Preview on Device with Data JSON throws exception

Question

Testing a simple Alexa skill in Authoring tool, with just one text box getting data from "Data JSON" tab throws an exception on doing preview on device. However same works fine when I hard code data directly in the render template.

I have a simple render document with just one text type. And a data JSON having just one property which binds with the text type. It renders fine on the Authoring tool simulator. However, it throws two errors on doing preview on device -
1. There was an error pushing the template to the device.
2. JSON errors found for layout and data integration. Fix errors and view on device again.

If I remove the binding and add the text right in the render document, preview works.

Also, default samples available on authoring tool works like a charm on both simulator and preview on device.

Render document
{ "type": "APL", "version": "1.0", "theme": "dark", "mainTemplate": { "parameters": [ "payload" ], "item": [ { "type": "Text", "color": "#FFFFFF", "text": "${payload.textTitle}" } ] } }

Data JSON
{ "textTitle": "Hello how are you" }

I think I am missing something very basic. This simple example should have worked.

I am previewing it on Echo Show 2nd generation

Answer 1

I've been playing around APL and run into this same issue. It seems that the datasource must contain objects, not primitives. So ${payload.titleText} fails some kind of schema check before sending to the device. And when you put it into an object under the datasource, e.g. ${payload.title.text}, no errors!

The following appears to work for me:

 {
  "type": "APL",
  "version": "1.0",
  "theme": "dark",
  "mainTemplate": {
    "parameters": [
      "payload"
    ],
    "item": [
      {
        "type": "Text",
        "color": "#FFFFFF",
        "text": "${payload.title.text}"
      }
    ]
  }
}

and this data:

{
  "title": { "text": "Hello how are you" }
}