Add an include controller's public context to its parent controller's public context for JSON output

Rendered includes are added to the calling controller's public context for HTML output like so:

const handler = () => {
  return {
    content: {
      foo: 'bar'
    },
    include: {
      _head: {
        controller: '_head'
      }
    }
  }
}

HTML view (Handlebars in this case):

<html>
  {{include._head}}
  <body>
    <p>{{foo}}</p>
  </body>
</html>

But when JSON is requested, only the parent controller's public context is included. The JSON output of the above example would be:

{
  foo: 'bar'
}

Any public context generated by the _head include is ignored. It might make more sense to extend the parent controller's public context with the include's public context when JSON is requested:

{
  foo: 'bar',
  include: {
    _head: {
      title: 'Page title',
      metaDescription: 'Page description',
      keywords: 'key, words'
    }
  }
}

jaysylvester / citizen

Add an include controller's public context to its parent controller's public context for JSON output #91