[RUBY] DRY way to assign hash values to an object

Question

Hi, I'm looking for a elegant way to assign the value stored inside an Hash into a pre-existed object. Just to be clear, if I have an object, say obj with two attributes, say name and age, I want to assign this values coming from an hash without do something like:

obj.name = hash[:name]
obj.age = hash[:age] 

Thanks for your attention. Simone

Answer 1

Don't know about elegant, but you can do:

[:name, :age].each do |att|
  obj.send("#{att}=", hash[att])
end

Answer 2

Best bet is probably to simply define a method like update_attributes which takes a hash and does it inside an instance method of the class.

Expanding on what others have written and what you seem to need I think your best bet would be:

hash.keys.each do |key|
  m = "#{key}="
  obj.send( m, hash[key] ) if obj.respond_to?( m )
end

This will account for:

• not having all the attributes of the class in the hash at all times, and
• any number of keys in the hash (not just :name, etc)

Answer 3

obj.methods.grep(/[^!=]=$/).each {|attr| obj.send(attr, hash[attr]) }