AngularJS 自定义指令
在 AngularJS 中使用自定义指令来扩展 HTML 的功能。自定义指令是使用"指令"函数定义的。自定义指令只是替换为其激活的元素。 AngularJS 应用程序在引导期间找到匹配的元素并使用自定义指令的 compile() 方法执行一次活动，然后根据指令的范围使用自定义指令的 link() 方法处理元素。 AngularJS 支持为以下类型的元素创建自定义指令。
Element directives-当遇到匹配元素时激活指令。
Attribute-当遇到匹配的属性时激活指令。
CSS-当遇到匹配的 css 样式时激活指令。
Comment-当遇到匹配的评论时激活指令。
了解自定义指令
定义自定义 html 标签。
<student name = "Mahesh"></student><br/>
<student name = "Piyush"></student>
定义自定义指令来处理上面的自定义 html 标签。
var mainApp = angular.module("mainApp", []);
//Create a directive, first parameter is the html element to be attached.
//We are attaching student html tag.
//this directive will be activated as soon as any student element is encountered in html
mainApp.directive('student', function() {
//define the directive object
var directive = {};
//restrict = E, signifies that directive is Element directive
directive.restrict = 'E';
//template replaces the complete element with its text.
directive.template = "Student: <b>{{student.name}}</b> ,
Roll No: <b>{{student.rollno}}</b>";
//scope is used to distinguish each student element based on criteria.
directive.scope = {
student : "=name"
}
//compile is called during application initialization. AngularJS calls
it once when html page is loaded.
directive.compile = function(element, attributes) {
element.css("border", "1px solid #cccccc");
//linkFunction is linked with each element with scope to get the element specific data.
var linkFunction = function($scope, element, attributes) {
element.html("Student: <b>"+$scope.student.name +"</b> ,
Roll No: <b>"+$scope.student.rollno+"</b><br/>");
element.css("background-color", "#ff00ff");
}
return linkFunction;
}
return directive;
});
定义控制器以更新指令的范围。这里我们使用 name 属性的值作为作用域的子级。
mainApp.controller('StudentController', function($scope) {
$scope.Mahesh = {};
$scope.Mahesh.name = "Mahesh Parashar";
$scope.Mahesh.rollno = 1;
$scope.Piyush = {};
$scope.Piyush.name = "Piyush Parashar";
$scope.Piyush.rollno = 2;
});
示例
<html>
<head>
<title>Angular JS Custom Directives</title>
</head>
<body>
<h2>AngularJS Sample Application</h2>
<div ng-app = "mainApp" ng-controller = "StudentController">
<student name = "Mahesh"></student><br/>
<student name = "Piyush"></student>
</div>
<script src = "https://ajax.googleapis.com/ajax/libs/angularjs/1.3.14/angular.min.js">
</script>
<script>
var mainApp = angular.module("mainApp", []);
mainApp.directive('student', function() {
var directive = {};
directive.restrict = 'E';
directive.template = "Student: <b>{{student.name}}</b> ,
Roll No: <b>{{student.rollno}}</b>";
directive.scope = {
student : "=name"
}
directive.compile = function(element, attributes) {
element.css("border", "1px solid #cccccc");
var linkFunction = function($scope, element, attributes) {
element.html("Student: <b>"+$scope.student.name +"</b> ,
Roll No: <b>"+$scope.student.rollno+"</b><br/>");
element.css("background-color", "#ff00ff");
}
return linkFunction;
}
return directive;
});
mainApp.controller('StudentController', function($scope) {
$scope.Mahesh = {};
$scope.Mahesh.name = "Mahesh Parashar";
$scope.Mahesh.rollno = 1;
$scope.Piyush = {};
$scope.Piyush.name = "Piyush Parashar";
$scope.Piyush.rollno = 2;
});
</script>
</body>
</html>
