Undefined method `networkinterface_path' in a has_many form_with

Question

I'm searching since hours because I can't find the error. I have the same situation (with ipaddress model), where it's working just fine. Maybe someone could explain why this happens and how I can fix it.

app\views\routinginformations_form.html.erb:

<% flash.each do |key, value| %>
<div class="<%= flash_class(key) %>">
  <%= value %>
</div>
<% end %>
<%= form_with(model: [@networkinterface, @routinginfo], local: true) do |form| %>
<div class="form-group">
  <%= form.label :metric %>
  <%= form.text_field :metric, class: "form-control" %>
</div>
<div class="form-group">
  <%= form.label :networkobject %>
  <%= form.collection_select(:networkobject_id, Networkobject.all, :id, :name, {include_blank: "#{t("routinginfo.selectno")}"}, { class: "form-control" }) %>
</div>
<div class="form-group">
  <%= form.label :gateway %>
  <%= form.collection_select(:gateway, Systemobject.all, :id, :hostname, {include_blank: "#{t("routinginfo.selectgw")}"}, { class: "form-control" }) %>
</div>

<%= form.submit class: "btn btn-primary" %>
<% end %>

On Submit, it gives me this error:

jensrailsdev | Started POST "/networkinterfaces/1/routinginformations" for 192.168.23.20 at 2019-11-16 15:00:15 +0000
jensrailsdev |    (0.1ms)  SELECT sqlite_version(*)
jensrailsdev | Processing by RoutinginformationsController#create as HTML
jensrailsdev |   Parameters: {"authenticity_token"=>"m9oTCgcZyf6a8Y6rj2na0Subvn3Wju+FCRnmAiDlV+kRwPFLZLmN4vZfxkDa6SksT5ZfT4DX8IKTLPu4157qAw==", "routinginformation"=>{"metric"=>"574", "networkobject_id"=>"1", "gateway"=>"1"}, "commit"=>"Create", "networkinterface_id"=>"1"}
jensrailsdev |   Networkinterface Load (0.1ms)  SELECT "networkinterfaces".* FROM "networkinterfaces" WHERE "networkinterfaces"."id" = ? LIMIT ?  [["id", 1], ["LIMIT", 1]]
jensrailsdev |   ↳ app/controllers/routinginformations_controller.rb:48:in `fetch_networkinterface'
jensrailsdev | Systemobject(#69889442002280) expected, got "1" which is an instance of String(#47418300423640)
jensrailsdev |   Rendering routinginformations/new.html.erb within layouts/application
jensrailsdev |   Systemobject Load (0.1ms)  SELECT "systemobjects".* FROM "systemobjects" WHERE "systemobjects"."id" = ? LIMIT ?  [["id", 1], ["LIMIT", 1]]
jensrailsdev |   ↳ app/views/routinginformations/new.html.erb:6
jensrailsdev |   Customer Load (0.1ms)  SELECT "customers".* FROM "customers" WHERE "customers"."id" = ? LIMIT ?  [["id", 1], ["LIMIT", 1]]
jensrailsdev |   ↳ app/views/routinginformations/new.html.erb:6
jensrailsdev |   Rendered routinginformations/_form.html.erb (Duration: 126.8ms | Allocations: 99817)
jensrailsdev |   Rendered routinginformations/new.html.erb within layouts/application (Duration: 147.2ms | Allocations: 120123)
jensrailsdev | Completed 500 Internal Server Error in 166ms (ActiveRecord: 3.3ms | Allocations: 136558)
jensrailsdev |
jensrailsdev |
jensrailsdev |
jensrailsdev | ActionView::Template::Error (undefined method `networkinterface_path' for #<#<Class:0x00007f20cebd7a90>:0x00007f20cebd5970>):
jensrailsdev |     3:   <%= value %>
jensrailsdev |     4: </div>
jensrailsdev |     5: <% end %>
jensrailsdev |     6: <%= form_with(model: [@networkinterface, @routinginfo], local: true) do |form| %>
jensrailsdev |     7: <div class="form-group">
jensrailsdev |     8:   <%= form.label :metric %>
jensrailsdev |     9:   <%= form.text_field :metric, class: "form-control" %>
jensrailsdev |
jensrailsdev | app/views/routinginformations/_form.html.erb:6
jensrailsdev | app/views/routinginformations/new.html.erb:13
jensrailsdev | app/controllers/routinginformations_controller.rb:15:in `rescue in create'
jensrailsdev | app/controllers/routinginformations_controller.rb:5:in `create'
jensrailsdev | app/controllers/application_controller.rb:6:in `switch_locale'

