Creating a belongs to association on a two way Many to Many - ruby-on-rails

QUESTION:
How would I create an association be between the a new model: post.rb and existing 2 models: category + work models? And how would I pluck the post.rb's attribute content:text, so that I may add a unique post from the work#new -> _form partial
I have a many to many relationship between work and category models :through categorywork
I would like to add a new model called post with an attribute called content:text I would like the association of this model to be, as such: Every Work has many categories, each category inside work has a unique post.
Unfortunately, I don't know how to properly draw out or explain this association, so I will draw a makeshift schema below for reference along with pictures.
e.g: textual reference
One Work
name: project A
Many Categories
project A -> category name:UxD
project A -> category name:ID
project A -> category name:Development
Unique Post
project A -> UxD -> post content:lorem ipsum 1
project A -> ID -> post content:lorem ipsum 2
project A -> Development -> post content:lorem ipsum 3
e.g: graphical reference
work#index
work#show?category1
work#show?category2
Models
How would I write the association to connect post.rb to the preexisting many-to-many relationship
category.rb
class Category < ActiveRecord::Base
validates :name, :presence => true
has_many :categoryworks
has_many :works, :through => :categoryworks
accepts_nested_attributes_for :works
attr_accessible :description, :name, :category_ids, :svg
end
work.rb
class Categorywork < ActiveRecord::Base
validates :name, :presence => true
has_many :categoryworks
has_many :categories, :through => :categoryworks
accepts_nested_attributes_for :categories
attr_accessible :name, :subtitle, :category_ids, :svg
end
categorywork.rb
class Categorywork < ActiveRecord::Base
belongs_to :category
belongs_to :work
attr_accessible :category_id, :work_id
end
Controllers
works_controller: example of many to many association in the new controller
What would I add to work_controller.rb to gain access of the post.rb attr content:text ?
def new
#work = Work.new
#all_categories = Category.all
#work_category = #work.categoryworks.build
respond_to do |format|
format.html # new.html.erb
format.json { render json: #work }
end
end
Views
_form Partial: showing the many-to-many between categories and Works
What would I write to add the post.rb attr content:text to each check box this form
<div class="field">
<%= hidden_field_tag "work[category_ids][]", nil %>
<% Category.all.each do |category| %>
<%= check_box_tag "work[category_ids][]", category.id, #work.category_ids.include?(category.id), id: dom_id(category) %>
<%= label_tag dom_id(category), category.name %><br>
<% end %>
</div>

