Utiliser des jolis templates d'e-mails dans WordPress et remplacer des mots par des variables

0usage.php

<?php

/*
* Usage de la fonction msk_send_mail
*/

$destinataire = 'pierre@mosaika.fr';

$data = array(
	'prenom' => 'Bruce',
	'nom' => 'Willis',
	'email' => 'bruce.willis@laposte.net',
	'url' => 'https://mosaika.fr'
);

$retour = msk_send_mail('template_when_this_happens', $destinataire, $data);

if (isset($retour['error']) && $retour['error'] == 0) {
	// L'e-mail a été envoyé
} else {
	// Erreur, vérifiez $retour['message'] pour en savoir plus
}

1send_nice_emails_with_wordpress.php

<?php

/**
 * Envoyer un e-mail : on se base sur un template et on remplace des "placeholders" par des variables dynamiques
 */
function msk_send_mail($template = '', $to = '', $data = array()) {
	// Définissez ici les différents modèles d'e-mail à suivre
	$available_templates = array(
		// Le template d'un premier e-mail
		'template_when_this_happens' => array(
			'subject' => __('Le sujet de l\'email s\'affiche ici', 'mosaika'),
			'content' => __('<p>Bonjour {{ prenom }} {{ nom }} !</p><p>Une nouvelle inscription sur notre site a été faite avec l\'e-mail {{ email }}. Pour vous connecter, <a href="{{ url }}">rendez-vous sur cette page</a>.</p>', 'mosaika')
		),

		// Le template d'un autre e-mail
		'another_template_when_that_happens' => array(
			'subject' => __('Le sujet de l\'email s\'affiche ici', 'mosaika'),
			'content' => __('<p>Bonjour {{ prenom }} {{ nom }} !</p><p>Une nouvelle inscription sur notre site a été faite avec l\'e-mail {{ email }}. Pour vous connecter, <a href="{{ url }}">rendez-vous sur cette page</a>.</p>', 'mosaika')
		),
	);

	if ($to == '') {
		$error = 'Erreur d\'envoi d\'un e-mail : destinataire vide.';
	} else if ($template == '') {
		$error = 'Erreur d\'envoi d\'un e-mail : template vide.';
	} else if (!array_key_exists($template, $available_templates)) {
		$error = 'Erreur d\'envoi d\'un e-mail : template inexistant.';
	} else {
		if (!is_array($to)) $to = array($to);
		// Si le site est en développement, on envoie l'e-mail à l'administrateur du site
		if (WP_DEBUG) $to = array(get_option('admin_email'));

		// On récupère le tableau correspondant au template à analyser/transformer
		$template_data = $available_templates[$template];

		$mail_subject_template = $template_data['subject'];
		$mail_content_template = $template_data['content'];

		// On transforme les {{ placeholders }} par les variables fournies dans $data (pour le sujet et le corps du mail)
		// Par exemple, {{ email }} est remplacé par la valeur de $data['email'], {{ prenom }} par la valeur de $data['prenom']
		$mail_subject = msk_transform_vars_to_value($mail_subject_template, $data);
		$mail_content = msk_transform_vars_to_value($mail_content_template, $data);

		// On intègre le corps/contenu de notre e-mail à la place de {{ body }} dans le fichier /emails/base.tpl
		$mail_html = msk_parse_email_body_content_in_template(array('body' => wpautop($mail_content)));

		// On s'assure que l'e-mail envoyé est au format HTML
		$mail_headers = array('Content-Type: text/html; charset=UTF-8');

		// On envoie l'email
		if (!wp_mail($to, $mail_subject, $mail_html, $mail_headers)) {
			$error = 'Erreur durant l\'envoi de l\'e-mail.';
		}

		if ($error) {
			return array('error' => 1, 'message' => $error);
		} else {
			return array('error' => 0);
		}
	}
}

