Mercadopago-Rails

MercadoPago-Rails is a very simple gem that helps you interact with mercadopago api. It uses meracado pago gem and mercado pago sdk to work internally. For the moment, this gem only supports buying only ONE type of product at a time.

Install

To install the gem just run

gem install mercado_pago_rails

or if you are using bundler add the following line to your Gemfile

gem 'mercado_pago_rails'

Usage

MercadoPagoModule

The module MercadoPagoModule adds the method generate_purchase that receives two parameters:

An object that holds the information of the purchase to be made
A hash containing three urls: success_url, failure_url and pending_url

The object needs to respond to the following methods:

external_reference: this will and id to be used by MercadoPago to refer to the object (it can be your database ID or whatever reference you wish).
quantity: amount of products to be bought.
unit_price: unit price of the product you are buying (hence, the total amount to be paid is quantity * unit_price).
currency: the currency in which the payment must be made (for instance, "ARS". For more information about this, refer here.
picture_url: url for the picture of the product. This is shown by MercadoPago at the time of the payment (this is optional)
payer_name: payer's name
payer_surname: payer's surname
payer_email: payer's email

The following object is an example of the mentioned above:

class MercadoPagoVoucherAdapter

  def initialize(voucher)
    @voucher = voucher
  end

  def quantity
    1
  end

  def unit_price
    @voucher.paid
  end

  def currency
    "ARS"
  end

  def picture_url
    @voucher.brand.logo.url
  end

  def payer_namer
    @voucher.user.name
  end

  def payer_surname
    @voucher.user.name
  end

  def payer_email
    @voucher.user.email
  end

  def external_reference
    @voucher.id
  end

  def title
    @voucher.brand.name
  end

  def new_status(status)
    @voucher.status = status
    @voucher.save
  end
end

The urls passed as a hash are used by MercadoPago to create links back to your application once the user has finished with the payment.

When the method returns, it creates an instance of MercadoPagoResponse. To check if there was an error while just invoke mercado_pago_response.success?. If there was an error, you can call mercado_pago_response.error_msg to get the error message. Otherwise, you can call mercado_pago_response.redirect_url and it will return the url where the user must go to complete the payment.

mercado_pago_response = generate_purchase(MercadoPagoVoucherAdapter.new(@voucher), success_url: root_url, pending_url: root_url, failure_url: root_url)
if !mercado_pago_response.success?
  flash[:error] = I18n.t('voucher.confirm.mercadopago.error')
  render action: "new", brand_id: params[:voucher][:brand_id]
else
  redirect_to mercado_pago_response.redirect_url
end

MercadoPagoHelper

This class contains the object in charge of communicating with MercadoPago. To use it, you must include AppConfiguration. Usign this gem, MercadoPagoHelper will load the client_id and client_secret that you where provided to interact with MercadoPago from the file .mercadopago.yml (or environment variable, just check the gem's documentation). This class also contains constants representing the different status that a purchase can adquire: APPROVED, PENDING, IN_PROCESS, REJECTED, REFUNDED, CANCELLED, IN_MEDIATION.

If you want, you can set handlers for the different status that a purchase might adquire. Just add the following lines in an initializer.

MercadoPagoHelper.set_handlers(approved: SuccessfulPurchaseContext, pending: PendingPurchaseContext, in_process: InProcessPurchaseContext,
              in_mediation: InMediationPurchaseContext, rejected: RejectedPurchaseContext, cancelled: CancelledPurchaseContext,
              refunded: RefundedPurchaseContext)

This handlers will be instanciated when get_context(response, obj) is called. The method checks the purchase's status instantiates the corresponding handler. All this handlers must receive in their initializer the response and the object that want to modify. This can be used in the following way: MercadoPagoHelper.get_context(info, voucher).handle

License

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.