I have the following associations:
#models/contact.rb
class Contact < ActiveRecord::Base
has_many :contacts_teams
has_many :teams, through: :contacts
accepts_nested_attributes_for :contacts_teams, allow_destroy: true
end
#models/contacts_team.rb
class ContactsTeam < ActiveRecord::Base
belongs_to :contact
belongs_to :team
end
#models/team.rb
class Team < ActiveRecord::Base
has_many :contacts_team
has_many :contacts, through: :contacts_teams
end
A contact should always have at least one associated team (which is specified in the rich join table of contacts_teams).
If the user tried to create a contact without an associated team: a validation should be thrown. If the user tries to remove all of a contact's associated teams: a validation should be thrown.
How do I do that?
I did look at the nested attributes docs. I also looked at this article and this article which are both a bit dated.
For completion: I am using the nested_form_fields gem to dynamically add new associated teams to a contact. Here is the relevant part on the form (which works, but currently not validating that at least one team was associated to the contact):
<%= f.nested_fields_for :contacts_teams do |ff| %>
<%= ff.remove_nested_fields_link %>
<%= ff.label :team_id %>
<%= ff.collection_select(:team_id, Team.all, :id, :name) %>
<% end %>
<br>
<div><%= f.add_nested_fields_link :contacts_teams, "Add Team"%></div>
So when "Add Team" is not clicked then nothing gets passed through the params related to teams, so no contacts_team record gets created. But when "Add Team" is clicked and a team is selected and form submitted, something like this gets passed through the params:
"contacts_teams_attributes"=>{"0"=>{"team_id"=>"1"}}
This does the validations for both creating and updating a contact: making sure there is at least one associated contacts_team. There is a current edge case which leads to a poor user experience. I posted that question here. For the most part though this does the trick.
#custom validation within models/contact.rb
class Contact < ActiveRecord::Base
...
validate :at_least_one_contacts_team
private
def at_least_one_contacts_team
# when creating a new contact: making sure at least one team exists
return errors.add :base, "Must have at least one Team" unless contacts_teams.length > 0
# when updating an existing contact: Making sure that at least one team would exist
return errors.add :base, "Must have at least one Team" if contacts_teams.reject{|contacts_team| contacts_team._destroy == true}.empty?
end
end
In Rails 5 this can be done using:
validates :contacts_teams, :presence => true
If you have a Profile model nested in a User model, and you want to validate the nested model, you can write something like this: (you also need validates_presence_of because validates_associated doesn't validate the profile if the user doesn't have any associated profile)
class User < ApplicationRecord
has_one :profile
accepts_nested_attributes_for :profile
validates_presence_of :profile
validates_associated :profile
docs recommend using reject_if and passing it a proc:
accepts_nested_attributes_for :posts, reject_if: proc { |attributes| attributes['title'].blank? }
http://api.rubyonrails.org/classes/ActiveRecord/NestedAttributes/ClassMethods.html
Model Names:
1: approval
2: approval_sirs
Associations:
1: approval
has_many :approval_sirs, :foreign_key => 'approval_id', :dependent => :destroy
accepts_nested_attributes_for :approval_sirs, :allow_destroy => true
2: approval_sirs
belongs_to :approval , :foreign_key => 'approval_id'
In approvals.rb
## nested form validations
validate :mandatory_field_of_demand_report_sirs
private
def mandatory_field_of_demand_report_sirs
self.approval_sirs.each do |approval_sir|
unless approval_sir.marked_for_destruction?
errors.add(:base, "Demand Report Field are mandatory in SIRs' Detail") unless approval_sir.demand_report.present?
end
end
end
Related
I'm having some difficulty expressing a linkage of a User to my Listing model.
I set up a Rails form when I associated a designer_id (added to listing_params as a private controller method) that would link a selected user to a Listing model when created:
#migration
add_column :listings, :designer_id, :integer
_form.html.erb
<%= collection_select :listing, :designer_id, #account.users, :id, :name, prompt: "Choose..." %>
Checking in the console, the form returned the correct user id as designer_id. Success!
