Translating "Pay by Check" example for Paid Memberships Pro.

1-translate-pay-by-check-pmpro.php

<?php
/**
 * This will translate "Pay by Check" into "Pay by Cheque or Bank Transfer" and load custom templates for confirmation and invoice.php
 * Please create a "templates" folder inside your PMPro Customizations Plugin as per this guide - https://www.paidmembershipspro.com/documentation/templates/customizing-via-a-custom-plugin/
 * Add this code to your PMPro Customizations Plugin - https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 * For more help visit www.paidmembershipspro.com
 */

function my_pmpro_text_strings( $translated_text, $text, $domain ) {
	switch ( $translated_text ) {
		case 'Pay by Check' :
			$translated_text = __( 'Pay by Cheque or Bank Transfer', 'paid-memberships-pro' );
			break;
	}
	return $translated_text;
}
add_filter( 'gettext', 'my_pmpro_text_strings', 20, 3 );

function my_pmpro_pages_shortcode_confirmation($content) {
	ob_start();
	include(plugin_dir_path(__FILE__) . "templates/confirmation.php");
	$temp_content = ob_get_contents();
	ob_end_clean();
	return $temp_content;
}
add_filter("pmpro_pages_shortcode_confirmation", "my_pmpro_pages_shortcode_confirmation");

function my_pmpro_pages_shortcode_invoice($content) {
	ob_start();
	include(plugin_dir_path(__FILE__) . "templates/invoice.php");
	$temp_content = ob_get_contents();
	ob_end_clean();
	return $temp_content;
}
add_filter("pmpro_pages_shortcode_invoice", "my_pmpro_pages_shortcode_invoice");

confirmation.php

<?php 

	global $wpdb, $current_user, $pmpro_invoice, $pmpro_msg, $pmpro_msgt;
	
	if($pmpro_msg)
	{
	?>
		<div class="pmpro_message <?php echo $pmpro_msgt?>"><?php echo $pmpro_msg?></div>
	<?php
	}
	
	if(empty($current_user->membership_level))
		$confirmation_message = "<p>" . __('Your payment has been submitted. Your membership will be activated shortly.', 'paid-memberships-pro' ) . "</p>";
	else
		$confirmation_message = "<p>" . sprintf(__('Thank you for your membership to %s. Your %s membership is now active.', 'paid-memberships-pro' ), get_bloginfo("name"), $current_user->membership_level->name) . "</p>";		
	
	//confirmation message for this level
	$level_message = $wpdb->get_var("SELECT l.confirmation FROM $wpdb->pmpro_membership_levels l LEFT JOIN $wpdb->pmpro_memberships_users mu ON l.id = mu.membership_id WHERE mu.status = 'active' AND mu.user_id = '" . $current_user->ID . "' LIMIT 1");
	if(!empty($level_message))
		$confirmation_message .= "\n" . stripslashes($level_message) . "\n";
?>	

<?php if(!empty($pmpro_invoice) && !empty($pmpro_invoice->id)) { ?>		
	
	<?php
		$pmpro_invoice->getUser();
		$pmpro_invoice->getMembershipLevel();			
				
		$confirmation_message .= "<p>" . sprintf(__('Below are details about your membership account and a receipt for your initial membership invoice. A welcome email with a copy of your initial membership invoice has been sent to %s.', 'paid-memberships-pro' ), $pmpro_invoice->user->user_email) . "</p>";
		
		//check instructions
		if($pmpro_invoice->gateway == "check" && !pmpro_isLevelFree($pmpro_invoice->membership_level))
			$confirmation_message .= wpautop(wp_unslash( pmpro_getOption("instructions") ) );
		
		/**
		 * All devs to filter the confirmation message.
		 * We also have a function in includes/filters.php that applies the the_content filters to this message.
		 * @param string $confirmation_message The confirmation message.
		 * @param object $pmpro_invoice The PMPro Invoice/Order object.
		 */
		$confirmation_message = apply_filters("pmpro_confirmation_message", $confirmation_message, $pmpro_invoice);				
		