/**
 * Transforme {{ variable }} en sa valeur correspondante dans le tableau fourni
 */
function msk_transform_vars_to_value($template, $vars) {
	$output = $template;

	foreach ($vars as $key => $value) {
		$tag_to_replace = "{{ $key }}";
		$output = str_replace($tag_to_replace, $value, $output);
	}

	return $output;
}

/**
 * Permet de récupérer tout le contenu HTML de l'e-mail à envoyer, avec tous les {{ placeholders }} remplacés par les valeurs fournies
 */
function msk_parse_email_body_content_in_template($data) {
	require_once(get_stylesheet_directory() . '/emails/emailTemplate.php');
	
	$defaults = array(
		'preheader' => 'Cet e-mail vous est envoyé par XYZ. <a href="http://mosaika.fr">Cliquez-ici</a> pour visiter notre site.',
		'logo' => get_stylesheet_directory_uri() . '/emails/logo.png',
		'body' => '',
		'footer' => 'Copyright 2017 XYZ.',
	);

	$tags = wp_parse_args($data, $defaults);

	$email_content = new MailTemplate(get_stylesheet_directory() . '/emails/base.tpl');

	foreach ($tags as $tag_name => $tag_value) {
		$email_content->set($tag_name, $tag_value);
	}

	return $email_content->output();
}

2emailTemplate.php

<?php

/**
 * Simple template engine class (use [@tag] tags in your templates).
 * (merci à http://www.broculos.net/2008/03/how-to-make-simple-html-template-engine.html#.WODf9N-YFhE pour le code)
 * 
 * @link http://www.broculos.net/ Broculos.net Programming Tutorials
 * @author Nuno Freitas <nunofreitas@gmail.com>
 * @version 1.0
 */
class MailTemplate {
	/**
	 * The filename of the template to load.
	 *
	 * @access protected
	 * @var string
	 */
    protected $file;
    
    /**
     * An array of values for replacing each tag on the template (the key for each value is its corresponding tag).
     *
     * @access protected
     * @var array
     */
    protected $values = array();
    
    /**
     * Creates a new Template object and sets its associated file.
     *
     * @param string $file the filename of the template to load
     */
    public function __construct($file) {
        $this->file = $file;
    }
    
    /**
     * Sets a value for replacing a specific tag.
     *
     * @param string $key the name of the tag to replace
     * @param string $value the value to replace
     */
    public function set($key, $value) {
        $this->values[$key] = $value;
    }
    
    /**
     * Outputs the content of the template, replacing the keys for its respective values.
     *
     * @return string
     */
    public function output() {
    	/**
    	 * Tries to verify if the file exists.
    	 * If it doesn't return with an error message.
    	 * Anything else loads the file contents and loops through the array replacing every key for its value.
    	 */
        if (!file_exists($this->file)) {
        	return "Error loading template file ($this->file).<br />";
        }
        $output = file_get_contents($this->file);
        
        foreach ($this->values as $key => $value) {
        	$tagToReplace = "{{ $key }}";
        	$output = str_replace($tagToReplace, $value, $output);
        }

        return $output;
    }
    
    /**
     * Merges the content from an array of templates and separates it with $separator.
     *
     * @param array $templates an array of Template objects to merge
     * @param string $separator the string that is used between each Template object
     * @return string
     */
    static public function merge($templates, $separator = "\n") {
    	/**
    	 * Loops through the array concatenating the outputs from each template, separating with $separator.
    	 * If a type different from Template is found we provide an error message. 
    	 */
        $output = "";
        
        foreach ($templates as $template) {
        	$content = (get_class($template) !== "Template")
        		? "Error, incorrect type - expected Template."
        		: $template->output();
        	$output .= $content . $separator;
        }
        
        return $output;
    }
}

?>

3base.tpl

<!doctype html>
<html>
  <head>
    <meta name="viewport" content="width=device-width" />
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <title>Mon super e-mail grâce à www.mosaika.fr</title>
    <style>
      /* -------------------------------------
          GLOBAL RESETS
      ------------------------------------- */
      img {
        border: none;
        -ms-interpolation-mode: bicubic;
        max-width: 100%; }

      body {
        background-color: #f6f6f6;
        font-family: "Helvetica Neue", "Helvetica", Tahoma, sans-serif;
        -webkit-font-smoothing: antialiased;
        font-size: 14px;
        line-height: 1.4;
        margin: 0;
        padding: 0; 
        -ms-text-size-adjust: 100%;
        -webkit-text-size-adjust: 100%; }

      table {
        border-collapse: separate;
        mso-table-lspace: 0pt;
        mso-table-rspace: 0pt;
        width: 100%; }
        table td {
          font-family: "Helvetica Neue", "Helvetica", Tahoma, sans-serif;
          vertical-align: middle; }

