String boolean: MethodMissing fun!

Check out this one, this is way i love rails.

elad = "smart"
elad.smart? # => true

using method_missing on the String object

def method_missing(method_name, *arguments)
  if method_name.to_s.ends_with?("?")
    self == method_name.to_s[0..-2]
  else
    super
  end
end

Model Reflection Overview

We all use ActiveRecord Reflection on the fly while programming, since we declare all the relations in the model and we are considering it as obvious.
i tried to search and see if there is a way to find those reflections and to alter it in runtime.

Model.reflections

i found this collection which contains all the information about the current model reflections.
for example.

• .macro: this will return the type of the current reflection (:has_many, etc..)


• .primary_key_name: the reflection primary key


• .options: the reflection SQL join options


• etc. etc.

for example, the following code will show me all the reflections for a model named Article:

1. >> y Article.reflections.values.collect {|e| e.macro.to_s  + " => " + e.primary_key_name.to_s }  
2. ---   
3. - has_many => taggee_id  
4. - belongs_to => layout_id  
5. - has_many => article_id  
6. - has_one => subject_id  
7. - belongs_to => user_id  
8. - has_many => taggee_id  
9. => nil  

Dynamically adding methods

This is divine, ruby is too great to be true. no explanation needed.

1. class Object  
2.   def def(method_name, &block)  
3.     (class << self; self end).send(:define_method, method_name, block)  
4.   end  
5. end  
6.   
7. x = Object.new  
8.   
9. string = "This is a test"  
10. x.def(:elad_says) {puts "Elad says: " + string}  
11.   
12. x.elad_says