Creating forms for polymorphic associations in Rails - ruby-on-rails

I have a couple classes that can each have comments:
class Movie < ActiveRecord::Base
has_many :comments, :as => :commentable
end
class Actor < ActiveRecord::Base
has_many :comments, :as => :commentable
end
class Comment < ActiveRecord::Base
belongs_to :commentable, :polymorphic => true
end
How do I create a form for a new movie-comment? I added
resources :movies do
resources :comments
end
to my routes.rb, and tried new_movie_comment_path(#movie), but this gives me a form containing commentable_id and commentable_type [which I want to be populated automatically, not entered by the user directly]. I also tried creating the form myself:
form_for [#movie, Comment.new] do |f|
f.text_field :text
f.submit
end
(where "text" is a field in the Comment table)
but this doesn't work either.
I'm not actually sure how to associate a comment with a movie at all. For example,
c = Comment.create(:text => "This is a comment.", :commentable_id => 1, :commentable_type => "movie")
doesn't seem to create a comment associated to the movie with id 1. (Movie.find(1).comments returns an empty array.)

As you have created the polymorphic association in your model, you need not worry about that anymore in the view. You just need to do this in your Comments controller.
#movie = Movie.find(id) # Find the movie with which you want to associate the comment
#comment = #movie.comments.create(:text => "This is a comment") # you can also use build
# instead of create like #comment = #movie.comments.create(:text => "This is a comment")
# and then #comment.save
# The above line will build your new comment through the movie which you will be having in
# #movie.
# Also this line will automatically save fill the commentable_id as the id of movie and
# the commentable_type as Movie.

You're going to have to be more descriptive than "...but this doesn't work either," but the general idea is:
#movie.comments.create( :text => params[:movie][:comment][:text] )
More typically:
#movie.comments.create( params[:comment] ) # or params[:movie][:comment]
The important thing is that you find #movie first and create your associated objects through it. That way you won't have to worry about Commentable or types or anything.

Related

Ruby on Rails - Need help associating models

Ok, am still a newbie in ruby on rails trying to learn my way around. I have two models (User model and Comment model). Basically a user has a simple profile with an 'about me' section and a photo's section on the same page. Users must be signed in to comment on other users profiles.
My User Model
class User < ActiveRecord::Base
attr_accessible :email, :name, :username, :gender, :password, :password_confirmation
has_secure_password
has_many :comments
.
.
end
My Comment Model
class Comment < ActiveRecord::Base
belongs_to :user
attr_accessible :content
.
.
end
In my comments table, I have a user_id column that stores the id of the user whose profile has been commented on and a commenter_id column that stores the id of the user commenting on the profile.
Comment Form
<%= form_for([#user, #user.comments.build]) do |f| %>
<%= f.text_area :content, cols: "45", rows: "3", class: "btn-block comment-box" %>
<%= f.submit "Comment", class: "btn" %>
<% end %>
My comments Controller
class CommentsController < ApplicationController
def create
#user = User.find(params[:user_id])
#comment = #user.comments.build(params[:comment])
#comment.commenter_id = current_user.id
if #comment.save
.........
else
.........
end
end
end
This works fine storing both user_id and commenter_id in the database. My problem comes when displaying the user comments on the show page. I want to get the name of the user who commented on a specific profile.
In my user controller
def show
#user = User.find(params[:id])
#comments = #user.comments
end
I want to get the name of the user from the commenter_id but it keeps throwing errors undefined method 'commenter' for #<Comment:0x007f32b8c37430> when I try something like comment.commenter.name. However, comment.user.name works fine but it doesn't return what I want. Am guessing am not getting the associations right.
I need help getting the correct associations in the models so as to get the name from the commenter_id.
My last question, how do I catch errors in the comments form? Its not the usual form_for(#user) where you do like #user.errors.any?.
routes.rb
resources :users do
resources :comments, only: [:create, :destroy]
end
Try something like this in your models
class User < ActiveRecord::Base
has_many :received_comments, :class_name => "Comment", :foreign_key => "user_id"
has_many :given_comments, :class_name => "Comment", :foreign_key => "commenter_id"
end
class Comment < ActiveRecord::Base
belongs_to :user # comment about profile
belongs_to :commenter, :class_name => "User", :foreign_key => "commenter_id"
end
check out: http://guides.rubyonrails.org/association_basics.html
you can probably come up with better naming on the has_many collections, received and given were the best I could do on short notice :)
Note: foreign_key is option in many cases, left it in above - i think it helps with clarity
has_many fk refers to the the column in the many table (other table)
belongs_to fk refers to the column in the many table (this table)