What I need to do now is access the User name using a Listing method, but I'm getting stuck- the issue is primarily making the translation from the id procured to the User referenced:
#listing.rb
def designer
self.designer_id == User.find_by_id(params[:name])
if self.designer_id = nil
return "N/A"
else
return "#{User.name}"
end
Much appreciated!
in the migration if you are on at least rails 4 you can do
add_reference(:listings, :designer)
you may need to do
add_reference(:listings, :designer, :foreign_key => { to_table: 'users'}
other options I often use
add_reference(:listings, :designer, :foreign_key => { to_table: 'users'} index: true, limit: 8)
Migration aside you can do this in the models.
class Listing
belongs_to :designer, class_name: 'User', inverse_of: :listings
end
and in users
class User
has_many :listings, inverse_of: :designer, dependent: :destroy
end
Getting the users name would then be,
listing.designer.name
if you are doing this in a controller you will want to pre-load the association so you are not introducing an n+1 query to a list of listings.
I may be missing something fundamental here, but I can't seem to get ActiveAdmin to work with a sortable has_many through relationship, with the ability to create new records.
So given the following models
class User < ActiveRecord::Base
has_many :user_videos
has_many :videos, through: :user_videos
accepts_nested_attributes_for :user_videos
accepts_nested_attributes_for :videos
...
end
class UserVideo < ActiveRecord::Base
belongs_to :user
belongs_to :video
accepts_nested_attributes_for :video
end
class Video < ActiveRecord::Base
has_many :user_videos
has_many :users, through: :user_videos
...
end
(I admit I'm throwing accepts_nested_attributes_for around somewhat in the hopes that something may work)
And Active Admin setup goes something like this (WIP of course):
f.inputs "User" do
f.has_many :user_videos, heading: 'Videos', sortable: :order, allow_destroy: true, new_record: 'New Record' do |v|
v.inputs for: :video do |video|
video.input :video_url
end
end
f.has_many :videos, heading: 'Videos', new_record: 'New Video' do |v|
v.input :video_url
end
end
f.actions
The first has_many on the :user_videos association does not seem to render any inputs. If there are records there, I can see that video.input :video_url is actually returning an li tag with label and input, however nothing gets rendered to the page. For new records the whole v.inputs bit does not get run (do I need to create the child records somehow there first?).
The second has_many will work in that you'll be able to add records, and update existing records, however it's impossible to sort as the order column is on the UserVideos model. I include this more as illustration than anything.
If anyone has any pointers for this, they would be most appreciated. :)
WHOA! I know I am late to the party, but this is a perfect opportunity to utilize the :delegate method!
Your UserVideo class would look something like this
class UserVideo < ActiveRecord::Base
belongs_to :user
belongs_to :video
validates_with VideoValidator
delegate :video_url, :video_url=, to: :video
end
Best of luck!
Since nobody seemed interested in tackling this, I took another approach - rather than trying to get ActiveAdmin / Formtastic to work with the existing model structure, I added getters and setters for the necessary field on the intersection model.
class UserVideo < ActiveRecord::Base
belongs_to :user
belongs_to :video
validates_with VideoValidator
def video_url
self.video = Video.create if video.nil?
self.video.video_url
end
def video_url=(video_url)
self.video = Video.create if video.nil?
self.video.video_url = video_url
# Video url is set via Active Admin, AA will not call save on the video as it does not realise it's changed
self.video.save! if video.present? and video.valid?
end
end
Doing this meant that Active Admin did not need to know about the Video model, and could just operate on the UserVideo model:
f.has_many :user_videos, heading: 'Videos', sortable: :order, allow_destroy: true, new_record: 'New Record' do |v|
v.input :video_url, :hint => (v.object.video.embed_code unless v.object.nil? or v.object.video.nil?)
end
If anyone has an actual solution rather than a work around, I'd love to hear it, but otherwise this is a possible solution for anyone searching for an answer to the same problem.
