Question

Now I know how to build xml without escaping values. How to tell Builder to not to escape values

However I need to build tags dynamically.

Desired result

<bank_info>Chase</bank_info>

What I have is

attr = 'bank_info'
builder = Builder::XmlMarkup.new
builder.attr { |x| x << 'bank_info' } # does not work

I can try making the whole thing as a giant string and eval that. But evaling is not that safe. Is there a better option that I am missing.

Answer 1

In general, the simplest way to call a method for which you have a name is to use send or __send__. Here:

builder = Builder::XmlMarkup.new
builder.__send__("bank_info") do  # same effect as:  builder.bank_info do
  builder << "Chase"
end

BTW, there is the variant public_send, in case you want to insure you are not calling a private method. It’s only in Ruby 1.9, you can require "backports" to use it in Ruby 1.8.

Note: in this case, send doesn’t work, as pointed out by @KandadaBoggu, because Builder overrides it; you must use __send__.