I'm new to angular and little bit confused with it. So basically I created a simple button and i want to run function foo() whitch assigns variable var one = 1; to $scope and outputs it in <p>{{one}}<p> every time its clicked like in live typing but this seems not working. Please provide me a solution to this.
<html ng-app="app">
<!-- Body tag augmented with ngController directive -->
<body ng-controller="myController">
<input type="text" ng-model="name">
<p>{{name}}</p>
<p>{{one}}</p>
<button ng-click="foo()">1</button>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.6/angular.min.js"></script>
<script src="controller.js"></script>
</body>
</html>
controller:
var app = angular.module('app',[]);
app.controller('myController', ['$scope',function($scope){
var one = 1;
$scope.name = name;
function foo(){
return $scope.one = one;
}
}]);
function foo() dont exist in $scope your controller "myController"
if you declaration:
$scope.foo = function(){}
in your controller, then this work for you
when you are calling controller function from the html, controller function should be scope. Other wise ng-click directive doesn't recognize the function.
same concept goes to binding variable to html. only scope variables can directly bind to html using curly brackets. so inside foo function var one should assign to scope.one in order to display it in the html.
angular.module("app",[])
.controller("ctrl",function($scope){
var one = 1;
$scope.name = name;
$scope.foo = function(){
$scope.one = one;
}
})
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.22/angular.min.js"></script>
<div ng-app="app" ng-controller="ctrl">
<input type="text" ng-model="name">
<p>{{name}}</p>
<p>{{one}}</p>
<button ng-click="foo()">1</button>
</div>
Related
i want execute a hello world function into a controller (call from html with button click), but i cant call this and i do not know why it does not work because not any show a error.
html code:
<html ng-app="app">
<div ng-controller="indexController">
<button type="button" ng-click="helloWorld()">action</button>
</div>
and controller js:
(function () {
'use stritct';
angular
.module('app',[])
.controller('indexController', indexController);
indexController.inject = ['$rootScope','$scope'];
function indexController($rootScope,$scope) {
var vm = this;
vm.helloWorld = helloWorld;
function helloWorld() {
console.log('hello');
}
}
})();
ng-click="helloWorld() will try to call $scope.helloWorld() function, that is undefined here.
helloWorld function is linked to your controller object, not to the Angular scope.
You have to set an alias of your controller, like ng-controller="indexController as index", and you will can call your helloWorld function like this: ng-click="index.helloWorld()".
To access functions or data in the template from your controller, you must define the function or value on the $scope object. Anything you define on the $scope object you can use in the template.
Instead of vm.helloWorld = helloWorld; try $scope.helloWorld = helloWorld;
In the same way, you can access data from your controller and display it in the template.
angular.module('app',[])
.controller('indexController', indexController);
indexController.$inject = ['$rootScope','$scope'];
function indexController($rootScope,$scope) {
$scope.helloWorld = function() {
console.log('hello');
}
$scope.message = 'From the controller!';
}
<html ng-app="app">
<body>
<div ng-controller="indexController">
<button type="button" ng-click="helloWorld()">action</button>
<p>{{ message }}</p>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
</body>
</html>
I see almost tutorial use anonymous function in AngularJS, instead of normal function, like function name(para1) {}. Please see this link: http://www.w3schools.com/angular/tryit.asp?filename=try_ng_controller_property
I change to normal function, but it cannot work, Please advise. Thanks.
<div ng-app="myApp" ng-controller="personCtrl as main">
First Name: <input type="text" ng-model="firstName"><br>
Last Name: <input type="text" ng-model="lastName"><br>
<br>
Full Name: {{main.fullName()}}
</div>
<script>
var app = angular.module('myApp', []);
app.controller('personCtrl', function($scope) {
$scope.firstName = "John";
$scope.lastName = "Doe";
function fullName() {
return $scope.firstName + " " + $scope.lastName;
};
});
</script>
The idea of $scope is to have an object where all fields and functions are defined on, so that you are able to reference the fields and functions from your template.
When you don't attach the function to $scope it will not be visible for angular to be called. So the contract is that in your controller function, you add everything you need to the $scope object passed by the framework and by doing so, you can later access the fields or call the functions from your template. Everything you reference in directives like ng-model or put into {{ }} will be evaluated by angular, but angular doesn't know what you mean with the expression fullName() as written in your snippet link or fails finding it in the controller when written as main.fullName().