app\views\routinginformations\new.html.erb:

<h1><%= t("routinginfo.newfor", name: "#{@networkinterface.name}" + " (" + "#{@networkinterface.aliasname}" + ")") %></h1>

<nav aria-label="breadcrumb">
    <ol class="breadcrumb">
        <li class="breadcrumb-item"><%= link_to t(:home), root_path %></li>
        <li class="breadcrumb-item"><%= link_to t("cust", name: @networkinterface.systemobject.customer.name), customer_path(@networkinterface.systemobject.customer) %></li>
        <li class="breadcrumb-item"><%= link_to t("system", name: @networkinterface.systemobject.hostname), customer_path(@networkinterface.systemobject.customer) %></li>
        <li class="breadcrumb-item"><%= link_to t("networkinterfaces.titleof", name: @networkinterface.name), networkinterface_ipaddresses_path(@networkinterface) %></li>
        <li class="breadcrumb-item active" aria-current="page"><%= t("routinginfo.new") %></li>
    </ol>
</nav>

<%= render 'form' %>

config\routes.rb:

Rails.application.routes.draw do
  resources :systemobjects, only: [] do
    resources :networkinterfaces
  end

  resources :networkinterfaces, only: [] do
    resources :ipaddresses
    resources :routinginformations
  end

  get 'main/index'
  root 'main#index'
end

app\models\routinginformation.rb:

class Routinginformation < ApplicationRecord
  belongs_to :gateway, class_name: 'Systemobject', foreign_key: :systemobject_id
  belongs_to :networkobject
  belongs_to :networkinterface
end

app\models\networkinterface.rb:

class Networkinterface < ApplicationRecord
  belongs_to :systemobject
  has_many :routinginformations
  has_many :ipaddresses
end

app\controllers\routinginformations_controller.rb

class RoutinginformationsController < ApplicationController
  before_action :fetch_networkinterface
  before_action :set_routinginfo, only: [ :edit, :update, :destroy ]

  def create
    console
    @routinginfo = @networkinterface.routinginformations.build(routinginfo_params)

    @routinginfo.save!
    flash[:success] = t('messages.succnew', name: 'unknown')
    redirect_to systemobject_networkinterfaces_path(@networkinterface.systemobject.id)
  rescue => e
    flash.now[:error] = t('messages.errnew', msg: e.to_s)
    logger.error(e.to_s)
    render 'new'
  end

  def new
    console
    @routinginfo = @networkinterface.routinginformations.build
    console
  end

  def show; end

  def update
    @routinginfo.update!(routinginfo_params)
    flash[:success] = t('messages.succedit', name: 'unknown')
    redirect_to systemobject_networkinterfaces_path(@ni.systemobject.id)
  rescue => e
    flash[:error] = t('messages.errnew', msg: e.to_s)
    render 'edit'
  end

  def edit
  end

  def destroy
    @routinginfo.destroy

    flash[:success] = t('messages.succdelete', name: 'unknown')
    redirect_to networkinterfaces_path(@ni.systemobject.id)
  end

  private

  def fetch_networkinterface
    @networkinterface = Networkinterface.find(params[:networkinterface_id])
  end

  def set_routinginfo
    @routinginfo = @networkinterface.routinginformations.find(params[:id])
  end

  def routinginfo_params
    params.require(:routinginformation).permit(:metric,
                                               :networkinterface_id,
                                               :networkobject_id,
                                               :gateway)
  end
end

I'm calling the new method from: app\views\networkinterfaces\index.html.erb:

[...]
<% if @sysobj.networkinterfaces.present?  %>
    <% @sysobj.networkinterfaces.each do |n| %>
[...]
                        <%= link_to new_networkinterface_routinginformation_path(n.id), class: "btn btn-secondary" do %>
                            <%= t(:new) %> &nbsp;
                            <%= mdi_tag("lan 20px") %>
                        <% end %></h2>
[...]

