Directive间的通信

这个例子主要的难点在于如何在子Expander里面访问外层Accordion的scope中的数据

注释解读一下

JS代码：

var expModule=angular.module('expanderModule',[])
expModule.directive('accordion', function() {
    return {
        restrict : 'EA',
        replace : true,
        //这里没有定义scope，将使用元素上的scope，就是下面ng-controller指定的SomeController的scope
        transclude : true,
        template : '<div ng-transclude></div>',
        controller : function() {
            var expanders = [];
            this.gotOpened = function(selectedExpander) {
                angular.forEach(expanders, function(expander) {
                    if (selectedExpander != expander) {
                        expander.showMe = false;
                    }
                });
            }
            this.addExpander = function(expander) {
                expanders.push(expander);
            }
        }
    }
});
expModule.directive('expander', function() {
    return {
        restrict : 'EA',
        replace : true,
        transclude : true,
        require : '^?accordion', //依赖
        scope : {
            title : '=expanderTitle'
        },
        template : '<div>'
                   + '<div class="title" ng-click="toggle()">{{title}}</div>'
                   + '<div class="body" ng-show="showMe" ng-transclude></div>'
                   + '</div>',
        link : function(scope, element, attrs, accordionController) {
            //注意link的第四个参数
            scope.showMe = false;
            accordionController.addExpander(scope);//调用外层指令的方法
            scope.toggle = function toggle() {
                scope.showMe = !scope.showMe;
                accordionController.gotOpened(scope);//调用外层指令的方法
            }
        }
    }
});
expModule.controller("SomeController",function($scope) {
    $scope.expanders = [{
        title : 'Click me to expand',
        text : 'Hi there folks, I am the content that was hidden but is now shown.'
    }, {
        title : 'Click this',
        text : 'I am even better text than you have seen previously'
    }, {
        title : 'Test',
        text : 'test'
    }];
});

HTML代码：

<html ng-app="expanderModule">
    <head>
        <meta http-equiv="content-type" content="text/html; charset=utf-8" />
        <script src="../angular-1.0.3/angular.min.js"></script>
        <link rel="stylesheet" type="text/css" href="Accordion.css"/>
    </head>
    <body ng-controller='SomeController' >
        <accordion>
            <expander class='expander' ng-repeat='expander in expanders' expander-title='expander.title'>
                {{expander.text}}
            </expander>
        </accordion>
    </body>
    <script src="Accordion.js"></script>
</html>

CSS代码：

.expander {
    border: 1px solid black;
    width: 250px;
}
.expander>.title {
    background-color: black;
    color: white;
    padding: .1em .3em;
    cursor: pointer;
}
.expander>.body {
    padding: .1em .3em;
}

运行效果：

require option

看看官网的原文怎么说

The myPane directive has a require option with value ^^myTabs. When a directive uses this option, $compile will throw an error unless the specified controller is found.
.The ^^ prefix means that this directive searches for the controller on its parents.
.The ^ prefix would make the directive look for the controller on its own element or its parents;
.without any prefix, the directive would look on its own element only.
.The ? prefix, if not found then pass null to the link as the fourth parameter

link函数的参数

Creating a Directive that Manipulates the DOM

link takes a function with the following signature, function link(scope, element, attrs, controller, transcludeFn) { ... }, where:

. scope is an Angular scope object.

. element is the jqLite-wrapped element that this directive matches.

. attrs is a hash object with key-value pairs of normalized attribute names and their corresponding attribute values.

. controller is the directive's required controller instance(s) or its own controller (if any). The exact value depends on the directive's require property.

. transcludeFn is a transclude linking function pre-bound to the correct transclusion scope.