Related

Unpermitted parameter for join table via multiple select in Rails

I'm running into an error when nesting parameters in Rails 5: Unpermitted parameter: specialties
I have an Expertise model:
class Expertise < ApplicationRecord
has_many :buckets, through: :specialties
has_many :specialties
end
A Bucket model:
class Bucket < ApplicationRecord
has_many :expertises, through: :specialties
has_many :specialties
end
And a Specialty model:
class Specialty < ApplicationRecord
belongs_to :expertise
belongs_to :bucket
end
I'm trying to allow the User to edit his or her Expertises and adjust the Specialties associated with them. The #buckets are passed in from the controller, and the form currently looks like this:
<%= form_for(expertise) do |f| %>
<%= f.fields_for :specialties do |s| %>
<%= s.collection_select :bucket_ids, #buckets, :id, :name, {}, { multiple: true, class: "input" } %>
<% end %>
<% end %>
I based the form on this answer.
Here's the relevant snippet from the ExpertisesController:
def expertise_params
params.require(:expertise).permit(:user_id, :name, :rating, :description, specialties_attributes: [:id, :expertise_id, :bucket_id, :_destroy, bucket_ids: []])
end
And here are the parameters that are being passed in:
Parameters: {"expertise"=>{"specialties"=>{"bucket_ids"=>["", "1"]}, "description"=>""}, "id"=>"97"}
Specialties should be an array, right? I'm not sure how to do that.
The aim is to easily enable the User to select from the available Buckets (#buckets) to toggle his or her Expertise Specialties on or off. So let's say there are 5 Buckets available, the User would only be able to toggle on/off 5 possible Specialties for that Expertise.
Unpermitted parameter: specialties
You didn't set up accept_nested_attributes_for which spits out with that error
class Expertise < ApplicationRecord
has_many :specialties
has_many :buckets, through: :specialties
accepts_nested_attributes_for :specialties
end
When I try that, the nested fields_for form doesn't return any
specialties and so the HTML element is empty. Then, when I try to use
#expertise.specialties.build, I get undefined method bucket_ids for
Specialty because bucket_ids isn't actually an attribute, but
bucket_id is. Worth keeping in mind that the User needs to be able to
toggle multiple Specialties, each of which is tied to a Bucket (via a
bucket_id), and from what I've ready I'm supposed to use bucket_ids
(the plural) there
You don't need to have plural form(_ids) just because to accept multiple values. Just keep bucket_id to accept multiple values. And don't forget to build the associated model in the controller
def new
#expertise = Expertise.new
#expertise.specialties.build
end
Change bucket_ids to bucket_id in the form
<%= s.collection_select :bucket_id, #buckets, :id, :name, {}, { multiple: true, class: "input" } %>
And finally, expertise_params should be
def expertise_params
params.require(:expertise).permit(:user_id, :name, :rating, :description, specialties_attributes: [:id, :expertise_id, :_destroy, bucket_id: []])
end
Update:
Ok after some research, it looks like it should be bucket_ids, but the bucket_ids should be allowed as attribute for expertise. Check this post and tweak your form and expertise_params accordingly. You won't be needing accept_nested_attributes_for too!
The situation: Expertise has_many Buckets through Specialties and you want to update some bucket status of a specific expertise. So you can do this:
class ExpertisesController < ApplicationController
def your_action
#expertise = Expertise.find params[:id]
bucket_ids = params[:expertise][:specialties][:bucket_ids]
#expertise.specialties.where(id: bucket_ids).update(status: :on)
end
end

Rails Invoicing App

I want to create an invoice in rails. Invoice can have items and each item will have quantity, tax & price. It's a typical invoice we see everyday.
In order to create an invoice what is the best approach.
What is the common model for invoice and items?
I know Items will be a separate model. But how can we have one view for invoice, which creates both the invoice and items added to it?
What I mean is, Inside a new invoice page, there will be list of the clients, and list of the items , But here i'm not sure how to make the association when i create invoice. Is there any good example that i can follow ?
Please I'd appreciate some Help. Or even just a walk through of the steps i need to follow in order to accomplish that...
Here's my basic ERD
Quite a broad question, here's what I'd do:
#app/models/invoice.rb
class Invoice < ActiveRecord::Base
belongs_to :user
has_many :line_items
has_many :items, through: :line_items
accepts_nested_attributes_for :line_items
end
#app/models/line_item.rb
class LineItem < ActiveRecord::Base
belongs_to :invoice
belongs_to :item
end
#app/models/item.rb
class Item < ActiveRecord::Base
belongs_to :company
has_many :line_items
has_many :invoices, through: :line_items
end
--
#app/models/user.rb
class User < ActiveRecord::Base
has_many :invoices
end
This will be the base level "invoice" association structure - your clients/users can be built on top of it.
Your routes etc can be as follows:
#config/routes.rb
resources :invoices
#app/controllers/invoices_controller.rb
class InvoicesController < ApplicationController
def new
#invoice = current_user.invoices.new
#invoice.line_items.build
end
def create
#invoice = current_user.invoices.new invoice_params
#invoice.save
end
end
Then your view will be something like this:
#app/views/invoices/new.html.erb
<%= form_for #invoice do |f| %>
<%= f.fields_for :line_items do |l| %>
<%= f.text_field :quantity %>
<%= f.collection_select :product_id, Product.all, :id, :name %>
<% end %>
<%= f.submit %>
<% end %>
This would create the corresponding #invoice, with which you'll be able to call as follows:
#user.invoices.first
Apart from this, I don't have anywhere enough specific information to help specifically
May I recommend using the payday gem? I have created invoice models in the past applications and I'll tell you what, it can get pretty tricky sometimes depending on the type of application you're building. But the reason I like using this gem besides the convenience factor is that it can also render your invoices as a customizable PDF.
It makes adding items to the invoice a breeze as well, for example from their GitHub page:
invoice = Payday::Invoice.new(:invoice_number => 12)
invoice.line_items << Payday::LineItem.new(:price => 20, :quantity => 5, :description => "Pants")
invoice.line_items << Payday::LineItem.new(:price => 10, :quantity => 3, :description => "Shirts")
invoice.line_items << Payday::LineItem.new(:price => 5, :quantity => 200, :description => "Hats")
invoice.render_pdf_to_file("/path/to_file.pdf")