RoR duplication fields

When an incorrect mandatory fields, the page reloads and you receive an incorrect entry fields and all fields in the form company_form duplicated.
User model(user.rb):
class User < ActiveRecord::Base
....
has_many :companies, :autosave => true
accepts_nested_attributes_for :companies
has_and_belongs_to_many :roles
def role?(role_name)
return !!self.roles.find_by_name(role_name)
end
def with_company
self.companies.build
self
end
end
Company model:
class Company < ActiveRecord::Base
...
belongs_to :user
...
end
views/devise/registration/new.html.haml:
= form_for(resource.with_company, :as => resource_name, :url => registration_path(resource_name), :html => { :class => 'form-horizontal'}) do |f|
...
= f.fields_for :companies do |company_form|
...
...
The problem is that your with_company method uses build to create the new Company object. build will automatically create the new object and save it to the database. So every time that form gets rendered, you'll add another Company to that User. Just hit reload on the page a few times and you should see what I mean.
I think the fix will be to use create instead of build in that method; this creates a new object but doesn't save it to the database.
More likely, though, you should be doing this in the controller that renders the view, rather than in the view itself. Devise doesn't always make this straightforward, but you should be able to create a new controller that inherits from the Devise controller and adds what you need. I do something similar in my current project here.
worked! change def with_company on
def with_company
if self.companies.empty?
self.companies.build
end
self
end

Filling out an inherited mongoid document using nested attributes

Given the following models:
class Company
include Mongoid::Document
has_many :workers, autosave: true
accepts_nested_attributes_for :workers
attr_accessible :workers_attributes
end
class Worker
include Mongoid::Document
field :hours
attr_accessible :hours
belongs_to :company
end
class Manager < Worker
field :order
has_many :contributors, :class_name => "Worker"
attr_accessible :order, :contributors
end
class Contributor < Worker
field :task
belongs_to :manager, :class_name => "Worker"
attr_accessible :task
end
How does one create a manager in a company in the controller and view using nested attributes?
Here's my guess:
def new
#company = Company.new
#company.workers = [Manager.new]
end
def create
#company = Company.new params[:user]
if #company.save
redirect_to root_url, :notice => "Company with manager created."
else
render :new
end
end
= semantic_form_for #company do |f|
= f.semantic_fields_for :workers do |worker_fields|
= worker_fields.inputs do
= worker_fields.input :hours
= worker_fields.input :order
problem is the order field which specifically belongs to the manager is not persisting after the create. Also when the data is improperly filled there is an error:
undefined method `order' for #<Worker:0x0000000646f018> (ActionView::Template::Error)
So is there a way for nested attributes to handle inheritance in the models from mongoid?
The question is related to Can nested attributes be used in combination with inheritance? except instead of active record using mongoid.
Honestly, this is a paraphrasing of my code... the real code is more complex situation although i believe these are all of the relevant parts. If you have more questions ask.
UPDATE:
I changed the view to the following:
= semantic_form_for #company do |f|
- #company.workers.each do |worker|
- if worker._type == "Manager"
= f.semantic_fields_for :workers, worker do |worker_fields|
= worker_fields.inputs do
= worker_fields.input :hours
= worker_fields.input :order
I do not get the error anymore, however the nested attributes do not update the company object properly. The params are the following:
{"company"=> {"workers_attributes"=>{"0"=>{"hours"=>"30", "order" => "fish", "id"=>"4e8aa6851d41c87a63000060"}}}}
Again edited for brevity. So the key part is that there is a hash between "0" => {data for manager}. The workers data seems to be held in a hash. I would expect the data to look more like the following:
params = { company => {
workers_attributes => [
{ hours => "30", "order" => "fish" }
]}}
This is different because the workers data is held in an array instead of a hash. Is there another step to get the nested attributes to save properly?
Thanks
what version of Mongoid are you using? Because I don't think the use of refereneces_many is encouraged -- Not that that's related to your problem here, just wanted to probe what version you're using. In the doc on the gorgeous Mongoid.org, get this, I had to learn it the hard way, they say for Updating your records, you need to the autossave set to true. That's NOT accurate. You need it for even creating
so:
class Company
include Mongoid::Document
has_many :workers, :autossave => true # your money shot
accepts_nested_attributes_for :workers
attr_accessible :workers_attributes
end
ADDED:
I was re-reading your code, I spotted the following that might be the problem: Your Company model is set to has_many :workers and is set to accept nested attribbutes for Worker when changes come in, correct? And there is a field named Order in your Manager model which is subclassed from Worker. Yet you're having a form whose nested fields part is pointed at Worker not at Manager, the model that actually has the Order field. And that's obviously not enough, because Company isn't having_many :managers yet, you may need to set it to has_many :managers in the Company model as well.

