I have two models.
Question.rb
Class Question
belongs_to :quiz
has_many :possible_answers
end
PossibleAnswer.rb
Class possible_answer
belongs_to :question
end
I am trying to add multiple possible answers to a question by doing these changes to questions controller and form.
questions_controller.rb
def new
#question = #quiz.questions.build
5.times { #question.possible_answers.build }
end
_form.html.erb
<p>
<label>Specify some choices:</label>
</p>
<%= f.fields_for :possible_answers do |c| %>
<p>
<%= c.text_field :title, placeholder: "Type your choice", class: "form-control" %>
</p>
<% end %>
By what I read it should give 5 fields to enter possible answers, but instead still giving single field. Can anybody please help me out here ?
I think you must do it this way:
def new
#question = #quiz.questions.build
5.times { #question.possible_answers << Possible_answer.build }
end
Related
Setup
I have a simple many to many relationship between a Submit and an Answer through SubmitAnswer.
Answers are grouped by a Question (in my case each question has three answers) - think of it as a multiple choice quiz.
I have been trying to use SimpleFormFor to make a form which renders a predetermined set of questions, where each question has a predetermined set of answers.
Something like this:
#form
<%= simple_form_for Submit.new, url: "/questionnaire" do |f| %>
<% #questions.each do |question| %>
<%= f.association :answers, collection: question.answers %>
<% end %>
<%= f.submit :done %>
<% end %>
#controller
def create
#submit = Submit.new(submit_params)
#submit.user = current_user
if #submit.save
redirect_to root_path
else
render :new
end
end
def submit_params
params.require(:submit).permit(answer_ids: [])
end
When I submit the form, Rails creates the join table, SubmitAnswers, automatically.
So here is the crux of the matter: Whats the easiest way to re-render the form, errors and all, if not all questions have been answered, ie if #submit.answers.length != #question.length ?
I can add a custom error with errors.add(:answers, 'error here'), but when I re-render, the correctly selected answers arent repopulated, which is suboptimal.
For completions sacke, here are my models:
class Submit < ApplicationRecord
belongs_to :user
has_many :submit_answers
has_many :answers, through: :submit_answers
end
class SubmitAnswer < ApplicationRecord
belongs_to :submit
belongs_to :answer
end
class Answer < ApplicationRecord
has_many :submit_answers
has_many :submits, through: :submit_answers
end
Alright, after some digging we did find the answer to make the form work, albeit with more pain that we anticipated a simple many-to-many should take.
#model
class Submit < ApplicationRecord
belongs_to :user
has_many :submit_answers
has_many :answers, through: :submit_answers
accepts_nested_attributes_for :submit_answers
end
#controller
def new
#submit = Submit.new
#questions.count.times { #submit.submit_answers.build }
end
def create
#submit = Submit.new(submit_params)
#submit.user = current_user
if #submit.save
redirect_to root_path
else
render :home
end
end
def submit_params
params.require(:submit).permit(submit_answers_attributes:[:answer_id])
end
#form
<%= simple_form_for #submit do |f| %>
<%= f.simple_fields_for :submit_answers do |sa| %>
<%= sa.input :answer_id, collection: #answers[sa.options[:child_index]], input_html: { class: "#{'is-invalid' if sa.object.errors.any?}"}, label: #questions[sa.options[:child_index]].name %>
<div class="invalid-feedback d-block">
<ul>
<% sa.object.errors.full_messages.each do |msg| %>
<li> <%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<%= f.submit :done %>
<% end %>
The solution is to use simple_fields_for/fields_for. Note that <%= sa.input :answer_id %> must be :answer_id, not :answer, which is something I had tried before.
Also one must allow accepts_nested_attributes_for :submit_answers, where :submit_answers is the join_table.
I prebuild my SubmitAnswers like so: #questions.count.times { #submit.submit_answers.build } which generates an input field for each question, all of which get saved on the form submit, a la build.
For the strong_params one needs to permit the incoming ids:
params.require(:submit).permit(submit_answers_attributes:[:answer_id]), so in this case submit_answers_attributes:[:answer_id].
For anyone wondering what the params look like:
{"authenticity_token"=>"[FILTERED]",
"submit"=>
{"submit_answers_attributes"=>
{"0"=>{"answer_id"=>""}, "1"=>{"answer_id"=>""}, "2"=>{"answer_id"=>""}, "3"=>{"answer_id"=>""}, "4"=>{"answer_id"=>""}, "5"=>{"answer_id"=>""}, "6"=>{"answer_id"=>""}}},
"commit"=>"done"}
As for the errors, im sure there might be a better way, but for now I have just manually added them with input_html: { class: "#{'is-invalid' if sa.object.errors.any?}"}.
