How to access the hash data - Ruby on rails

Question

I have this object with data that I want to access:

[#<ConceptPayment id: nil, amount: 1, price: 1000.0, concept_id: 3, concept_type: "RegisterType", created_at: nil, updated_at: nil, transaction_sara_id: nil, code: nil, date_code: nil, discount_amount: nil, type_discount_id: nil, observations: nil>]

I tried to parse it to a json with to_json :

"[{\"id\":null,\"amount\":1,\"price\":1000.0,\"concept_id\":3,\"concept_type\":\"RegisterType\",\"created_at\":null,\"updated_at\":null,\"transaction_sara_id\":null,\"code\":null,\"date_code\":null,\"discount_amount\":null,\"type_discount_id\":null,\"observations\":null}]"

then I did this JSON.parse

[{"id"=>nil, "amount"=>1, "price"=>1000.0, "concept_id"=>3, "concept_type"=>"RegisterType", "created_at"=>nil, "updated_at"=>nil, "transaction_sara_id"=>nil, "code"=>nil, "date_code"=>nil, "discount_amount"=>nil, "type_discount_id"=>nil, "observations"=>nil}]

but I can not access the data, I just want to achieve this data[:price]

How can I get access to the data? What is the way to convert an object or access the data of a json?

Answer 1

Have you tried data[0]['price'] or data['price'] ?

It looks like something an activerecord query would return. In that case you can just assign the query result to let's say 'data' and access each member with data['member_name'] unless the query return multiple items in that case you would have to specify the index first eg data[index_number]['member_name']

I believe you could also do something like data.first.price or data.price

Rails 4: how to access an attribute of an ActiveRecord_Relation-Object?

Active Record Query Interface

Hope this helps.

Answer 2

In your code keys are String . But you try to find value with Symbol key.

In this case you have to use symbolize_names option.

string = "[{\"id\":null,\"amount\":1,\"price\":1000.0,\"concept_id\":3,\"concept_type\":\"RegisterType\",\"created_at\":null,\"updated_at\":null,\"transaction_sara_id\":null,\"code\":null,\"date_code\":null,\"discount_amount\":null,\"type_discount_id\":null,\"observations\":null}]"

data = JSON.parse(string, symbolize_names: true).first

data[:price] #=> 1000.0

Answer 3

NOTE: Assuming you are storing the ConceptPayment object as cp_obj :

I think what you need is deep_symbolize_keys . Your question does not detail what kind of object ConceptPayment is.

---

If it is a Model object , the following should work:

1. Use as_json to get the object as a hash. Try cp_obj.as_json . It normally gets you the object in JSON format (Rails 5.2).
2. Then you should use deep_symbolize_keys , like so: my_hash = cp_obj.as_json.deep_symbolize_keys and then you should be able to do my_hash[:price] .

Example (I just ran this on my Rails console against a User class that I have):

irb(main):002:0> user = User.find 6
  User Load (7.5ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2  [["id", 6], ["LIMIT", 1]]
=> #<User id: 6, full_name: "Geeks", email: "geeks@abc.com", created_at: "2019-02-04 06:59:33", updated_at: "2019-02-04 06:59:33">
irb(main):003:0> user.as_json
=> {"id"=>6, "full_name"=>"Geeks", "email"=>"geeks@abc.com", "created_at"=>Mon, 04 Feb 2019 12:29:33 IST +05:30, "updated_at"=>Mon, 04 Feb 2019 12:29:33 IST +05:30}
irb(main):004:0> my_hash = user.as_json.deep_symbolize_keys
=> {:id=>6, :full_name=>"Geeks", :email=>"geeks@abc.com", :created_at=>Mon, 04 Feb 2019 12:29:33 IST +05:30, :updated_at=>Mon, 04 Feb 2019 12:29:33 IST +05:30}
irb(main):005:0> my_hash[:full_name]
=> "Geeks"

---

If it is not a model object , then I believe JSON.parse(cp_obj.to_json).deep_symbolize_keys should work (as you are able to get JSON.parse to work already)!

Example:

irb(main):011:0> JSON.parse('{"name":"vaibhav", "more" : {"details": "balding guy! :P"}}').deep_symbolize_keys[:more][:details]
=> "balding guy! :P"

I hope that helps.