ruby Mustache.render does not have 3rd parameter for partials like JS Mustache.render

Question

I have a AJAX that send JSON to client, so it can render a Mustache template on the client side. The Mustache template has a partial. Everything goes fine. I'll borrow the example from here

Sample 11: Partials (JS Version of Mustache)

var data = { depts: [
    {   name: "Engineering",
        employees: [
            {firstName: "Christophe", lastName: "Coenraets"},
            {firstName: "John", lastName: "Smith"}]
    },
    {   name: "Sales",
        employees: [
            {firstName: "Paula", lastName: "Taylor"},
            {firstName: "Lisa", lastName: "Jones"}]
    }]
};

var tpl = "{{#depts}}<h1>{{name}}</h1>" +
          "<ul>{{#employees}}{{>employee}}{{/employees}}</ul>{{/depts}}";
var partials = {employee: "<li>{{firstName}} {{lastName}}</li>"};
var html = Mustache.render(tpl, data, partials);
$('#sampleArea').html(html);

As you can see in the call to Mustache.render , there is a 3rd argument that you can pass PARTIALS, works great in JS.

I need to do the exactly same thing in Ruby, but the problem is, in Ruby Mustache, the 3rd argument doesn't exist . I've seen the Mustache source and I've debugged it, it has something to do with the "context" of Mustache, but could not figure it out how to pass a PARTIAL like in the JS version of Mustache.

I've tried:

Mustache.render( mytemplate, { data: myjson, partial: mypartial })

but it doesn't render myjson

Answer 1

In the Ruby implementation, partials are loaded from the filesystem by Mustache.partial , which, by default, checks for a file named mypartial.mustache in the current directory. You can override the default behavior by subclassing Mustache for your own specific needs:

class MyMustache < Mustache
  PARTIALS = {
    employee: "<li>{{firstName}} {{lastName}}</li>"
  }

  def partial(name)
    PARTIALS[name.to_sym]
  end
end

puts MyMustache.render(tpl, data)

The Ruby implementation is remarkably well documented, but mostly in the source comments. Check it out for more info :)

Source