Check box that creates nested objects in rails - ruby-on-rails

I'm building an app that creates exams. For the part where a user selects the answers on the exam, I want to use a checkbox (or a radio button) to allow them to pick the answer.
I want all the user-selected answers to be a table in itself called "responses". I can't figure out how to use a radio button to create records.
All the response record needs to do is take the ID's of the Exam, User, and Score. Score is a table that tracks the user's scores and the number of correct answers.
Here's my examination model (rails wouldn't let me use the word "exam"). I have it set for nested attributes.
class Examination < ApplicationRecord
belongs_to :user
has_many :questions, dependent: :destroy
has_many :scores
has_many :responses
has_secure_password
accepts_nested_attributes_for :responses, allow_destroy: true
end
The response model is pretty basic:
class Response < ApplicationRecord
belongs_to :user
belongs_to :score
belongs_to :examination
end
Here's the "take an exam" page:
<%= link_to "Back to all exams", examinations_path %>
<h2><%= #exam.name %></h2>
<h3><%= #exam.intro %></h3>
<%= form_for #exam do |f| %>
<%= f.hidden_field :name, value: #exam.name %>
<%= fields_for :responses do |res_f| %>
<% #exam.questions.each_with_index do |question, i| %>
<% index = i + 1 %>
<h2>Question #<%=index%></h2><span style="font-size: 24px; font-weight: normal">(<%= question.points %> Points)</span>
<hr>
<h3><%= question.body %></h3>
<% question.answers.each do |ans| %>
<table>
<tr>
<td><%= res_f.check_box :answer_id , ans.id, :examination_id , #exam.id, :user_id %></td>
<td><%= ans.body %></td>
</tr>
</table>
<% end %>
<% end %>
<% end %>
<%= f.submit 'Submit' %>
<% end %>
This code doesn't run because Rails expects the responses records to exist in order to use the form. It throws this error:
undefined method `merge' for 484:Integer
If I tweak that checkbox code to this:
<%= res_f.check_box :answer_id %>
The code will run and it will give me the following params on submit:
Started PATCH "/examinations/34" for 127.0.0.1 at 2018-02-24 16:22:41 -0800
Processing by ExaminationsController#update as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"y4vcPByUKnDdM6NsWDhwxh8MxJLZU4TQo+/fUrmKYEfb3qLn5FVieJAYirNRaSl0w5hJax20w5Ycs/wz1bMEKw==", "examination"=>{"name"=>"Samuel Smith’s Oatmeal Stout"}, "responses"=>{"answer_id"=>"1"}, "commit"=>"Submit", "id"=>"34"}
I know it's not right but I was hoping it would create a record at least. All the checkbox has to do it create a response record. It should be able to grab the answer_id, exam_id and user_id. That's it.
Does anyone know how to do this?
Edit in response to Pablo 7:
Here are the other models (they're pretty basic right now)
class Score < ApplicationRecord
belongs_to :user
belongs_to :examination
has_many :responses, dependent: :destroy
end
class User < ApplicationRecord
has_many :examinations, dependent: :destroy
has_many :scores, dependent: :destroy
has_many :responses, dependent: :destroy
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
end
class Question < ApplicationRecord
belongs_to :examination
has_many :answers, dependent: :destroy
accepts_nested_attributes_for :answers, allow_destroy: true
validates_presence_of :body
validates_presence_of :question_type
end
#exam and Examination are the same. There is a "take" action in the Examination controller that allows a user to take an exam:
def take
#exam = Examination.find(params[:id])
#score = #exam.scores.build
#score.user_id = current_user.id
#score.save
end
So an exam belongs to the user that created it. The same user or a different one can take an exam using the take action. They would then have a score that belongs to them.

