Properly handling Stripe errors and exceptions w/ Ruby for one-time charge

Question

I've looked over the Stripe documentation on errors, but am still having some trouble handling / redirecting these errors properly. Basically no matter what happens I want them to go back to the edit action (via edit_profile_path) and display them a message (whether successful or not).

I have a form on the edit action that POSTs to the update action. This is working properly with a valid credit card (charge is in Stripe dashboard). I am using Stripe.js.

class ExtrasController < ApplicationController

  def edit
    @extras = current_user.extras
  end

  def update

    Stripe.api_key = "hidden"

    token = params[:stripeToken]

    begin
      charge = Stripe::Charge.create(
        :amount => 5000, # amount in cents
        :currency => "usd",
        :card => token,
        :description => current_user.email
      )
    rescue Stripe::CardError => e
      # redirect_to edit_extras_path, notice: e.message
      # What I'm trying to do, but obviously results in AbstractController::DoubleRenderError
    rescue => e
      # Something else happened, completely unrelated to Stripe
      # Display a generic error message
    end

    redirect_to edit_extras_path, notice: "Card charged successfully."
  end

end

Answer 1

Though you now can pass a flash message to redirect_to, you can also still manipulate the flash by itself.

So a minor change to your update code lets you do what you want:

def update

  Stripe.api_key = "hidden"

  token = params[:stripeToken]

  begin
    charge = Stripe::Charge.create(
      :amount => 5000, # amount in cents
      :currency => "usd",
      :card => token,
      :description => current_user.email
    )
    # No exceptions were raised; Set our success message.
    flash[:notice] = 'Card charged successfully.'
  rescue Stripe::CardError => e
    # CardError; display an error message.
    flash[:notice] = 'That card is presently on fire!'
  rescue => e
    # Some other error; display an error message.
    flash[:notice] = 'Some error occurred.'
  end

  redirect_to edit_extras_path
end

To make your messages more clear in their purpose, you might want to swap out notice in the error states for an alert or error flash type; you can then easily style them with CSS to indicate success or failure at a glance. (Bootstrap and Foundation, for example, each provide styles for displaying alerts of various types.)