Ruby access nested attributes with symbol -

i'm trying write method takes an object, a symbol (or else, here's question) , "upcases" value @ key (for example).

simple case:

foo = { a: 'hi', b: 'there' }  def upc_value(object, key)   object[key].upcase! end  upc_value(foo, :b)  puts foo #=> { a: 'hi', b: 'there' } 

but want method work nested attributes if foo object more complex.

more complex case:

foo = { a: 'hi', b: [{ c: 'foo', d: 'bar' }, { c: 'bob', d: 'lisa' }] }  def upc_value(object, key)   object[key].upcase! end  # able like:     upc_value(foo, :b[:d])  puts foo #=> { a: 'hi', b: [{ c: 'foo', d: 'bar' }, { c: 'bob', d: 'lisa' }] } 

i can't , i'm curious if "deep_symbol" exists...

---

real problem:
real thing i'm trying achieve here module removes host every field contains url before model saved.
it's included in every model needs , call fields_containing_url method takes symbols of fields.
problem have nested attributes on 1 of models , need access them same method takes symbols...

thank you help!

here's start. it's recursive method changing data in place :

def deep_transform(object, key, &block)   case object   when array     object.each |element|       deep_transform(element, key, &block)     end   when hash     object.each_value |value|       deep_transform(value, key, &block)     end     if value = object[key]       object[key] = yield(value)     end   end end  foo = { a: 'hi', b: 'there' } deep_transform(foo, :b){ |str| str.upcase } p foo # {:a=>"hi", :b=>"there"}  foo = { a: 'hi', b: [{ c: 'foo', d: 'bar' }, { c: 'bob', d: 'lisa' }] } deep_transform(foo, :d, &:upcase) # alternative way call method p foo # {:a=>"hi", :b=>[{:c=>"foo", :d=>"bar"}, {:c=>"bob", :d=>"lisa"}]} 

note method mutate every value related :d key. don't specify :b[:d] in example.