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问题:

I have an app which I am building with angular, I have about 8-10 views to build out. All the views have a shared footer, based on the view and a set of business rules i need to conditionally show / hide some of the content on the footer.

So. I have controllers for each view, and then one for the footer. I include the common footer layout using ng-include, where the html I am including references the footer controller in the ng-controller.

Index.html

<body ng-controller="MainCtrl as vm">
    <p>Message from Main Controller '{{vm.mainMessage}}'</p>
    <div ng-include="'commonFooter.html'"></div>
</body>

commonFooter.html

<div ng-controller="FooterCtrl as vm">
    <p>Message from Footer Controller '{{vm.message}}'</p>
    <p ng-show="vm.showSomthing">Conditional footer Content</p>
</div>

I want each views controller to determine the state of the footer and whether specific content is hidden or not. (shouldDisplaySomthingInFooter below)

app.controller('MainCtrl', function($scope) {
  var vm = this;
  vm.mainMessage= 'HEELO';
  vm.shouldDisplaySomthingInFooter = true;
  window.console.log('Main scope id: ' + $scope.$id);
});

Then i had intended that in the FooterController would reach back into the parent controller and pull out the specific settings to enable / disable content based on the business rules.

app.controller('FooterCtrl', function($scope) {
    var vm = this;
  vm.message = 'vm footer';

  window.console.log('Footer scope id: ' + $scope.$id);
  window.console.log('Footer parent scope id: ' + $scope.$parent.$id);
  window.console.log('Footer grandparent scope id: ' + $scope.$parent.$parent.$id);
  window.console.log('Footer grandparent scope name: ' + $scope.$parent.$parent.mainMessage);
  window.console.log('Footer grandparent scope condition: ' + $scope.$parent.$parent.shouldDisplaySomthingInFooter);

  vm.showSomthing = false; //how to pull from parent scope to bind the ng-show to a value set in the parent from within a ng-include?
});

I have this example here: http://plnkr.co/edit/ucI5Cu4jjPgZNUitY2w0?p=preview

What I am finding is that I when I reach into the parent scope to pull out the content it is coming back as undefined, and I am not sure why.

I can see that the scopes are nested to the grandparent level by checking the scopeid, I believe this is because the ng-include adds an extra scope layer below the view scopes.

Extra points: If i can not have to use the $scope object and can stick with the var vm = this; way of doing it that would be preferable. But beggars cant be choosers :)

app.controller('MainCtrl', function($scope) {
  var vm = this;

Thank you very much in advance.

回答1:

If you scope your outside controller as vm and your inside controller as foo, you can then separate them easily and refer to vm within the inside controller.

Demo

HTML:

<body ng-controller="MainCtrl as vm">
    <p>Message from Main Controller '{{vm.mainMessage}}'</p>
    <div ng-include="'commonFooter.html'"></div>
</body>

CommonFooter.html:

<div ng-controller="FooterCtrl as footer">
    <p>Message from Footer Controller '{{footer.message}}'</p>
    <p ng-show="vm.shouldDisplaySomethingInFooter">Conditional footer Content</p>
</div>

app.js:

var app = angular.module('plunker', []);

app.controller('MainCtrl', function() {
    var self = this;
    self.mainMessage = 'Hello world';
    self.shouldDisplaySomethingInFooter = true;
});

app.controller('FooterCtrl', function() {
    var self = this;
    self.message = 'vm footer';
});

Note: I renamed your var vm = this to var self = this for clarity and to reduce confusion between your views and your controllers.

Expected output:

回答2:

You've misunderstood what the controller as syntax (see documentation) is used for. It is just a way to expose a particular controller on your local scope, so that you can access its properties from a template. When you use someController as vm in both your parent and footer templates, you don't somehow create a connection between the controllers or anything like that. You're just setting a vm property on your footer's scope, so when you use it in your footer template, you're accessing the footer's controller (and you've blocked your way to the parent controller).

For what you're trying to do, you basically don't need the controller as syntax at all. Just properly put your data on $scope and let the scope hierarchy do the rest for you.

In your parent controller:

$scope.features.rock = true;
$scope.features.roll = false;

In your footer template

<p ng-show="features.rock">...</p>
<p ng-show="features.roll">...</p>

You can now also see and change the features from your other controllers (as their scopes are descendants of parent controller's scope).

回答3:

I fiddled around with your plunker, but also changed var vm = this; to $scope, so I'm failing at extra points :-)

I would strongly advise against the usage of $scope.$parent exactly for the reason you show. Various directives such as ng-include, ng-show etc, generate their own scopes.

You have no control if someone in the future changes your html and adds scopes, intentionally or otherwise.

I recommend using functions that reside on your MainCtrl and accessing them via inheriting scopes.

Plunker

$scope.getShouldShow = function() {
    return $scope.shouldDisplaySomthingInFooter;
  };
  $scope.setShouldShow = function(val) {
    $scope.shouldDisplaySomthingInFooter = val;
  };

  $scope.getMainMessage = function () {
    return $scope.mainMessage;
  }

And calling them:

<p ng-show="getShouldShow();">Conditional footer Content</p>

And:

  window.console.log('Footer grandparent scope name: ' + $scope.getMainMessage());
  window.console.log('Footer grandparent scope condition: ' + $scope.getShouldShow());