I think you must do some changes to your models:
A Response should belong to a Question (it's the question the user is responding).
A Response should belong to an Answer (it's the correct Answer for the question; the one that the user checks). If you want to allow multiple correct answers, this should be changed.
A Response should not belong to an Examination and should not belong to a User. In fact, a Response belongs to a Score and that's enough because the Score already belongs to an Examination and to a User.
An Examination should not have many responses. In fact, an Examination has many scores and scores have many responses. If you want, you can use has_many :responses, through: :scores
A User should not have many Responses. They have many Scores and Scores have many Responses. If you want, you can use has_many :responses, through: :scores
When you create a new score (in take), you should create empty responses for each question in the examination:
def take
#exam = Examination.find(params[:id])
#score = #exam.scores.build(user_id: current_user.id)
#exam.questions.each { |question| #score.responses.build(question_id: question.id) }
#I don't think you should save here.
#This method is like the new method
#You should save when the score is submitted
##score.save
end
In your form:
I would change the form to the score model (not examination). If you are using nested routes it could be [#exam, #score]
This may have many errors, as I cannot test it right now. I hope the idea is clear:
<%= form_for #score do |f| %>
<%= f.hidden_field :name, value: #score.examination.name %>
<% #score.responses.each_with_index do |response, i| %>
<%= f.fields_for response do |res_f| %>
<% index = i + 1 %>
<h2>Question #<%= index %></h2>
<span style="font-size: 24px; font-weight: normal">
(<%= response.question.points %> Points)
</span>
<hr>
<h3><%= response.question.body %></h3>
<%= res_f.collection_radio_buttons :answer_id, response.question.answers, :id, :body %>
<% end %>
<% end %>
<%= f.submit 'Submit' %>
<% end %>
The submit should call a method in Score model to create a Score (ScoresController.create)

Thanks Pablo, I finally got it working. Your code didn't quite work but it put me on the right path. I changed the model associations around as you suggested. That does make more sense.
Here are my models:
class Answer < ApplicationRecord
belongs_to :question
has_many :responses, dependent: :destroy
end
class Examination < ApplicationRecord
belongs_to :user
has_many :questions, dependent: :destroy
has_many :answers, :through => :questions
has_many :scores
has_secure_password
end
class Question < ApplicationRecord
belongs_to :examination
has_many :answers, dependent: :destroy
has_many :responses
accepts_nested_attributes_for :answers, allow_destroy: true, :reject_if => :all_blank
validates_presence_of :body
validates_presence_of :question_type
end
class Response < ApplicationRecord
belongs_to :score
belongs_to :answer
belongs_to :question
end
class Score < ApplicationRecord
belongs_to :user
belongs_to :examination
has_many :responses, dependent: :destroy
accepts_nested_attributes_for :responses, allow_destroy: true, reject_if: :no_answer_id?
private
def no_answer_id?(att)
att['answer_id'].blank?
end
end
I had to add that special method to the Score model to account for unchecked responses. Otherwise, it would throw an error.
I moved the "take a test" logic and view to the Score controller. With your code, I was getting a double loop (questions listed multiple times). I learned that you can actually access the responses through the "form_for" form loop using "res_f.object". That's pretty cool.
I also had to add a hidden field on the radio button collection form to get the question id.
Here it is:
<%= link_to "Back to all exams", examinations_path %><br/>
<h2><%= #exam.name %></h2>
<h3><%= #exam.intro %></h3>
<%= form_for [#exam, #score] do |f| %>
<%= f.hidden_field :user_id, value: current_user.id %>
<%= f.fields_for :responses do |res_f| %>
<h2>Question # <%= res_f.object.question.position %></h2>
<span style="font-size: 24px; font-weight: normal">
(<%= res_f.object.question.points %> Points)
</span>
<hr>
<h3><%= res_f.object.question.body %></h3>
<p><%= res_f.collection_radio_buttons :answer_id, res_f.object.question.answers, :id, :body do |b| %></p>
<div>
<%= b.radio_button %>
<%= b.label %>
<%= res_f.hidden_field :question_id, value: res_f.object.question.id %>
</div>
<% end %>
<% end %>
<%= f.submit 'Submit' %>
<% end %>
And the Scores controller:
class ScoresController < ApplicationController
def new
#exam = Examination.find(params[:examination_id])
#score = #exam.scores.build(user_id: current_user.id)
#exam.questions.each do |question|
res = #score.responses.build(question_id: question.id)
logger.info question.id
logger.info res
end
end
def create
#exam = Examination.find(params[:examination_id])
#score = #exam.scores.build(score_params)
if #score.save
redirect_to examination_path(#exam)
else
logger.info #score.errors.full_messages
redirect_to root_path
end
end
protected
def score_params
params.require(:score).permit(:examination_id, :user_id,
responses_attributes: [:id, :answer_id, :question_id, :selected])
end
end
This all works fine if there is only one correct answer. I'll have to modify it later to account for multiple answers. At least it works! I'll give you the credit Pablo.
Cheers

