Question

I previously had:

serialize :params, JSON

But this would return the JSON and convert hash key symbols to strings. I want to reference the hash using symbols, as is most common when working with hashes. I feed it symbols, Rails returns strings. To avoid this, I created my own getter/setter. The setter is simple enough (JSON encode), the getter is:

  def params
    read_attribute(:params) || JSON.parse(read_attribute(:params).to_json).with_indifferent_access
  end

I couldn’t reference params directly because that would cause a loop, so I’m using read_attribute, and now my hash keys can be referenced with symbols or strings. However, this does not update the hash:

model.params.merge!(test: 'test')
puts model.params # => returns default params without merge

Which makes me think the hash is being referenced by copy.

My question is twofold. Can I extend active record JSON serialization to return indifferent access hash (or not convert symbols to strings), and still have hash work as above with merge? If not, what can I do to improve my getter so that model.params.merge! works?

I was hoping for something along the lines of (which works):

  def params_merge!(hash)
    write_attribute(:params, read_attribute(:params).merge(hash))
  end

  # usage: model.params_merge!(test: 'test')

Better yet, just get Rails to return a hash with indifferent access or not convert my symbols into strings! Appreciate any help.

Answer 1

use the built-in serialize method :

class Whatever < ActiveRecord::Base
 serialize :params, HashWithIndifferentAccess
end

see ActiveRecord::Base docs on serialization for more info.