Module: Poro::Util::ModuleFinder

Defined in:
lib/poro/util/module_finder.rb

Class Method Summary collapse

Class Method Details

.find(arg, relative_root = Module, strict = false) ⇒ Object

Finds the given module by string.

Arguments:

arg

The module/class name to find.

relative_root

If given, tries to find the requested class/module within this module/class. May be a string.

strict

Normally–mostly like Ruby–a top-level class will be returned at any step if no module/class matches in the namespace it is searching. If this is true, then a last check is made to see if the returned module/class is actually inside of the relative root.

If given a class, it returns it directly. TODO: Make it look it up if relative_root is not Module or Object.

Raises:

  • (NameError) 


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# File 'lib/poro/util/module_finder.rb', line 19

def self.find(arg, relative_root=Module, strict=false)
  # If the argument is a kind of class, just return right away.
  return arg if arg.kind_of?(Module) || arg.kind_of?(Class)
  
  # Now we need to treat it as a string:
  arg = arg.to_s
  raise NameError, "Could not find a module or class from nothing." if arg.nil? || arg.empty?
  
  # First, define the recursive function.
  recursive_resolve = lambda do |curr_mod, names|
    head, *rest = names.to_a
    if( head.nil? && rest.empty? )
      curr_mod
    elsif( !(head.to_s.empty?) && curr_mod.respond_to?(:const_defined?) && curr_mod.const_defined?(head) )
      recursive_resolve.call( curr_mod.const_get(head), rest)
    else
      raise NameError, "Could not find a module or class from #{arg.inspect}"
    end
  end
  
  # If starting with ::, then the constant is aboslutely referenced.
  relative_root = Module if arg[0,2]=='::'
  
  # Split into names
  start_index = arg[0,2]=='::' ? 2 : 0
  mod_names = arg[start_index..-1].split('::')
  
  # Now get the module or class.
  relative_root = self.send(__method__, relative_root)
  mod = recursive_resolve.call(relative_root, mod_names)
  
  # Now, if we are strict, verify it is of the type we are looking for.
  if !(relative_root==Module || relative_root==Object) && !(mod.name.include?(relative_root.name))
    base_message = "Could not find a module or class #{mod.name.inspect} inside of #{relative_root.name.inspect}"
    if( strict )
      raise NameError, base_message
    else
      STDERR.puts "WARNING: #{base_message}, top level mod/class used instead."
    end
  end
  
  # Return
  return mod
end