Rails 5 model Initialise wrong number of arguments? - ruby-on-rails

Question

Hi there im trying to create a model for a runescape item. Using there api and httparty. Im having a number of issues. But this one is regarding the use of overriding the initialize method saying it has the wrong number of arguments.
class Item < ApplicationRecord
require 'json'
include HTTParty
base_uri 'http://services.runescape.com/m=itemdb_oldschool/'
attr_accessor :name, :description, :price, :icon_url
def initialize(name, description, price, icon_url)
super
self.name = name
self.description = description
self.price = price
self.icon_url = icon_url
end
def self.find(name)
response = get("/api/catalogue/detail.json?item=#{name}")
if response.success?
parsed = JSON.parse(response)
self.new(
parsed["item"]["name"],
parsed["item"]["description"],
parsed["item"]["current"]["price"],
parsed["item"]["icon_large"]
)
else
# this just raises the net/http response that was raised
raise response.response
end
end
end
So in rails console i run the following command to test it:
item_test = Item.find("227")
ArgumentError: wrong number of arguments (given 4, expected 0..1)
from /Users/jacksharville/.rvm/gems/ruby-2.3.1/gems/activerecord-5.0.1/lib/active_record/core.rb:312:in `initialize'
from /Users/jacksharville/Desktop/OSCRUDDY/app/models/item.rb:13:in `initialize'
from /Users/jacksharville/.rvm/gems/ruby-2.3.1/gems/activerecord-5.0.1/lib/active_record/inheritance.rb:65:in `new'
But the initialize takes 4 arguments. When reduce it to one then it says it requires 4. Which leaves me very confused.
Im not even sure that overriding the base initialise is the way forward to do something like this. So if you have a better idea please let me know i'm new to this.
In conclusion my question is why is my object not being created correctly? Secondly is this the right approach for creating the object?

Answer 1

The problem I see here is that you are trying to mixin HTTParty with an ActiveRecord subclass, when really you should have two separate classes. The Item class should be responsible for interfacing with your database. You should create another class, i.e. ItemResource with Httparty, which will have the responsibility of connecting to the Runescape resource and respond with a response. You should use this to grab the data from the resource, and create an Item record with that data. Single Responsibility Principle
One thing to keep in mind is that you should almost never be redefining initialize for any models that inherit from ApplicationRecord. Checkout the API
EDIT
This code should get you relatively close
#app/models/item.rb
class Item < ApplicationRecord; end
#app/models/item_resource.rb | app/resources/item_resource.rb or something similar
require 'json'
class ItemResource
include HTTParty
self.base_uri 'http://services.runescape.com/m=itemdb_oldschool/'
def find name
response = get("/api/catalogue/detail.json?item=#{name}")
if response.success?
parsed = JSON.parse(response)
Item.new(
name: parsed["item"]["name"],
description: parsed["item"]["description"],
price: parsed["item"]["current"]["price"],
icon_large: parsed["item"]["icon_large"]
)
else
raise response.response
end
end
end
#somewhere else
item = ItemResource.find 'Elysian Spirit Shield'
if item.save
#do stuff
else
#handle failure
end