I don't see, where and why he's calling "networkinterface_path". Same thing for ipaddresses just works fine:

jensrailsdev | Started GET "/networkinterfaces/1/ipaddresses/new" for 192.168.23.20 at 2019-11-16 17:00:27 +0000
jensrailsdev | Processing by IpaddressesController#new as HTML
jensrailsdev |   Parameters: {"networkinterface_id"=>"1"}
jensrailsdev |   Networkinterface Load (0.2ms)  SELECT "networkinterfaces".* FROM "networkinterfaces" WHERE "networkinterfaces"."id" = ? LIMIT ?  [["id", 1], ["LIMIT", 1]]
jensrailsdev |   ↳ app/controllers/ipaddresses_controller.rb:44:in `get_ni'
jensrailsdev |   Rendering ipaddresses/new.html.erb within layouts/application
jensrailsdev |   Systemobject Load (0.1ms)  SELECT "systemobjects".* FROM "systemobjects" WHERE "systemobjects"."id" = ? LIMIT ?  [["id", 1], ["LIMIT", 1]]
jensrailsdev |   ↳ app/views/ipaddresses/new.html.erb:6
jensrailsdev |   Customer Load (0.1ms)  SELECT "customers".* FROM "customers" WHERE "customers"."id" = ? LIMIT ?  [["id", 1], ["LIMIT", 1]]
jensrailsdev |   ↳ app/views/ipaddresses/new.html.erb:6
jensrailsdev |   Rendered ipaddresses/_form.html.erb (Duration: 1.6ms | Allocations: 1091)
jensrailsdev |   Rendered ipaddresses/new.html.erb within layouts/application (Duration: 5.4ms | Allocations: 2881)
jensrailsdev | Completed 200 OK in 25ms (Views: 15.9ms | ActiveRecord: 0.8ms | Allocations: 24340)
jensrailsdev |
jensrailsdev |
jensrailsdev | Started POST "/networkinterfaces/1/ipaddresses" for 192.168.23.20 at 2019-11-16 17:00:40 +0000
jensrailsdev | Processing by IpaddressesController#create as HTML
jensrailsdev |   Parameters: {"authenticity_token"=>"KMfiwxQsUdUGcKIdYgICSDyYdgN/sEOdaHMpf/6UpN2qz9ZoJ+culi9oQCnObSMvlD45TXDXPRpqOeDkfOzLNA==", "ipaddress"=>{"ipv4address"=>"19.101.12.33", "ipv6address"=>"", "ipv4subnetmask"=>"24", "ipv6subnetmask"=>"", "externalip"=>"0", "natted"=>"0"}, "commit"=>"Create", "networkinterface_id"=>"1"}       
jensrailsdev |   Networkinterface Load (0.1ms)  SELECT "networkinterfaces".* FROM "networkinterfaces" WHERE "networkinterfaces"."id" = ? LIMIT ?  [["id", 1], ["LIMIT", 1]]
jensrailsdev |   ↳ app/controllers/ipaddresses_controller.rb:44:in `get_ni'
jensrailsdev |    (0.1ms)  begin transaction
jensrailsdev |   ↳ app/controllers/ipaddresses_controller.rb:8:in `create'
jensrailsdev |   Ipaddress Create (215.3ms)  INSERT INTO "ipaddresses" ("ipv4address", "ipv6address", "ipv4subnetmask", "externalip", "natted", "networkinterface_id", "created_at", "updated_at") VALUES (?, ?, ?, ?, ?, ?, ?, ?)  [["ipv4address", "19.101.12.33"], ["ipv6address", ""], ["ipv4subnetmask", 24], ["externalip", 0], ["natted", 0], ["
networkinterface_id", 1], ["created_at", "2019-11-16 17:00:40.421205"], ["updated_at", "2019-11-16 17:00:40.421205"]]