Rails has_many relationship with prefilled views

I have a pretty basic Rails 4 app, and am using Cocoon's nested forms to manage the has_many... :through model association.
class Student < ActiveRecord::Base
has_many :evaluations
has_many :assessments, through: :evaluations
# ... etc
end
class Evaluation < ActiveRecord::Base
belongs_to :student
belongs_to :assessment
# ... etc
end
class Assessment < ActiveRecord::Base
has_many :evaluations
has_many :students, through: :evaluations
accepts_nested_attributes_for :evaluation, reject_if: :all_blank
# ... etc
end
When I use Cocoon in the View, I want to use the New Assessment view to pre-fill all the Student records in order to create a new Evaluation for each one. I don't want to have to do some hacky logic on the controller side to add some new records manually, so how would I structure the incoming request? With Cocoon I see that requests have some number in the space where the id would go (I've replaced these with ?? below).
{"utf8"=>"✓", "authenticity_token"=>"whatever", "assessment"=>{"description"=>"quiz 3", "date(3i)"=>"24", "date(2i)"=>"10", "date(1i)"=>"2015", "assessments_attributes"=>{"??"=>{"student_id"=>"2", "grade" => "A"}, "??"=>{"student_id"=>"1", "grade" => "B"}, "??"=>{"student_id"=>"3", "grade"=>"C"}}, }}, "commit"=>"Create Assessment"}
I see in the Coccoon source code that this is somehow generated but I can't figure out how it works with the Rails engine to make this into a new record without an ID.
What algorithm should I use (or rules should I follow) to fill in the id above to make a new record?
"??"
Never a good sign in your params.
With Cocoon I see that requests have some number in the space where the id would go
That ID is nothing more than the next ID in the fields_for array that Rails creates. It's not your record's id (more explained below).
From your setup, here's what I'd do:
#app/models/student.rb
class Student < ActiveRecord::Base
has_many :evaluations
has_many :assessments, through: :evaluations
end
#app/models/evaluation.rb
class Evaluation < ActiveRecord::Base
belongs_to :student
belongs_to :assessment
end
#app/models/assessment.rb
class Assessment < ActiveRecord::Base
has_many :evaluations
has_many :students, through: :evaluations
accepts_nested_attributes_for :evaluations, reject_if: :all_blank
end
This will allow you to do the following:
#app/controllers/assessments_controller.rb
class AssessmentsController < ApplicationController
def new
#assessment = Assessment.new
#students = Student.all
#students.each do
#assessment.evaluations.build
end
end
end
Allowing you:
#app/views/assessments/new.html.erb
<%= form_for #assessment do |f| %>
<%= f.fields_for :evaluations, #students do |e| %>
<%= e.hidden_field :student_id %>
<%= e.text_field :grade %>
<% end %>
<%= f.submit %>
<% end %>
As far as I can tell, this will provide the functionality you need.
Remember that each evaluation can connect with existing students, meaning that if you pull #students = Student.all, it will populate the fields_for accordingly.
If you wanted to add new students through your form, it's a slightly different ballgame.
Cocoon
You should also be clear about the role of Cocoon.
You seem like an experienced dev so I'll cut to the chase - Cocoon is front-end, what you're asking is back-end.
Specifically, Cocoon is meant to give you the ability to add a number of fields_for associated fields to a form. This was discussed in this Railscast...
Technically, Cocoon is just a way to create new fields_for records for a form. It's only required if you want to dynamically "add" fields (the RailsCast will tell you more).
Thus, if you wanted to just have a "static" array of associative data fields (which is I think what you're asking), you'll be able to use fields_for as submitted in both Max and my answers.
Thanks to #rich-peck I was able to figure out exactly what I wanted to do. I'm leaving his answer as accepted because it was basically how I got to my own. :)
assessments/new.html.haml (just raw, no fancy formatting)
= form_for #assessment do |f|
= f.fields_for :evaluations do |ff|
.meaningless-div
= ff.object.student.name
= ff.hidden_field :student_id, value: ff.object.student_id
= ff.label :comment
= ff.text_field :comment
%br/
assessments_controller.rb
def new
#assessment = Assessment.new
#students = Student.all
#students.each do |student|
#assessment.evaluations.build(student: student)
end
end