      /* -------------------------------------
          BODY & CONTAINER
      ------------------------------------- */

      .body {
        background-color: #f6f6f6;
        width: 100%; }

      /* Set a max-width, and make it display as block so it will automatically stretch to that width, but will also shrink down on a phone or something */
      .container {
        display: block;
        Margin: 0 auto !important;
        /* makes it centered */
        max-width: 580px;
        padding: 10px;
        width: auto !important;
        width: 580px; }

      /* This should also be a block element, so that it will fill 100% of the .container */
      .content {
        box-sizing: border-box;
        display: block;
        Margin: 0 auto;
        max-width: 580px;
        padding: 10px; }

      /* -------------------------------------
          HEADER, FOOTER, MAIN
      ------------------------------------- */
      .main {
        background: #fff;
        border-radius: 3px;
        width: 100%; }

      .wrapper {
        box-sizing: border-box;
        padding: 20px; }

      .footer {
        clear: both;
        padding-top: 10px;
        text-align: center;
        width: 100%; }
        .footer td,
        .footer p,
        .footer span,
        .footer a {
          color: #999999;
          font-size: 12px;
          text-align: center; }

      /* -------------------------------------
          TYPOGRAPHY
      ------------------------------------- */
      h1,
      h2,
      h3,
      h4 {
        font-weight:bold;
        color:#00578f;
        margin-top:20px;
        margin-bottom:10px;
        font-family: "Helvetica Neue", "Helvetica", Tahoma, sans-serif;
        line-height: 1.4;
        margin: 0;
      }

      h1 {
        font-size: 32px;
      }

      h2 {
        font-size: 28px;
      }

      h3 {
        font-size: 24px;
      }

      h4 {
        font-size: 20px;
      }

      h5 {
        font-size: 17px;
      }

      blockquote {
        border-left:3px solid #DADADA;
        margin-left: 20px;
        padding-left: 20px;
        font-style: italic;
      }

      p,
      ul,
      ol {
        font-family: "Helvetica Neue", "Helvetica", Tahoma, sans-serif;
        font-size: 14px;
        font-weight: normal;
        margin: 0;
        Margin-bottom: 15px; }
        p li,
        ul li,
        ol li {
          list-style-position: inside;
          margin-left: 5px; }

      a {
        color: #3498db;
        text-decoration: underline; }

      /* -------------------------------------
          BUTTONS
      ------------------------------------- */
      .btn {
        box-sizing: border-box;
        width: 100%; }
        .btn > tbody > tr > td {
          padding-bottom: 15px; }
        .btn table {
          width: auto; }
        .btn table td {
          background-color: #ffffff;
          border-radius: 5px;
          text-align: center; }
        .btn a {
          background-color: #ffffff;
          border: solid 1px #3498db;
          border-radius: 5px;
          box-sizing: border-box;
          color: #3498db;
          cursor: pointer;
          display: inline-block;
          font-size: 14px;
          font-weight: bold;
          margin: 0;
          padding: 12px 25px;
          text-decoration: none;
          text-transform: capitalize; }

      .btn-primary table td {
        background-color: #3498db; }

      .btn-primary a {
        background-color: #3498db;
        border-color: #3498db;
        color: #ffffff; }

      /* -------------------------------------
          OTHER STYLES THAT MIGHT BE USEFUL
      ------------------------------------- */
      .last {
        margin-bottom: 0; }