		echo $confirmation_message;
	?>
	
	
	<h3>
		<?php printf(__('Invoice #%s on %s', 'paid-memberships-pro' ), $pmpro_invoice->code, date_i18n(get_option('date_format'), $pmpro_invoice->timestamp));?>		
	</h3>
	<a class="pmpro_a-print" href="javascript:window.print()"><?php _e('Print', 'paid-memberships-pro' );?></a>
	<ul>
		<?php do_action("pmpro_invoice_bullets_top", $pmpro_invoice); ?>
		<li><strong><?php _e('Account', 'paid-memberships-pro' );?>:</strong> <?php echo $current_user->display_name?> (<?php echo $current_user->user_email?>)</li>
		<li><strong><?php _e('Membership Level', 'paid-memberships-pro' );?>:</strong> <?php echo $current_user->membership_level->name?></li>
		<?php if($current_user->membership_level->enddate) { ?>
			<li><strong><?php _e('Membership Expires', 'paid-memberships-pro' );?>:</strong> <?php echo date_i18n(get_option('date_format'), $current_user->membership_level->enddate)?></li>
		<?php } ?>
		<?php if($pmpro_invoice->getDiscountCode()) { ?>
			<li><strong><?php _e('Discount Code', 'paid-memberships-pro' );?>:</strong> <?php echo $pmpro_invoice->discount_code->code?></li>
		<?php } ?>
		<?php do_action("pmpro_invoice_bullets_bottom", $pmpro_invoice); ?>
	</ul>
	<hr />	
	<div class="pmpro_invoice_details">
		<?php if(!empty($pmpro_invoice->billing->name)) { ?>
			<div class="pmpro_invoice-billing-address">
				<strong><?php _e('Billing Address', 'paid-memberships-pro' );?></strong>
				<p><?php echo $pmpro_invoice->billing->name?><br />
				<?php echo $pmpro_invoice->billing->street?><br />						
				<?php if($pmpro_invoice->billing->city && $pmpro_invoice->billing->state) { ?>
					<?php echo $pmpro_invoice->billing->city?>, <?php echo $pmpro_invoice->billing->state?> <?php echo $pmpro_invoice->billing->zip?> <?php echo $pmpro_invoice->billing->country?><br />												
				<?php } ?>
				<?php echo formatPhone($pmpro_invoice->billing->phone)?>
				</p>
			</div> <!-- end pmpro_invoice-billing-address -->
		<?php } ?>
		
		<?php if($pmpro_invoice->accountnumber) { ?>
			<div class="pmpro_invoice-payment-method">
				<strong><?php _e('Payment Method', 'paid-memberships-pro' );?></strong>
				<p><?php echo $pmpro_invoice->cardtype?> <?php _e('ending in', 'paid-memberships-pro' );?> <?php echo last4($pmpro_invoice->accountnumber)?></p>
				<p><?php _e('Expiration', 'paid-memberships-pro' );?>: <?php echo $pmpro_invoice->expirationmonth?>/<?php echo $pmpro_invoice->expirationyear?></p>
			</div> <!-- end pmpro_invoice-payment-method -->
		<?php } elseif($pmpro_invoice->payment_type) { ?>
			<?php 
				if( 'Check' == $pmpro_invoice->payment_type ) {
					_e( 'Pay by Check', 'paid-memberships-pro' );
				} else {
					echo $pmpro_invoice->payment_type; 
				}
				
			?>
		<?php } ?>
		
		<div class="pmpro_invoice-total">
			<strong><?php _e('Total Billed', 'paid-memberships-pro' );?></strong>
			<p><?php if($pmpro_invoice->total != '0.00') { ?>
				<?php if(!empty($pmpro_invoice->tax)) { ?>
					<?php _e('Subtotal', 'paid-memberships-pro' );?>: <?php echo pmpro_formatPrice($pmpro_invoice->subtotal);?><br />
					<?php _e('Tax', 'paid-memberships-pro' );?>: <?php echo pmpro_formatPrice($pmpro_invoice->tax);?><br />
					<?php if(!empty($pmpro_invoice->couponamount)) { ?>
						<?php _e('Coupon', 'paid-memberships-pro' );?>: (<?php echo pmpro_formatPrice($pmpro_invoice->couponamount);?>)<br />
					<?php } ?>
					<strong><?php _e('Total', 'paid-memberships-pro' );?>: <?php echo pmpro_formatPrice($pmpro_invoice->total);?></strong>
				<?php } else { ?>
					<?php echo pmpro_formatPrice($pmpro_invoice->total);?>
				<?php } ?>						
			<?php } else { ?>
				<small class="pmpro_grey"><?php echo pmpro_formatPrice(0);?></small>
			<?php } ?></p>
		</div> <!-- end pmpro_invoice-total -->

	</div> <!-- end pmpro_invoice -->
	<hr />
<?php 
	} 
	else 
	{
		$confirmation_message .= "<p>" . sprintf(__('Below are details about your membership account. A welcome email has been sent to %s.', 'paid-memberships-pro' ), $current_user->user_email) . "</p>";
		
