Using WordPress templating for HTML emails

Question

Using WordPress templating for HTML emails

Malibur

2019年4月14日 12:15

I am working on a plugin that needs to send out an email after a form submission.

I am using wp_mail() for this and it works fine. My problem is that in my code the HTML is generated by a bunch of PHP strings being added to a variable like so:

$content = $html_headers;
$content .= 'h1' . the_title($post_id) . '/h1';
$content .= 'p' . $post_body . '/p;

..etc

I currently have more than 30 lines like that; and that allows me to finally do:

    //add filter to allow html
    add_filter('wp_mail_content_type', create_function('', 'return "text/html"; '));

    //Send email
    wp_mail( '[email protected]', 'mail tester', $content, 'From: some one [email protected]' );

    //remove filter to allow html (avoids some conflict.)
    remove_filter('wp_mail_content_type', create_function('', 'return "text/html"; '));

I would prefer it if I could reference a separate file that uses normal WordPress theme template-tags in order to generate the content of the mail, so that in a separate file I'd have something like this:

!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"
html xmlns="http://www.w3.org/1999/xhtml"
    head
        (headertags)
    /head
    body
        h1?php the_title($post_id); ?/h1
        p?php my_custom_template_body_tag(); ?/p
    /body
/html

but I don't know how to then return that content to the wp_mail() function. I have tried using file_get_contents() but that just ignores PHP generated content, and I've looked into the heredoc syntax. But I find that quite ugly and error prone. Do I have any other options. I really love it if I could do something like this:

$content = parse_and_return_content_of('path/to/template/file', $arg);

Thank you

Topic html-email wp-mail templates Wordpress

Category Web

Aron · Accepted Answer · 2019年4月14日 12:15

You could do something a little more like merge fields. That way you can keep your html and PHP separated by using an email template with placeholders and run a string replace on them. Something like the following:

HTML

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        (headertags)
    </head>
    <body>
        <h1>[POST.TITLE]</h1>
        <p>[POST.CONTENT]</p>
    </body>
</html>

PHP

$html_email_template_file = 'some/path/mytemplate-example.html';

// assign contents of file to $content var
$content = file_get_contents($html_email_template_file);

$content = str_replace('[POST.TITLE]', $post->post_title, $content);
$content = str_replace('[POST.CONTENT]', $post->post_excerpt, $content);

// send your email here ...

ifdion · Accepted Answer · 2015年1月18日 00:42

You should use ob_get_contents()

    ob_start();
    include('template/email-header.php');
    printf(__('<p>A very special welcome to you, %1$s. Thank you for joining %2$s!</p>', 'cell-email'), $greetings, get_bloginfo('name'));
    printf(__('<p> Your password is <strong style="color:orange">%s</strong> <br> Please keep it secret and keep it safe! </p>', 'cell-email'), $plaintext_pass);
    printf(__('<p>We hope you enjoy your stay at %s. If you have any problems, questions, opinions, praise, comments, suggestions, please feel free to contact us at any time</p>', 'cell-email'), get_bloginfo('name'));
    include('template/email-footer.php');
    $message = ob_get_contents();
    ob_end_clean();
    wp_mail($user_email, $email_subject, $message);

And on the template/email-header.php, you can use

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <meta property="og:title" content="<?php echo $email_subject ?>" />
    <title><?php echo $email_subject ?></title>
</head>
<body leftmargin="0" marginwidth="0" topmargin="0" marginheight="0" offset="0" style="width: 100% !important; -webkit-text-size-adjust: none; margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; background-color: #FAFAFA;" bgcolor="#FAFAFA">
<!-- the rest of the html here -->
<?php // and php generated content if you prefer ?>

Using WordPress templating for HTML emails

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