Rails join collection not recognizing parameters - ruby-on-rails

Question

I'm trying to create a record in a join table named Interventions. Basically in my application a user can do many interventions on an incident, and an incident can have interventions by many users. I pass the needed strong parameters, but the application gives the following errors when I try to save: "Incident must exist" and "User must exist". I spent hours on this, and can't figure out what is the problem. Can you please help me? I post the relevant code here:
user.rb (model)
has_many :interventions
has_many :incidents, through: :interventions
incident.rb (model)
has_many :interventions
has_many :users, through: :interventions
intervention.rb (model)
belongs_to :incident_priority
belongs_to :intervention_status
interventions_controller.rb
def new
#incident = Incident.find(params[:incident])
#user = User.find(current_user.id)
#intervention = Intervention.new(:user_id => #user, :incident_id => #incident)
#project = #incident.channel.project
#mirth = Mirth.find_by server_id: #incident.mirth_server_id
end
def create
#incident = Incident.find(params[:incident_id])
#user = User.find(params[:user_id])
#intervention = Intervention.create(intervention_params)
#project = #incident.channel.project
#mirth = Mirth.find_by server_id: #incident.mirth_server_id
respond_to do |format|
if #intervention.save
format.html { redirect_to new_intervention_path(#incident), notice: 'Intervention was successfully created.' }
format.json { render :show, status: :created, location: #intervention }
else
format.html { render :new, incident: :incident_id }
format.json { render json: #intervention.errors, status: :unprocessable_entity }
end
end
end
< .... >
def intervention_params
params.require(:intervention).permit(:user_id, :incident_id, :incident_priority_id, :begin_date, :end_date, :description,
:intervention_status_id, :forwarded_to)
end
In my view (interventions_form.html.erb):
<%= form_for(#intervention) do |f| %>
<% if #intervention.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#intervention.errors.count, "error") %> prohibited this intervention from being saved:</h2>
<ul>
<% #intervention.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="form-group form-inline">
<%= hidden_field_tag :user_id, #user.id %>
<%= hidden_field_tag :incident_id, #incident.id %>
<strong>Interveniente:</strong>
<%= #user.first_name %> <%= #user.last_name %>
</div>
<div class="form-group form-inline">
<%= f.label 'Prioridade' %>
<%= f.collection_select :incident_priority_id, IncidentPriority.all, :id, :description, {}, {class: "form-control"} %>
</div>
<div class="form-group form-inline">
<%= f.label 'Data início intervenção' %>
<%= f.datetime_select :begin_date %>
</div>
<div class="form-group form-inline">
<%= f.label 'Data fim intervenção' %>
<%= f.datetime_select :end_date, :include_blank => true %>
</div>
<div class="form-group form-inline">
<%= f.label 'Observações' %>
<%= f.text_area :description %>
</div>
<div class="form-group form-inline">
<%= f.label 'Estado' %>
<%= f.collection_select :intervention_status_id, InterventionStatus.all, :id, :description, {}, {class: "form-control"} %>
</div>
<div class="form-group form-inline">
<%= f.label 'Encaminhado para:' %>
<%= f.text_area :forwarded_to %>
</div>
<div class="actions" align="right">
<%= link_to 'Voltar', incidents_path(:mirth => #mirth, :project => #project), class: "btn btn-info" %>
<%= f.submit "Gravar", class: "btn btn-info" %>
</div>
I run debug and the values in the hidden_field_tags are correctly filled. Also in the controller the #user and #incident are correctly populated, but #intervention has nil in the foreign keys :user_id and :incident_id.
Thanks in advance!

Answer 1

You need to associate the user and the incident with the intervention.
in your model...
class Intervention
belongs_to :user
belongs_to :incident
in your create method...
def create
#incident = Incident.find(params[:incident_id])
#user = User.find(params[:user_id])
#intervention = Intervention.create(intervention_params)
#intervention.incident = #incident
#intervention.user = #user
...

Answer 2

You need to change this:
def create
#incident = Incident.find(params[:incident_id])
#user = User.find(params[:user_id])
# ...
end
For this:
def create
#incident = Incident.find(params[:incident_id])
#user = User.find(params[:user_id])
intervention_params.merge(user_id: #user.id, incident_id: #incident.id)
# ...
end
And your model:
class Intervention
belongs_to :user
belongs_to :incident