Rails - Join Table with Attributes (HABTM + Through) But how do I create / delete records?

I have a User model and Interest Model being joined by a join table called Choice (details below). I'm using the HABTM relationship with through since I have an attribute within the join table as well.
User.rb
has_many :choices
has_many :interests, :through => :choices
Interest.rb
has_many :choices
has_many :users, :through => :choices
Choice.rb
belongs_to :user
belongs_to :interest
So the question is how do I add records to this newly created choice table. For example =>
#user = User.find(1)
#interest = Interest.find(1)
????? Choice << user.id + interest.id + 4(score attribute) ??????
The last part is the part I'm having a problem with..I have these 3 parameters and didn't how to add them in and what the syntax was?
You have a couple options for adding a choice, but what probably makes the most sense would be to add choices by scoping to the user instance:
Assuming:
#user = User.find(1)
#interest = Interest.find(1)
You could add a choice like so:
#user.choices.create(:interest => #interest, :score => 4)
You could also do something like this in your controller:
def create
#choice = #user.choices.build(params[:choice])
if #choice.save
# saved
else
# not saved
end
end
This assumes your form has fields for choice[:interest_id] and choice[:score]

Associating multiple ids on creation of Item

G'day guys,
I'm currently flitting through building a test "Auction" website to learn rails. I've set up my Auction and User models and have it so that only authenticated users can edit or delete auctions that are associated with them.
What I'm having difficulty doing is associating bid items with the Auction.
My models are as follows:
class Auction < ActiveRecord::Base
belongs_to :creator, :class_name => "User"
has_many :bids
validates_presence_of :title
validates_presence_of :description
validates_presence_of :curprice
validates_presence_of :finish_time
attr_reader :bids
def initialize
#bids = []
end
def add_bid(bid)
#bids << bid
end
end
class Bid < ActiveRecord::Base
belongs_to :auction, :class_name => "Auction", :foreign_key => "auction_id"
belongs_to :bidder, :class_name => "User", :foreign_key => "bidder_id"
validates_presence_of :amount
validates_numericality_of :amount
#retracted = false
end
class User < ActiveRecord::Base
has_many :auctions, :foreign_key => "owner_id"
has_many :bids, :foreign_key => "owner_id"
#auth stuff here
end
I'm attempting to add a bid record to an auction, but the auction_id simply will not add to the record.
I create a bid with a value from within a view of the auction, having the #auction as the local variable.
<% form_for :bid, :url => {:controller => "auction", :action => "add_bids"} do |f|%>
<p>Bid Amount <%= f.text_field :amount %></p>
<%= submit_tag "Add Bid", :auction_id => #auction %>
<% end %>
This is connected to the following code:
def add_bids
#bid = current_user.bids.create(params[:bid])
if #bid.save
flash[:notice] = "New Bid Added"
redirect_to :action => "view_auction", :id => #bid.auction_id
end
end
The problem I am getting is that the auction_id is not put into the bid element. I've tried setting it in the form HTML, but I think I'm missing something very simple.
My Data model, to recap is
Users have both bids and auctions
Auctions have a user and have many bids
Bids have a user and have a auction
I've been struggling with trying to fix this for the past 4 hours and I'm starting to get really downhearted about it all.
Any help would be really appreciated!
You're not quite doing things the Rails way, and that's causing you a bit of confusion.
Successful coding in Rails is all about convention over configuration. Meaning, Rails will guess at what you mean unless you tell it otherwise. There's usually a couple of things it will try if it guesses wrong. But in general stick to the deterministic names and you'll be fine.
There are so many errors in your code, so I'm going to clean it up and put comments every way to let you know what's wrong.
app/models/auction.rb
class Auction < ActiveRecord::Base
belongs_to :creator, :class_name => "User"
has_many :bids
# Given the nature of your relationships, you're going to want to add this
# to quickly find out who bid on an object.
has_many :bidders, :through => :bids
validates_presence_of :title
validates_presence_of :description
validates_presence_of :curprice
validates_presence_of :finish_time attr_reader :bids
#These two methods are unnecessary.
# Also don't override initialize in ActiveRecord. Instead use after_initialize
#def initialize Supplied by rails when you do has_many :bids
# #bids = [] #bids will be populated by what is picked up from
#end the database based on the has_many relationship
#def add_bid(bid) Supplied by rails when you do has_many :bids
# #bids << bid auction.bids << is a public method after has_many :bids
#end
end
app/models/bid.rb
class Bid < ActiveRecord::Base
