work with rescue in Rails

Question

Hi,

I am working with the following piece;

def index
  @user = User.find(params[:id]) 
  rescue
    flash[:notice] = "ERROR"
    redirect_to(:action => 'index')
  else 
    flash[:notice] = "OK"
    redirect_to(:action => 'index')
end

Now I either case whether I have a correct ID or not, I am always getting "OK" in my view, what am I doing wrong?

I need that when I have no ID in the DB to show "ERROR". I have also tried to use rescue ActiveRecord::RecordNotFound but same happens.

All help is appreciated.

Answer 1

If there is no user with that id, then User.find will return nil. Returning nil is not an error case and will not trigger a rescue.

Answer 2

All code after the end of the rescue is interprete only if there are no return in rescue. So you can return in end of you rescue

def index
  begin
    @user = User.find(params[:id]) 
  rescue
    flash[:notice] = "ERROR"
    redirect_to(:action => 'index')
    return
  end
  flash[:notice] = "OK"
  redirect_to(:action => 'index')
end

or

def index
  @user = User.find(params[:id]) 
  # after is interpret only if no exception before
  flash[:notice] = "OK"
  redirect_to(:action => 'index')
rescue
  flash[:notice] = "ERROR"
  redirect_to(:action => 'index')
end

But in your case the better is to use rescue_from or rescue_in_public

like

class UserController < ApplicationController
  def rescue_in_public(exception)
    flash[:notice] = "ERROR"
    redirect_to(:action => 'index')
  end

  def index
    @user = User.find(params[:id]) 
    flash[:notice] = "OK"
    redirect_to(:action => 'index')
  end
end

But the using of rescue_in_public is really not a good advise