templateInstance.model in Polymer 1.0

Question

In polymer 0.5, this.templateInstance.model provided a way of accessing properties defined in the scope of an encompassing is="auto-binding" (or any other) template of this element.

Now, in polymer 1.0 what is the equivalent way of accessing properties of the encompassing is="dom-bind" (or any other) template?

EDIT:

For example, in the snippet below both elements <my-el-a> and <my-el-b> intend to set values to the encompassing <template is="dom-bind">'s counterA and counterB properties respectively.

<my-el-b> does so succesfully via a reflective property counter (notify:true).

<my-el-a> intends to do so via the "parent"/templateInstance.model but fails. This used to work in Polymer 0.5. How can I get this to work in Polymer 1.0? In other words, what's the equivalent for templateInstance.model?

<script>
  ! function() {
    var counterA = 0;
    Polymer({
      is: 'my-el-a',
      ready: function() {
        counterA += 1;
        this.instanceTemplate.model.counterA = counterA; //used to work in Polymer 0.5
      }
    })
  }();
</script>

<script>
  ! function() {
    var counterB = 0;
    Polymer({
      is: 'my-el-b',
      properties: {
        counter: {
          value: 0,
          type: Number,
          notify: true
        }
      },
      ready: function() {
        counterB += 1;
        this.counter = counterB;
        console.log(this);
      }
    })
  }();
</script>

<template is="dom-bind">
  <div>CounterA: <span>{{counterA}}</span>
  </div>
  <div>CounterB: <span>{{counterB}}</span>
  </div>
  <my-el-a></my-el-a>
  <my-el-b counter="{{counterB}}"></my-el-b>
</template>

es_code es_code · Accepted Answer · 2015-06-20T08:05:16

It's not yet documented but evident from the source code that I can access the template instance properties from dataHost defined as:

var dataHost = (this.dataHost && this.dataHost._rootDataHost) || this.dataHost;

In the context of the example given in the question, I can replace:

this.instanceTemplate.model.counterA = counterA;

with:

var dataHost = (this.dataHost && this.dataHost._rootDataHost) || this.dataHost;
dataHost.counterA = counterA;

In other words, templateInstance.model is replaced with dataHost.

templateInstance.model in Polymer 1.0

4 Answers