		/**
		 * All devs to filter the confirmation message.
		 * Documented above.
		 * We also have a function in includes/filters.php that applies the the_content filters to this message.		 
		 */
		$confirmation_message = apply_filters("pmpro_confirmation_message", $confirmation_message, false);
		
		echo $confirmation_message;
	?>	
	<ul>
		<li><strong><?php _e('Account', 'paid-memberships-pro' );?>:</strong> <?php echo $current_user->display_name?> (<?php echo $current_user->user_email?>)</li>
		<li><strong><?php _e('Membership Level', 'paid-memberships-pro' );?>:</strong> <?php if(!empty($current_user->membership_level)) echo $current_user->membership_level->name; else _e("Pending", 'paid-memberships-pro' );?></li>
	</ul>	
<?php 
	} 
?>  
<nav id="nav-below" class="navigation" role="navigation">
	<div class="nav-next alignright">
		<?php if(!empty($current_user->membership_level)) { ?>
			<a href="<?php echo pmpro_url("account")?>"><?php _e('View Your Membership Account &rarr;', 'paid-memberships-pro' );?></a>
		<?php } else { ?>
			<?php _e('If your account is not activated within a few minutes, please contact the site owner.', 'paid-memberships-pro' );?>
		<?php } ?>
	</div>
</nav>

invoice.php

<?php 
	global $wpdb, $pmpro_invoice, $pmpro_msg, $pmpro_msgt, $current_user;
	
	if($pmpro_msg)
	{
	?>
	<div class="pmpro_message <?php echo $pmpro_msgt?>"><?php echo $pmpro_msg?></div>
	<?php
	}
?>	

<?php 
	if($pmpro_invoice) 
	{ 
		?>
		<?php
			$pmpro_invoice->getUser();
			$pmpro_invoice->getMembershipLevel();
		?>
		
		<h3>
			<?php printf(__('Invoice #%s on %s', 'paid-memberships-pro' ), $pmpro_invoice->code, date_i18n(get_option('date_format'), $pmpro_invoice->timestamp));?>	
		</h3>
		<a class="pmpro_a-print" href="javascript:window.print()"><?php _e('Print', 'paid-memberships-pro' ); ?></a>
		<ul>
			<?php do_action("pmpro_invoice_bullets_top", $pmpro_invoice); ?>
			<li><strong><?php _e('Account', 'paid-memberships-pro' );?>:</strong> <?php echo $pmpro_invoice->user->display_name?> (<?php echo $pmpro_invoice->user->user_email?>)</li>
			<li><strong><?php _e('Membership Level', 'paid-memberships-pro' );?>:</strong> <?php echo $pmpro_invoice->membership_level->name?></li>
			<?php if($current_user->membership_level->enddate) { ?>
				<li><strong><?php _e('Membership Expires', 'paid-memberships-pro' );?>:</strong> <?php echo date_i18n(get_option('date_format'), $current_user->membership_level->enddate)?></li>
			<?php } ?>
			<?php if($pmpro_invoice->getDiscountCode()) { ?>
				<li><strong><?php _e('Discount Code', 'paid-memberships-pro' );?>:</strong> <?php echo $pmpro_invoice->discount_code->code?></li>
			<?php } ?>
			<?php do_action("pmpro_invoice_bullets_bottom", $pmpro_invoice); ?>
		</ul>
		
		<?php
			//check instructions		
			if($pmpro_invoice->gateway == "check" && !pmpro_isLevelFree($pmpro_invoice->membership_level))
				echo wpautop(pmpro_getOption("instructions"));
		?>
		
		<hr />	
		<div class="pmpro_invoice_details">
			<?php if(!empty($pmpro_invoice->billing->name)) { ?>
				<div class="pmpro_invoice-billing-address">
					<strong><?php _e('Billing Address', 'paid-memberships-pro' );?></strong>
					<p><?php echo $pmpro_invoice->billing->name?><br />
					<?php echo $pmpro_invoice->billing->street?><br />						
					<?php if($pmpro_invoice->billing->city && $pmpro_invoice->billing->state) { ?>
						<?php echo $pmpro_invoice->billing->city?>, <?php echo $pmpro_invoice->billing->state?> <?php echo $pmpro_invoice->billing->zip?> <?php echo $pmpro_invoice->billing->country?><br />												
					<?php } ?>
					<?php echo formatPhone($pmpro_invoice->billing->phone)?>
					</p>
				</div> <!-- end pmpro_invoice-billing-address -->
			<?php } ?>

			<?php if($pmpro_invoice->accountnumber) { ?>
				<div class="pmpro_invoice-payment-method">
					<strong><?php _e('Payment Method', 'paid-memberships-pro' );?></strong>
					<p><?php echo $pmpro_invoice->cardtype?> <?php _e('ending in', 'paid-memberships-pro' );?> <?php echo last4($pmpro_invoice->accountnumber)?></p>
					<p><?php _e('Expiration', 'paid-memberships-pro' );?>: <?php echo $pmpro_invoice->expirationmonth?>/<?php echo $pmpro_invoice->expirationyear?></p>
				</div> <!-- end pmpro_invoice-payment-method -->
			<?php } elseif($pmpro_invoice->payment_type) { ?>
				<?php 
				if( 'Check' == $pmpro_invoice->payment_type ) {
					_e( 'Pay by Check', 'paid-memberships-pro' );
				} else {
					echo $pmpro_invoice->payment_type; 
				}
				
