how to access parent component scope from a child components scope in ember?

Question

I'm curious if this is even possible in ember. This is an easy thing to do in angular ( plunkr: http://plnkr.co/edit/O2e0ukyXdKMs4FcgKGmX?p=preview ):

The goal is to make an easy to use, generic, reusable accordion api for api consumers.

The api I want the caller to be able to use is this (just like the angular api):

{{#ember-accordion listOfAccordionPaneObjects=model}}

  {{#ember-accordion-heading}}
     heading template html {{accordionPaneObject.firstName}}
  {{/ember-accordion-heading}}

  {{#ember-accordion-body}}
     this is the accordion body  {{accordionPaneObject.lastName}}
  {{/ember-accordion-body}}

{{/ember-accordion}}

Here is a working example I wrote using angular:

<!doctype html>
<html ng-app="angular-accordion">
<head>
    <style>
        .angular-accordion-header {
            background-color: #999;
            color: #ffffff;
            padding: 10px;
            margin: 0;
            line-height: 14px;
            -webkit-border-top-left-radius: 5px;
            -webkit-border-top-right-radius: 5px;
            -moz-border-radius-topleft: 5px;
            -moz-border-radius-topright: 5px;
            border-top-left-radius: 5px;
            border-top-right-radius: 5px;
            cursor: pointer;
            text-decoration: none;
            font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
            font-size: 14px;
        }

        .angular-accordion-container {
            height: 100%;
            width: 100%;
        }

        .angular-accordion-pane {
            padding: 2px;
        }

        .angularaccordionheaderselected {
            background-color: #bbb;
            color: #333;
            font-weight: bold;
        }

        .angular-accordion-header:hover {
            text-decoration: underline !important;
        }

        .angularaccordionheaderselected:hover {
            text-decoration: underline !important;
        }

        .angular-accordion-pane-content {
            padding: 5px;
            overflow-y: auto;
            border-left: 1px solid #bbb;
            border-right: 1px solid #bbb;
            border-bottom: 1px solid #bbb;
            -webkit-border-bottom-left-radius: 5px;
            -webkit-border-bottom-right-radius: 5px;
            -moz-border-radius-bottomleft: 5px;
            -moz-border-radius-bottomright: 5px;
            border-bottom-left-radius: 5px;
            border-bottom-right-radius: 5px;
        }

        .angulardisabledpane {
            opacity: .2;
        }
    </style>
</head>
<body style="margin: 0;">


<div style="height: 90%; width: 100%; margin: 0;" ng-controller="outerController">

    <angular-accordion list-of-accordion-pane-objects="outerControllerData">
        <pane>
            <pane-header>Header {{accordionPaneObject}}</pane-header>
            <pane-content>Content {{accordionPaneObject}}</pane-content>
        </pane>
    </angular-accordion>

</div>

    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.1/angular.js"></script>
    <script>
        angular.module('angular-accordion', [])
                .directive('angularAccordion', function() {
                    var template = '';

                    return {
                        restrict: 'E',
                        transclude: true,
                        replace: true,
                        template: '<div>' +
                                        '<div ng-transclude class="angular-accordion-container" ng-repeat="accordionPaneObject in listOfAccordionPaneObjects"></div>' +
                                  '</div>',
                        controller: ['$scope', function($scope) {
                            var panes = [];

                            this.addPane = function(pane) {
                                panes.push(pane);
                            };
                        }],
                        scope: {
                            listOfAccordionPaneObjects: '='
                        }
                    };
                })
                .directive('pane', function() {
                    return {
                        restrict: 'E',
                        transclude: true,
                        replace: true,
                        template: '<div ng-transclude class="angular-accordion-pane"></div>'
                    };
                })
                .directive('paneHeader', function() {
                    return {
                        restrict: 'E',
                        require: '^angularAccordion',
                        transclude: true,
                        replace: true,
                        link: function(scope, iElement, iAttrs, controller) {
                            controller.addPane(scope);

                            scope.toggle = function() {
                                scope.expanded = !scope.expanded;
                            };
                        },
                        template: '<div ng-transclude class="angular-accordion-header" ng-click="toggle()"></div>'
                    };
                })
                .directive('paneContent', function() {
                    return {
                        restrict: 'EA',
                        require: '^paneHeader',
                        transclude: true,
                        replace: true,
                        template: '<div ng-transclude class="angular-accordion-pane-content" ng-show="expanded"></div>'
                    };
                })
                .controller('outerController', ['$scope', function($scope) {
                    $scope.outerControllerData = [1, 2, 3];
                }]);
    </script>
</body>
</html>

here's where I'm stuck doing the same with ember:

index.html

<!DOCTYPE html>
<html>
    <body>
        <script src="//cdnjs.cloudflare.com/ajax/libs/require.js/2.1.9/require.js" data-main="main.js"></script>
    </body>
</html>

