Current post's author name in the author meta tag

Question

I am trying to add the current post's author as the content for the meta author tag. I wrapped this particular meta in an is_single condition and then tried:

<meta name="author" content="<?php get_the_author(); ?>" />

as well as tried this:

<meta name="author" content="<?php the_author(); ?>" />

For both the above, Facebook debugger responded with:

Meta with name instead of property : The meta tag on the page was specified with name 'author', which matches a configured property of this object type. It will be ignored unless specified with the meta property attribute instead of the meta name attribute.

---

Then I tried:

<meta property="article:author" content="<?php the_author(); ?>" />

as well as tried this:

<meta property="article:author" content="<?php get_the_author(); ?>" />

For both the above, Facebook debugger responded with:

Parser Mismatched Metadata : The parser's result for this metadata did not match the input metadata. Likely, this was caused by the data being ordered in an unexpected way, multiple values being given for a property only expecting a single value, or property values for a given property being mismatched. Here are the input properties that were not seen in the parsed result: 'article:author'.

---

What am I doing wrong as all of the above four metas just return a blank content (<meta name="author" content/>) for the author tag.

Answer 1

You cad add it via functions.php with a hook, instead of inside the loop (you don't really want to add a loop to header.php):

function add_author_meta() {

    if (is_single()){
        global $post;
        $author = get_the_author_meta('user_nicename', $post->post_author);
        echo "<meta name=\"author\" content=\"$author\">";
    }
}
add_action( 'wp_enqueue_scripts', 'add_author_meta' );

Answer 2

Add this into header.php

<meta name="author" content="<?php the_author_meta('user_nicename', $post->post_author); ?>">

Answer 3

You can add meta tags using wp_head hook action from functions.php of the Themes files or create a custom plugin.

Here you can check example.

add_action('wp_head', 'fc_opengraph');

function fc_opengraph() {


  if ( is_single() || is_page() ) {

    $post_id = get_queried_object_id(); // get current post id

    $author_name = 'set your author name';

    $site_name = get_bloginfo('name');

    $description = wp_trim_words( get_post_field('post_content', $post_id), 25 );

    $image = get_the_post_thumbnail_url($post_id);

    if( !empty( get_post_meta($post_id, 'og_image', true) ) ) $image = get_post_meta($post_id, 'og_image', true);

    $locale = get_locale();

    echo '<meta property="og:locale" content="' . esc_attr($locale) . '" />';
    echo '<meta property="og:type" content="article" />';
    echo '<meta property="author" content="' . esc_attr($author_name) . '" />';
    echo '<meta property="og:description" content="' . esc_attr($description) . '" />';
    echo '<meta property="og:url" content="' . esc_url($url) . '" />';
    echo '<meta property="og:site_name" content="' . esc_attr($site_name) . '" />';

    if($image) echo '<meta property="og:image" content="' . esc_url($image) . '" />';

  }

}

Please check this url for the hook documentation: https://developer.wordpress.org/reference/hooks/wp_head/