I have been stuck on this problem for a while.
Need to make a form for competitions category with custom inputs. It should take all values from Information table and build the inputs, but the tricky part is that it should be saved to Category_informations table.
class Competition < ApplicationRecord
has_many :categories
has_many :informations
end
class Category < ApplicationRecord
belongs_to :competetion
has_many :category_informations
has_many :information, through: competition
end
class CategoryInformation
belongs_to :catagory
belongs_to :information
end
class Information < ApplicationRecord
belongs_to :competetion
has_many :category_informations
end
Competition -> name
Category -> name, competition_id
Information -> name, competition_id
Category_informations -> value, category_id, information_id
Take a look at this gem: https://github.com/plataformatec/simple_form
Simple Form aims to be as flexible as possible while helping you with powerful components to create your forms.
Let's take a simple example:
class Machine < ActiveRecord::Base
has_many :parts , inverse_of: :machine
accepts_nested_attributes_for :parts
end
class Part < ActiveRecord::Base
# name:string
belongs_to :machine
end
With these models, we can use simple_form to update the machine and its associated parts in a single form:
<%= simple_form_for #machine do |m| %>
<%= m.simple_fields_for :parts do |p| %>
<%= p.input :name %>
<% end %>
<% end %>
For 'new' action, build the nested model from the controller:
class MachinesController < ApplicationController
def new
#machine = Machine.new
#machine.parts.build
end
end
Source: https://github.com/plataformatec/simple_form/wiki/Nested-Models
Sounds to me like you're looking for accepts_nested_attributes_for
See:
https://apidock.com/rails/v3.2.3/ActiveRecord/NestedAttributes/ClassMethods/accepts_nested_attributes_for
https://rubyplus.com/articles/3681-Complex-Forms-in-Rails-5
Also, check out the cocoon gem.
Related
I am having issue with saving a has_many through relation with nested attributes. Due to complexity and requirment in the application the relation is as follows
Table structure,
agreements:
id
agreement_rooms:
id
agreement_id
room_id
details:
id
agreement_rooms_id
For more clarification, agreement_rooms table is related to many other models which will be having agreement_rooms_id in them.
Rails Associations,
class Agreement < ActiveRecord::Base
has_many :details,:through => :agreement_rooms
accepts_nested_attributes_for :details
end
class AgreementRoom < ActiveRecord::Base
has_many :details
end
class Detail < ActiveRecord::Base
belongs_to :agreement_room
accepts_nested_attributes_for :agreement_room
end
When i try to create a agreements record with details hash in it, i get the following error,
Agreement.last.details.create()
ActiveRecord::HasManyThroughCantAssociateThroughHasOneOrManyReflection: Cannot modify association 'agreement#details' because the source reflection class 'Detail' is associated to 'agreementRoom' via :has_many.
I am not sure how to get this nested attributed working with has_many through relation for the above example. Please help out to figure the issue.
Thanks in advance.
#app/models/aggreement.rb
class Agreement < ActiveRecord::Base
has_many :agreement_rooms
accepts_nested_attributes_for :agreement_rooms
end
#app/models/agreement_room.rb
class AgreementRoom < ActiveRecord::Base
belongs_to :agreement
belongs_to :room
has_many :details
accepts_nested_attributes_for :details
end
#app/models/room.rb
class Room < ActiveRecord::Base
has_many :agreement_rooms
has_many :agreements, through: :agreement_rooms
end
#app/models/detail.rb
class Detail < ActiveRecord::Base
belongs_to :agreement_room
end
--
#app/controllers/agreements_controller.rb
class AgreementsController < ApplicationController
def new
#agreement = Agreement.new
#agreement.agreement_rooms.build.details.build
end
def create
#agreement = Agreement.new agreement_params
#agreement.save
end
private
def agreement_params
params.require(:agreement).permit(:agreement, :param, agreement_rooms_attributes: [ details_attributes: [:x] ])
end
end
#app/views/agreements/new.html.erb
<%= form_for #agreement do |f| %>
<%= f.fields_for :agreement_rooms do |ar| %>
<%= ar.fields_for :details do |d| %>
<%= d.text_field :x %>
<% end %>
<% end %>
<%= f.submit %>
<% end %>
you need to define both associations:
class Agreement < ActiveRecord::Base
has_and_belongs_to_many :agreement_rooms # or has_many if you prefer
has_many :details,:through => :agreement_rooms
accepts_nested_attributes_for :details
end
check the docs
As i said before the model association design we has was not proper and due to poor maintenance it has to be in the same way, atleast for now. So i had to write a dirty patch to fix it.
