Give a "Member Number" from a list of defined values and show it on the PMPro account page.

generate_member_number_from_defined_list.php

/*
	Member Numbers from Defined List
	* Member numbers are generated when users are registered or when the membership account page is accessed for the first time.
*/
//Generate member_number when a user is registered.
function generate_member_number($user_id)
{
	global $member_number_array = array("1111", "2222", "3333");	//add additional codes to this array

	$member_number = get_user_meta($user_id, "member_number", true);
	
	//if no member number, create one
	if(empty($member_number))
	{
		//select a random number from the array
		$k = array_rand($member_number_array);
		$member_number = $member_number_array[$k];

		//save to user meta
		update_user_meta($user_id, "member_number", $member_number);
		
		return $member_number;
	}
}
add_action('pmpro_after_checkout', 'generate_member_number');

//Show it on the membership account page.
function pmpromn_pmpro_account_bullets_bottom()
{
	if(is_user_logged_in())
	{
		global $current_user;
		
		//get member number
		$member_number = get_user_meta($current_user->ID, "member_number", true);
		
		//if no number, generate one
		if(empty($member_number))
			$member_number = generate_member_number($current_user->ID);
		
		//show it
		if(!empty($member_number))
		{
		?>
		<li><strong><?php _e("Member Number", "pmpro");?>:</strong> <?php echo $member_number?></li>
		<?php
		}
	}
}
add_action('pmpro_account_bullets_bottom', 'pmpromn_pmpro_account_bullets_bottom');
add_action('pmpro_invoice_bullets_bottom', 'pmpromn_pmpro_account_bullets_bottom');

//show member_number in confirmation emails
function pmpromn_pmpro_email_filter($email)
{
	global $wpdb;
 	
	//only update admin confirmation emails
	if(strpos($email->template, "checkout") !== false)
	{
		if(!empty($email->data) && !empty($email->data['user_login']))
		{
			$user = get_user_by("login", $email->data['user_login']);			
			if(!empty($user) && !empty($user->ID))
			{
				$member_number = get_user_meta($user->ID, "member_number", true);
				
				if(!empty($member_number))
					$email->body = str_replace("<p>Membership Level", "<p>Member Number:" . $member_number . "</p><p>Membership Level", $email->body);
			}
		}
	}
		
	return $email;
}
add_filter("pmpro_email_filter", "pmpromn_pmpro_email_filter", 30, 2);

function pmpromn_pmpro_memberslist_extra_cols_body($theuser)
{?>
	<td><?php
		$member_number = get_user_meta($theuser->ID, "member_number", true);
		if($member_number)
			echo $member_number;
		else
			echo "";?>
	</td><?php
}

add_action("pmpro_memberslist_extra_cols_body", "pmpromn_pmpro_memberslist_extra_cols_body");

function pmpromn_pmpro_memberslist_extra_cols_header()
{?>
	<th><?php _e('Member Number', 'pmpro');?></th><?php
}
add_action("pmpro_memberslist_extra_cols_header", "pmpromn_pmpro_memberslist_extra_cols_header");