详解AngularJS中自定义指令的使用

作者：bea

自定义指令中使用AngularJS扩展HTML的功能。自定义指令使用的“指令”的功能定义。自定义指令只是替换了它被激活的元素。引导过程中AngularJS应用程序找到了匹配的元素，并做好使用自定义指令compile()方法一次活动再处理使用基于指令的范围自定义指令link()方法的元素。 AngularJS提供支持，以下列元素的类型来创建自定义指令。

    Element directives - 指令遇到时激活一个匹配的元素。
    Attribute - - 指令遇到时激活一个匹配的属性。
    CSS - - 指令遇到时激活匹配CSS样式。
    Comment - - 指令遇到时激活匹配的注释。

了解自定义指令
定义自定义的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;
});

定义控制器以更新范围为指令。在这里，我们使用name属性值作为子的作用域。

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;
});

例子

<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="http://ajax.googleapis.com/ajax/libs/angularjs/1.2.15/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>

结果
在Web浏览器中打开textAngularJS.html。看到结果如下：

有用 | 无用

详解AngularJS中自定义指令的使用

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