jensrailsdev |   ↳ app/controllers/ipaddresses_controller.rb:8:in `create'
jensrailsdev |    (18.5ms)  commit transaction
jensrailsdev |   ↳ app/controllers/ipaddresses_controller.rb:8:in `create'
jensrailsdev |   Systemobject Load (0.1ms)  SELECT "systemobjects".* FROM "systemobjects" WHERE "systemobjects"."id" = ? LIMIT ?  [["id", 1], ["LIMIT", 1]]
jensrailsdev |   ↳ app/controllers/ipaddresses_controller.rb:10:in `create'
jensrailsdev | Redirected to http://10.23.8.2:3000/systemobjects/1/networkinterfaces
jensrailsdev | Completed 302 Found in 243ms (ActiveRecord: 234.2ms | Allocations: 5490)
jensrailsdev |
jensrailsdev |
jensrailsdev | Started GET "/systemobjects/1/networkinterfaces" for 192.168.23.20 at 2019-11-16 17:00:40 +0000
jensrailsdev | Processing by NetworkinterfacesController#index as HTML
jensrailsdev |   Parameters: {"systemobject_id"=>"1"}
jensrailsdev |   Systemobject Load (0.2ms)  SELECT "systemobjects".* FROM "systemobjects" WHERE "systemobjects"."id" = ? LIMIT ?  [["id", 1], ["LIMIT", 1]]
jensrailsdev |   ↳ app/controllers/networkinterfaces_controller.rb:40:in `get_sysobj'
jensrailsdev |   Rendering networkinterfaces/index.html.erb within layouts/application
jensrailsdev |   Customer Load (0.2ms)  SELECT "customers".* FROM "customers" WHERE "customers"."id" = ? LIMIT ?  [["id", 1], ["LIMIT", 1]]
jensrailsdev |   ↳ app/views/networkinterfaces/index.html.erb:9
jensrailsdev |   Networkinterface Load (0.1ms)  SELECT "networkinterfaces".* FROM "networkinterfaces" WHERE "networkinterfaces"."systemobject_id" = ?  [["systemobject_id", 1]]
jensrailsdev |   ↳ app/views/networkinterfaces/index.html.erb:20
jensrailsdev |   Ipaddress Load (0.1ms)  SELECT "ipaddresses".* FROM "ipaddresses" WHERE "ipaddresses"."networkinterface_id" = ?  [["networkinterface_id", 1]]
jensrailsdev |   ↳ app/views/networkinterfaces/index.html.erb:54
jensrailsdev |   Routinginformation Load (0.1ms)  SELECT "routinginformations".* FROM "routinginformations" WHERE "routinginformations"."networkinterface_id" = ?  [["networkinterface_id", 1]]
jensrailsdev |   ↳ app/views/networkinterfaces/index.html.erb:73
jensrailsdev |   Rendered networkinterfaces/index.html.erb within layouts/application (Duration: 8.5ms | Allocations: 4981)
jensrailsdev | Completed 200 OK in 35ms (Views: 32.5ms | ActiveRecord: 0.8ms | Allocations: 19917)

Answer 1

I found the error by myself. It wasn't a wrong path or some problems with routing. It was a problem with aliasing "systemobject" as "gateway". I don't know how I can do it, but switching "back" app\models\routinginformation.rb to:

class Routinginformation < ApplicationRecord
  belongs_to :systemobject
  belongs_to :networkobject
  belongs_to :networkinterface
end

(and corresponding the collection_select in _form.html.erb too), it "suddenly" worked.