Wordpress Code Snippets

Here is a collection of code snippets that I use and have found helpful.

• Add a pattern attribute to a Jetpack contact form field
• Add a max character limit to a Jetpack contact form field
• Custom Page Titles
• Custom Page Titles with Yoast
• Customising the Custom Post Type Query
• Enabling Shortcodes within the Custom HTML Widget
• Send Post Comments to Custom Email Addresses

Add a pattern attribute to a Jetpack contact form field

Restricting what URLs site visitors can enter into a Jetpack form URL field - in this case only YouTube URLs.

add_filter( 'grunion_contact_form_field_html', function( $rendered_field, $field_label, $id ) {
    if ( $field_label === 'Website' ) { // Update this value if your URL field has a different name.
        $rendered_field = preg_replace(
            '/pattern="([^"]*)"/',
            'pattern="^https:\/\/(?:(?:www\.)?youtube\.com|youtu\.be)\/.*$"',
            $rendered_field
        );
        // Update the custom validity message
        $rendered_field = preg_replace(
            '/setCustomValidity\\("[^&]*"\\)/',
            'setCustomValidity("Please enter a valid YouTube URL")',
            $rendered_field
        );
    }
    return $rendered_field;
}, 10, 3 )

Add a max character limit to a Jetpack contact form field

Add a max character limit of 500 to the messages field, along with a span element explaining the limit.

add_filter( 'grunion_contact_form_field_html', function( $rendered_field, $field_label, $id ) {
    if ( $field_label === 'Message' && strpos( $rendered_field, '<textarea' ) !== false ) {
        $rendered_field = preg_replace(
            '/<textarea/',
            '<textarea maxlength="500"',
            $rendered_field,
            1
        );

        $limit_text = sprintf(
            /* translators: %d: maximum number of characters allowed */
            esc_html__( 'Maximum %d characters allowed', 'your-text-domain' ),
            500
        );
        
        $rendered_field = str_replace(
            '</div>',
            '<span id="message-limit-' . esc_attr($id) . '" class="message-limit-text" style="display: block; margin-top: 4px; font-size: 0.8em; color: #666;">' . $limit_text . '</span></div>',
            $rendered_field
        );
    }
    return $rendered_field;
}, 10, 3 );

Custom Page Titles

Assuming you have added theme support for title-tag.

function custom_theme_titles( $titleparts ) {
    if ( is_front_page() ) {
		$pagetitle = $titleparts['title'];
        $titleparts['title'] = $pagetitle;
        unset( $titleparts['site'] );
    }

    elseif ( is_404() ) {
    	$pagetitle = "404";
     	$sep = " | ";
        $name = get_bloginfo( 'name', 'display' );
        $sep2 = " - ";
        $desc = get_bloginfo( 'description', 'display' );
        $titleparts['title'] = $pagetitle.$sep.$name.$sep2.$desc;
        unset( $titleparts['site'] );
    }

    elseif (is_category() ) {
		$category = get_the_category();
		$catName = $category[0]->cat_name;		
		$pagetitle = "Blog - ".$catName." archives";		
    	$sep = " | ";
        $name = get_bloginfo( 'name', 'display' );
        $sep2 = " - ";
        $desc = get_bloginfo( 'description', 'display' );
        $titleparts['title'] = $pagetitle.$sep.$name.$sep2.$desc;
        unset( $titleparts['site'] );
    }

    else {
  		$pagetitle = $titleparts['title'];
        $sep = " | ";
        $name = get_bloginfo( 'name', 'display' );
        $sep2 = " - ";
        $desc = get_bloginfo( 'description', 'display' );
        $titleparts['title'] = $pagetitle.$sep.$name.$sep2.$desc;
        unset( $titleparts['site'] );
    }
    return $titleparts;
}

add_filter( 'document_title_parts', 'custom_theme_titles', PHP_INT_MAX );

Custom Page Titles with Yoast

For creating custom page titles if you have Yoast SEO installed and activated.

function custom_theme_titles_yoast( $title ) {
    $sep = '|';
    $name = get_bloginfo( 'name' );
	$desc = get_bloginfo( 'description', 'display' );

    if( is_front_page() ) {
		$pagetitle = $title;
		return "{$pagetitle}";
    }

     elseif( is_404() ) {
  		$pagetitle = "404";
		return "{$pagetitle} {$sep} {$name} - {$desc}";
    }

    else {
		$pagetitle = $title;   
		return "{$pagetitle} {$sep} {$name} - {$desc}";
    }
}

add_filter( 'wpseo_title', 'custom_theme_titles_yoast', PHP_INT_MAX );

Customising the Custom Post Type Query

Working with pre_get_posts to modify custom post type (events) output on a page (only displaying posts that have a checkbox checked (using the advanced custom fields plugin) and only showing a maximum of 3 posts per page).

function ka_event_query( $query ) {
	if( $query->is_main_query() && !$query->is_feed() && !is_admin() && $query->is_post_type_archive( 'events' ) ) {
		//Filtering out posts that have checkbox checked (therefore marked as true)
		$meta_query = array(
			array(
				'key' => 'event_current', //key as created in advanced custom field
				'value' => true,
				'compare' => 'BOOLEAN'
			)
		);
		$query->set( 'meta_query', $meta_query );
		 //Display only 3 posts
		$query->set( 'posts_per_page', '3' );
	}
}

add_action( 'pre_get_posts', 'ka_event_query' );

Enabling Shortcodes within the Custom HTML Widget

Enabling shortcodes within the Text Widget does not transfer over to the newer Custom HTML Widget. This allows shortcodes in the Custom HTML Widget.

add_filter('widget_custom_html_content','do_shortcode');

Send Post Comments to Custom Email Addresses

Here is a solution to make sure all post comments go to the post author (allowing for custom post-types as well) and a second specified email address. Alternatively just leave the specified email address as the only option.

function ka_comment_moderation_recipients( $emails, $comment_id ) {
    $comment = get_comment( $comment_id );

    if(empty($comment)) {
        return $emails;
    }

    $post = get_post( $comment->comment_post_ID );

    // Refine if you only want comments from a custom post type (or remove this section)
    if($post->post_type != "custom_post_type") {
        return $emails;
    }

    $user = get_user_by( 'id', $post->post_author );
 
    // Return the post author email if the author can modify, as well as a custom email
    if ( user_can( $user->ID, 'edit_published_posts' ) && ! empty( $user->user_email ) ) {
        $emails = array( $user->user_email, 'info@example.com');
    }

    //Else return just the custom email
    else {
        $emails = array('info@example.com');
    }
 
    return $emails;
}

add_filter( 'comment_moderation_recipients', 'ka_comment_moderation_recipients', 11, 2 );
add_filter( 'comment_notification_recipients', 'ka_comment_moderation_recipients', 11, 2 );