Question

I’m trying to create a ruby on rails for the network in my building. I want to set it up with switches having many ports and each port has a name, jack, and room.

I’m getting the following error when trying to view a switch:

undefined method `port' for #<Switch:0x2b49d7643c90>

Extracted source (around line #2):

1: <h1><%= @switch.title %></h1>
2: <p><strong>Switch :</strong> <%= @switch.port.name %><br />
3: </p>
4: <p><%= @switch.description %></p>
5: <hr />

Here is my controller method:

class SwitchController < ApplicationController
    def list
            @switches = Switch.find(:all)
    end
    def show
            @switch = Switch.find(params[:id])
    end
    def new
            @switch = Switch.new
    end
    def create
            @switch = Switch.new(params[:switch])
            if @switch.save
                    redirect_to :action => 'list'
            else
                    @ports = Port.find(:all)
                    render :action => 'new'
            end
    end
    def edit
            @switch = Switch.find(params[:id])
            @ports = Port.find(:all)
    end
    def update
            @switch = Switch.find(params[:id])
            if @switch.update_attributes(params[:switch])
                    redirect_to :action => 'show', :id => @switch
            else
                    @ports = Port.find(:all)
                    render :action => 'edit'
            end
    end
    def delete
            Switch.find(params[:id]).destroy
            redirect_to :action => 'list'
    end
    def show_ports
            @port = Port.find(params[:id])
    end

end

Here are my models:

class Switch < ActiveRecord::Base
   has_many :ports
   validates_uniqueness_of :title
end

class Port < ActiveRecord::Base
   belongs_to :switch
   validates_presence_of :name
   validates_presence_of :jack
   validates_presence_of :room
end

And here are my migrations:

class Switches < ActiveRecord::Migration
  def self.up
     create_table :switches do |t|
        t.string     :title
        t.text       :description
     end
  end
  def self.down
    drop_table :switches
  end
end

class Ports < ActiveRecord::Migration
  def self.up
     create_table :ports do |t|
        t.string     :name
        t.string     :jack
        t.string     :room
     end
     Port.create :name => "1/0/1"
  end
  def self.down
    drop_table :ports
  end
end

And finally, here is my show.html.erb

<h1><%= @switch.title %></h1>
<p><strong>Switch :</strong> <%= @switch.port.name %><br />
</p>
<p><%= @switch.description %></p>
<hr />
<%= link_to 'Back', {:action => 'list'} %>

I know I’m missing some crucial code somewhere, thanks in advance for any help!

Answer 1

If a Switch has many ports, there is no attribute port, just ports, which is a collection (zero, one or many ports).