main.js

require.config({
    paths: {
        'ember': 'bower_components/ember/ember',
        'handlebars': 'bower_components/handlebars/handlebars',
        'jquery': 'bower_components/jquery/jquery',
        'text': 'bower_components/requirejs-text/text'
    },
    shim: {
        ember: {
            deps: ['jquery', 'handlebars'],
            exports: 'Ember'
        }
    }
});

define(function(require) {
    var Ember = require('ember'),
        EmberAccordionComponent = require('src/EmberAccordionComponent'),
        EmberAccordionTemplate = require('text!templates/ember-accordion.hbs'),
        EmberAccordionHeaderTemplate = require('text!templates/ember-accordion-header.hbs'),
        EmberAccordionBodyTemplate = require('text!templates/ember-accordion-body.hbs'),
        ApplicationTemplate = require('text!templates/application.hbs'),
        IndexTemplate = require('text!templates/index.hbs');

    var App = Ember.Application.create({
        LOG_STACKTRACE_ON_DEPRECATION : true,
        LOG_BINDINGS                  : true,
        LOG_TRANSITIONS               : true,
        LOG_TRANSITIONS_INTERNAL      : true,
        LOG_VIEW_LOOKUPS              : true,
        LOG_ACTIVE_GENERATION         : true
    });

    Ember.TEMPLATES = {};
    Ember.TEMPLATES['application'] = Ember.Handlebars.compile(ApplicationTemplate);
    Ember.TEMPLATES['index'] = Ember.Handlebars.compile(IndexTemplate);
    Ember.TEMPLATES['components/ember-accordion'] = Ember.Handlebars.compile(EmberAccordionTemplate);
    Ember.TEMPLATES['components/ember-accordion-header'] = Ember.Handlebars.compile(EmberAccordionHeaderTemplate);
    Ember.TEMPLATES['components/ember-accordion-body'] = Ember.Handlebars.compile(EmberAccordionBodyTemplate);

    App.EmberAccordionComponent = EmberAccordionComponent;

    App.IndexRoute = Ember.Route.extend({
        model: function() {
            return [
                {
                    name: 'Bob'
                },
                {
                    name: 'Jill'
                }]
        }
    })
});

EmberAccordionComponent.js

define(function(require) {
    require('ember');

    var EmberAccordionComponent = Ember.Component.extend({});

    return EmberAccordionComponent;
});

application.hbs

{{outlet}}

ember-accordion-header.hbs

<div style="color: blue;">
    {{yield}}
</div>

ember-accordion-body.hbs

<div style="color: green;">
    {{yield}}
</div>

index.hbs

{{#ember-accordion listOfAccordionPaneObjects=model}}
    {{#ember-accordion-header}}
        {{log this.constructor}}
        {{log this}}
        Header {{accordionPaneObject.name}}
    {{/ember-accordion-header}}
    {{#ember-accordion-body}}
        Body {{accordionPaneObject.name}}
    {{/ember-accordion-body}}
{{/ember-accordion}}

ember-accordion.hbs

{{#each accordionPaneObject in listOfAccordionPaneObjects}}
    {{yield}}
{{/each}}

--

This is tricky to debug. So putting in the:

{{log this.constructor}}

and the:

{{log this}}

into the:

{{#ember-accordion-header}}

outputs the following:

Class.model = undefined (why?)
Ember.ArrayController

I've tried overriding the private _yield method of Ember.Component as suggested by this article ( http://www.thesoftwaresimpleton.com/blog/2013/11/21/component-block/ ):

var EmberAccordionHeaderComponent = Ember.Component.extend({
    _yield: function(context, options) {
        var get = Ember.get,
            view = options.data.view,
            parentView = this._parentView,
            template = get(this, 'template');

        if (template) {
            Ember.assert("A Component must have a parent view in order to yield.", parentView);
            view.appendChild(Ember.View, {
                isVirtual: true,
                tagName: '',
                _contextView: parentView,
                template: template,
                context: get(view, 'context'), // the default is get(parentView, 'context'),
                controller: get(view, 'controller'), // the default is get(parentView, 'context'),
                templateData: { keywords: parentView.cloneKeywords() }
            });
        }
    }
});

but when I do this I still don't have access to accordionPaneObject in my child component scope, and my {{log this.constructor}} now points to: .EmberAccordionHeaderComponent

So it looks like I'm getting somewhere, I just need to go one more level up.

