys First AngularJS stuff are just standardized directives, so they're part of that "looking for directives" procedure. When AngularJS finds said directives, it says "Okay, you've got an ng-click on this element; I'll keep an eye on that".
To actually add new AngularJS-ified elements - or add AngularJS behavior to existing elements, as I believe is more the case with you - you'll need to use the $compile function, which basically says "hey, AngularJS! I made a new thing and want you to watch it!"
This SO answer -- Working with $compile in angularjs has a pretty decent explanation of how to use the $compile function.
(function() {
"use strict";
var btn = document.querySelector('#myBtn');
btn.setAttribute("ng-click", "doSomething()");
angular.module("myApp", []).controller("mainCtrl", mainCtrl);
function mainCtrl($scope){
$scope.doSomething = function(){
alert('abc');
}
}
angular.bootstrap(document, ['myApp']);
})();
Please check the JSFiddle , the difference is you have to modified the html before angular bootstrapped so your modified html and js code can be compiled properly. Here is a AngularJS Developer Guide - Bootstrap with more infomation of angularjs bootstrap
I'm new in angular and i'm looking for the best way to do what I want.
In my main page I have 2 directives, one is used to display a button (and maybe other stuff). And another used to display a kind of dialog box/menu.
Each directive has its own controller.
I want to show or hide the second directive when I click on the button in the first one.
I don't really know what are goods or wrong approaches. Should I use a service injected in both controller and set a variable with ng-show in the second directive? This solution doesn't really hide the directive because I need a div inside the directive to hide its content and isn't too much to use a service only for one boolean?
Should I use a kind of global variable (rootscope?) or inject the first controller inside the second one?
Or maybe use a third controller in my main page (used with a service?) or use only one controller for both directive?
Basically without directive I would probably used only one main controller for my whole page and set a variable.
In fact the first directive is just a kind of button used to display "something", and the second directive just a kind of popup waiting a boolean to be displayed. That's why I finally used a service containing a boolean with a getter and a setter to avoid any interaction beetween both controller.
My both controller use this service, the first one to set the value when we click on the element and the second controller provide just a visibility on the getter for my ng-show.
I don't know if it is the best way to do but I am satisfied for now.
Small example here (without directive but with same logic) :
http://codepen.io/dufaux/pen/dXMrPm
angular.module('myModule', []);
angular.module("myModule")
.controller("ButtonCtrl", buttonCtrl)
.controller("PopUpCtrl", popUpCtrl)
.service("DisplayerService", displayerService);
//ButtonCtrl
buttonCtrl.$inject = ["DisplayerService", "$scope"];
function buttonCtrl(DisplayerService, $scope) {
var vm = this;
vm.display = function(){
DisplayerService.setDisplay(!DisplayerService.getDisplay());
}
}
//PopUpCtrl
popUpCtrl.$inject = ["DisplayerService"];
function popUpCtrl(DisplayerService) {
var vm = this;
vm.displayable = function(){
return DisplayerService.getDisplay();
}
}
//Service
function displayerService(){
var vm = this;
vm.display = false;
vm.setDisplay = function(value){
vm.display = value;
}
vm.getDisplay = function(){
return vm.display;
}
}
--
<body data-ng-app="myModule">
<div data-ng-controller="ButtonCtrl as btnCtrl" >
<button data-ng-click="btnCtrl.display()">
display
</button>
</div>
[...]
<div data-ng-controller="PopUpCtrl as popUpCtrl" >
<div data-ng-show="popUpCtrl.displayable()">
hello world
</div>
</div>
</body>
I'm trying to making some custom elements with AngularJS's and bind some events to it, then I notice $scope.var won't update UI when used in a binding function.
Here is a simplified example that describing the probelm:
HTML:
<!doctype html>
<html ng-app="test">
<head>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.0.6/angular.min.js"></script>
<script src="script.js"></script>
</head>
<body>
<div ng-controller="Ctrl2">
<span>{{result}}</span>
<br />
<button ng-click="a()">A</button>
<button my-button>B</button>
</div>
</body>
</html>
JS:
function Ctrl2($scope) {
$scope.result = 'Click Button to change this string';
$scope.a = function (e) {
$scope.result = 'A';
}
$scope.b = function (e) {
$scope.result = 'B';
}
}
var mod = angular.module('test', []);
mod.directive('myButton', function () {
return function (scope, element, attrs) {
//change scope.result from here works
//But not in bind functions
//scope.result = 'B';
element.bind('click', scope.b);
}
});
DEMO : http://plnkr.co/edit/g3S56xez6Q90mjbFogkL?p=preview
Basicly, I bind click event to my-button and want to change $scope.result when user clicked button B (similar to ng-click:a() on button A). But the view won't update to the new $scope.result if I do this way.
What did I do wrong? Thanks.
Event handlers are called "outside" Angular, so although your $scope properties will be updated, the view will not update because Angular doesn't know about these changes.
Call $scope.$apply() at the bottom of your event handler. This will cause a digest cycle to run, and Angular will notice the changes you made to the $scope (because of the $watches that Angular set up due to using {{ ... }} in your HTML) and update the view.
