[JAVA] Introduction of pay.jp

How to install Pay.jp

It is a credit card payment agency service that can be introduced with a simple open API.

Why

The amount of code is very small, and you can easily submit a form with Javascript, so I will introduce it (I will omit it)

Creating an application

Terminal

% cd ~/projects(as you like)
% rails _6.0.0_ new payjp_practice -d mysql
% cd payjp_practice
% rails db:create

Order model creation

Terminal

% rails g model order

Create Orders table

db/migrate/**************_create_orders.rb

class CreateOrders < ActiveRecord::Migration[6.0]
  def change
    create_table :orders do |t|
      t.integer :price  ,null: false
      t.timestamps
    end
  end
end

Don't forget!

Terminal

% rails db:migrate

Validation

app/models/order.rb

class Order < ApplicationRecord
  validates :price, presence: true
end

routing

config/routes.rb

Rails.application.routes.draw do
  root to: 'orders#index'
  resources :orders, only:[:create]
end

orders controller

Terminal

% rails g controller orders

app/controllers/orders_controller.rb

class OrdersController < ApplicationController

  def index
  end

  def create
  end

end

Create a view

java:app/views/orders/index.html.erb

<%= form_with  model: @order, id: 'charge-form', class: 'card-form',local: true do |f| %>
  <div class='form-wrap'>
    <%= f.label :price, "Amount of money" %>
    <%= f.text_field :price, class:"price", placeholder:"Example)2000" %>
  </div>
  <%= f.submit "Purchase" ,class:"button" %>
<% end %>

CSS description

app/assets/stylesheets/style.css

.card-form{
  width: 500px;
}

.form-wrap{
  display: flex;
  flex-direction: column;
}

.exp_month{
  resize:none;
}

.exp_year{
  resize:none;
}

.input-expiration-date-wrap{
  display: flex;
}


.button{
  margin-top: 30px;
  height: 30px;
  width: 100px;
}

Controller editing

app/controllers/orders_controller.rb

class OrdersController < ApplicationController

  def index
    @order = Order.new
  end

  def create
    @order = Order.new(order_params)
    if @order.valid?
      @order.save
      return redirect_to root_path
    else
      render 'index'
    end
  end

  private

  def order_params
    params.require(:order).permit(:price)
  end

end

Partial template

java:app/views/orders/index.html.erb

<%= form_with  model: @order, id: 'charge-form', class: 'card-form',local: true do |f| %>
  <%= render 'layouts/error_messages', model: @order %>
  <div class='form-wrap'>
<%#abridgement%>

View description

java:app/views/orders/index.html.erb

<%= form_with  model: @order, id: 'charge-form', class: 'card-form',local: true do |f| %>
  <%= render 'layouts/error_messages', model: @order %>
  <div class='form-wrap'>
    <%= f.label :price, "Amount of money" %>
    <%= f.text_field :price, class:"price", placeholder:"Example)2000" %>
  </div>
  <div class='form-wrap'>
    <%= f.label :number,  "card number" %>
    <%= f.text_field :number, class:"number", placeholder:"card number(Half-width alphanumeric characters)", maxlength:"16" %>
  </div>
  <div class='form-wrap'>
    <%= f.label :cvc ,"ＣＶＣ" %>
    <%= f.text_field :cvc, class:"cvc", placeholder:"4-digit or 3-digit number on the back of the card", maxlength:"3" %>
  </div>
  <div class='form-wrap'>
    <p>expiration date</p>
    <div class='input-expiration-date-wrap'>
      <%= f.text_field :exp_month, class:"exp_month", placeholder:"Example)3" %>
      <p>Month</p>
      <%= f.text_field :exp_year, class:"exp_year", placeholder:"Example)24" %>
      <p>Year</p>
    </div>
  </div>
  <%= f.submit "Purchase" ,class:"button" %>
<% end %>

remove turbolinks & add code

java:app/views/layouts/application.html.erb

<%#abridgement%>
    <%= stylesheet_link_tag 'application', media: 'all'  %>
    <%= javascript_pack_tag 'application' %>
<%#abridgement%>

app/javascript/packs/application.js

//abridgement
require("@rails/ujs").start()
// require("turbolinks").start() //Comment out
require("@rails/activestorage").start()
require("channels")
//abridgement

Read payjp.js

java:app/views/layouts/application.html.erb

<%#abridgement%>
    <%= csrf_meta_tags %>
    <%= csp_meta_tag %>
    <script type="text/javascript" src="https://js.pay.jp/v1/"></script>
    <%= stylesheet_link_tag 'application', media: 'all' %>
    <%= javascript_pack_tag 'application' %>
<%#abridgement%>

