Using define_method to define global methods outside of a module

Question

I'd like to write this:

[:p, :h1, :h3].each do |tag|
  define_method(tag) { |text| "<#{tag}>#{text}</#{tag}>" }
end

It's just some simple methods to wrap text in HTML tags. I want to be able to use these methods in the rest of the script. Unfortunately the define_method method seems to only work inside of a module. But if I did this inside a module, I wouldn't be able to cleanly write p "This is a paragraph.", it'd be something like HTML::p "This is a paragraph." which would be pretty terrible.

So how do I define methods like this globally?

Answer 1

I don't know your whole situation, but you probably don't really want to be defining global methods. If you don't want to type the HTML:: then add an include HTML statement at the beginning of your code.

Answer 2

One hack would be to create the method inside Object, which would then be global method you desire:

class Object
  def create_method(name, &block)
    self.class.send(:define_method, name, &block)
  end
end

tag = 'p'
a = Object.new
a.create_method(tag.intern) {|v| puts "<#{tag}>#{v}</#{tag}>"}

send(tag.intern, 'content') # => <p>content</p>

Answer 3

If you really need to do it:

[:p, :h1, :h3].each do |tag|
    Object.send(:define_method, tag) { |text| "<#{tag}>#{text}</#{tag}>" }
end