ember-block-params-polyfill

This Ember CLI Addon polyfills the block param feature first introduced in Ember 1.10.

How to use

It's pretty straight forward for component templates, just go ahead and pass in arguments to your yield helper.

{{yield arg1 arg2}}

However, when you're using the yielded block param in normal templates, the params will be injected into context.

{{#test-block-param-component up=0}}{{! as |down|}}
  Yield before scope: <span class="mid-scope">{{down}}</span> (1)
  {{#test-block-param-component up=down}}{{! as |down|}}
    Yield <span class="inner-scope">{{down}}</span> (2)

    From controller scope: <span class="inner-scope-ctrl">{{controllerValue}}</span>
  {{/test-block-param-component}}
  Yield after scope: <span class="mid-scope">{{down}}</span> (1)
{{/test-block-param-component}}

It's recommended to add a comment at the end to indicate there is an injected property. Furthermore, this aids in upgrading where you can find and replace all instances of }}{{!

Limitations

Normal templates does not have the freedom to choose block param names.

Currently only tested under 1.8.1