Step by Step Guide to Building a Xero API Integration in PHP

Introduction

Hey there, fellow developer! Ready to dive into the world of Xero API integration? You're in for a treat. Xero's API is a powerhouse for managing financial data, and with the xeroapi/xero-php-oauth2 package, we're going to make it sing in PHP. Let's get cracking!

Prerequisites

Before we jump in, make sure you've got:

• A PHP environment (7.2+ recommended)
• Composer installed (trust me, it's a lifesaver)
• A Xero developer account (if you don't have one, hop over to Xero's developer portal and sign up)

Setting up the project

First things first, let's get our project set up:

composer require xeroapi/xero-php-oauth2

This will install the package and set up autoloading for us. Easy peasy!

Xero API Authentication

Now for the fun part - authentication. Head over to the Xero developer portal and create a new app. You'll get your client ID and client secret - guard these with your life!

Here's a quick OAuth 2.0 flow implementation:

<?php

use XeroAPI\XeroPHP\Provider\Provider;

$provider = new Provider([
    'clientId'     => 'YOUR_CLIENT_ID',
    'clientSecret' => 'YOUR_CLIENT_SECRET',
    'redirectUri'  => 'https://example.com/callback',
]);

// Authorization request
$authUrl = $provider->getAuthorizationUrl();
header('Location: ' . $authUrl);
exit;

// Token exchange (in your callback URL)
$token = $provider->getAccessToken('authorization_code', [
    'code' => $_GET['code']
]);

// Store the token securely

Making API calls

With our token in hand, let's make some magic happen:

$xero = new \XeroAPI\XeroPHP\Api\AccountingApi(
    new \GuzzleHttp\Client(),
    $provider->getTokenConfig($token)
);

// Fetch contacts
$contacts = $xero->getContacts($token->getTenantId());

// Create an invoice
$invoice = new \XeroAPI\XeroPHP\Models\Accounting\Invoice();
// ... set invoice properties
$result = $xero->createInvoices($token->getTenantId(), $invoice);

Handling responses and errors

Always expect the unexpected:

try {
    $result = $xero->getContacts($token->getTenantId());
    $contacts = json_decode($result);
} catch (\XeroAPI\XeroPHP\ApiException $e) {
    error_log('Xero API Error: ' . $e->getMessage());
}

Best practices

• Respect rate limits - Xero's not a fan of spam
• Store tokens securely - consider encryption
• Implement webhooks for real-time updates (your future self will thank you)

Testing and debugging

Use Xero's sandbox environment to test your integration. It's like a playground, but for code!

If you're stuck, check the response headers - they often contain clues about what went wrong.

Conclusion

And there you have it! You're now armed and dangerous with Xero API integration skills. Remember, the best way to learn is by doing, so get out there and start coding!

Code repository

For a complete working example, check out this GitHub repo. Happy coding!