Databases
StackOverflow2013
Postsdbo
POEmber-data model computed value, return value instead of promise
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POEmber-data model computed value, return value instead of promise
    primarykey
    data
    text
    <p>I have ember models called <code>survey</code>, <code>question</code>, and <code>response</code>. <code>survey</code>s have multiple <code>question</code>s, which have multiple <code>response</code>s. Each <code>response</code> has an attribute <code>count</code>.</p> <p>How do I set a <code>total_response_count</code> computed value in the <code>survey</code> model? In emberjs 1.0.0, the <code>questions</code> are in a DS.PromiseArray (due to the async: true), so when I return the computed value, it shows up in my template as an Object rather than a value.</p> <p>I can easily access <code>responses</code> from the <code>question</code> model because <code>responses</code> are embedded in <code>question</code>. However, Ember automatically makes promises for the <code>questions</code> referenced by <code>survey</code> because {async: true}.</p> <p>Survey Model:</p> <pre><code>App.Survey = DS.Model.extend({ title: DS.attr('string'), owner_id: DS.belongsTo('user'), questions: DS.hasMany('question', {async:true}), total_responses: function() { var question_cb = function(prevValue, item) { return prevValue + item.get('total_responses'); }; return this.get('questions').then(function(questions){ return questions.reduce(question_cb, 0); }); }.property('questions') }); </code></pre> <p>Question Model:</p> <pre><code>App.Question = DS.Model.extend({ survey: DS.belongsTo('survey'), question: DS.attr('string'), responses: DS.hasMany('response'), total_responses: function() { var response_cb = function(prevValue, item) { return prevValue + item.get('count'); }; return this.get('responses').reduce(response_cb, 0); }.property('responses') }); </code></pre> <p>Response Model:</p> <pre><code>App.Response = DS.Model.extend({ response: DS.attr('string'), count: DS.attr('number'), question: DS.belongsTo('question') }); </code></pre> <p>I'm using ember-1.0.0 and ember-data 1.0 beta-2.</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USaz_
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POEmber-data model computed value, return value instead of promise
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POEmber-data model computed value, return value instead of promise
      1. This table or related slice is empty.
      1. VTUpMod
    1. COCan you try calling reduce directly on the `this.get('questions')` PromiseArray?
      singulars
      1. POEmber-data model computed value, return value instead of promise
      1. USBradley Priest
    2. COI did; it doesn't work because it tries to reduce the PromiseArray directly, and since it's an "array of length 0" it returns 0.
      singulars
      1. POEmber-data model computed value, return value instead of promise
      1. USaz_
    3. COHow about computing from both `questions` and `questions.isFulfilled`?
      singulars
      1. POEmber-data model computed value, return value instead of promise
      1. USBradley Priest
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload