自定义指令
angularjs中有很多内置指令，一般都是以ng开头的；比如：ng-app,ng-click,ng-repeat等等。本文介绍angularjs的自定义指令的用法。
指令的定义
首先在html标签处设置ng-app的属性值，然后在js文件中就可以调用angular.module得到一个module，最后就可以用module.directive定义一个指令。代码如下：
html文件
<!DOCTYPE html>
<html ng-app="directive">
<head lang="en">
<meta charset="UTF-8">
<title>directive</title>
<script src="../bower_components/angular/angular.min.js"></script>
<script src="./directive.js"></script>
</head>
<body>
<div my-directive></div>
</body>
</html>js文件
var app = angular.module('directive',[]);
app.directive('myDirective',function(){
return {
restrict:"A",
require:true,
template:"<span>hello angular</span>",
};
});这个例子只使用了directive的最简单的参数配置，下面是一个详细的参数配置列表
app.directive('myDirective', function factory(injectables) {
return {
restrict: string,//指令的使用方式，包括标签，属性，类，注释
priority: number,//指令执行的优先级
template: string,//指令使用的模板，用HTML字符串的形式表示
templateUrl: string,//从指定的url地址加载模板
replace: bool,//是否用模板替换当前元素，若为false，则append在当前元素上
transclude: bool,//是否将当前元素的内容转移到模板中
scope: bool or object,//指定指令的作用域
controller: function controllerConstructor($scope, $element, $attrs, $transclude){...},//定义与其他指令进行交互的接口函数
require: string,//指定需要依赖的其他指令
link: function postLink(scope, iElement, iAttrs) {...},//以编程的方式操作DOM，包括添加监听器等
compile: function compile(tElement, tAttrs, transclude){
return: {
pre: function preLink(scope, iElement, iAttrs, controller){...},
post: function postLink(scope, iElement, iAttrs, controller){...}
}
}
};
});下面介绍几个常用的参数
restrict
四个值”A”,”E”,”C”,”M”，分别代码属性，标签，类，注释，如下：
restrict:"A" <div my-directive></div>
restrict:"E" <my-directive></my-directive>
restrict:"C" <div class="my-diretive"></div>
restrict:"M" <!--directive:my-directive-->只测试了A和E的值，感兴趣的朋友可以测试一下其他。
template 和 templateUrl
这两个参数只需要设置一个就行。
transclude
该参数的意思是替换指令的内容，更改上面的例子。html更改部分
<div my-directive>hello angular</div>js更改部分
app.directive('myDirective',function(){
return {
restrict:"A",
require:true,
transclude:true,//增加transclude参数的设置
template:"<div><span ng-transclude></span></div>",//将指令的内容替换到span标签下
};
});scope
false 默认值。使用父作用域作为自己的作用域
true 新建一个作用域，该作用域继承父作用域
javascript对象 当scope为javascript对象时，键值对的形式定义。直接看例子吧！
html：
<!DOCTYPE html>
<html ng-app="directive">
<head lang="en">
<meta charset="UTF-8">
<title>directive</title>
<script src="../bower_components/angular/angular.min.js"></script>
<script src="./directive.js"></script>
</head>
<body>
<div ng-controller="directive">
<div my-directive etitle="title">{{text}}</div>
</div>
</body>
</html>js:
var app = angular.module('directive',[]);
app.directive('myDirective',function(){
return {
restrict:'A',
template:'<div><span style="background-color:red;">{{mytitle}}</span><div ng-transclude></div></div>',
require:true,
replace:true,
transclude:true,
//将etitle属性绑定到父控制器的scope域中
scope:{
mytitle:'=etitle'
},
}
});
app.controller('directive',function($scope){
$scope.title = "学习";
$scope.text = "angular js概念多";
});link
link的值是一个function，一般用在在dom上绑定动作的。请看下面实现的一个折叠面板的例子。
<!DOCTYPE html>
<html ng-app="directive">
<head lang="en">
<meta charset="UTF-8">
<title>directive</title>
<script src="../bower_components/angular/angular.min.js"></script>
<script src="./directive.js"></script>
</head>
<body>
<div ng-controller="directive">
<expander etitle="title">{{text}}</expander>
</div>
</body>
</html>var app = angular.module('directive',[]);
app.directive('expander',function(){
return {
restrict:'E',
template:'<div><span style="background-color:red;" ng-click="toggleText()">{{mytitle}}</span><div ng-transclude ng-show="showText"></div></div>',
require:true,
replace:true,
transclude:true,
//将etitle属性绑定到父控制器的scope域中
scope:{
mytitle:'=etitle'
},
link: function(scope,element,attr,accordionCtrl){
scope.showText = false;
scope.toggleText = function(){
scope.showText = ! scope.showText;
}
}
}
});
app.controller('directive',function($scope){
$scope.title = "angular 学习";
$scope.text = "angular js概念多";
});expander指令中的link参数中增加了showText的值和toggleText的点击函数。
最后，再看一个多个折叠面板的例子
<!DOCTYPE html>
<html ng-app="directive">
<head lang="en">
<meta charset="UTF-8">
<title>directive</title>
<script src="../bower_components/angular/angular.min.js"></script>
<script src="./directive.js"></script>
</head>
<body>
<div ng-controller="directive">
<accordion>
<expander ng-repeat="expander in expanders" etitle="expander.title">{{expander.text}}</expander>
</accordion>
</div>
</body>
</html>ng-repeat便利expanders的所有元素
var app = angular.module('directive',[]);
app.directive('expander',function(){
return {
restrict:'E',
template:'<div><span style="background-color:red;" ng-click="toggleText()">{{mytitle}}</span><div ng-transclude ng-show="showText"></div></div>',
require:'^?accordion',
replace:true,
transclude:true,
//将etitle属性绑定到父控制器的scope域中
scope:{
mytitle:'=etitle'
},
link: function(scope,element,attr,accordionCtrl){
scope.showText = false;
accordionCtrl.addExpander(scope);
scope.toggleText = function(){
scope.showText = ! scope.showText;
accordionCtrl.getOpened(scope);
}
}
}
});
app.controller('directive',function($scope){
$scope.expanders = [
{title:"angular",text:"angular js概念多"},
{title:"react",text:"react + reduce + ui路由机制"}
];
});
app.directive('accordion',function(){
return {
restrict:"E",
template:'<div ng-transclude></div>',
replace:true,
transclude:true,
controller:function(){
var expanders = [];
this.getOpened = function(selectExpander){
angular.forEach(expanders,function(e){
if (selectExpander != e){
e.showText = false;
}
});
}
this.addExpander = function(e){
expanders.push(e);
}
}
}
});