无法从Rails控制器中的POST中提取嵌套的JSON数据

Question

I am trying to configure my controller to process the params sent through a POST from another website. My log shows that the parameters that I receive are as follows:

{"page_id"=>"8b62f4ac-8588-11e3-a094-12314000b04c", "page_name"=>"test form", "variant"=>"b", "page_url"=>" http://get.xxxxxxx.com/test-form ", "data.json"=>"{\\"name\\":[\\"Dave\\"],\\"email\\":[\\"xxxx@me.com\\"],\\"phone\\":[\\"4447177265\\"],\\"ip_address\\":[\\"64.114.175.126\\"],\\"time_submitted\\":[\\"07:34 AM UTC\\"]}", "data.xml"=>"\\n\\n Dave\\n xxxx@me.com\\n 2507177265\\n 64.114.175.126\\n 07:34 AM UTC\\n"}

Initially I thought that Rails would automatically parse the JSON in the params and I could access them in the normal way. So I wrote the Registrations Controller like this:

class Api::RegistrationsController < Devise::RegistrationsController

  skip_before_filter :verify_authenticity_token
  respond_to :json

  def create

    @user = User.new(user_params)

    if @user.save
      render json: @user.as_json( email: @user.email), status: 201
      return
    else
      warden.custom_failure!
      render json: @user.errors, status: 422
    end
  end

  def user_params
    params.require(:'data.json').permit(:email, :name, :phone, :comments, :residency, :qualification, :acknowledgement) if params.present?
  end

end

However, it is simply not working at all. I get an error undefined method 'permit' for string. So obviously I'm not accessing the JSON correctly. Is it possible that because the JSON is escaped that it's throwing the errors?

I've been googling and asking in IRC for a couple of days but I'm not any farther ahead.

I can pass a properly formatted JSON to the controller and it works fine (with changes to the require arguments)

I'm stumped since I need to be able to create a new user with the JSON data. Any help would be HUGELY appreciated. I just don't know what direction to even go from here.

Answer 1

The params.require(:'data.json') returns a JSON body which is a string, however your controller does not interpret the string but expects a Hash.

You can convert the JSON string to a Hash object using the parse class method for JSON like so:

require 'json'
JSON::parse(json_string)