Add root context lookup

[shootaroo]

Access to root context in partial by {{root}}.

ex.

---
name: foo
bar:
  name: bar

---
{{name}}
{{> leaf bar}}


leaf.hbs:
{{name}} {{root.name}}

of

foo
bar foo

See handlebars-lang/handlebars.js#525 (comment)

[doowb]

This looks nice. I'll take a look at it and run it through some assemble tests tomorrow.

Thank you.

[doowb]

@shootaroo sorry, I lost track of this PR since it's in a repo that we don't have a lot of activity on. I'm testing it today to see how it works out. Thanks again for the PR.

[shootaroo]

👏

[jonschlinkert]

see: handlebars-lang/handlebars.js@f650b0d

[shootaroo]

@jonschlinkert thanks!
I tried the {{@root}}, but there was a case that does not work.

I'll try to check it whether the case what.

[shootaroo]

The cause was that options.data is not over the handlebars.compile.

It is all right only the following modifications when applicable the {{@root}}.

-        tmpl = handlebars.compile(tmpl, options);
+        tmpl = handlebars.compile(tmpl, _.defaults({data: true}, options));

[doowb]

Okay, I see now. I think we can make that change, but we want to leave out the custom name lookup and use the latest handlebars that has @root.

[shootaroo]

@doowb Is good. I wait for the new release of handlebars.

[doowb]

Closing since we've updated to Handlebars 4 and we can use the {{@root}} property.