WordPress - Automatically generate meta description from content

auto-description-tag-wp

function create_meta_desc() {
    global $post;
if (!is_single()) { return; }
    $meta = strip_tags($post->post_content);
    $meta = strip_shortcodes($post->post_content);
    $meta = str_replace(array("\n", "\r", "\t"), ' ', $meta);
    $meta = substr($meta, 0, 125);
    echo "<meta name='description' content='$meta' />";
}
add_action('wp_head', 'create_meta_desc');

Also, Can I use your code with this plugin to allow me to have automatically generated meta description from content?

Please see this plugin: https://en-ca.wordpress.org/plugins/head-meta-data/

Can I use your code in this plugin you think?

What would be the exact markup code for this and do I put this in the head:

function create_meta_desc() {
global $post;
if (!is_single()) { return; }
$meta = strip_tags($post->post_content);
$meta = strip_shortcodes($post->post_content);
$meta = str_replace(array("\n", "\r", "\t"), ' ', $meta);
$meta = substr($meta, 0, 125);
echo "";
}
add_action('wp_head', 'create_meta_desc');

This is a really handy gist! I made some modifications to allow it to use the post_excerpt for a meta description if it existed, and generate a description for posts types without an excerpt, such as pages.

I also always have problems with strip_shortcodes() stripping out all my content, so I ran the content filter before strip_tags and strip_shortcodes .

function create_meta_desc() {
    global $post;
	if (!is_singular()) {return; }
	elseif(!empty( $post->post_excerpt)) {
		echo "<meta name='description' content='$post->post_excerpt' />";
	}
	else{
		$meta = apply_filters('the_content', $post->post_content);
		$meta = strip_tags($meta);
		$meta = strip_shortcodes($meta );
		$meta = str_replace(array("\n", "\r", "\t"), ' ', $meta);
		$meta = substr($meta, 0, 400);
		echo "<meta name='description' content='$meta' />";
	}
}
add_action('wp_head', 'create_meta_desc');

Thanks for this gist, but it need little update for people who migrate from classic editor to Gutenberg.

You must add"<!-- wp:paragraph -->", "<p>"to str_replace, in Gutenberg all paragraphs are begining (and ending) with <!-- wp:paragraph --> also sometimes Gutenberg add <p> to html.

// $meta = str_replace( array("\n", "\r", "\t", "<!-- wp:paragraph -->", "<p>", "<!--nextpage-->"), ' ', $meta );