			?>
			<?php } ?>

			<div class="pmpro_invoice-total">
				<strong><?php _e('Total Billed', 'paid-memberships-pro' );?></strong>
				<p><?php if($pmpro_invoice->total != '0.00') { ?>
					<?php if(!empty($pmpro_invoice->tax)) { ?>
						<?php _e('Subtotal', 'paid-memberships-pro' );?>: <?php echo pmpro_formatPrice($pmpro_invoice->subtotal);?><br />
						<?php _e('Tax', 'paid-memberships-pro' );?>: <?php echo pmpro_formatPrice($pmpro_invoice->tax);?><br />
						<?php if(!empty($pmpro_invoice->couponamount)) { ?>
							<?php _e('Coupon', 'paid-memberships-pro' );?>: (<?php echo pmpro_formatPrice($pmpro_invoice->couponamount);?>)<br />
						<?php } ?>
						<strong><?php _e('Total', 'paid-memberships-pro' );?>: <?php echo pmpro_formatPrice($pmpro_invoice->total);?></strong>
					<?php } else { ?>
						<?php echo pmpro_formatPrice($pmpro_invoice->total);?>
					<?php } ?>						
				<?php } else { ?>
					<small class="pmpro_grey"><?php echo pmpro_formatPrice(0);?></small>
				<?php } ?></p>
			</div> <!-- end pmpro_invoice-total -->
		</div> <!-- end pmpro_invoice -->
		<hr />
		<?php 
	} 
	else 
	{
		//Show all invoices for user if no invoice ID is passed	
		$invoices = $wpdb->get_results("SELECT o.*, UNIX_TIMESTAMP(o.timestamp) as timestamp, l.name as membership_level_name FROM $wpdb->pmpro_membership_orders o LEFT JOIN $wpdb->pmpro_membership_levels l ON o.membership_id = l.id WHERE o.user_id = '$current_user->ID' ORDER BY timestamp DESC");
		if($invoices)
		{
			?>
			<table id="pmpro_invoices_table" class="pmpro_invoice" width="100%" cellpadding="0" cellspacing="0" border="0">
			<thead>
				<tr>
					<th><?php _e('Date', 'paid-memberships-pro' ); ?></th>
					<th><?php _e('Invoice #', 'paid-memberships-pro' ); ?></th>
					<th><?php _e('Level', 'paid-memberships-pro' ); ?></th>
					<th><?php _e('Total Billed', 'paid-memberships-pro' ); ?></th>					
				</tr>
			</thead>
			<tbody>
			<?php
				foreach($invoices as $invoice)
				{ 
					?>
					<tr>
						<td><a href="<?php echo pmpro_url("invoice", "?invoice=" . $invoice->code)?>"><?php echo date_i18n(get_option("date_format"), $invoice->timestamp)?></a></td>
						<td><a href="<?php echo pmpro_url("invoice", "?invoice=" . $invoice->code)?>"><?php echo $invoice->code; ?></a></td>
						<td><?php echo $invoice->membership_level_name;?></td>
						<td><?php echo pmpro_formatPrice($invoice->total);?></td>											
					</tr>
					<?php
				}
			?>
			</tbody>
			</table>
			<?php
		}
		else
		{
			?>
			<p><?php _e('No invoices found.', 'paid-memberships-pro' );?></p>
			<?php
		}
	} 
?>
<nav id="nav-below" class="navigation" role="navigation">
	<div class="nav-next alignright">
		<a href="<?php echo pmpro_url("account")?>"><?php _e('View Your Membership Account &rarr;', 'paid-memberships-pro' );?></a>
	</div>
	<?php if($pmpro_invoice) { ?>
		<div class="nav-prev alignleft">
			<a href="<?php echo pmpro_url("invoice")?>"><?php _e('&larr; View All Invoices', 'paid-memberships-pro' );?></a>
		</div>
	<?php } ?>
</nav>

What is the purpose of the empty templates folder?

@grifini, I believe this was an example for a very specific user setup. You'd then copy these files into your templates folder to load the templates from the plugin and not from a child theme.

If you need any further help, feel free to reach out on www.paidmembershipspro.com

NOTE: THIS IS DEPRECATED BY NOW. I DO NOT RECOMMEND USING THIS ANYMORE.