Related

Rails has_many :through nested forms with simple form

I am trying to make a player character generator. I have a form that hopefully will allow me to attach skills with their values to a character sheet model. I made models like this:
class CharacterSheet < ApplicationRecord
has_many :character_sheet_skills, dependent: :destroy
has_many :skills, through: :character_sheet_skills
belongs_to :user
accepts_nested_attributes_for :skills
end
class Skill < ApplicationRecord
has_many :character_sheet_skills, dependent: :destroy
has_many :character_sheets, through: :character_sheet_skills
attr_reader :value
end
class CharacterSheetSkill < ApplicationRecord
belongs_to :skill
belongs_to :character_sheet
end
Character sheet model holds data about player character and skill model has all skills available in game. In CharacterSheetSkill I'd like to store the skills that the player chooses for his character together with an integer field setting the skill value.
When opening form, I already have a full list of skills in database. All I want to do in form is create a character sheet that has all of these skills with added value. I tried using "fields_for" in form, but I couldn't really get that to work. Right now it looks like this:
<%= simple_form_for [#user, #sheet] do |f| %>
<%= f.input :name %>
<%= f.input :experience, readonly: true, input_html: {'data-target': 'new-character-sheet.exp', class: 'bg-transparent'} %>
...
<%= f.simple_fields_for :skills do |s| %>
<%= s.input :name %>
<%= s.input :value %>
<% end %>
<% end %>
How can I make that form so it saves character sheet together with CharacterSheetSkills?
A better idea here is to use skills as a normalization table where you store the "master" definition of a skill such as the name and the description.
class CharacterSheetSkill < ApplicationRecord
belongs_to :skill
belongs_to :character_sheet
delegate :name, to: :skill
end
You then use fields_for :character_sheet_skills to create rows on the join table explicitly:
<%= f.fields_for :character_sheet_skills do |cs| %>
<fieldset>
<legend><%= cs.name %></legend>
<div class="field">
<%= cs.label :value %>
<%= cs.number_field :value %>
</div>
<%= cs.hidden_field :skill_id %>
</fieldset>
<% end %>
Instead of a hidden fields you could use a select if you want let the user select the skills.
Of course nothing will show up unless you "seed" the inputs:
class CharacterSheetController < ApplicationController
def new
#character_sheet = CharacterSheet.new do |cs|
# this seeds the association so that the fields appear
Skill.all.each do |skill|
cs.character_sheet_skills.new(skill: skill)
end
end
end
def create
#character_sheet = CharacterSheet.new(character_sheet_params)
if #character_sheet.save
redirect_to #character_sheet
else
render :new
end
end
private
def character_sheet_params
params.require(:character_sheet)
.permit(
:foo, :bar, :baz,
character_sheet_skill_attributes: [:skill_id, :value]
)
end
end

Rails: Passing nested attribute parameters

So im working through the Odin Project's "Flight Booker" project. https://www.theodinproject.com/courses/ruby-on-rails/lessons/building-advanced-forms. Which essentially is what it sounds like and im running into a problem with passing nested attributes.
First and foremost the Relevant Models:
class Booking < ApplicationRecord
belongs_to :passenger
belongs_to :flight
accepts_nested_attributes_for :passenger
end
class Flight < ApplicationRecord
has_many :bookings, dependent: :destroy
has_many :passengers, through: :bookings
belongs_to :to_airport, class_name: 'Airport', foreign_key: 'origin_id'
belongs_to :from_airport, class_name: 'Airport', foreign_key: 'destination_id'
end
class Passenger < ApplicationRecord
has_many :bookings, dependent: :destroy
has_many :flights, through: :bookings
end
The passenger schema just contains an email and name for right now. But the problem is when I pass the information to the "booking" controller. Here is my "New" form for booking.
<%= form_for #booking do |f| %>
<%= f.hidden_field :flight_id, value: params[:booking][:flight_num] %>
<%= f.hidden_field :passengers_num, value: params[:booking][:passengers_num] %>
<% params[:booking][:passengers_num].to_i.times do |passenger| %>
<%= fields_for :passenger do |passenger| %>
<%= passenger.label :name, 'Name', class: "Label" %>
<%= passenger.text_field :name %>
<%= passenger.label :email, 'email', class: "Label" %>
<%= passenger.email_field :email %>
<% end %>
<% end %>
<%= f.submit "Book Flight" %>
<% end %>
(Ignore the hidden fields for now, they are passed from the "Flights" search page and Im getting those just fine.)
So I am getting the multiple forms (name and email fields) but when I "Submit" I am only getting parameters for the last field sets. (So if there are 3 sets of name/email fields, I only get parameters for the last one).
It's possible im not understanding the fields_for however as I can't find a ton of good examples.
Thanks!
There could be many issues with your implementation...I'll layout a few...
Move <% params[:booking][:passengers_num].to_i.times do |passenger| %> logic into the new action of your bookings controller...ie
def new
#booking = Booking.new
3.times { #booking.passengers.new } # or whatever your logic is to display x amount of passenger fields
end
Make sure that in your bookings controller you are permitting the nested attributes like this...
params.require(:booking).permit(passengers_attributes: [:name, :email])
As far as the form, you'll need to treat it like a form within a form (makes sense...nested attributes created from a nested form!) and use the block variable...like this
<ul>
<%= f.fields_for :passengers do |passenger_form| %>
<li>
<%= passenger_form.label :name
<%= passenger_form.text_field :name %>
</li>
<!-- other permitted fields -->
<% end %>
</ul>

