From: Jan Svitok <jan.svitok@...>
Date: 2006-12-08T23:08:08+09:00
Subject: Re: insert into erb binding

On 12/8/06, Jeremy Wells <jwells@servalsystems.co.uk> wrote:
> surely this won't work as the binding in my case is coming from an
> external source, so the ruby in the eval won't have access to the
> variable in the render method?

So once more: The trick is to use eval with binding as an additional argument.
That means when eval gets a binding as the second argument, it will operate
in that context. In this case, if you eval("@var = 123",
some_binding), the variable @var will be set in that binding.

Beware that you are modifying the original binding, so you might
corrupt the original caller.
Maybe @binding = apply_binding.dup will be neccessary.

(I added @ in the template - it was missing)

require 'erb'

# TEMPLATE = "<xml><%=@variable1%> <%=variable2%></xml>"
TEMPLATE = "<xml><%=@variable1%> <%=@variable2%></xml>"

class Renderer
    def initialize(template_file, apply_binding)
       @file = template_file
       @binding = apply_binding
    end

    def render
        # @variable2 = "There"
        eval("@variable2 = \"There\"", @binding)

        # template = ERB.new(File.read(@file))
        template = ERB.new(TEMPLATE)

        template_results = template.result(@binding)

        # Perform on template results

	template_results
    end
end

require 'test/unit'

class TestERB < Test::Unit::TestCase
	def test_variable
		@variable1 = "Hello"

		renderer = Renderer.new('template.xml', binding)
		assert_equal "<xml>Hello There</xml>", renderer.render
	end

end