On a final note, the sa.object # => SubmitAnswer allows me to retrieve the Model, the errors of that Model or whatever else one might want.
I am a new student learning about Ruby on Rails. For my current assignment I have to build a Question feature. Everything works but the deletion of a "Question".
I am trying to follow the Form Helper One to Many. Thanks for looking.
Instructions
Complete QuestionsController and its corresponding views. Accept input for resolved in the Question form using a checkbox.
Test your changes in the browser. Confirm that you can:
see an index of all questions,
view an individual question,
create new questions,
edit and update questions, and
delete questions.
When I go to edit a question and then proceed to delete it with the checkbox this error is thrown:
No association found for name `question'. Has it been defined yet?
Here is my console output:
Started GET "/questions/1/edit" for ::1 at 2015-04-23 15:42:11 -0400
Processing by QuestionsController#edit as HTML
Parameters: {"id"=>"1"}
Completed 500 Internal Server Error in 2ms (ActiveRecord: 0.0ms)
ArgumentError (No association found for name `question'. Has it been defined yet?):
app/models/question.rb:3:in `<class:Question>'
app/models/question.rb:1:in `<top (required)>'
app/controllers/questions_controller.rb:27:in `edit'
questions_controller.rb
class QuestionsController < ApplicationController
def index
#questions = Question.all
end
def show
#question = Question.find(params[:id])
end
def create
#question = Question.new(params.require(:question).permit(:title, :body, :resolved))
if #question.save
flash[:notice] = "Question was saved."
redirect_to #question
else
flash[:error] = "There was an error saving the question. Please try again."
render :new
end
end
def new
#question = Question.new
end
def edit
#question = Question.find(params[:id])
end
def update
#question = Question.find(params[:id])
if #question.update_attributes(params.require(:question).permit(:title, :body, :resolved, :_destroy))
flash[:noteice] = "Question was updated."
redirect_to #question
else
flash[:error] = "There was an error saving the question. Please try again."
render :edit
end
end
end
question.rb
class Question < ActiveRecord::Base
has_many :answers
accepts_nested_attributes_for :question, allow_destroy: true
end
edit.html.erb
<div class="col-md-8">
<%= form_for #question do |f| %>
<div class="form-group">
<%= f.label :title %>
<%= f.text_field :title, class: 'form-control', placeholder: "Enter question title" %>
</div>
<div class="form-group">
<%= f.label :body %>
<%= f.text_area :body, rows: 8, class: 'form-control', placeholder: "Enter question body" %>
</div>
<div class="form-group">
<%= f.label :resolved %>
<%= f.check_box :resolved %>
</div>
<div class="form-group">
<%= f.label :destroy %>
<%= f.check_box :_destroy %>
</div>
<div class="form-group">
<%= f.submit "Save", class: 'btn btn-success' %>
</div>
<% end %>
Edit: added my answers.rb.
answers.rb
class Answer < ActiveRecord::Base
belongs_to :question
end
Nested attributes are for the relation. Your Question has many Answers. The point of accepts_nested_attributes_for is that it lets you update "nested" associations from the parent model. The argument is the name of the association to accept attributes for. In this case, your questions should accept nested attributes for their answers:
class Question < ActiveRecord::Base
has_many :answers
accepts_nested_attributes_for :answers
end
See the documentation, where the example class Book accepts nested attributes for author and pages. A Book does not accept nested attributes for a book, similarly your question should not accept nested attributes for a question.
As far as deleting the question, you cannot use accepts_nested_attributes to point a model back to itself so that _destroy will destroy the parent model.
You'll have to check for the presence of that attribute and destroy the record in your controller.
The problem is the accepts_nested_attributes_for line in the Question class.
You wrote
accepts_nested_attributes_for :question
but it likely should be
accepts_nested_attributes_for :answers
since that is the name of the has_many relationship. Rails is barking because there is no such relationship called :question inside the Question class. Your class should look like this:
class Question < ActiveRecord::Base
has_many :answers
accepts_nested_attributes_for :answers, allow_destroy: true
end
You need in answers.rb
belongs_to :question
in order to complete the association
I have migrated the :bank_name and :bank_account objects in User model.
I want two objects can be define from the Listings model in the listings/view to the User model columns.
I have already done (belongs_to, has_many)relations between two models.