When I try that using this code in EmberAccordionHeaderComponent.js:

var EmberAccordionHeaderComponent = Ember.Component.extend({
    _yield: function(context, options) {
        var get = Ember.get,
            view = options.data.view,
            parentView = this._parentView,
            grandParentView = this._parentView._parentView,
            template = get(this, 'template');

        if (template) {
            Ember.assert("A Component must have a parent view in order to yield.", parentView);
            view.appendChild(Ember.View, {
                isVirtual: true,
                tagName: '',
                _contextView: parentView,
                template: template,
                context: get(grandParentView, 'context'), // the default is get(parentView, 'context'),
                controller: get(grandParentView, 'controller'), // the default is get(parentView, 'context'),
                templateData: { keywords: parentView.cloneKeywords() }
            });
        }
    }
});

I still don't access to accordionPaneObject in, but now I see {{log this.constructor}} outputting .EmberAccordionComponent. So it appears I'm in the right scope, but the data still doesn't bind.

Interestingly enough, if I use any of these variations of reassigning context and controller in my overridden _yield, I can access the data I am after in the console using:

this._parentView._context.content

score 7 · Accepted Answer · answered Nov 24 '13 at 17:26

I updated your code with some comments please give a look http://emberjs.jsbin.com/ivOyiZa/1/edit.

Javascript

App = Ember.Application.create();

App.IndexRoute = Ember.Route.extend({
  model: function() {
    return [
      { head: "foo head", body: "foo body " },
      { head: "bar head", body: "bar body " },
      { head: "ya head", body: "yo body " }
    ];
  }
});

App.EmberAccordionComponent = Ember.Component.extend({
  // each accordion header/body item, will have a instance of that view.
  // so we can isolate the expanded state for each accordion header/body
  emberAccordionItemView: Ember.View.extend({    
    expanded: false
  }),
  _yield: function(context, options) {
    var get = Ember.get, 
    view = options.data.view,
    parentView = this._parentView,
    template = get(this, 'template');

    if (template) {
      Ember.assert("A Component must have a parent view in order to yield.", parentView);      
      view.appendChild(Ember.View, {
        isVirtual: true,
        tagName: '',
        _contextView: parentView,
        template: template,
        context: get(view, 'context'), // the default is get(parentView, 'context'),
        controller: get(view, 'controller'), // the default is get(parentView, 'context'),
        templateData: { keywords: parentView.cloneKeywords() }
      });
    }
  }
});

App.EmberAccordionHeaderComponent = Ember.Component.extend({  
  classNames: ['ember-accordion-header'],  
  click: function() {
    // here we toggle the emberAccordionItemView.expanded property
    this.toggleProperty('parentView.expanded');  
  }
});

Templates

  <script type="text/x-handlebars" data-template-name="index">
    {{#ember-accordion listOfAccordionPaneObjects=model}}                        
          {{#ember-accordion-header}}
              {{head}} <!-- each object passed in listOfAccordionPaneObjects=model can be accessed here -->
          {{/ember-accordion-header}}
          {{#ember-accordion-body}}
              {{body}} <!-- each object passed in listOfAccordionPaneObjects=model can be accessed here -->
          {{/ember-accordion-body}}        
    {{/ember-accordion}}        
  </script>

  <script type="text/x-handlebars" data-template-name="components/ember-accordion">     
    {{#each listOfAccordionPaneObjects itemViewClass="view.emberAccordionItemView"}}            
      <div class="ember-accordion-container">
        <div class="ember-accordion-pane">          
            {{yield}}          
        </div>
      </div>      
    {{/each}}
  </script>

  <script type="text/x-handlebars" data-template-name="components/ember-accordion-header">        
    {{yield}}    
  </script>

  <script type="text/x-handlebars" data-template-name="components/ember-accordion-body">    
    <!-- when EmberAccordionHeaderComponent.click is called, the expanded property change and the content can be visible or not, based on expanded truth -->
    {{#if parentView.expanded}}
      <div class="ember-accordion-pane-content">
        {{yield}}
      </div>
    {{/if}}
  </script>

Css

.ember-accordion-header {
  background-color: #999;
  color: #ffffff;
  padding: 10px;
  margin: 0;
  line-height: 14px;
  -webkit-border-top-left-radius: 5px;
  -webkit-border-top-right-radius: 5px;
  -moz-border-radius-topleft: 5px;
  -moz-border-radius-topright: 5px;
  border-top-left-radius: 5px;
  border-top-right-radius: 5px;
  cursor: pointer;
  text-decoration: none;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 14px;
}

.ember-accordion-container {
  height: 100%;
  width: 100%;
}

.ember-accordion-pane {
  padding: 2px;
}

.emberaccordionheaderselected {
  background-color: #bbb;
  color: #333;
  font-weight: bold;
}

.ember-accordion-header:hover {
  text-decoration: underline !important;
}

.emberaccordionheaderselected:hover {
  text-decoration: underline !important;
}

.ember-accordion-pane-content {
  padding: 5px;
  overflow-y: auto;
  border-left: 1px solid #bbb;
  border-right: 1px solid #bbb;
  border-bottom: 1px solid #bbb;
  -webkit-border-bottom-left-radius: 5px;
  -webkit-border-bottom-right-radius: 5px;
  -moz-border-radius-bottomleft: 5px;
  -moz-border-radius-bottomright: 5px;
  border-bottom-left-radius: 5px;
  border-bottom-right-radius: 5px;
}

