Using Gravity Forms ‘gform_paypal_invoice’ PHP filter

The gform_paypal_invoice filter allows you to modify the invoice number sent to PayPal for the PayPal Standard Add-on.

Usage

add_filter('gform_paypal_invoice', 'your_function_name', 10, 3);

Parameters

  • $invoice_id (integer): Empty string.
  • $form (Form Object): The form from which the PayPal transaction was submitted.
  • $entry (Entry Object): The entry used to generate the PayPal transaction.

More information

See Gravity Forms Docs: gform_paypal_invoice

Examples

Use Entry ID as Invoice ID

This example sets the invoice ID to the entry ID.

add_filter('gform_paypal_invoice', 'change_invoice', 10, 3);

function change_invoice($invoice_id, $form, $entry) {
    return rgar($entry, 'id');
}

Append Prefix to Invoice ID

This example appends a custom prefix to the invoice ID.

add_filter('gform_paypal_invoice', 'append_invoice_prefix', 10, 3);

function append_invoice_prefix($invoice_id, $form, $entry) {
    $prefix = 'INV-';
    return $prefix . rgar($entry, 'id');
}

Add Form ID to Invoice ID

This example adds the form ID to the invoice ID.

add_filter('gform_paypal_invoice', 'add_form_id_to_invoice', 10, 3);

function add_form_id_to_invoice($invoice_id, $form, $entry) {
    return rgar($entry, 'id') . '-' . rgar($form, 'id');
}

Generate Random Invoice ID

This example generates a random invoice ID using a combination of entry ID and a random number.

add_filter('gform_paypal_invoice', 'generate_random_invoice_id', 10, 3);

function generate_random_invoice_id($invoice_id, $form, $entry) {
    $random_number = mt_rand(1000, 9999);
    return rgar($entry, 'id') . '-' . $random_number;
}

Use Entry Date as Invoice ID

This example sets the invoice ID to the entry’s submission date.

add_filter('gform_paypal_invoice', 'set_entry_date_as_invoice_id', 10, 3);

function set_entry_date_as_invoice_id($invoice_id, $form, $entry) {
    return str_replace('-', '', rgar($entry, 'date_created'));
}