dynamic.html

<!-- Expects the data context to have a `template` property (the name of
the template to render) and an optional `data` property. If the `data`
property is not specified, then the parent data context will be used
instead. Uses the __dynamicWithDataContext template below to actually
render the template. -->
<template name="__dynamic">
  {{checkContext}}
  {{#if dataContextPresent}}
    {{> __dynamicWithDataContext}}
  {{else}}
    {{! if there was no explicit 'data' argument, use the parent context}}
    {{> __dynamicWithDataContext template=template data=..}}
  {{/if}}
</template>

<!-- Expects the data context to have a `template` property (the name of
the template to render) and a `data` property, which can be falsey. -->
<template name="__dynamicWithDataContext">
  {{#with chooseTemplate template}}
    {{> .. ../data}}    {{!-- The .. is evaluated inside {{#with ../data}} --}}
  {{/with}}
</template>