Using WordPress custom fields to drive WP Flexible Maps

gistfile1.phtml

<?php

/*
In reply to this request:
http://wordpress.org/support/topic/plugin-wp-flexible-map-updating-the-map-from-custom-field-data

add a simple [map] shortcode to WordPress that allows maps to be
created from custom fields:

  "map zoom" = the zoom level (will default to 12 if not set)
  "map coordinates" = coordinates for the map
  "map address" = address for the map

You must specify either coordinates or address (not both).
*/

if (!is_admin()) {
    add_shortcode('map', 'custom_shortcodeMap');
}

/**
* handle shortcode for map display
*
* @param array shortcode attributes as supplied by the WP shortcode API
* @return string output to substitute for the shortcode
*/
function custom_shortcodeMap($attrs) {
    global $post;

    $html = '';

    if (isset($post) && function_exists('flexmap_show_map')) {
        $zoom = get_post_meta($post->ID, 'map zoom', true);
        if (!$zoom) {
            $zoom = 12;
        }

        $coords = get_post_meta($post->ID, 'map coordinates', true);
        if ($coords) {
            $map = array(
                'center' => $coords,
                'width' => 500,
                'height' => 400,
                'zoom' => $zoom,
            );
            $html = apply_filters('flexmap_getmap', $map);
        }
        else {
            $address = get_post_meta($post->ID, 'map address', true);
            if ($address) {
                $map = array(
                    'address' => $address,
                    'width' => 500,
                    'height' => 400,
                    'zoom' => $zoom,
                );
                $html = apply_filters('flexmap_getmap', $map);
            }
        }
    }

    return $html;
}