Tokenization preparation

app/javascript/packs/application.js

//abridgement
require("@rails/ujs").start()
// require("turbolinks").start()
require("@rails/activestorage").start()
require("channels")
require("../card")
//abridgement

Event firing

app/javascript/card.js

const pay = () => {
  const form = document.getElementById("charge-form");
  form.addEventListener("submit", (e) => {
    e.preventDefault();
    console.log("Event fired when submitting form")
  });
};

window.addEventListener("load", pay);

Public key setting

app/javascript/card.js

const pay = () => {
  Payjp.setPublicKey("pk_test_******************"); // PAY.JP test public key
  const form = document.getElementById("charge-form");
  form.addEventListener("submit", (e) => {
    e.preventDefault();
    console.log("Event fired when submitting form")
  });
};

window.addEventListener("load", pay);

Get form information

app/javascript/card.js

const pay = () => {
  Payjp.setPublicKey("pk_test_******************"); // PAY.JP test public key
  const form = document.getElementById("charge-form");
  form.addEventListener("submit", (e) => {
    e.preventDefault();

    const formResult = document.getElementById("charge-form");
    const formData = new FormData(formResult);

    const card = {
      number: formData.get("order[number]"),
      cvc: formData.get("order[cvc]"),
      exp_month: formData.get("order[exp_month]"),
      exp_year: `20${formData.get("order[exp_year]")}`,
    };
  });
};

window.addEventListener("load", pay);

Card information tokenization

app/javascript/card.js

const pay = () => {
  Payjp.setPublicKey("pk_test_******************"); // PAY.JP test public key
  const form = document.getElementById("charge-form");
  form.addEventListener("submit", (e) => {
    e.preventDefault();

    const formResult = document.getElementById("charge-form");
    const formData = new FormData(formResult);

    const card = {
      number: formData.get("order[number]"),
      cvc: formData.get("order[cvc]"),
      exp_month: formData.get("order[exp_month]"),
      exp_year: `20${formData.get("order[exp_year]")}`,
    };

    Payjp.createToken(card, (status, response) => {
      if (status == 200) {
        const token = response.id;
        console.log(token)
      }
    });
  });
};

window.addEventListener("load", pay);

Let's check by entering the test card information prepared by pay.jp once!

Card number 4242424242424242 (16 digits) CVC 123 Expiration date Future from registration (04/25, etc.)

Include the token value in the form

app/javascript/card.js

const pay = () => {
  Payjp.setPublicKey("pk_test_******************"); // PAY.JP test public key
  const form = document.getElementById("charge-form");
  form.addEventListener("submit", (e) => {
    e.preventDefault();

    const formResult = document.getElementById("charge-form");
    const formData = new FormData(formResult);

    const card = {
      number: formData.get("order[number]"),
      cvc: formData.get("order[cvc]"),
      exp_month: formData.get("order[exp_month]"),
      exp_year: `20${formData.get("order[exp_year]")}`,
    };

    Payjp.createToken(card, (status, response) => {
      if (status == 200) {
        const token = response.id;
        const renderDom = document.getElementById("charge-form");
        const tokenObj = `<input value=${token} name='token'>`;
        renderDom.insertAdjacentHTML("beforeend", tokenObj);
        debugger;
      }
    });
  });
};

window.addEventListener("load", pay);

Hide token value

app/javascript/card.js

const pay = () => {
  Payjp.setPublicKey("pk_test_******************"); // PAY.JP test public key
  const form = document.getElementById("charge-form");
  form.addEventListener("submit", (e) => {
    e.preventDefault();

    const formResult = document.getElementById("charge-form");
    const formData = new FormData(formResult);

    const card = {
      number: formData.get("order[number]"),
      cvc: formData.get("order[cvc]"),
      exp_month: formData.get("order[exp_month]"),
      exp_year: `20${formData.get("order[exp_year]")}`,
    };

    Payjp.createToken(card, (status, response) => {
      if (status == 200) {
        const token = response.id;
        const renderDom = document.getElementById("charge-form");
        const tokenObj = `<input value=${token} name='token' type="hidden"> `;
        renderDom.insertAdjacentHTML("beforeend", tokenObj);
        debugger;
      }
    });
  });
};

window.addEventListener("load", pay);

Delete credit card information

app/javascript/card.js

const pay = () => {
  Payjp.setPublicKey("pk_test_******************"); // PAY.JP test public key
  const form = document.getElementById("charge-form");
  form.addEventListener("submit", (e) => {
    e.preventDefault();

    const formResult = document.getElementById("charge-form");
    const formData = new FormData(formResult);

    const card = {
      number: formData.get("order[number]"),
      cvc: formData.get("order[cvc]"),
      exp_month: formData.get("order[exp_month]"),
      exp_year: `20${formData.get("order[exp_year]")}`,
    };