# :class_name and :foreign_key are ony necessary when rails cannot guess from a
# association name. :class_name default is the association singularized and
# capitalized. :foreign_key default is association_id
belongs_to :auction #, :class_name => "Auction", :foreign_key => "auction_id"
# here we need :class_name because Rails is looking for a Bidder class.
# also there's an inconsistency. Later user refers to has_many bids with
# a foreign_key of owner_id, which one is it? bidder_id or owner_id?
# if it's owner_id? you will need the :foreign_key option.
belongs_to :bidder, :class_name => "User" #, :foreign_key => "bidder_id"
validates_presence_of :amount
validates_numericality_of :amount
# This will never get called in a useful way.
# It really should be done in the migration, setting default
# value for bids.retracted to false
# #retracted = false
end
app/models/user.rb
class User < ActiveRecord::Base
# This makes sense, because an auction can have many bidders, who are also users.
has_many :auctions, :foreign_key => "owner_id"
# This doesn't. A bid belongs to a user, there's no need to change the name.
# See above note re: owner_id vs. bidder_id
has_many :bids, :foreign_key => "owner_id"
# You could also use this to quickly get a list of auctions a user has bid on
has_many :bid_on_auctions, :through => :bids, :source => :auction
... auth stuff ...
end
So far so good, right?
The view isn't bad but it's missing the form parts for the bid amount. This code assumes that you store the value of the bid in an amount column. I also arbitrarily named it auctions/bid
app/views/auctions/bid.html.erb
<% form_for :bid, #auction.bids.new do |f|%>
<%= f.label_for :amount %>
<%= f.text_field :amount%>
<!-- Don't need to supply #auction.id, because form_for does it for you. -->
<%= submit_tag "Add Bid" %>
params hash generated by the form: that is passed to the controller:
params =
{
:bid =>
{
:auction_id => #auction.id
:amount => value of text_field
}
}
params hash generated by the from as you wrote it (note: I'm guessing at names because they were left out of the posted code):
params =
{
:id => #auction_id ,
:bid => { :amount => value of text_field }
}
However, your controller code is where all your problems are coming from this is almost entirely wrong. I'm guessing this is in the auction controller, which seems wrong because you're trying to create a bid. Lets see why:
app/controllers/auctions_controller.rb
...
def add_bids
# not bad, but... #bid will only fill in the owner_id/bidder_id. and bid amount.
#bid = current_user.bids.create(params[:bid])
# create calls save, so this next line is redundant. It still works though.
# because nothing's happening between them to alter the outcome of save.
if #bid.save
flash[:notice] = "New Bid Added"
# you should be using restful routes, this almost works, but is ugly and deprecated.
# it doesn't work becasue #bid.auction_id is never set. In fact you never use
# the auction_id any where, which was in your params_hash as params[:id]
redirect_to :action => "view_auction", :id => #bid.auction_id
end
end
...
Here's how your controller should work. First of all, this should be in the bids_controller, not auctions_controller
app/controllers/bids_controller.rb
...
def create
#bid = Bid.new(params[:bid]) # absorb values from form via params
#bid.bidder = current_user # link bid to current_user.
#auction = bid.auction based on.
# #auction is set, set because we added it to the #bid object the form was based on.
if #bid.save
flash[:notice] = "New Bid Added"
redirect_to #auction #assumes there is a show method in auctions_controller
else
render "auctions/show" # or what ever you called the above view
end
end
...
You'll also need to make sure the following is in your routes.rb (in addition to what may already be there. These few lines will set you up with RESTful routes.
config/routes.rb
ActionController::Routing::Routes.draw do |map|
...
map.resources :auctions
map.resources :bids
...
end
In any case you weren't far off. It seems you're off to a decent start, and could probably benefit from reading a book about rails. Just blindly following tutorials doesn't do you much good if you don't understand the underlying framework. It doesn't help that 90% of the tutorials out there are for older versions of rails and way out of date.
A lot of your code is the old way of doing things. Particularly redirect_to :action => "view_auction", :id => #bid.auction_id and <% form_for :bid, :url => {:controller => "auction", :action => "add_bids"} do |f|%>. With RESTful routing, they become redirect_to #auction and <% form_for #auction.bid.new do |f| %>`
Here's something resources you should read up on:
ActiveRecord::Associations: defines has_many, belongs_to, their options, and the convenience methods they add.
Understanding MVC: Provides a better understanding of the flow of information as it relates to Rails
RESTful resources: Understanding resources.
Form Helpers: In depth description of form_for and why the above code works.

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