Collecting hashes into OpenStruct creates “table” entry

Question

Why this (evaluated in Rails console)

[{:a => :b}].collect {|x| OpenStruct.new(x)}.to_json

adds a \"table\" record in there?

Answer 1

I get around the problem by subclassing OpenStruct like so:

class DataStruct < OpenStruct
  def as_json(*args)
    super.as_json['table']
  end
end

then you can easily convert to JSON like so:

o = DataStruct.new(a:1, b:DataStruct.new(c:3))
o.to_json
# => "{\"a\":1,\"b\":{\"c\":3}}"

Neat huh? So in answer to your question, you'd write this instead:

[{:a => :b}].collect {|x| DataStruct.new(x)}.to_json

giving you:

=> "[{\"a\":\"b\"}]"