This might be also a result of different problem but with the same symptoms.
If you destroy a parent scope of the one that is assigned to the view, its changes will not affect the view in any way even after $apply() call. See the example - you can change the view value through the text input, but when you click Destroy parent scope!, model is not updated anymore.
I do not consider this as a bug. It is rather result of too hacky code in application :-)
I faced this problem when using Angular Bootstrap's modal. I tried to open second modal with scope of the first one. Then, I immediately closed the first modal which caused the parent scope to be destroyed.
use timeout
$timeout(function () {
code....
},
0);
I don't use Angular regularly, but I understand that one of the key features is that when data is updated on a form element, it is automatically updated in the model.
If you are instead using a library like jQuery, you must manually attach an event to the form input that updates the model when it is changed, as in $('#myInput').on('change', updateModel);
Although the above handler will be fired when myInput is changed by the user, it will not be fired if myInput is changed by Javascript code such as $('#myInput').val('hello world');
My question is, how does Angular know when a form input is changed in Javascript code?
Angular applies a scope digest every time it's needed (by an Angular function) during which it checks the states of all the scope variables, including the models used, of course.
If you modify some of those variables manually, using JavaScript, jQuery, etc... Angular will not know that the changes have occured and you need to tell it so either by doing $scope.$apply() or by wrapping the code block in a $timeout callback (these are the most commonly used methods).
If you don't do it manually, you'd have to wait for some (if any) other Angular event to trigger the digest cycle, which is never good.
See this example, note how nothing happens when you just update the value, but you need to do it manually (ng-click does it) in order for DOM to update:
angular.module('app', [])
.controller('Ctrl', function($scope){
$scope.ourValue = 'Initial Value';
window.exposedFunc = function(v, digest) {
$scope.ourValue = v;
if (digest) {
$scope.$apply();
}
}
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="app" ng-controller="Ctrl">
<button onclick="exposedFunc('First Button Value')">Update Value - No Digest</button>
<button onclick="exposedFunc('Second Button Value', true)">Update Value - Force Digest</button>
<button ng-click="">Force Digest only</button>
<p>{{ourValue}}</p>
</div>
Here's a super simple example of binding using keyup event. It should be enough to get you started on your projects:
var res = document.getElementById('r');
function handleChange(v) {
res.textContent = v;
}
<input onkeyup="handleChange(this.value)" type="text" value="Initial value" />
<p id="r">No binding yet</p>
Have a template that I'd like to load using ng-include and assign a controller instance to. This new template/scope/controller needs to be loaded in response to a user interaction (hover or click).
The content of the template has to be set using element.innerHTML because the content is set by a 3rd party.
The user can then click out of the new div and I would like to destroy the controller/scope that was created.
Pseudocode for what I want to achieve:
popup.setContent("<div ng-controller='PopupController'><div ng-include=\"views/LayerPopup.html\"></div></div>");
How do I tell angular to process the ng-include and ng-controller just as though the page was being loaded for the first time?
Thanks!
Edit:
Add plunker to illustrate question
http://plnkr.co/edit/DPuURCoq2hJ0LCLIN2dc?p=preview
http://jsfiddle.net/ADukg/5420/
Not using ngInclude, but it does fill these criteria:
You pass in a templateURL.
Pass in the name of the controller you would like to use.
Pass in the third party content (which in turn gets set with $element.innerHTML).
Setup a click listener someplace outside the $scope of the popup, which triggers a kill command on the popup.
This is how I imagine you would instantiate it:
<directive tpl="tpl.html"
ctrl="DirectiveController"
third-party-content="{{thirdPartyContent}}">
</directive>
Not sure this will suit you, but I had a fun time putting it together and maybe it'll prove useful to someone else.
In any case, I have to agree with the comments you've recieved so far. It's a bit cryptic as to what you have to work with right now and what possible options are available to you.
Here is a plunker of what you are trying to do. If you click on a button, a popup will show a template, and you can click on the template and it will stay up, but if you click out of it, it will get removed.
HTML
<body ng-controller="MainCtrl" ng-click="closePopup()">
<button ng-click="openPopup($event)" id="clicktarget">Click</button>
<p>Hello {{name}}!</p>
<div ng-include="getPopup()" ng-click="$event.stopPropagation()">
</div>
<script type="text/ng-template" id="theTemplate.html">
<div ng-controller="PopupController">
<div ng-include="'LayerPopup.html'"></div>
</div>
</script>
</body>
JS
angular.module('plunker', [])
.controller('MainCtrl', function($scope, $templateCache) {
$scope.name = 'World';
$scope.popupTmpl = null;
$scope.openPopup = function($event){
$scope.popupTmpl = 'theTemplate.html';
$event.stopPropagation();
};
$scope.getPopup = function(){
return $scope.popupTmpl;
};
$scope.closePopup = function(){
$scope.popupTmpl = null;
};
})
.controller('PopupController', ['$scope', function($scope) {
$scope.aVariableMaybe = 'lulz something';
}]);
On a side note, try to get rid of that JQuery stuff when you are using Angular. Angular can do everything on its own