Cannot create property '$key' on boolean 'true'

[ExWei]

Description

When using <firebase-query> with data structure like

{
$id: true
}

it throws an error
Cannot create property '$key' on boolean 'true'

Steps to reproduce

Create data like

{
    "notes-by-user": {
        "userId1": {
            "noteId1": true,
            "noteId2": true,
        }
    }
}

and <firebase-query> element like

<firebase-query
   path="/notes-by-user/userId1"
   data="{{notes}}">
</firebase-query>

[cdata]

Hi, thanks for reporting. Using <firebase-query> on locations where all of the children have primitive (boolean, string, number) values is not supported. Please consider nesting these values in objects.

[darktears]

But https://firebase.google.com/docs/database/web/structure-data#fanout actually give the above as an example. So how you reproduce the advice in the link so that it works with firebase-query?

[darktears]

@cdata this limitation pretty much kills doing fast lookup on the key. In the example I pasted there is no way one could do groups/[[an_id]]. Now one has to get the entire collection (groups) and iterate over it, it doesn't seem to scale TBH. Maybe you have a better suggestion.

[salah-saleh]

Hi @cdata, I also stumbled upon this issue today. I think this limitation is a real concern and the issue shouldn't be closed without fixing, or what do you think?

[midesweb]

As workaround you can use firebase-document instead of firebase-query.
And then use a new element to convert your object into an array, like this:

<firebase-document
      app-name="{{firebaseApp}}"
      path="some/path"
      data="{{dataObject}}"
></firebase-document>
<object-to-array
      object="[[dataObject]]"
      array="{{dataArray}}"
></object-to-array>

The element "object-to-array" should be like this:

<dom-module id="object-to-array">
  <script>
  (function() {
    'use strict';

    Polymer({
      is: 'object-to-array',

      properties: {
        object: {
          type: Object,
          observer: 'toArray'
        },
        array: {
          type: Array,
          value: function(){
            return [];
          },
          notify: true
        }
      },
      toArray: function(o) {
          var numelems = this.array.length;
          this.splice('array', 0, numelems);
          this.async(this.renewContent, 1);
      },
      renewContent: function() {
        for (var id in this.object){
            this.push('array', id);
          }
      }
    });
  })();
  </script>
</dom-module>

[bvhme]

We've also structured our firebase this way according with the Firebase docs' explanation that you should work in the way @ExWei showed. I found out this didn't work when I noticed that firebase-query misses a orderByValue option. Our whole platform is built on this design pattern, so upgrading from firebase-element to polymerfire is very dificult for us.