How to validate presence of at least one nested object?

Code
class Survey < ApplicationRecord
has_many :questions, inverse_of: :survey, :dependent => :destroy
accepts_nested_attributes_for :questions
validates_associated :questions
end
class Question < ApplicationRecord
belongs_to :survey, inverse_of: :questions
validates_presence_of :survey
end
My Surveys Controller
def new
#survey = Survey.new
2.times {#survey.questions.build}
end
Form
<%= form_for #survey do |f|%>
<p>
<%= f.label :name%>
<%= f.text_field :name%>
</p>
<%= f.fields_for :questions do |builder|%>
<p>
<%= builder.text_area :content, rows: 3%>
</p>
<% end %>
<p><%= f.submit %></p>
<% end %>
As you can see when user creates a survey the form provides two questions, i want user to supply at least one question when creating the survey. How can it be achieve???
You could just test for the length of the array and simply do:
validates :questions, length: {minimum: 1, message: 'should have at least 1 question defined.'}
One of the options is to use custom validation:
validate :questions_count
private
# or something more explicit, like `at_least_one_question` (credits to #MrYoshiji)
def questions_count
errors.add(
:base,
'You can not save a survey without questions. Add at least one question'
) if questions.none?
end
Basically, the validation will be fired every time you create or "touch" (update) the survey object, and it will fail, if survey will not have at least one question associated.

Nested checkboxes in Rails

I'm trying to create an event app where each event has multiple tables and each table has multiple people sitting at a table the event has multiple tickets which map the people to the tables that they are sitting at -> in order to achieve this I have created a checkbox nested in the fields_for :tables (which is in turn in the event form) I presume something is wrong with either the strong parameters or the form itself but I have not been able to find any information that provides a solution to the problem.After checking the checkboxes in the form indicating which people are going to be sitting at this table and submitting the form and returning to the form I find that the checkboxes are no longer checked???
here are the contents of my model files
# models
class Event < ActiveRecord::Base
has_many :tables, dependent: :destroy
has_many :people , through: :tickets
has_many :tickets
accepts_nested_attributes_for :tickets, allow_destroy: true
accepts_nested_attributes_for :tables, allow_destroy: true
end
class Table < ActiveRecord::Base
belongs_to :event
has_many :tickets
has_many :people, through: :tickets
end
class Ticket < ActiveRecord::Base
belongs_to :table
belongs_to :person
end
class Person < ActiveRecord::Base
has_many :tickets
has_many :tables, through: :tickets
end
Here is the form with parts omitted for brevity.
<%= form_for(#event) do |f| %>
...
<%= f.fields_for :tables do |builder| %>
<%= render 'table_field', f: builder %>
<% end %>
<%= link_to_add_fields "Add Table", f, :tables %>
...
<% end %>
And here is the checkbox list I have implemented within the table_field.
<% Person.all.each do |person| %>
<div class="field">
<%= check_box_tag "table[people_ids][]", person.id, f.object.people.include?(person) %> <%= f.label [person.first_name, person.last_name].join(" ") %>
</div>
<% end %>
this is the event_params
def event_params
params.require(:event).permit(:name, :description, :start, :end, :latitude, :longitude, :address, :data, :people_ids => [], tables_attributes: [:id, :number, :size, :people_ids => []]).tap do |whitelisted|
whitelisted[:data] = params[:event][:data]
end
How do I get the checkboxes to be persistently checked in this form?
You can use http://apidock.com/rails/v4.0.2/ActionView/Helpers/FormOptionsHelper/collection_check_boxes
<%= f.collection_check_boxes(:people_ids, Person.all, :id, :name) do |person| %>
<%= person.label { person.check_box } %>
<% end %>
It will persist data as well.