But when I filled the bank_name and bank_account text_fields in Listing/view, I get the following error:
undefined method `bank_name' for #Listing:400123298
Here is my listing/view code:
<%= form_for(#listing, :html => { :multipart => true }) do |f| %>
...
<div class="form-group">
<%= f.label :bank_name %><br>
<%= f.text_field :bank_name, class: "form-control" %>
</div>
<div class="form-group">
<%= f.label :bank_account %><br>
<%= f.text_field :bank_account, class: "form-control" %>
</div>
</end>
listing/controller:
def new
#listing = Listing.new
end
def create
#listing = Listing.new(listing_params)
#listing.user_id = current_user.id
#listing.user_id = User.bank_name.build(params[:bank_name])
#listing.user_id = User.bank_account.build(params[:bank_account])
end
Several issues for you
Nested
As mentioned in the comments, what you're looking at is a nested model structure.
Simply, this means you'll be able to create an associative model from your "parent" - giving you the ability to define the attributes you need in your "parent" model, passing them through to the nested. This functionality is handled by accepts_nested_attributes_for in your parent model
The best resource you can use is this Railscast (only the start):
--
Fix
Here's how you can fix the problem:
#app/models/listing.rb
class Listing < ActiveRecord::Base
belongs_to :user
accepts_nested_attributes_for :user
end
#app/models/user.rb
class User < ActiveRecord::Base
has_one :bank_account
accepts_nested_attributes_for :bank_account
end
#app/models/bank_account.rb
class BankAccount < ActiveRecord::Base
belongs_to :user
end
#app/controllers/listings_controller.rb
class ListingsController < ApplicationController
def new
#listing = current_user.listings.new
#listing.user.build_bank_account
end
def create
#listing = Listing.new listing_params
#listing.save
end
private
def listing_params
params.require(:listing).permit(:listing, :params, user_attributes: [ bank_account_attributes: [] ])
end
end
This will help you do the following:
#app/views/listings/new.html.erb
<%= form_for #listing do |f| %>
...
<%= f.fields_for :user do |u| %>
<%= u.fields_for :bank_account do |b| %>
<%= b.text_field :name %>
<%= b.text_field :number %>
<% end %>
<% end %>
<%= f.submit %>
<% end %>
There is a slight twist to this tail, in that I'm not sure whether your passing of attributes through to your User model. This would be okay if the user was being created at the same time as your other attributes, but as it isn't, we may need to refactor the process of passing the nested data through
If this does not work, please comment & we can work to fix it!
I have 3 text_fields in my view in which I enter students name. Of course you can enter one student or three students but I want to make sure that at least one student was provided because a project must have a student assigned to it.
Here is my view:
<%= form_for #project, url: projects_path do |f| %>
<p>
<%= f.label :name, "Name" %>
<%= f.text_field :name %>
</p>
<p>
<%= f.fields_for :students do |s| %>
<%= s.label :name %>
<%= s.text_field :name %>
<% end %>
</p>
<p>
<%= f.submit "Submit" %>
</p>
<% end %>
And new method from Projects controller:
def new
#project = Project.new()
3.times do
student = #project.students.build
end
end
What I want to achieve is to check if at least one student was provided and if not just show alert or disable submiting.
Edit
Models used in this project:
class Student < ActiveRecord::Base
belongs_to :project
end
class Project < ActiveRecord::Base
has_many :students
accepts_nested_attributes_for :students
validate :validate_student_count
def validate_student_count
errors.add(:students, "at least one is required") if students.count < 1
end
end
Lots of very similar questions on the internet. Here's some examples: Validate the number of has_many items in Ruby on Rails and Validate that an object has one or more associated objects
Just add a custom validation rule as:
validate :validate_student_count
def validate_student_count
errors.add(:students, "at least one is required") if students.count < 1
end
I am using build, fields_for, and accepts_nested_attributes_for to create a new registration note on the same form as a new registration (has many registration notes). Great.
Problem: On the edit form for the existing registration, I want another new registration note to be created, but I don't want to see a field for each of the existing registration notes.
I have this
class Registration < ActiveRecord::Base
attr_accessible :foo, :bar, :registration_notes_attributes
has_many :registration_notes
accepts_nested_attributes_for :registration_notes
end
and this
class RegistrationsController < ApplicationController
def edit
#registration = Registration.find(params[:id])
#registration.registration_notes.build
end
end
and in the view I am doing this:
<%= form_for #registration do |r| %>
<%= r.text_field :foo %>
<%= r.text_field :bar %>
<%= r.fields_for :registration_notes do |n| %>
<%= n.text_area :content %>
<% end %>
<% end %>
and it is creating a blank text area for a new registration note (good) and each existing registration note for that registration (no thank you).
