Option[] and Mustache templates

[Wille Faler]

Hi guys,

Yet another mustache question:

Is there any way of automatically unwrapping an option value in Mustache?

For instance, given:

case class Widget(name: Option[String)

viewModel = Map("widget" -> Widget(Some("someWidget"))

..and the template: 

        {{#widget}}

            Name: {{name}}

        {{/widget}}

..it will render "Name: Some(someWidget)"

..which really isn't very useful, as Option/Some/None are primarily Scala constructs, not for human reading in a result of a template..

/ Wille

[James Strachan]

Great catch! We'd supported handling None properly (like null) for the
longest time, but were not unwrapping the Some.

I've raised this issue
http://www.assembla.com/spaces/scalate/support/tickets/197

Its always surprised me a little that Option doesn't implement
Traversable, so I've also raised this issue so that when using an
Option[Person] value you can use it in a mustache section / inverted
section to iterate over a complex object wrapped in an Option
http://www.assembla.com/spaces/scalate/support/tickets/198

Both these issues are now resolved in master. See the test case for
more detail...
https://github.com/scalate/scalate/blob/master/scalate-core/src/test/scala/org/fusesource/scalate/mustache/OptionTest.scala#L26

Incidentally if you're ever wondering how Mustache navigates object
contexts and implements sections, its all in this Scope.scala file..
https://github.com/scalate/scalate/blob/master/scalate-core/src/main/scala/org/fusesource/scalate/mustache/Scope.scala

And here's the generic Scalate way we turn values into markup/output
handling null & None (and now Some) etc
https://github.com/scalate/scalate/blob/master/scalate-core/src/main/scala/org/fusesource/scalate/RenderContext.scala#L193

--
James
-------
FuseSource
Email: ja...@fusesource.com
Web: http://fusesource.com
Twitter: jstrachan
Blog: http://macstrac.blogspot.com/

Open Source Integration

[Trevor Hartman]

Looks like this doesn't work as expected when it's an Option[List[T]].

It treats it like a boolean and never iterates through the list.

    val foo = Some(List(1, 2, 3))

    {{#foo}}

      this is foo {{.}}

    {{/foo}}

Expected output:

this is foo 1

this is foo 2
this is foo 3

Actual output:

this is foo 123