Using has_key in array in rails from multi-level JSON data - ruby-on-rails-3

Question

I have a set of JSON data that has multiple levels of data. Snippet of the JSON (ignore the missing formatting please):
DATA SET A:
"interaction": {
"author": {
"username": "johndoe",
"name": "John Doe"
}
},
"gender": "male"
DATA SET B:
"interaction": {
"author": {
"name": "Jane Doe"
}
},
"gender": "male"
In a single-level I can use:
if record.has_key?('gender')
and that will return a true/false value if the key is present.
If I try to seed data and the key isn't present, it will throw an error and stop seeding.
My question: How would I check to see if the "username" key exists. Data Set B, for example, doesn't have a username key and would throw an error, but I can't figure out how to modify the has_key() command to check for a few levels down.
Thanks for the help.

Answer 1

I've decided to work around the has_key method and used a begin/rescue/end.
begin
#data.username = record['interaction']['author']['username']
rescue
#data.username = nil
end

Answer 2

Here's a possibility:
# where a and b are loaded from JSON
a = {
'interaction' => {
'author' => {
'username' => 'johndoe',
'name' => 'jd'
}
}
}
b = {
'interaction' => {
'author' => {
'oijoijoij' => 'johndoe',
'name' => 'jd'
}
}
}
class Hash
def recursive_has_key?(key)
has_key?(key) or values.any? { |v| v.is_a?(Hash) and v.recursive_has_key?(key) }
end
end
puts a.recursive_has_key?('username')
puts b.recursive_has_key?('username')
Which outputs
$ ruby foo.rb
true
false