I'm trying to obtain a subset of records for a grouped_collection_select, in the schema I have a Brand and a Model, and we handle different lines of products, when we request a product, we specify the line that we are going to request, so, we can have the Brands, and the models of that line, so the models are defined as follows:
Model for Brand
class Brand < ActiveRecord::Base
validates :brand_key, uniqueness: true, presence:true
has_many :models
accepts_nested_attributes_for :models, allow_destroy: true
end
Model for Modelx
class Modelx < ActiveRecord::Base
belongs_to :brand
belongs_to :line
validates :model_key, uniqueness: true, presence:true
end
Model for Line
class Line < ActiveRecord::Base
validates :line_key, uniqueness: true, presence:true, length: {in: 1..6}
has_many :line_features, -> { order(:sort_order) }
has_many :modelx
accepts_nested_attributes_for :line_features, allow_destroy: true
end
Model for Product
class Product < ActiveRecord::Base
belongs_to :vendor
belongs_to :line
belongs_to :brand
belongs_to :modelx
belongs_to :operating_status
has_many :line_features, -> { order(:sort_order)}
store_accessor :line_features
end
Controller for Product (new)
def new
#brands=brand.where(id: Modelx.select(:brand_id).where(line_id: params[:line_id]))
#modelxs=Modelx.where(line_id: params[:line_id])
...
end
excerpt from partial form
<%= f.collection_select( :brand_id, #brands, :id, :brand,{:prompt =>'Brands'}) %>
<%= f.grouped_collection_select(:modelx_id, #brands, :modelx, :brand, :id, :modelox) %>
Now, the problem that I'm facing is that when I display a model I need to present only the models available for that brand and line, but, the request is bringing all the models for the brand as it's supposed to be and I don't know how to discriminate those lines that are not needed.
Any help, hint or suggestion is highly appreciated.
Update to question
I don't know if this is a workaround or a solution to the question, but, it was the only way that I found to get to a solution for the requirement, for that reason I'm posting as an update instead of answering the question for whom it may help.
Reviewed the documentation once again and find out that the method :modelx referred by <%= f.grouped_collection_select(:modelx_id, #brands, :modelx, :brand, :id, :modelox) %> was requesting all the models as noted in apidock, this method was the solution for the problem.
Created a method in the brand model according to the subset depicted above, due to the fact that the grouping was made by brand, here the excerpt
Model for Brand (Excerpt)
...
def modelx_ltvi
Modelx.where("line_id = ? and brand_id =?",$line_id, self.id)
end
Special Note: Due to my inexperience, I was not able to pass the value of the :line_id from the form, so, I put it in a global variable.
Modified the form partial
Excerpt from partial form
...
<% $line_id=#product.line_id %>
...
<%= f.grouped_collection_select(:modelx_id,
#brands, :modelx_ltvi, :brand,
:id, :modelx) %>
<% end %>
And that makes the hamster run.
Filter your models by the brands you just found, something like:
#brands=Brand.where(id: Modelx.select(:brand_id).where(line_id: params[:line_id]))
#modelxs=Modelx.where(line_id: params[:line_id], brand_id: #brands.map(&:id))
#selected_model_names = #modelxs.map(&:name).sort.uniq
I have two models: Project and ProjectDiscipline:
class Project < ActiveRecord::Base
has_many :project_disciplinizations, :dependent => :destroy
has_many :project_disciplines, through: :project_disciplinizations
attr_accessible :project_discipline_ids
attr_accessible :project_disciplines_attributes
accepts_nested_attributes_for :project_disciplines, :reject_if => proc { |attributes| attributes['name'].blank? }
end
class ProjectDiscipline < ActiveRecord::Base
attr_accessible :name
has_many :project_disciplinizations, :dependent => :destroy
has_many :projects, through: :project_disciplinizations
end
class ProjectDisciplinization < ActiveRecord::Base
attr_accessible :project_discipline_id, :project_id
belongs_to :project_discipline
belongs_to :project
end
On the new/edit Project form, I have a list of disciplines and a check box for each one of them so users can pick disciplines:
<div class="control-group">
<label class="control-label">Check disciplines that apply</label>
<div class="controls">
<%= f.collection_check_boxes(:project_discipline_ids, ProjectDiscipline.order('name'), :id, :name, {}, {:class => 'checkbox'}) {|input| input.label(:class => 'checkbox') { input.check_box + input.text }} %>
<p class="help-block">You must choose at least one discipline.</p>
</div>
</div>
I want to add a validation to require that at least one discipline is checked. I've tried but I haven't figured out yet. How can I add this validation?
