指令使$ scope。$ watch发射两次？
[英]Directive making $scope.$watch fire twice?
问题描述
I have the following $watch statement: 
我有以下$watch语句：
$scope.$watch('text', function () {
$scope.obj = new Obj(text);
$scope.obj.next();
});
$scope.text is the ng-model of the following input: $scope.text是以下输入的ng-model ：
<input id="text" type="text" ng-model="text" name="text"/>
This works fine. 这很好。 However, when I abstract out the above input box along with some other HTML into a directive, the $scope.$watch chunk begins firing twice upon changes in $scope.text . 但是，当我将上面的输入框以及其他一些HTML抽象到指令中时， $scope.$watch块在$scope.text更改时开始触发两次。 Here is the directive I am abstracting out into: 这是我要抽象为的指令：
myApp.directive('objDirective', function() {
return {
restrict: 'E',
transclude: true,
scope: myApp.$scope,
controller: 'objController',
template: '<form name="textform" id="textform">' +
'<input id="text" type="text" ng-model="text"' +
'name="text"/></form>',
replace: true
};
});
In short: $watch properly fires once when input box changes, but when input box is placed into a directive, it fires twice. 简而言之： $watch在输入框更改时会正确触发一次，但是在将输入框放入指令中时，它将触发两次。 Why is this? 为什么是这样？
2 个解决方案
解决方案1
1 2015-04-04 14:52:50
The $watch does not fire twice in this Plunker 该$ watch在此Plunker中不会触发两次
JS JS
app = angular.module("app", []);
app.directive("test", [ function() {
return {
restrict: "E",
transclude: true,
template: '<form name="textform" id="textform">' +
'<input id="text" type="text" ng-model="text"' +
'name="text"/></form>',
replace: true,
scope: app.$scope,
controller: ["$scope", function($scope) {
$scope.$watch("text", function(newValue) {
if (angular.isDefined(newValue)) {
console.log(newValue);
}
});
}]
};
}]);
Markup 标记
<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.3.15/angular.min.js"></script>
<link rel="stylesheet" href="style.css">
<script src="script.js"></script>
</head>
<body ng-app="app">
<test></test>
</body>
</html>
解决方案2
1 已采纳 2015-04-04 15:29:28
Solved: 解决了：
The problem was simply that I was defining both the controller in the HTML and in the directive. 问题很简单，就是我在HTML和指令中都定义了控制器。
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