Ruby on Rails - how to belong to many? - ruby-on-rails

Question

I have a table called Report, and another called Phases. Let's say I have 10 phases and I want to have checkboxes on the report form that lists out all the phases. How can I collect the items that are checked and store that data in the database?
Do I need to have columns such as phase_one:integer phase_two:integer phase_three:integer and just pull back the ones that aren't null? Or can I somehow store the IDs of x phases in one column and pull back those IDs in an array?

Answer 1

To clarify NateSHolland's answer, you can use has_and_belongs_to_many if the phases are predefined:
#app/models/report.rb
class Report < ActiveRecord::Base
has_and_belongs_to_many :phases
end
#app/models/phase.rb
class Phase < ActiveRecord::Base
has_and_belongs_to_many :reports
end
This will allow you to populate the phase_ids (collection_singular_ids) attribute from your form:
#config/routes.rb
resources :reports
#app/controllers/reports_controller.rb
class ReportsController < ApplicationController
def new
#report = Report.new
#phases = Phase.all
end
def create
#report = Report.new report_params
#report.save
end
private
def report_params
params.require(:report).permit(:phase_ids)
end
end
#app/views/reports/new.html.erb
<%= form_for #report do |f| %>
<%= f.collection_check_boxes :phase_ids, #phases, :id, :name %>
<%= f.submit %>
<% end %>
This would allow you to specify which phases your report has, although it will not have any changes.
What I think you'd be better doing is using has_many :through, allowing you to define which phase you're referencing:
#app/models/report.rb
class Report < ActiveRecord::Base
has_many :progress
has_many :phases, through: :progress
accepts_nested_attributes_for :progress #-> define level
end
#app/models/progress.rb
class Progress < ActiveRecord::Base
#id report_id phase_id phase_lvl created_at updated_at
belongs_to :report
belongs_to :phase
end
#app/models/phase.rb
class Phase < ActiveRecord::Base
has_many :progress
has_many :reports, through: :progress
end
The important factor here is the phase_lvl column - it's my understanding that you have certain "levels" which your phases will be a part of. I can't describe it properly, but to give you context, you'll have something like...
Report is written (phase 5)
Report is published (phase 3)
Report is Sent (phase 15)
The above will give you the ability to define which "level" each phase denotes. I think this is the distinction you're looking for.
This would be a little more tricky to implement, but worth it:
#app/controllers/reports_controller.rb
class ReportsController < ApplicationController
def new
#report = Report.new
#phases = Phase.all
10.times do
#report.progress.build
end
end
def create
#report = Report.new report_params
#report.save
end
private
def report_params
params.require(:report).permit(progress_attributes: [:phase_id, :phase_lvl])
end
end
This will give you the ability to define the following:
#app/views/reports/new.html.erb
<%= form_for #report do |f| %>
<%= f.fields_for :progress do |p| %>
<%= p.collection_select :phase_id, #phases, :id, :name %>
<%= p.number_field :phase_lvl %>
<% end %>
<%= f.submit %>
<% end %>

Answer 2

It sounds like what you may want is a many to many relationship or a has_and_belongs_to_many. To do this you will need to create a join table between Report and Process that will have a report_id column and a phase_id. For more information check out this documentation: http://guides.rubyonrails.org/association_basics.html#the-has-and-belongs-to-many-association
In the models you will need to add:
Class Report < ActiveRecord::Base
has_and_belongs_to_many :phases
...
end
and
Class Phase < ActiveRecord::Base
has_and_belongs_to_many :reports
...
end