      .first {
        margin-top: 0; }

      .align-center {
        text-align: center; }

      .align-right {
        text-align: right; }

      .align-left {
        text-align: left; }

      .clear {
        clear: both; }

      .mt0 {
        margin-top: 0; }

      .mb0 {
        margin-bottom: 0; }

      .preheader {
        color: transparent;
        display: none;
        height: 0;
        max-height: 0;
        max-width: 0;
        opacity: 0;
        overflow: hidden;
        mso-hide: all;
        visibility: hidden;
        width: 0; }

      .powered-by a {
        text-decoration: none; }

      hr {
        border: 0;
        border-bottom: 1px solid #e6e6e6;
        Margin: 16px 0; }

      .logo {
        text-align: center;
      }

      .logo a { 
        display:block; 
        text-align: center;
      }
      
      .logo a img { 
        margin:0 auto;
      }

      .logo hr {
        border: 0;
        border-bottom: 2px solid #e6e6e6;
        margin: 12px 0 0; }

      /* -------------------------------------
          RESPONSIVE AND MOBILE FRIENDLY STYLES
      ------------------------------------- */
      @media only screen and (max-width: 620px) {
        table[class=body] h1 {
          font-size: 28px !important;
          margin-bottom: 10px !important; }
        table[class=body] p,
        table[class=body] ul,
        table[class=body] ol,
        table[class=body] td,
        table[class=body] span,
        table[class=body] a {
          font-size: 16px !important; }
        table[class=body] .wrapper,
        table[class=body] .article {
          padding: 10px !important; }
        table[class=body] .content {
          padding: 0 !important; }
        table[class=body] .container {
          padding: 0 !important;
          width: 100% !important; }
        table[class=body] .main {
          border-left-width: 0 !important;
          border-radius: 0 !important;
          border-right-width: 0 !important; }
        table[class=body] .btn table {
          width: 100% !important; }
        table[class=body] .btn a {
          width: 100% !important; }
        table[class=body] .img-responsive {
          height: auto !important;
          max-width: 100% !important;
          width: auto !important; }}

      /* -------------------------------------
          PRESERVE THESE STYLES IN THE HEAD
      ------------------------------------- */
      @media all {
        .ExternalClass {
          width: 100%; }
        .ExternalClass,
        .ExternalClass p,
        .ExternalClass span,
        .ExternalClass font,
        .ExternalClass td,
        .ExternalClass div {
          line-height: 100%; }
        .apple-link a {
          color: inherit !important;
          font-family: inherit !important;
          font-size: inherit !important;
          font-weight: inherit !important;
          line-height: inherit !important;
          text-decoration: none !important; } 
        .btn-primary table td:hover {
          background-color: #34495e !important; }
        .btn-primary a:hover {
          background-color: #34495e !important;
          border-color: #34495e !important; } }

    </style>
  </head>
  <body class="">
    <table border="0" cellpadding="0" cellspacing="0" class="body">
      <tr>
        <td>&nbsp;</td>
        <td class="container">
          <div class="content">
            <!-- START CENTERED WHITE CONTAINER -->
            <span class="preheader">{{ preheader }}</span>
            <table class="main">
              <tr>
                <td class="wrapper logo">
                  <table border="0" cellpadding="0" cellspacing="0">
                    <tr>
                      <td>
                        <a href="http://www.mosaika.fr/"><img src="{{ logo }}" width="221" height="86" /></a>
                        <hr>
                      </td>
                    </tr>
                  </table>
                </td>
              </tr>
              <!-- START MAIN CONTENT AREA -->
              <tr>
                <td class="wrapper">
                  <table border="0" cellpadding="0" cellspacing="0">
                    <tr>
                      <td>
                        {{ body }}
                      </td>
                    </tr>
                  </table>
                </td>
              </tr>
              <!-- END MAIN CONTENT AREA -->
              </table>
            <!-- START FOOTER -->
            <div class="footer">
              <table border="0" cellpadding="0" cellspacing="0">
                <tr>
                  <td class="content-block">
                    <span class="apple-link">{{ footer }}</span>
                  </td>
                </tr>
              </table>
            </div>
          </div>
        </td>
        <td>&nbsp;</td>
      </tr>
    </table>
  </body>
</html>