Question

How do I write this method in RoR?

if item is nil or item.user!='my_value' redirect_to "/"

Want to call it like so:

@item = Item.find(params[:id])
method_described_earlier(@item)

Or other way.
Want to see how rails pro would do it.

Answer 1

You should use a before_filter, which will run before any set of controller actions you indicate. For example:

class SomeController < ApplicationController
  before_filter :require_special_item, only: [:myaction, :other_action, ...]

  def myaction
    # do something with @item
  end

  private

    def require_special_item
      @item = Item.find(params[:id])
      if @item is nil or @item.user!='my_value'
        redirect_to "/"
      end
    end
end

The method require_special_item will always run before myaction and any other actions you indicate, redirecting the user if the found item doesn’t meet your requirements.