For details on the concept of $scope have a look at the angular docs on scopes.
What you can do (and it is also a good practice) is to declare your function and then (maybe in tha init of the controlelr) assign them to the $scope ..so is more clear when you'll re read it something like:
<!DOCTYPE html>
<html>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.min.js"></script>
<body>
<div ng-app="myApp" ng-controller="personCtrl">
First Name: <input type="text" ng-model="firstName"><br>
Last Name: <input type="text" ng-model="lastName"><br>
<br>
Full Name: {{fullName()}}
</div>
<script>
var app = angular.module('myApp', []);
app.controller('personCtrl', function($scope) {
$scope.firstName = "John";
$scope.lastName = "Doe";
$scope.fullName = fullName; //<-- here you assign it
function fullName() {
return $scope.firstName + " " + $scope.lastName;
};
});
</script>
</body>
</html>
I use controller as approach instead of $scope. I have some problems with method calling from HTML. So, the question is that, how many ways exist in declare and call functions in this approach.
first: (If I want to do s.th. at first)
var vm= this ;
vm.dataOne=[];
function funcOne() {
myService.serviceFunc()
.then(function (response) {
vm.dataOne= response.data;
});
};
function activate() {
funcOne();
}
activate();
second: (If I want to initialize a variable based on a function returned value )
vm.dataTwo = function () {
doSomeThing();
}
Is there any way, too?
How should define a function in controller
which will be called from HTML, as
ng-click = "ctrl.dataTwo()";
Functions the way you've defined are private:
function functionOne() {
}; // Just function body, no need of semicolon
These are known as function declarations. Currently, they are only accessible within your controller.
To be able to call them, attach them to the controller so they become controller variables:
vm.functionOne = functionOne;
An advantage of this approach is that you can define functions after actually calling them, as opposed to how you do with $scope or $this. They are recognized via hoisting, and called.
About your initializing a returned value from a function, just call it:
vm.someVariable = someFunction();
Some references:
var functionName = function() {} vs function functionName() {}
Private Members in JavaScript
Angular Function Declarations, Function Expressions, and Readable Code
Angular Style Guide
First way using ng-controller="cntrl as vm" syntax:
<!DOCTYPE html>
<html>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.min.js"></script>
<script>
angular.module('MyApp', [])
.controller('MyCntrl', function($scope) {
var vm = this;
vm.name = 'Custom Directive';
});
</script>
<body>
<div ng-app="MyApp" ng-controller="MyCntrl as vm">
{{vm.name}}
</div>
</body>
</html>
Second way using controllerAs as one of the attribute of directive:
<!DOCTYPE html>
<html>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.min.js"></script>
<script>
angular.module('MyApp', [])
.directive('customDir', function() {
return {
restrict: 'EA',
template: '<div>{{vm.name}}</div>',
controller: function(){
var vm = this;
vm.name = 'Custom Directive';
},
controllerAs: 'vm'
}
});
</script>
<body>
<div ng-app="MyApp">
<div custom-dir></div>
</div>
</body>
</html>
Way to calling a function with "controller as" syntax which is defined in controller but called in html:
<!DOCTYPE html>
<html>
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.min.js"></script>
<script>
angular.module('MyApp', [])
.controller('MyCntrl', function($scope) {
var vm = this;
vm.name = 'Custom Directive';
vm.someFunction = function() {
vm.name = 'Button is Clicked!!!';
};
});
</script>
<body>
<div ng-app="MyApp" ng-controller="MyCntrl as vm">
{{vm.name}}
<input type='button' ng-click="vm.someFunction()" value="Click" />
</div>
</body>
</html>
Other way, use function as constructor and add functionality to prototype
function Ctrl($window) {
this.$window = $window;
}
Ctrl.inject = ['$window']
Ctrl.prototype.click = function() {
this.$window.alert('clicked')
}
angular.module('app', [])
.controller('ctrl', Ctrl)
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app='app' ng-controller='ctrl as c'>
<button ng-click='c.click()'>Click me!</button>
</div>
I'm trying to display a div if an object is non-empty. Using this answer, Im trying to use angular.equals to check emptyness, but its not behaving as expected
var test = angular.module('test',[]);
test.controller('testCtrl', ['$scope', function($scope){
$scope.foo={};
$scope.bar="bam"
}]);
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="test">
<div ng-controller="testCtrl">
<div ng-show="!angular.equals(foo,{})">{{bar}}</div>
</div>
</div>
The expectation here is that the value of bar will only show if foo is not equal to an empty object. However, foo is clearly set to {} and yet bar still shows.
