From: Yukihiro Matsumoto <matz@...>
Date: 2005-03-16T10:46:19+09:00
Subject: Re: eval/binding question

Hi,

In message "Re: eval/binding question"
    on Wed, 16 Mar 2005 02:45:41 +0900, Stefan Kaes <skaes@gmx.net> writes:

|In the real environment, the names of the locally assigned variables can 
|not be determined in advance, of course.

I'm sorry to say you can't pre-compile eRB allowing local variable set
not determined in advance.  I know allowing this will make your
program 25% faster, but this also would make any other programs
slower.

If you have limited set of local variables, you can do something like:

  require 'erb'

  class Test
    def initialize(path, *lv)
      @erb = ERB.new(File.read(path), nil, '%')
      @locals = {}
      evalstr = "def run_erb\n" +
        lv.collect{|k| "#{k} = @locals[\"#{k}\"]\n"}.join +
        "#{@erb.src}\n_erbout\nend\n"
      print evalstr, "\n\n"
      eval evalstr, nil, path, 0
    end
    def values(hash)
      @locals.update(hash)
      hash.each {|k,v|
        self.instance_variable_set("@#{k}", v)
      }
    end
  end

  t = Test.new("/tmp/test.rhtml", 'mumu')
  t.values("mumu" => "HELLO")
  print t.run_erb

							matz.