Am I using the rails form properly? - ruby-on-rails

Question

I feel like I have no idea what I'm doing.. I have a vague Idea. I'm hoping I did this all right so far.
Any way you can see to refactor this would be greatly appreciated.
One thing I noticed it does wrong is it won't load the proper options that were previously submitted if there is an error and it posts to the same URL. The text inputs seem to load the previous value but the select and the radio buttons reset to the default every submit.
ResourcesController#new
def new
#resource = Resource.new
#title = "Submit Resource"
#categories = Category.all
end
ResourcesController#create (notice I have #categories = Category.all in both... according to DRY im not sure where else it should go, or it only works on the first form submit.
def create
#title = "Submit Resource"
#categories = Category.all
#resource = Resource.new(params[:resource])
category_ids = #categories.map { |c| c[1] }
if #resource.valid? and category_ids.include? params[:category_id]
#resource.cost = params[:cost]
#resource.category_id = params[:category_id]
#resource.save
redirect_to root_url
else
render :action => :new
end
end
Resource.rb (model)
# == Schema Information
#
# Table name: resources
#
# id :integer not null, primary key
# upvotes :integer default(0)
# downvotes :integer default(0)
# url :string(255)
# title :string(255)
# cost :integer default(0)
# description :text
# flags :integer
# category_id :integer
# user_id :integer
# created_at :datetime not null
# updated_at :datetime not null
#
class Resource < ActiveRecord::Base
belongs_to :category
belongs_to :user
has_many :favorites
has_many :resource_tags
has_many :tags, :through => :resource_tags
attr_accessible :url, :title, :cost, :description, :category_id, :user_id
# Pseudo-Enum
COST = [:free, :paid, :both]
url_regex = /^(?:http|https):\/\/[a-z0-9]+([\-\.]{1}[a-z0-9]+)*\.[a-z]{2,6}(:[0-9]{1,5})?(\/.*)?$/ix
validates :url, :presence => true,
:format => { :with => url_regex,
:message => "must be valid"},
:uniqueness => { :case_sensitive => false,
:message => "has already been submitted"}
validates :title, :presence => true,
:length => { :within => 6..75 }
validates :cost, :presence => true
validates :description, :presence => true,
:length => { :within => 25..200 }
validates :category_id, :presence => true,
:format => { :with => /\d+/ }
validates :user_id, :presence => true,
:format => { :with => /\d+/ }
def cost
COST[read_attribute(:cost)]
end
def cost=(value)
write_attribute(:cost, COST.index(value.downcase.to_sym))
end
def category_id
read_attribute(:category_id).to_i
end
def category_id=(value)
write_attribute(:category_id, value.to_i)
end
end
My view file for the Resource#new form
<div class="field">
<%= f.label :category %>
<%= select_tag(:category_id, options_for_select(#categories.map {|c|[c.name, c.id]})) %>
</div>
Last Q: i havent worked with the user_id field yet. This is going to be pulled from devise and will associate a User with a submitted resource. But how do I assign this without making some sort of input, like a hidden input. Would this go on behind the scenes in the controller?

Answer 1

To your last question:
devise adds a current_user method which is the logged in user. So if a user has multiple resources you could do something like:
#resource = current_user.resources.new(params[:resource])
First question:
When a form is rendered it is done so based on the #resource & #categories variables. When you post the form the create action is called which creates a new #resource. If the save fails for whatever reason the form is rerendered using the new #resource variable. The problem you have is that #resource.category is not set when you show the form again. So you'll have to do this before the is_valid? check.
def create
#title = "Submit Resource"
#categories = Category.all
#resource = Resource.new(params[:resource])
#resource.category = Category.find(params[:category_id])
if #resource.valid? # won't be valid if there is no category found.
#resource.cost = params[:cost]
#resource.save
redirect_to root_url
else
render :action => :new
end
end
But the real problem is with your form. It should nest the category_id in the resource params so that the category is set when you do Resource.new(params[:resource]).
Check the POST request body in your console or something and see if it's nested in the resource or not. I don't know the exact syntax for it but if you change this you can drop the #resource.category = Category.find line.

Answer 2

To piggyback on Sandip, you can dry up your actions by using a before_filter
class ResourcesController < ApplicationController
before_filter :load_categories, :only => [:show, :create]
def new
#resource = Resource.new
end
def create
#resource = Resource.new(params[:resource])
#resource.category = Category.find(params[:category_id])
if #resource.valid? # won't be valid if there is no category found.
#resource.cost = params[:cost]
#resource.save
redirect_to root_url
else
render :action => :new
end
end
private
def load_categories
#categories = Category.all
end
end
also if you plan on sticking #title inside of your application layout, I would change #title in your view to:
yield(:title) || 'My Site'
and on the appropriate pages use:
content_for(:title) do
Submit Resource
It will default to 'My Site' unless otherwise specified.

Answer 3

Looks like there is problem with create action
def create
#title = "Submit Resource"
#categories = Category.all
#resource = Resource.new(params[:resource])
if #categories.collect(&:id).include?(params[:category_id].to_i)
#resource.category_id = params[:category_id]
end
#resource.user = current_user
if #resource.valid?
#resource.cost = params[:cost]
#resource.save
redirect_to root_url
else
render :action => :new
end
end
view
<div class="field">
<%= f.label :category %>
<%= select_tag(:category_id, options_for_select(#categories.map {|c|[c.name, c.id]}, :selected => #resource.category_id)) %>
</div>