Ruby: How do I assign values in the controller when using nested forms?

I have 3 models: Employers, Partners and Collaborations.
As an Employer, I want to add a record to my Partner model and to my Collaboration model to be able to indicate a collaboration between a Partner and a Employer. I therefore have the following columns in my database/tabels.
Models
class Employer < ActiveRecord::Base
has_many :collaborations
has_many :partners, :through => :collaborations
end
class Partner < ActiveRecord::Base
has_many :collaborations
has_many :employers, :through => :collaborations
accepts_nested_attributes_for :collaborations
end
class Collaboration < ActiveRecord::Base
belongs_to :employer
belongs_to :partner
end
Tables
Collaborations
employer_id:integer
partner_id:integer
tarive:string
Partners
added_by:integer
name:string
Because I want to be able to add a Partner/Collaboration within 1 form, I use nested forms. So I can add a partner (name, etc) and a collaboration (tarive, etc) in one go.
My (simple_form) form looks like this (I have named_space resource).
Te reduce clutter, I removed as much HTML mark_up as I could, this is not the issue.
Form
/views/employer/partners/_form
= simple_form_for [:employer, #partner], html: { multipart: true } do |f|
Partner
= f.input :name, input_html: { class: 'form-control' }
= f.simple_fields_for :collaborations do |ff|
Tarive
= ff.input :tarive, input_html: { class: 'form-control' }
= f.button :submit, "Save"
My controller looks like
class Employer::PartnersController < ActionController::Base
def new
#partner = Partner.new
#partner.collaborations.build
end
def create
#partner = Partner.new(partner_params)
#partner.collaborations.build
#partner.added_by = current_employer.id
#partner.collaborations.employer_id = current_employer.employer_id
#partner.collaborations.partner_id = #partner.id
#partner.collaborations.added_by = current_employer.id
if #partner.save
redirect_to employer_partner_path(#partner), notice: "Succes!"
else
render 'new'
end
end
def partner_params
params.require(:partner).permit(:id, :name, collaborations_attributes: [:id, :employer_id, :partner_id, :tarive])
end
end
Problem
The problem/question I have is this. The attributes are assigned nicely and added in the model. But I want to add a employer_id as well, which I have in current_employer.employer.id (Devise). I do not want to work with hidden forms, just to avoid this issue.
I assigned 'parent' models always like #partner.added_by = current_employer.id and that works beautifully.
When I use:
#partner.collaborations.employer_id = current_employer.employer_id
I get an error, saying #partner.collaborations.employer_id is empty.
Question
How can I assign a variable to the nested_form (Collaboration) in my controller#create?
Or more specifically: how can I assign current_employer.employer_id to #partner.collaborations.employer_id?
There are several ways:
Merge the params
Deal with objects, not foreign keys
Personally, I feel your create method looks really inefficient. Indeed, you should know about fat model skinny controller - most of your associative logic should be kept in the model.
It could be improved using the following:
#app/controllers/employers/partners_controller.rb
class Employers::PartnersController < ApplicationController
def new
#partner = current_employer.partners.new #-> this *should* build the associated collaborations object
end
def create
#partner = current_employer.partners.new partner_params
#partner.save ? redirect_to(employer_partner_path(#partner), notice: "Succes!") : render('new')
end
private
def partner_params
params.require(:partner).permit(:id, :name, collaborations_attributes: [:tarive]) #when dealing with objects, foreign keys are set automatically
end
end
This would allow you to use:
#app/views/employers/partners/new.html.erb
= simple_form_for #partner do |f| #-> #partner is built off the current_employer object
= f.input :name
= f.simple_fields_for :collaborations do |ff|
= ff.input :tarive
= f.submit
... and the models:
#app/models/partner.rb
class Partner < ActiveRecord::Base
belongs_to :employer, foreign_key: :added_by
has_many :collaborations
has_many :employers, through: :collaborations
accepts_nested_attributes_for :collaborations
end
#app/models/collaboration.rb
class Collaboration < ActiveRecord::Base
belongs_to :employer
belongs_to :partner
belongs_to :creator, foreign_key: :added_by
before_create :set_creator
private
def set_creator
self.creator = self.employer_id #-> will probably need to change
end
end
#app/models/employer.rb
class Employer < ActiveRecord::Base
has_many :collaborations
has_many :employers, through: :collaborations
end
This may not give you the ability to set tarive, however if you cut down the manual declarations in your model, we should be able to look at getting that sorted.
The main thing you need to do is slim down your code in the controller. You're being very specific, and as a consequence, you're encountering problems like that which you mentioned.

