From: Jan Svitok <jan.svitok@...>
Date: 2006-12-07T21:11:57+09:00
Subject: Re: insert into erb binding

On 12/7/06, Jeremy Wells <jwells@servalsystems.co.uk> wrote:
> I have a class that takes a template, parses it through ERB, then takes
> the output for some custom manipulation. When the class is created as an
> object a binding is passed to it to be passed to the template. Is it
> possible to get the class to insert a variable into the binding? Example:
>
> Template:
> <xml><%=@variable1%> <%=variable2%></xml>
>
> class:
> class Renderer
>     def initialize(template_file, apply_binding)
>        @file = template_file
>        @binding = apply_binding
>     end
>
>     def render
>        @variable2 = "There"
>
>        template = ERB.new(File.read(@file))
>        template_results = template.result(@binding)
>
>        # Perform on template results
>     end
> end
>
> Program:
> @variable1 = "Hello"
> renderer = Renderer.new('template.xml', binding)
> renderer.render
>
> current output: <xml>Hello</xml>
> desired output: <xml>Hello There</xml>
>
> So I want the renderer class to add @variable2 to the binding before
> calling the template.

IIRC this is (more or less) from Rails code:

        def evaluate_locals(local_assigns = {})
                b = binding
                local_assigns.each { |key, value| eval "#{key} =
local_assigns[\"#{key}\"]", b }
                b
        end

The trick is to use eval with binding as an additional argument.