paper-paypal-component

A Nodejs module implementation of Paypal API

Use this light SDK to access the simple payal APis to send payment.

The aim of this project is to help developpers to create single page application selling website by providing a simple server side implementation of the paypal SDK and a lightweight client side library to work with it.

• index.js
• paypal-api.js

Requirelent :

• Nodejs (lastest version)
• npm
• Bower

I - Create your HTTP server using Nodejs

First you need to create a simple http server using nodejs and a node module called Express

Note: You could use a HTTP server without Express but it make it easier to create route in your application

a) Install module using npm

To install a node modules nodejs use npm a javascript dependency manager that list every modules available and their dependencies

(You can visit http://npmjs.com)

Use the command line to install your needed modules.

First run : npm init to create you project package.json file, and follow the instructions.

$ npm init

Then use npm install to install packages

$ npm install --save express

Note: The --save option will add the node module dependency to your package.json file

The modules will be installed in a node_modules folder

b) create a simple server

To create a simple HTTP server create a app folder and in it create a server.js file.

/*  app/server.js */
/**
 * We require all the node modules needed
 * to create a simple HTTP server
 */
 
// The follow dependencies are required to create a simple HTTP server
var express = require('express');
var app = express();
 
// Use a route wildcart
// /!\ To defined specific route, reclare it before the wildcart /!\
app.get('*', function (req, res) {
  res.send('Hello World!');
});
 
app.listen(3000, function () {
  console.log('Example app listening on port 3000!');
});

This simple server will serve your file over the localhost using the port 3000

II - Require paper-paypal-component node module

To use our Paypal mini SDK, you need to install our node module.

To do so, use npm to install the module

$ npm install --save paper-paypal-component

Server side

Now you've installed the module, you need to update server.js file to add that module.

As we have done it for Express earlier, just require paper-paypal-component

var paypal = require('paper-paypal-component');
 
// paper-paypal-component routes
paypal.init(app, __dirname);

We also need to define static routes to load resources like CSS or Javascript client side.

Here we create a route for node_modules to load the paypal-api.js file

 
app.use("/node_modules", express.static(__dirname + '/node_modules'));
 
// ...

Client side

To help you working with the server side module we've created a client side library, that already know all routes and arguments to work with the Paypal APIs.

Include the library in you application and start using it like so :

<!--
...
-->
        <script src='/node_modules/paper-paypal-component/dist/paypal/paypal-api.js'></script> 
    </body>
</html>
 

Note : To ensure the library is correctly loaded use the console : *console.log(PaypalApi);*

III - Usage

First of all, we need to create a config file to store the paypal clientID, and the secret key

// config.json
{
    "clientID": "YOUR_CLENT_ID",
    "secret": "YOUR_SECRET_KEY"
}

Note : The config.js must be at the same level that your server.js

To use the Paypal SDK, there are 3 mains methods available

/**
 * GetToken send a request to Paypal
 * to authenticate the client and get an access token
 * to the Paypal APIs
 * @param  {callable}callback The action to be performed after Paypal respond with the token
 * 
 */
Paypal.getToken(callback);
 
/**
 * SendPayment send a payment request to Paypal
 * If the response is successfull, the user is asked to authenticate using its credentials
 * Then the user is send back to the website to confirm payment
 * @param  {object} params Object containing parameters to send to PayPal
 * 		   {string} price [required]
 * 		   {string} currency [required]
 * 		   {string} description [required]
 * 		   {string} cancelUrl The helper will build URL from current domain name. Only the URI is needed
 * 		   {string} returnUrl The helper will build URL from current domain name. Only the URI is needed
 * 		   {string} callback  The actions to perform after the payment succeed
 *
 * Note: As Paypal Express Checkout don't support multiple checkout at once
 * The payment transaction object must correspond to the total of all element in cart to be checked out
 */
Paypal.sendPayment(paramsObject);
 
/**
 * ExecutePayment send a confirmation request to payment to execute the transaction
 * @param {string} accessToken The client access token to Paypal APIs
 * @param {callable} callback The actions to perform after the transaction succed
 */
Paypal.executePayment(acessToken, callback)

Workflow :

      _paypalSubmit: function() {
          var paypalApi = paypalApi;
          // Set the transtaction object
          var transaction = {};
          transaction.description = "";
          
          // this.cart represend the cart object
          // Note: Transaction must bbe filled
          this.cart.forEach(function (el) {
            transaction.description += el.item.description + "\n";
          });
          
          // We can imagine the the cart total is pre computed in the cart object
          transaction.total = this.cart.total;
          transaction.currency = 'USD';
          
          paypalApi.getToken(function () {
            paypalApi.sendPayment({
              transaction: transaction,
              returnUrl: '/confirm'
            });
          });
      },

Then after the user authentocate into Paypal and return to the website

     _executePayment: function() {
        // listen for the loading event
        // then dislay payement confirmtion
        var shopConfirm = this;
        var paypalApi = window.paypalApi;
        // Get token to be sure to be able to talk with Paypal
        // Note: It also can be stored in the browser storage
        paypalApi.getToken(function (accessToken) {
          paypalApi.executePayment(accessToken, function (response) {
            if (paypalApi.state == "approved") {
              // Change the view to success view
              shopConfirm._pushState('success');
              // Clear the cart
              shopConfirm.fire('clear-cart');
            } else {
              // Display an error page
              shopConfirm._pushState('error');
            }
          })
        });
      },