AngularJS自定义指令

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：