Its simply skipping nested attributes for this specific model alone, so it can be saved separately by passing the master record id to this record.
As its a dirty solution i'm not marking it as the answer. Just added it hoping someone can have a solution if needed.
Thanks for the help
I have a Region > Store > Device hierarchy, where each of these things can have a config_set.
class Region < ActiveRecord::Base
has_many :stores, dependent: :destroy
has_one :config_set, as: :configurable
end
class Store < ActiveRecord::Base
has_many :devices
has_one :config_set, as: :configurable
belongs_to :region
end
class Device < ActiveRecord::Base
has_one :config_set, as: :configurable
belongs_to :store
end
class ConfigSet < ActiveRecord::Base
belongs_to :configurable, polymorphic: true
end
From the config_set show page, I want to generate a link to whatever configurable that config_set belongs to. link_to is using polymorphic_url internally, which wants either a #device, a [#store, #device], or a [#region, #store, #device]. Is there a simple way to deal with this?
Found out a not very nice solution abusing the fact that to polymorphic_url #device and [nil, #device] are equivalent, combined with ruby's try :
<%= link_to 'Back', [#config_set.configurable.try(:store).try(:region), #config_set.configurable.try(:store) || #config_set.configurable.try(:region), #config_set.configurable] %>
What is the most efficient way for retrieving all unique venues with a specified set of features?
In the controller, I have:
#venues = Venue.all
#venues = #venues.features.where('feature.id == ' 1).distinct
Here's how my models are defined:
class Neighborhood < ActiveRecord::Base
has_many :venues
end
class Venue < ActiveRecord::Base
belongs_to :neighborhood
has_many :features
end
class FeatureType < ActiveRecord::Base
has_many :features
end
class Feature < ActiveRecord::Base
belongs_to :venue
belongs_to :feature_type
end
Just think about this using English. If a Venue has many Features and you ask "What is the Id of the Feature?" the response is going to be: "There are many Features, which one?"
The :has_many association gives you the following method: venure.features. That gives you all the of the "many" associated features. To get the Id of just one, you could do something like: venue.features.first.id.
Venue has_many features, so you must loop over the collection, vs a belongs_to where there is a single relationship between the models
<% venue.features.each do |feature| %>
<%= debug feature %>
<% end %>
Is there any possible way to use nested_attributes_for in the way show below?
Basically I want to create a person, one or more cars and add details to each car. This is just a mock up, not a very realistic example. I get snagged when trying to build the details for the car as it hasn't been created yet.
Models:
class Person < ActiveRecord::Base
has_many :cars
accepts_nested_attributes_for :car
end
class Car < ActiveRecord::Base
belongs_to :person
has_many :details
accepts_nested_attributes_for :details
end
class Detail < ActiveRecord::Base
belongs_to :car
end
Form:
form_for #person do |f|
#fields
f.fields_for :car do |car|
#fields
car.fields_for :details |detail|
=detail.text_field :content
end
end
end
Have a look at that http://railscasts.com/episodes/196-nested-model-form-part-1?view=asciicast
I am having trouble with some theory.
I have a model called Promos, and I also have a model called Categories.
I want the admin to be able to create set Categories from which the users will select in a dropdown to assign the Promo. So Promos will belong to a Category but the assignment ought to happen in the create.
What is the recommended structure?
To ensure that every Promo has a Category:
class Category < ActiveRecord::Base
has_many :promos
end
class Promo < ActiveRecord::Base
belongs_to :category
validates_association_of :category
end
How to set the Category at Promo creation time
promo = Promo.new(:category => #category)
As far as forms go:
<% form_for :promo do |f| %>
<%= f.collection_select :category_id, Category.all, :id, :name, :prompt => "Choose a category" %>
...
Other promo fields
...
<% end %>
Matching controller code:
class PromosController < ActionController
def create
#promo = Promo.create(params[:promo])
...
redirect or render whether #promo was successfully created
...
end
end
A user has_many a promos, which belongs to a category.
A category has_many promos.
Such as:
class User < Activerecord::Base
has_many :promos
class Promo < Activerecord::Base
belongs_to :user
belongs_to :category
class Category < Activerecord::Base
has_many :promos