Shows how to set up a template for including meta tags in a Participants Database singe record page when using the Image Expansion add-on

pdb-single-opengraph.php

<?php
/**
 * @name pdb single opengraph template
 * @version 0.1
 * 
 * template for printing opengraph meta tags
 *
 * this variant is for use with the Participants Database Image Expansion add-on 
 *
 * simplified information on using social media meta tags can be found here:
 * https://css-tricks.com/essential-meta-tags-social-media/
 * 
 * you will need to adapt this to the data fields you are using and how you are using them, 
 * please don't expect this to work for you without modifying it to match your setup!
 */

// first check to make sure we have a record loaded
if ( $this->participant_id > 0 ) :

if ( ! function_exists( 'get_attachment_url_by_slug' ) ) :
/**
 * provides the full URL to a media file, given the media item name (or slug)
 * 
 * @param string $slug name of the media item
 * @return string URL to the media file
 */
function get_attachment_url_by_slug( $slug ) {
  $args = array(
    'post_type' => 'attachment',
    'name' => sanitize_title($slug),
    'posts_per_page' => 1,
    'post_status' => 'inherit',
  );
  $_header = get_posts( $args );
  $header = $_header ? array_pop($_header) : null;
  return $header ? wp_get_attachment_url($header->ID) : '';
}
endif;

// set up the template object
$record = new PDb_Template( $this );
?>

<!-- Start Participants Database Meta Tags -->

<?php // this will be shown as the headline of the share ?>
<meta property="og:title" content="<?php echo $record->get_value('first_name') . ' ' . $record->get_value('last_name') ?>">

<?php // this will typically appear under the headline, it should be a short descriptive text ?>
<meta property="og:description" content="<?php echo $record->get_value('description') ?>">

<?php // this needs to be the URL to the image to show in the share ?>
<meta property="og:image" content="<?php echo get_attachment_url_by_slug( $record->get_value('photo') ) ?>">

<?php // this is the URL of the current page ?>
<meta property="og:url" content="<?php echo 'https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'] ?>">

<?php // for twitter, add a caption. This could be the same as the title or description ?>
<meta name="twitter:card" content="<?php echo $record->get_value('photo_caption') ?>">

<!-- End Participants Database Meta Tags -->

<?php endif;
      

To create a share link, you'll need a custom template for your single record display as well. In that template, put a link like this:

<a href="https://www.facebook.com/sharer/sharer.php?u=<?php echo urlencode( Participants_Db::single_record_url( $this->participant_id ) ) ?>">Share on Facebook</a>