WPJobBoard

Payment API

In order to add new payment method to WPJB, you need to do few things. Create new WordPress plugin, create class that will extend Wpjb_Payment_Interface and apply filter that will register new payment method.

Below you can download working example that will add Payment by cash to WPJobBoard, the only thing you need to do is upload it to wp-content/plugins directory and activate “WPJobBoard Mod” plugin in wp-admin/plugins.php section.

If everything will be ok, in Add Job form “Payment Method” field should appear with options “PayPal” and “Pay by cash”.

Download Payment API Example

Implementing new payment class

At the begining of the article i mentioned that the new payment method should implement Wpjb_Payment_Interface, this basically comes down to having class with 5 mandatory methods:

• getEngine()
  (string) payment engine name this method should return lowercase a-z string uniquely identyfying your payment engine
• getTitle()
  (string) shuld return title that will be visible to end user
• getForm()
  (string) class name of an object that is responsible for generating payment method configuration
• render()
  (string) should return payment button or text informing how to make payment
• processTransaction(array $post, array $get)
  (null) validates if the payment was correct. If the payment is incorrect then processTransaction() should throw an error. This method is executed when the payment gateway you are integrating with received a payment and send a request to your site to check if everything is ok

This is a basic scheme for payment integration class

class Wpjb_Payment_MyPaymentGateway extends Wpjb_Payment_Abstract 
{
 public function __construct(Wpjb_Model_Payment $data = null) 
 {
   $this->_data = $data; 
 }
 public function getEngine() {
   return "my_payment_gateway";
 }
 public function getTitle() {
   return "My payment gateway"; 
 }
 public function getForm() {
   return "MyPaymentGatewayForm";
 }
 public function bind(array $post, array $get) {
   // this is a good place to set $this->data
   $this->setObject(new Wpjb_Model_Payment($get["id"]));
   parent::bind($post, $get);
 }
 public function processTransaction() {
   $post = $this->_post; // $_POST
   $get = $this->_get; // $_GET
   if($post["id"] < 1) {
     throw new Exception("Incorrect something");
   }
   // payment verification vary for each payment engine
   // you will need to figure this one on your own
   // note that as a parameters you receive $post and $get
   // which are the same as $_POST and $_GET
   // this should allow you to validate payment
 }
 public function render() {
   $html = "";
   $arr = array("action"=>"wpjb_payment_accept", "engine"=>$this->getEngine());
   $data = $this->_data;
   /* @var $data Wpjb_Model_Payment */
   // online payment gateways usually require you to pass notify url
   $html .= "Notify URL: " . admin_url('admin-ajax.php')."?".http_build_query($arr) . "<br/>";
   // and complete URL that is url when user should be redirected after payment
   $html .= wpjb_link_to("step_complete", $this->_data) . "<br/>";
   // and of course amount to pay and currency
   $html .= "To pay: " . ($this->_data->payment_sum-$this->_data->payment_paid) . " " .$this->_data->payment_currency;
   if($this->conf("message")) {
     // we are adding now message from payment configuration form
     // that will be created below
     $html .= "<div>".$this->conf("message")."</div>";
   }
   $html .= "<br/><br/>";
   return $html;
 }
}

Please note that the class has also __construct() and getObject() methods which you can simply copy and paste them into your own class.

Below is minimal version of the configuration form

class MyPaymentGatewayForm extends Wpjb_Form_Abstract_Payment
{
  public function init() {
    parent::init();
    $this->addGroup("my", __("My Group", "wpjobboard"));
    // adding custom textare field to the form
    $e = $this->create("message", "textarea");
    $e->setValue($this->conf("message"));
    $e->setLabel(__("Message", "wpjobboard"));
    $this->addElement($e, "my");
 }
}

Registering your payment method

Now all you need to do is register your newly created payment integration using wpjb_payment_list filter

function wpjb_payment_mypaymentgateway($list) {
  global $wpjobboard;
  $cash = new Wpjb_Payment_MyPaymentGateway;
  // registers new payment method
  $list[$cash->getEngine()] = get_class($cash);
  return $list;
}
add_filter('wpjb_payments_list', 'wpjb_payment_mypaymentgateway');

If you wonder where to put this code. You can either put it in your theme functions.php file or for more experienced users you can build it as a new plugin like the Payment API example does (this is actually recommended approach although harder to complete).