    Payjp.createToken(card, (status, response) => {
      if (status == 200) {
        const token = response.id;
        const renderDom = document.getElementById("charge-form");
        const tokenObj = `<input value=${token} name='token' type="hidden"> `;
        renderDom.insertAdjacentHTML("beforeend", tokenObj);
      }

      document.getElementById("order_number").removeAttribute("name");
      document.getElementById("order_cvc").removeAttribute("name");
      document.getElementById("order_exp_month").removeAttribute("name");
      document.getElementById("order_exp_year").removeAttribute("name");
    });
  });
};

window.addEventListener("load", pay);

Submit form information to server side

app/javascript/card.js

const pay = () => {
  Payjp.setPublicKey("pk_test_******************"); // PAY.JP test public key
  const form = document.getElementById("charge-form");
  form.addEventListener("submit", (e) => {
    e.preventDefault();

    const formResult = document.getElementById("charge-form");
    const formData = new FormData(formResult);

    const card = {
      number: formData.get("order[number]"),
      cvc: formData.get("order[cvc]"),
      exp_month: formData.get("order[exp_month]"),
      exp_year: `20${formData.get("order[exp_year]")}`,
    };

    Payjp.createToken(card, (status, response) => {
      if (status == 200) {
        const token = response.id;
        const renderDom = document.getElementById("charge-form");
        const tokenObj = `<input value=${token} name='token' type="hidden"> `;
        renderDom.insertAdjacentHTML("beforeend", tokenObj);
      }

      document.getElementById("order_number").removeAttribute("name");
      document.getElementById("order_cvc").removeAttribute("name");
      document.getElementById("order_exp_month").removeAttribute("name");
      document.getElementById("order_exp_year").removeAttribute("name");

      document.getElementById("charge-form").submit();
    });
  });
};

window.addEventListener("load", pay);

Strong parameter editing

app/controllers/orders_controller.rb

#abridgement

  private

  def order_params
    params.require(:order).permit(:price).merge(token: params[:token])
  end

end

Added to Order model

app/models/order.rb

class Order < ApplicationRecord
  attr_accessor :token
  validates :price, presence: true
end

Introducing Gem

Gemfile

#abridgement
gem 'payjp'

Payment processing description and refactoring

app/controllers/orders_controller.rb

class OrdersController < ApplicationController

  def index
    @order = Order.new
  end

  def create
    @order = Order.new(order_params)
    if @order.valid?
      pay_item
      @order.save
      return redirect_to root_path
    else
      render 'index'
    end
  end

  private

  def order_params
    params.require(:order).permit(:price).merge(token: params[:token])
  end

  def pay_item
    Payjp.api_key = "sk_test_***********"  #Own PAY.Write the JP test private key
    Payjp::Charge.create(
      amount: order_params[:price],  #Product price
      card: order_params[:token],    #Card token
      currency: 'jpy'                 #Currency type (Japanese Yen)
    )
  end

end

Validation

app/models/order.rb

class Order < ApplicationRecord
  attr_accessor :token
  validates :price, presence: true
  validates :token, presence: true
end

Environment variables (for Mac Catalina and later)

Terminal

% vim ~/.zshrc
#Press i to switch to insert mode and add the following. Do not delete the existing description.
export PAYJP_SECRET_KEY='sk_test_************'
export PAYJP_PUBLIC_KEY='pk_test_************'
#After editing, press the esc key:Type wq to save and exit

Terminal

#Edited.Reload zshrc to use the added environment variables
% source ~/.zshrc

Invitation of environment variables assigned private key

app/controllers/orders_controller.rb

#abridgement
def pay_item
   Payjp.api_key = ENV["PAYJP_SECRET_KEY"]
   Payjp::Charge.create(
     amount: order_params[:price],
     card: order_params[:token],
     currency:'jpy'
   )
end

Calling environment variables with JavaScript

Terminal

% touch config/initializers/webpacker.rb

config/initializers/webpacker.rb

Webpacker::Compiler.env["PAYJP_PUBLIC_KEY"] = ENV["PAYJP_PUBLIC_KEY"]

app/javascript/card.js

const pay = () => {
 Payjp.setPublicKey(process.env.PAYJP_PUBLIC_KEY);
  //abridgement

Summary

Although it was easy, there may have been a lot of descriptions. However, it may be good to suppress it because it introduces a relatively simple payment function among APIs. In most cases, you will add columns etc. in the original, so it is recommended to write slowly in order! that's all!