所以这是我的指示
directives.directive('postprocess',function($compile)
{
return {
restrict : 'E',require: '^ngModel',scope: {
ngModel: '='
},link: function(scope,element,attrs) {
var parsed = scope.ngModel;
el = $compile(parsed)(scope);
element.html("");
//add some other html entities/styles.
element.append(el);
console.log(parsed);
}
};
});
的html
<postprocess ng-model="some_model.its_property" style="padding-top: 10px;" />
在控制器的某处,我更新模型属性
some_model.its_property = 'Holla';
但是它不会更新相应的指令.它在加载时工作得很好,告诉我可能不是完全是一个范围问题.
<!doctype html>
<html lang="en" ng-app="myApp">
<head>
<Meta charset="UTF-8">
<title>Document</title>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.8/angular.min.js"></script>
<script>
var myApp = angular.module('myApp',[]);
myApp.directive('postprocess',function ($timeout) {
return {
restrict : 'E',transclude: 'true',scope: {
myVariable: '='
},attrs) {
$timeout(function () {
scope.myVariable = 'Bye bye!'
},200);
}
};
});
myApp.controller('myAppCtrl',['$scope','$timeout',function ($scope,$timeout) {
$scope.myVariable = {
value : 'Holla'
};
console.log($scope.myVariable.value); // -> prints initial value
$timeout(function () {
console.log($scope.myVariable.value); // -> prints value after it is changed by the directive
},2000);
}])
</script>
</head>
<body ng-controller="myAppCtrl">
<postprocess my-variable="myVariable.value" style="padding-top: 10px;" />
</body>
</html>
>控制器将初始值设置为“Holla”
>该指令通过my-variable属性接收该值
>使用双向数据绑定对scope.myVariable所做的任何更改更新主控制器的$scope.myVariable
>几秒钟之后$scope.myVariable更改为“再见”
看看你的console.log
$watch和$apply
Angular’s two-way data binding is the root of all awesome in Angular. However,it’s not magic,and there are some situations where you need to give it a nudge in the right direction.
When you bind a value to an element in Angular using ng-model,ng-repeat,etc.,Angular creates a $watch on that value. Then whenever a value on a scope changes,all $watches observing that element are executed,and everything updates.
Sometimes,usually when you’re writing a custom directive,you will have to define your own $watch on a scope value to make the directive react to changes.
On the flip side,sometimes you change a scope value in some code but the app doesn’t react to it. Angular checks for scope variable changes after pieces of your code have finished running; for example,when ng-click calls a function on your scope,Angular will check for changes and react. However,some code is outside of Angular and you’ll have to call scope.$apply() yourself to trigger the update. This is most commonly seen in event handlers in custom directives.