Side note before the answer, based on the structure of your models I would use has_and_belongs_to_many instead of using this explicit linking model since it appears the linking model doesn't add anything of value.
Either way though, the answer is the same, which is to use a custom validation. Depending on whether you go with things the way they are or simplify to a has_and_belongs_to many you'll want to validate slightly differently.
validate :has_project_disciplines
def has_project_disciplines
errors.add(:base, 'must add at least one discipline') if self.project_disciplinizations.blank?
end
or with has_and_belongs_to_many
validate :has_project_disciplines
def has_project_disciplines
errors.add(:base, 'must add at least one discipline') if self.project_disciplines.blank?
end
I prefer simpler approach:
class Project < ActiveRecord::Base
validates :disciplines, presence: true
end
This code do absolutely the same as code by John Naegle or Alex Peachey, because of validates_presence_of exploit blank? method too.
You can write your own validator
class Project < ActiveRecord::Base
validate :at_least_one_discipline
private
def at_least_one_discipline
# Check that at least one exists after items have been de-selected
unless disciplines.detect {|d| !d.marked_for_destruction? }
errors.add(:disciplines, "must have at least one discipline")
end
end
end
How do you edit the attributes of a join model when using accepts_nested_attributes_for?
I have 3 models: Topics and Articles joined by Linkers
class Topic < ActiveRecord::Base
has_many :linkers
has_many :articles, :through => :linkers, :foreign_key => :article_id
accepts_nested_attributes_for :articles
end
class Article < ActiveRecord::Base
has_many :linkers
has_many :topics, :through => :linkers, :foreign_key => :topic_id
end
class Linker < ActiveRecord::Base
#this is the join model, has extra attributes like "relevance"
belongs_to :topic
belongs_to :article
end
So when I build the article in the "new" action of the topics controller...
#topic.articles.build
...and make the nested form in topics/new.html.erb...
<% form_for(#topic) do |topic_form| %>
...fields...
<% topic_form.fields_for :articles do |article_form| %>
...fields...
...Rails automatically creates the linker, which is great.
Now for my question: My Linker model also has attributes that I want to be able to change via the "new topic" form. But the linker that Rails automatically creates has nil values for all its attributes except topic_id and article_id. How can I put fields for those other linker attributes into the "new topic" form so they don't come out nil?
Figured out the answer. The trick was:
#topic.linkers.build.build_article
That builds the linkers, then builds the article for each linker. So, in the models:
topic.rb needs accepts_nested_attributes_for :linkers
linker.rb needs accepts_nested_attributes_for :article
Then in the form:
<%= form_for(#topic) do |topic_form| %>
...fields...
<%= topic_form.fields_for :linkers do |linker_form| %>
...linker fields...
<%= linker_form.fields_for :article do |article_form| %>
...article fields...
When the form generated by Rails is submitted to the Rails controller#action, the params will have a structure similar to this (some made up attributes added):
params = {
"topic" => {
"name" => "Ruby on Rails' Nested Attributes",
"linkers_attributes" => {
"0" => {
"is_active" => false,
"article_attributes" => {
"title" => "Deeply Nested Attributes",
"description" => "How Ruby on Rails implements nested attributes."
}
}
}
}
}
Notice how linkers_attributes is actually a zero-indexed Hash with String keys, and not an Array? Well, this is because the form field keys that are sent to the server look like this:
topic[name]
topic[linkers_attributes][0][is_active]
topic[linkers_attributes][0][article_attributes][title]
Creating the record is now as simple as:
TopicController < ApplicationController
def create
#topic = Topic.create!(params[:topic])
end
end
A quick GOTCHA for when using has_one in your solution.
I will just copy paste the answer given by user KandadaBoggu in this thread.
The build method signature is different for has_one and has_many associations.
class User < ActiveRecord::Base
has_one :profile
has_many :messages
end
The build syntax for has_many association:
user.messages.build
The build syntax for has_one association:
user.build_profile # this will work
user.profile.build # this will throw error
Read the has_one association documentation for more details.