Chương 4-Bài 5. Cách sử dụng AngularJS Event

AngularJS Events

Chúng ta có thể `bắt các sự kiện (event listener)` diễn ra trên các phần tử HTML bằng cách sử dụng các tiền chỉ lệnh (directives) của AngularJS như sau:

• ng-blur
• ng-change
• ng-click
• ng-copy
• ng-cut
• ng-dblclick
• ng-focus
• ng-keydown
• ng-keypress
• ng-keyup
• ng-mousedown
• ng-mouseenter
• ng-mouseleave
• ng-mousemove
• ng-mouseover
• ng-mouseup
• ng-paste

The event directives allows us to run AngularJS functions at certain user events. An AngularJS event will not overwrite an HTML event, both events will be executed.

Mouse Events

Mouse events occur when the cursor moves over an element, in this order:

1. ng-mouseover
2. ng-mouseenter
3. ng-mousemove
4. ng-mouseleave

Or when a mouse button is clicked on an element, in this order:

1. ng-mousedown
2. ng-mouseup
3. ng-click

You can add mouse events on any HTML element.

<div ng-app="myApp" ng-controller="myCtrl">

<h1 ng-mousemove="count = count + 1">Mouse over me!</h1>

<h2>{{ count }}</h2>

</div>
<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
    $scope.count = 0;
});
</script>

The ng-click Directive

The ng-click directive defines AngularJS code that will be executed when the element is being clicked.

<div ng-app="myApp" ng-controller="myCtrl">

<button ng-click="count = count + 1">Click me!</button>

<p>{{ count }}</p>

</div>
<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
    $scope.count = 0;
});
</script>

<div ng-app="myApp" ng-controller="myCtrl">

<button ng-click="myFunction()">Click me!</button>

<p>{{ count }}</p>

</div>
<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
    $scope.count = 0;
    $scope.myFunction = function() {
        $scope.count++;
    }
});
</script>

Toggle, True/False

If you want to show a section of HTML code when a button is clicked, and hide when the button is clicked again, like a dropdown menu, make the button behave like a toggle switch:

<div ng-app="myApp" ng-controller="myCtrl">

<button ng-click="myFunc()">Click Me!</button>

<div ng-show="showMe">
    <h1>Menu:</h1>
    <div>Pizza</div>
    <div>Pasta</div>
    <div>Pesce</div>
</div>

</div>
<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
    $scope.showMe = false;
    $scope.myFunc = function() {
        $scope.showMe = !$scope.showMe;
    }
});
</script>