Ruby on Rails Scaffold - Modify Show Method

Question

Hello,

I am a beginner when it comes to Ruby on Rails, so I need a little bit of help. I started reading a basic tutorial recently, which was taught using Scaffolding. I made a "Clients" model: script/generate scaffold clients name:string ip_address:string speed:integer ... Inside the clients_controller.rb file, there is a method called show:

  # GET /clients/1
  # GET /clients/1.xml
  def show
    @client = Client.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.xml  { render :xml => @client }
    end
  end

For queries, I'd go to localhost:3000/clients/{Enter the ID here}. Instead of searching with the ID are the argument, I'd like to search with another value, like ip_address or speed, so I thought all I would have to do is change :id to :ip_address in "@client = Client.find(params[:id])". However, that does not work, so would someone please tell me how I can achieve a search with another parameter. Thanks!

Answer 1

This doesn't work because of the way things are routed

When you do something like

map.resources :client (See config/routes.rb)

This happens automatically when you use scaffold. It sets up routes based on the assumption you're using an id.

One of these routes is something like

map.connect 'clients/:id', :controller => 'client', :action => 'show'

So :id is passed as a parameter as part of the URL.

You shouldn't have the IP be the primary identifier unless they're distinct - and even then it kind of messes with the RESTful routing.

---

If you want to have the ability to search by IP, modify your index action for the clients

def index
  if params[:ip].present?
    @clients = Client.find_by_ip_address(params[:ip]);
  else
    @clients = Client.all
  end
end

Then you can search by ip by going to clients?ip=###.###.###

Answer 2

This line in your routes.rb file

map.connect 'clients/:id', :controller => 'client', :action => 'show'

implies that when the dispatcher receives an URI in the format "clients/abcdxyz' with GET Method, it will redirect it to show method with the value "abcdxyz" available in params hash with key :id.

EDIT

---

Since you have used scaffold, the clients resource will be RESTful. That means that when you send a GET request to "/clients/:id' URI, you will be redirected to show page of that particular client.

---

In your controller code you can access it as

params[:id] # which will be "abcdxyz"

The find method that is generated by scaffold searches on the primary key i.e 'id' column. You need to change that statement to either

@client = Client.find_by_ip_address(params[:id]) #find_by_column_name

OR

@client = Client.find(:first, :conditions => [":ip_address = ?", params[:id]])

:-)