Is there a way to only create a new note for that registration and leave the existing ones alone?
EDIT: My previous answer (see below) was bugging me because it's not very nice (it still loops through all the other registration_notes needlessly). After reading the API a bit more, the best way to get the behaviour the OP wanted is to replace:
<%= r.fields_for :registration_notes do |n| %>
with:
<%= r.fields_for :registration_notes, #registration.registration_notes.build do |n| %>
fields_for optionally takes a second parameter which is the specific object to pass to the builder (see the API), which is built inline. It's probably actually better to create and pass the new note in the controller instead of in the form though (just to move the logic out of the view).
Original answer (I was so close):
Just to clarify, you want your edit form to include a new nested registration note (and ignore any other existing ones)? I haven't tested this, but you should be able to do so by replacing:
<%= r.fields_for :registration_notes do |n| %>
with:
<%= r.fields_for #registration.registration_notes.build do |n| %>
EDIT: Okay, from a quick test of my own that doesn't work, but instead you can do:
<%= r.fields_for :registration_notes do |n| %>
<%= n.text_area :content if n.object.id.nil? %>
<% end %>
This will only add the text area if the id of the registration note is nil (ie. it hasn't been saved yet).
Also, I actually tested this first and it does work ;)
If you want to create a new registration form on your edit action, you can just instantiate a new registration_note object. Right now, your form is for the existing registration object.
I believe this is what you want:
class RegistrationsController < ApplicationController
def edit
#new_registration_note = RegistrationNote.new
#registration = Registration.find(params[:id])
#registration.registration_notes.build
end
end
In your view, you should pass a hidden param that references the registration record id:
<%= form_for #new_registration_note do |r| %>
<%= r.hidden_field :registration_id, :value => #registration.id %>
<%= r.text_area :content %>
<% end %>
Now, you can create your new registration note that belongs to #registration. Make sure you have a column in your registration_notes table to point to the registration. You can read more about associations here: http://guides.rubyonrails.org/association_basics.html
Thank you so much for your help as I said in my post the only problem with the approach from "Zaid Crouch"(I don't know how to make a reference to a user hehe) is that if the form has error fields the form will be clear and boom after the page reloading you'll have nothing filled in your form and can you imagine if you form is like 20 or 30 fields that would be a terrible user experience of course
Here is my solution that works with validation models:
class Registration < ActiveRecord::Base
attr_accessible :foo, :bar, :registration_notes_attributes
has_many :registration_notes
has_one :new_registration, class_name: 'RegistrationNote'
accepts_nested_attributes_for :new_registration
end
class RegistrationsController < ApplicationController
def edit
#registration = Registration.find(params[:id])
#registration.build_new_registration
end
end
<%= form_for #registration do |r| %>
<%= r.text_field :foo %>
<%= r.text_field :bar %>
<%= r.fields_for :new_registration do |n| %>
<%= n.text_area :content %>
<% end %>
<% end %>
I'm using simple_form in my example if you want to see the same working with validations and transaction take a look at the complete post here:
http://elh.mx/ruby/using-simple_form-for-nested-attributes-models-in-a-has_many-relation-for-only-new-records/
As Heriberto Perez correctly pointed out the solution in the most upvoted answer will simply discard everything if there's a validation error on one of the fields.
My approach is similar to Heriberto's but nevertheless a bit different:
Model:
class Registration < ActiveRecord::Base
has_many :registration_notes
accepts_nested_attributes_for :registration_notes
# Because 0 is never 1 this association will never return any records.
# Above all this association don't return any existing persisted records.
has_many :new_registration_notes, -> { where('0 = 1') }
, class_name: 'RegistrationNote'
accepts_nested_attributes_for :new_registration_notes
end
Controller:
class RegistrationsController < ApplicationController
before_action :set_registration
def edit
#registration.new_registration_notes.build
end
private
def set_registration
#registration = Registration.find(params[:id])
end
def new_registration_params
params.require(:registration).permit(new_registrations_attributes: [:content])
end
end
View:
<%= form_for #registration do |r| %>
<%= r.text_field :foo %>
<%= r.text_field :bar %>
<%= r.fields_for :new_registration_notes do |n| %>
<%= n.text_area :content %>
<% end %>
<% end %>