Proof of concept WP shortcode to display fields from logged in and other contacts

civicrm_user_fields.php

<?php

/*

This is very much WIP / proof of concept / scratching an itch. Lots of stuff missing, like ACL.

Just sharing some early attempts at WP plugin development. Feedback welcome.

For example...

[civicrm_user_fields]

Name: {user.display_name}
Address {user.address.street_address}}

[/civicrm_user_fields]

OR you can display data about other contacts by including the contact ID as a url query parameter
WARNING: no ACL on the below code!

url like https://example.org/about-me/?fid=123

[civicrm_user_fields querymap=friend:fid]

Name: {user.display_name} is friends with {friend.display_name} who lives in {friend.address.city}

[/civicrm_user_fields]

*/
add_shortcode('civicrm_user_fields', 'civicrm_user_fields');

function civicrm_user_fields($attr, $content)
{
    $contacts['user']['params']['id'] = CRM_Core_Session::singleton()->getLoggedInContactID();

    $parsed = $content;

    while (strlen($parsed)) {
        $tokenStart = strpos($parsed, '{');
        if ($tokenStart !== false) {
            $tokenEnd = strpos($parsed, '}');
            $tokens[] = substr($parsed, $tokenStart, $tokenEnd - $tokenStart + 1);
            $parsed = substr($parsed, $tokenEnd + 1);
        } else {
            $parsed = '';
        }
    }

    $tokens = array_unique($tokens);

    foreach ($tokens as $token) {
        $parts = explode('.', substr($token, 1, -1));
        if (count($parts) == 2) {
            $contacts[$parts[0]]['params']['return'][] = $parts[1];
        } elseif (count($parts) == 3) {
            $contacts[$parts[0]]['related'][$parts[1]]['params']['return'][] = $parts[2];
        }
    }

    $queryMaps = explode(',', $attr['querymap']);
    foreach ($queryMaps as $querymap) {
        $parts = explode(':', $querymap);
        if (isset($contacts[$parts[0]])) {
            $contacts[$parts[0]]['params']['id'] = $_GET[$parts[1]];
            if (isset($contacts[$parts[0]]['related'])) {
                foreach ($contacts[$parts[0]]['related'] as &$related) {
                    $related['params']['contact_id'] = $_GET[$parts[1]];
                    $related['params']['is_primary'] = 1;
                }
            }
        }
    }

    foreach ($contacts as &$contact) {
        $contact['result'] = civicrm_api3('Contact', 'getsingle', $contact['params']);
        if (isset($contact['related'])) {
            foreach ($contact['related'] as $entity => &$related) {
                $related['result'] = civicrm_api3($entity, 'getsingle', $related['params']);
            }
        }

    }

    foreach ($tokens as $n => $token) {
        $parts = explode('.', substr($token, 1, -1));
        if (count($parts) == 2) {
            $values[$n] = $contacts[$parts[0]]['result'][$parts[1]];
        } elseif (count($parts) == 3) {
            $values[$n] = $contacts[$parts[0]]['related'][$parts[1]]['result'][$parts[2]];
        }
    }

    return str_replace($tokens, $values, $content);
}