Module: FunctionExporter

Defined in:
lib/function_importer.rb

Overview

add module a method to export function.

Defined Under Namespace

Classes: NameError

Instance Method Summary collapse

Instance Method Details

#create_export_module(*args) ⇒ Object 



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# File 'lib/function_importer.rb', line 39

def create_export_module *args
  parent_mod = self.dup

  method_of = {};
  case args.first
  when Hash
    args.first.each do |key, val|
      method_of[key.to_s] = val
    end
  else
    args.each do |i| 
      method_of[i.to_s] = true
    end
  end

  no_need_methods = []
  parent_mod.instance_methods.each do |meth|
    unless method_of[meth.to_s]
      no_need_methods.push meth
    end
  end

  orig_mod = self
  parent_mod.module_eval do
    # renate method.
    method_of.each do |key, val|
      begin
        raise NameError, "no such method #{key} exist in #{orig_mod}" unless instance_method(key)
      rescue ::NameError => e
        raise NameError, "no such method #{key} exist in #{orig_mod}"
      end
      next if val.kind_of? TrueClass
      alias_method val, key
      undef_method key
    end
    no_need_methods.each do |meth|
      undef_method meth
    end
  end

  parent_mod
end

#export(context, *args) ⇒ Object

Example:

module Utils
  extend FunctionExporter

  def escape str
    "escaped_#{str}"
  end
end

module Foo
  Utils.export self, :escape

  def run
    p(escape('str')) #=> "escaped_str"
  end
end

# you can rename method when argument is Hash.
module Bar
  Utils.export self, :escape => :my_escape

  def run
    p(my_escape('str')) #=> "escaped_str"
  end
end



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# File 'lib/function_importer.rb', line 32

def export context, *args
  parent_mod = create_export_module(*args)
  context.module_eval do
    include parent_mod
  end
end