Custom HTML Template to wp_mail()

custom-template-wp-mail.php

<?php

/**
 * Plugin Name:       Custom Email Template wp_mail()
 * Plugin URI:        https://pakaiwp.com/
 * Description:       Plugin sederhana untuk menggunakan custom html pada fungsi wp_mail()
 * Version:           1.0
 * Requires at least: 5.2
 * Requires PHP:      7.2
 * Author:            Dhimas Kirana
 * Author URI:        https://www.dhimaskirana.com/
 * License:           GPL v2 or later
 * License URI:       https://www.gnu.org/licenses/gpl-2.0.html
 */

/**
 * Custom HTML Template to wp_mail()
 *
 * Replace myprefix_ with your prefix
 * 
 * The HTML Template saved as custom-email-template.php in the same folder
 *
 */

function myprefix_email_template( $message ) {

	// Render Template
	ob_start();
	include( 'custom-email-template.php' );
	$myprefix_template = ob_get_contents();
	ob_end_clean();

	// Replace Placeholder
	$message = str_replace('%%MAILCONTENT%%', $message, $myprefix_template);

	// Replace Some Placeholder
	$to_replace = array(
		'%%HOME_URL%%'         => get_option( 'home' ),
		'%%BLOG_NAME%%'        => get_option( 'blogname' ),
		'%%BLOG_DESCRIPTION%%' => get_option( 'blogdescription' )
	);
	foreach ($to_replace as $placeholder => $var ) {
		if(is_array($var) ) {
			do {
				$var = reset($var);
			} while(is_array($var));
		}
		$message = str_replace($placeholder, $var, $message);
	}

	// Return Template with Data
	return $message;

}

add_filter( 'wp_mail_content_type', 'set_content_type' );
function set_content_type($type) {
	if( $type != 'text/html' ) {
		// If not html, work with content and filter it
		add_filter( 'myprefix_filter_email', 'wp_kses_post', 50 );
		myprefix_content_filters();
	}
	return $content_type = 'text/html';
}

add_filter( 'wp_mail', 'my_wp_mail_filter' );
function my_wp_mail_filter( $args ) {
	$message = $args['message'];
	$args['message'] = myprefix_email_template( apply_filters('myprefix_filter_email', $message) );
	return $args;
}

function myprefix_content_filters() {
	add_filter( 'myprefix_filter_email', 'wptexturize' );
	add_filter( 'myprefix_filter_email', 'convert_chars' );
	add_filter( 'myprefix_filter_email', 'wpautop' );
	add_filter( 'myprefix_filter_email', 'clean_retrieve_password' );
}

function clean_retrieve_password( $message ) {
	return make_clickable( preg_replace( '@<(http[^> ]+)>@', '$1', $message ) );
}