Refactoring the class component of submitted parameters-CodePudding

The following pattern is encountered:

params[:vehicle][:user_id]
params[:location][:user_id]
params[...etc...][:user_id]

what syntax allows the creation of a method that inputs the current class as the symbol within the param ? for example

class VehiclesController

def edit
  v = Vehicle.where('user_id = ? AND user_id = ?', params[:vehicle][:user_id], current_user.id).first
end

class LocationsController

def edit
  l = Location.where('user_id = ? AND user_id = ?', params[:location][:user_id], current_user.id).first
end

CodePudding user response：

You can add a method to ApplicationController:

class ApplicationController < ActionController::Base
  private

  def form_params
    params[controller_name.singularize]
  end
end

and use it in other controllers:

class VehiclesController < ApplicationController
  def create
    form_params # => #<ActionController::Parameters {"user_id"=>"1"} permitted: false>
  end
end

For permitted params, could be this:

class ApplicationController < ActionController::Base
  private

  def form_params
    params.require(controller_name.singularize).permit(permitted_params)
  end

  def permitted_params
    [] # nothing is permitted by default
  end
end

class VehiclesController < ApplicationController
  def create
    form_params # => #<ActionController::Parameters {"user_id"=>"1"} permitted: true>
  end

  private

  # Override `permitted_params`
  def permitted_params
    # FIXME: Seems `user_id` is not needed when you have `current_user.id`.
    #        Besides, it is bad to expose current `user_id` in the form, 
    #        because I can start messing with it and start submitting 
    #        different ids in your forms; like a payment form, make someone  
    #        else pay for my charges.
    [:user_id]
  end
end