我已经看过这个video并且我有一个问题，我无法找到答案。有一个标题http://plnkr.co/edit/L8OMoB?p=preview
HTML
<div ng-app="app">
<div ng-controller="MyCtrl">
<my-select-view on="color">
<my-view label="Red" value="red"><span class="red-text">Red Content</span></my-view>
<my-view label="Blue" value="blue"><span class="blue-text">Blue Content</span></my-view>
<my-view label="Green" value="green"><span class="green-text">Green Content</span></my-view>
<my-view label="Something" value="something"><span class="something-text">Something Content</span></my-view>
</my-select-view>
</div>
</div>
JS
angular.module('app', ['ngSanitize'])
.directive("mySelectView", function($compile) {
return {
restrict: "E",
scope: { item : "=on"},
controller: function($scope, $element) {
$scope.views = [];
this.addView = function(label, value, content) {
$scope.views.push({ label: label, value: value, content: content });
}
},
link: function(scope, element, attrs, ctrl) {
var selectTpl = "<select ng-model='item'" +
" ng-options='view.value as view.label for view in views'" +
" ng-change='changeView()'></select>";
...
}
}
})
.directive("myView", function() {
return {
restrict: "E",
require: "^mySelectView",
link: function(scope, element, attrs, ctrl) {
ctrl.addView(attrs.label, attrs.value, element.html());
}
};
})
.controller("MyCtrl", function($scope) {
$scope.color = "something";
});
我想知道一件事。我们得到了指令＆＃34; mySelectView＆＃34;，其中包含＆＃34; link＆＃34;功能。这个＆＃34;链接＆＃34;功能取决于＆＃34;观点＆＃34;要定义的变量并包含某些内容。
获得它的唯一方法是通过调用＆＃34;链接＆＃34;在其他指令＆＃34; myView＆＃34;上运行。该指令对previous指令有一个require参数。
所以我的问题是：＆＃34;链接＆＃34;指令功能＆＃34; mySelectView＆＃34;在＆＃34; link＆＃34;之后执行指令的功能＆＃34; myView＆＃34;。我假设这是因为＆＃34; ng-option＆＃34;需要$ scope.views的属性才能正确显示内容。这意味着＆＃34; myView＆＃34;的链接功能获得执行并添加视图。
但是怎么样？谁决定这个订单？为什么＆＃34;链接＆＃34;由于未定义的$ scope.views，第一个指令的功能不高兴失败？任何帮助将不胜感激！