If you want to access the angular object from templates or expressions, you have to make it available on the scope of where you want to use it. In this case you can put it on the testCtrl's scope.
var test = angular.module('test',[]);
test.controller('testCtrl', ['$scope', function($scope){
$scope.angular = angular;
$scope.foo={};
$scope.bar="bam"
}]);
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="test">
<div ng-controller="testCtrl">
<div ng-show="!angular.equals(foo,{})">{{bar}}</div>
</div>
</div>
I generally put utility objects on $rootScope, so they're available from everywhere.
A cleaner way would be to only add the angular equals method to the $scope:
var test = angular.module('test',[]);
test.controller('testCtrl', ['$scope', function($scope){
$scope.angularEquals = angular.equals;
}
Then you can use the equals method in the template, like:
<div ng-show="!angularEquals(foo,{})">{{bar}}</div>
Your view is looking for a function on the scope, and $scope.angular.equals does not exist. You need to write one like this:
var test = angular.module('test', []);
test.controller('testCtrl', ['$scope',
function($scope) {
$scope.foo = {};
$scope.bar = "bam";
$scope.isEmpty = function(obj) {
return angular.equals(obj,{});
};
}
]);
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="test">
<div ng-controller="testCtrl">
<div ng-hide="isEmpty(foo)">{{bar}}</div>
</div>
</div>
Angular functions can't be used inline, AFAIK.
You could do the equal check with a function inside the controller instead and return the result.
I have a controller with such:
$scope.myVar = 0;
$scope.back = function () {
$scope.myVar--;
};
$scope.next = function () {
$scope.myVar++;
};
If next() (with ngClick) is called 3 times, we get:
//1
//2
//3
but if back() (with ngSwipeLeft) is called it returns
//-1
when I'm obviously expecting
//2
What am I missing here?
update: including ngTouch details - this seems to be the problem.. ngTouch is included.
When I watch the myVar value - its like it exists twice - one with the ngSwipeLeft call, and one with the ngClick call
Your snippet looks fine to me. You need to provide more code, error might be somewhere else. Look at the code below.
<!doctype html>
<html ng-app="myapp">
<head>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.12/angular.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.2.20/angular-touch.min.js"></script>
<script>
var app = angular.module('myapp',['ngTouch']);
var controller = app.controller('mycontroller', ['$scope',function($scope){
$scope.myVar = 0;
$scope.back = function () {
$scope.myVar--;
};
$scope.next = function () {
$scope.myVar++;
};
}]);
</script>
</head>
<body ng-controller="mycontroller">
<div>
<h1>MyVar: {{myVar}}!</h1>
<input type="button" value="back" ng-click="back()"/>
<input type="button" value="next" ng-click="next()"/>
</div>
</body>
</html>
Ok, so I've figured out my problem - I wasn't providing enough detail in the question - but if someone runs into something similar in the future, heres what was going on:
I was declaring my controller with ng-controller="myCtrl" in the templates, but also using routing, where I declared my controller like:
$routeProvider.when('/', {
templateUrl: 'myUrl.html',
controller: 'myCtrl'
});
This was instantiating the controller twice, and obviously causing problems (although that seemed to the only one to surface for now).
Removing the controller definition from the routing or the view did the trick.
need to see your html not sure about your problem, here is a sample working code,
<div ng-app="myapp">
<div ng-controller="IncDecController">
<span>current value is {{myVar}}</span>
<img src="https://angularjs.org/img/AngularJS-large.png" ng-swipe-left="back()"></img>
<button ng-click="next()">next</button>
</div>
</div>
script:
angular.module('myapp', ['ngTouch'])
.controller('IncDecController', ['$scope', function ($scope) {
$scope.myVar = 0;
$scope.back = function () {
$scope.myVar--;
};
$scope.next = function () {
$scope.myVar++;
};
}])