Allows customers to select membership duration at checkout. Adjusts the amount charged and expiration date of the membership accordingly.

pmpro-select-membership-duration.php

<?php

/*
 * Add this code below to your PMPro Customizations Plugin - https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 * Allows customers to select membership duration at checkout. Adjusts the amount charged and expiration date of the membership accordingly.
 * Requires the Paid Memberships Pro Register Helper Add On to be installed and activated in order to work - https://www.paidmembershipspro.com/add-ons/pmpro-register-helper-add-checkout-and-profile-fields/
 */

function my_pmprorh_init() {

	//don't break if Register Helper is not loaded
	if ( ! function_exists( 'pmprorh_add_registration_field' ) ) {
		return false;
	}
	
	//define the fields
	$fields = array();
	$fields[] = new PMProRH_Field(
		'membership_duration',
		'select',					
		array(
			'label' => 'Membership Duration',
			'options' => array( 'no' => '--', 2 => '2 Years', 3 => '3 Years' ),
			'levels' => array( 2 ) // Make sure this is to only show for yearly membership options.
		)
	);
	//add the fields into a new checkout_boxes are of the checkout page
	foreach( $fields as $field )
		pmprorh_add_registration_field(
			'checkout_boxes',				// location on checkout page
			$field						// PMProRH_Field object
		);
	//that's it. see the PMPro Register Helper readme for more information and examples.
}
add_action( 'init', 'my_pmprorh_init' );
// Adds the duration functionality that alters the amount charged and the expiration date of the membership depending on what the user selects.
function my_pmpro_checkout_level( $level ) {

	$duration = isset( $_REQUEST['membership_duration'] ) ? $_REQUEST['membership_duration'] : '';

	// Bail if no duration is set.
	if ( empty( $duration ) ) {
	return $level;
	}

	// Bail if the user hasn't selected a duration and keep level intact.
	if ( 'no' === $duration ) {
		return $level;
	}
		
	// Duration for 2 years, give 20% discount.
	if ( '2' === $duration ) {
    		$duration = 2;
    		$discount_percentage = 0.2;
	}

	// Duration for 3 years, give 25% discount.
	if ( '3' === $duration ) {     
		$duration = 3;
		$discount_percentage = 0.25;
	}

	 
	// Set the duration to selected and adjust the charged amount. Please Note - the new amount will only show upon redirecting to payment gateway page.
	if ( is_int( $duration ) ) {

		// Set the level's duration.
		$level->expiration_number = $duration;
		$level->expiration_period = 'Year';

		// Let's calculate the new price with discount.
		$new_amount = $duration * $level->initial_payment;
		$discount_amount = $new_amount * $discount_percentage;

		// Set the level's new price.
		$level->initial_payment = round( $new_amount - $discount_amount );
	}
	 
	return $level;
}
add_filter( "pmpro_checkout_level", "my_pmpro_checkout_level" );