rails nested form with has_many :through relationship

Here are my models:
class Project < ActiveRecord::Base
has_many :project_applications
has_many :questions
accepts_nested_attributes_for :questions, :allow_destroy => true, :reject_if => proc { |a| a[:content].blank? }
end
class Question < ActiveRecord::Base
belongs_to :project
has_many :answers
has_many :project_applications, through: :answers
end
class Answer < ActiveRecord::Base
belongs_to :question
belongs_to :project_application
end
class ProjectApplication < ActiveRecord::Base
belongs_to :project
belongs_to :student
has_many :answers
has_many :questions, through: :answers
end
A project is created by an employer, and a student can create a project_application. The project_application should present the questions and then show form fields that correspond to the questions answers. I cannot for the life of me figure out how the form view should look. I need a form_for ProjectApplication that accepts nested attributes for answers. I have the following in my controller:
class ProjectApplicationsController < ApplicationController
def new
#project = Project.find(params[:project_id])
#project_application = ProjectApplication.new
#project_application.project = #project
#project_application.project.questions.each do |question|
#answer = question.answers.build
#answer.project_application = #project_application #this line does not work
puts 'answer' + #answer.inspect.to_s
end
puts 'here are the answers' + #project_application.answers.inspect.to_s
end
end
The problem with this is that the answers are not correctly being associated with project_applications because the project_applications don't have an id yet (because they have not been created) so the association can't happen, so the answer fields are not displayed. Here is the view code (does not work) that I have now:
<%= form_for #project_application, url: project_project_applications_path(#project.id), method: :post, remote: true do |f| %>
<%= f.fields_for :project do |proj| %>
<%= proj.fields_for :questions do |quest| %>
<%= quest.fields_for :answers do |answer| %>
<%= answer.text_area :content %>
<% end %>
<% end %>
<% end %>
<%= f.submit "APPLY" %>
<% end %>
How do I change the view and/or controller to properly display answer fields correctly associated with questions and the project application?
My understanding:
You have projects
Each project has many questions & project_applications
Each question belongs to a project, has many answers through project_applications
For each project, you'd like to create applications with the applicable answers. Here's what I'd do:
Models
class Project < ActiveRecord::Base
has_many :project_applications
has_many :questions
end
class Question < ActiveRecord::Base
belongs_to :project
has_many :answers
has_many :project_applications, through: :answers
end
class Answer < ActiveRecord::Base
belongs_to :question
belongs_to :project_application
end
class ProjectApplication < ActiveRecord::Base
belongs_to :project
belongs_to :student
has_many :answers
has_many :questions, through: :project
accepts_nested_attributes_for :answers
def self.build
application = self.new
application.answers.build
end
end
Controller
#app/controllers/project_applications_controller.rb
def new
#projectapplication = ProjectApplication.build
#project = #projectapplication.project
end
def create
end
private
def application_params
params.require(:project_application).permit(:application, :attributes, :here, answer_attributes: [:content])
end
Views
#app/views/project_applications/new.html.erb
<%= form_for #projectapplication do |f| %>
<%= f.text_field :application_fields %>
<% #project.questions.each do |question| %>
<%= f.fields_for :answers, question do |answer| %>
<%= answer.hidden_field :question_id, question.id %>
<%= answer.text_field :content, placeholder: question.content %>
<% end %>
<% end %>
<% end %>
Process
This works by creating a new project_application, sending answers directly to the answer model. Because answers are directly associated with questions, and projectsthrough questions, you should be able to get it working without passing any more data
This might not work outright, but I'm sure with some tweaking it will deliver the desired result

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