How can I elegantly construct a form for a model that has a polymorphic association?

Here are my models:
class Lesson < ActiveRecord::Base
belongs_to :topic, :polymorphic => true
validates_presence_of :topic_type, :topic_id
end
class Subject < ActiveRecord::Base
has_many :lessons, :as => :topic
end
class Category < ActiveRecord::Base
has_many :lessons, :as => :topic
end
Now, what I need is a form that will allow the user to create or update Lessons. The questions is, how can I provide a select menu that offers a mix of Subjects and Categories? (To the user, on this particular form, Subjects and Categories are interchangeable, but that's not the case elsewhere.)
Ideally, this would look something like this:
views/lessons/_form.html.haml
= simple_form_for(#lesson) do |f|
= f.input :title
= f.association :topic, :collection => (#subjects + #categories)
That won't work because we'd only be specifying the topic_id, and we need the topic_types as well. But how can we specify those values?
I guess the crux of the problem is that I really want a single select menu that specifies two values corresponding to two different attributes (topic_id and topic_type). Is there any elegant railsy way to do this?
A few notes:
a) Single table inheritance would make this issue go away, but I'd like to avoid this, as Categories and Subjects have their own relationship… I'll spare you the details.
b) I might could pull some javascript shenanigans, yes? But that sounds messy, and if there's a cleaner way to do it, some magic form helper or something, then that's certainly preferable.
c) Though I'm using simple_form, I'm not wedded to it, in case that's complicating matters.
Thanks
If you don't wish to use STI, you can do something similar: create a new model Topic(name:string) which will polymorphically reference Subject or Category.
class Lesson < ActiveRecord::Base
belongs_to :topic
validates_presence_of :topic_id
end
class Topic < ActiveRecord::Base
belongs_to :topicable, :polymorphic => true
end
class Subject < ActiveRecord::Base
has_one :topic, :as => :topicable
has_many :lessons, :through => :topic
accepts_nested_attributes_for :topic
end
class Category < ActiveRecord::Base
has_one :topic, :as => :topicable
has_many :lessons, :through => :topic
accepts_nested_attributes_for :topic
end
In the view where you create a new Subject/Category:
<%= form_for #subject do |subject_form| %>
<%= subject_form.fields_for :topic do |topic_fields| %>
<%= topic_fields.text_field :name %>
<% end %>
<% end %>
After thinking this through, the less dirty implementation IMO would be to hire the JS shenanigans (b):
= f.input_field :topic_type, as: :hidden, class: 'topic_type'
- (#subjects + #categories).each do |topic|
= f.radio_button :topic_id, topic.id, {:'data-type' => topic.class.name, class: 'topic_id'}
With a sprinkle of JS (your needs may vary):
$('input:radio.topic_id').change(function() {
$('input:hidden.topic_type').val($(this).attr('data-type'));
});
Notes:
I use a radio button to select a topic (category or subject) in a list
The class name of each of possible topic is stored in an attribute 'data-type'
When a radio button is selected, the class name is copied to the hidden input via JS
Using: HTML5, jQuery, haml, simple_form

Resources