How To Write A Custom Payment Plugin For Woocommerce

* Add content to the WC emails.

*

* @access public

* @param WC_Order $order

* @param bool $sent_to_admin

* @param bool $plain_text

*/

public function email_instructions( $order, $sent_to_admin, $plain_text = false ) {

if ( $this->instructions && ! $sent_to_admin && $this->id === $order->get_payment_method() ) {

echo wp_kses_post( wpautop( wptexturize( $this->instructions ) ) . PHP_EOL );

}

}

}

Explanation:

• Class Definition: `class WC_Gateway_Custom extends WC_Payment_Gateway { … }` Extends the core WooCommerce payment gateway class.
• `__construct()`: The constructor sets up the gateway’s ID, title, description, and settings. Crucially, it loads the settings form fields and hooks actions for updating settings, displaying the thank you page, and adding instructions to emails.
• `init_form_fields()`: Defines the settings that will appear in the WooCommerce admin panel for this gateway (enabled/disabled, title, description, instructions). This allows administrators to configure the gateway.
• `payment_fields()`: This function is responsible for displaying the payment form on the checkout page. The example shows how to add a custom text field. You’ll need to customize this to capture any required payment information from the user.
• `process_payment()`: This is the most important function. It’s called when the order is placed. In this example, it simply marks the order as processing, reduces stock levels, and empties the cart. You’ll need to replace this with the code that actually communicates with your payment processor. This involves:
• Collecting the payment data submitted in `payment_fields()`.
• Authenticating with your payment gateway.
• Sending the payment request.
• Receiving and interpreting the response.
• Updating the order status based on the response (e.g., `completed`, `failed`).
• `thankyou_page()`: Displays custom instructions on the order confirmation (“Thank You”) page.
• `email_instructions()`: Adds instructions to the order confirmation email.

#### 3. Processing Payments (The Core Logic)

The `process_payment()` function is where your payment processing magic happens. This is where you’ll interact with your chosen payment gateway’s API. Here’s a simplified example of what that might look like (assuming a hypothetical API):

 /** 
Process the payment and return the result.
 
* @param int $order_id
 
@return array
 */ public function process_payment( $order_id ) { 

$order = wc_get_order( $order_id );

// Get submitted payment data from payment_fields()

$custom_field_value = $_POST[‘custom_field’]; //Example retrieval, sanitize before use!

// Replace with your actual API credentials

$api_key = $this->get_option( ‘api_key’ ); // Assuming you added an API key field in init_form_fields()

// Prepare the payment request

$payment_data = array(

‘api_key’ => Explore this article on How To Create A Cart Page In Woocommerce $api_key,

‘amount’ => $order->get_total(),

‘currency’ => get_woocommerce_currency(),

‘description’ => ‘Payment for order #’ . $order_id,

‘custom_field’ => sanitize_text_field( $custom_field_value ), //Sanitize input!

);

// SEND PAYMENT REQUEST TO YOUR PAYMENT GATEWAY HERE

$response = $this->send_payment_request( $payment_data ); // Assuming you have a method to send the request

if ( $response[‘success’] ) {

// Payment was successful

// Mark order as completed

$order->payment_complete();

$order->add_order_note( __( ‘Payment successful via Custom Payment Gateway.’, ‘woocommerce’ ) );

// Reduce stock levels

wc_reduce_stock_levels( $order_id );

// Remove cart

WC()->cart->empty_cart();

// Return thankyou redirect

return array(

‘result’ => ‘success’,

‘redirect’ => $this->get_return_url( $order )

);

} else {

// Payment failed

wc_add_notice( $response[‘error_message’], ‘error’ );

$order->add_order_note( __( ‘Payment failed via Custom Payment Gateway: ‘ . $response[‘error_message’], ‘woocommerce’ ) );

return array(

‘result’ => ‘failure’,

);

}

}

/

 public function payment_fields() { 

 public function process_payment( $order_id ) {