.emberdisabledpane {
  opacity: .2;
}

Thank you so much Marcio! This looks awesome, I'll check it out asap. — davidjnelson, Nov 24 '13 at 18:58
Thanks Marcio, this is AWESOME! What was the key to getting it to work? The emberAccordionItemView looks to be the key. — davidjnelson, Nov 25 '13 at 21:20
You are welcome! Ignoring the `_yield` trick. `emberAccordionItemView` is a important part, because we isolate the `expanded` property for each accordion head and body. — Marcio Junior, Nov 25 '13 at 21:48
I think it's wrong to ignore the `_yield` trick. In fact, that trick breaks this implementation in the latest version of Ember. Instead, you can use components in a more compositional manner to achieve a similar result: http://emberjs.jsbin.com/korujadupu/2/edit?html,js,output Here I've used a trick (namely the `setTarget` method that runs on init) to allow actions sent by `EmberAccordionHeaderComponent` to bubble to the surrounding `EmberAccordionItemComponent`. — nickiaconis, Apr 08 '15 at 21:01

Kingpin2k · Answer 2 · 2013-11-23T06:20:04.233

0

Yes, it's easy to do.

Here's a really simplistic, un-styled example, where it's on hover instead of click, but click is in the jsbin if you uncomment it, and comment out the mouseenter/mouseleave functions.

http://emberjs.jsbin.com/ijEwItO/3/edit

<script type="text/x-handlebars" data-template-name="components/unicorn-accordian">
  <ul>
    {{#each item in content itemController='unicornItem' itemView='unicornItem'}}
      <li>{{item.title}}
      {{#if bodyVisible}}
         <br/>
         {{item.body}}
      {{/if}}
      </li>
    {{/each}}
  </ul>
 </script>


App.UnicornAccordianComponent = Em.Component.extend();

App.UnicornItemController = Em.ObjectController.extend({
  bodyVisible: false
});

App.UnicornItemView = Em.View.extend({
  mouseEnter: function(){
    this.set('controller.bodyVisible', true);
  },

  mouseLeave: function(){
    this.set('controller.bodyVisible', false); 
  }
});

edited Nov 23 '13 at 06:20

answered Nov 23 '13 at 05:41

Kingpin2k

47,277
10
78
96

thanks, but I'm looking for a more comprehensive api for the caller. I'll update the question. – davidjnelson Nov 23 '13 at 07:48
this is the api I'm shooting for: {{#ember-accordion listOfAccordionPaneObjects=model}} {{#ember-accordion-heading}} heading template html {{accordionPaneObject.firstName}} {{/ember-accordion-heading}} {{#ember-accordion-body}} this is the accordion body {{accordionPaneObject.lastName}} {{/ember-accordion-body}} {{/ember-accordion}} – davidjnelson Nov 23 '13 at 21:28

Duncan Walker · Answer 3 · 2014-02-25T15:38:40.903

0

Surely a much easier-to-implement solution is to pass the view (or other parent) as an argument to the component. This will give you access to all the properties of the view whilst still retaining the advantages of using a contained component. For example:

{{#ember-accordion listOfAccordionPaneObjects=model info=view}}{{!-- Pass view in here--}}

    {{log view.info}}{{!-- This will log what view.parentView would have done--}}

  {{ember-accordion-heading firstName=accordionPaneObject.firstName}}

  {{ember-accordion-body lastName=accordionPaneObject.lastName}}

{{/ember-accordion}}

Your header template would look something like this:

Header template html here {{firstName}}

And your body template would look something like this:

Body html here {{lastName}}

edited Feb 25 '14 at 15:38

answered Feb 25 '14 at 02:37

Duncan Walker

2,182
19
28

Thanks Duncan. How would that solve the problem of ember-accordion-heading having access to each element in listOfAccordionPaneObjects? – davidjnelson Feb 25 '14 at 03:24
Well you can pass anything you want into #ember-accordion-heading, so a similar method could pass the object accordionPaneObject from whatever object it is a property of. From your question, though, it seems like #ember-accordion-heading only acts to wrap {{firstName}} in a html layout, in which case a partial or plain hbs/handlebars would be preferred and wouldn't change the scope of the component in the first place. – Duncan Walker Feb 25 '14 at 04:43
1

Though, I add that such a solution probably detracts from the minimal effort, API-like experience you want people to have using the accordion. – Duncan Walker Feb 25 '14 at 04:45
@davidjnelson - I realized I should have edited my answer with the example so see if what I added above is helpful. – Duncan Walker Feb 25 '14 at 15:42

how to access parent component scope from a child components scope in ember?

3 Answers3

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