Issue #56: Fix map already initialized with AJAX, fix container ID un…

…iqueness (#58)

js/leaflet.backdrop.js

@@ -83,7 +83,7 @@
       $(backdropSettings.leaflet).each(function () {
         // skip to the next iteration if the map already exists
         var container = L.DomUtil.get(this.mapId);
-        if (!container || container._leaflet) {
+        if (!container || container._leaflet_id || container._leaflet) {
           return;
         }
 

leaflet.module

@@ -110,7 +110,10 @@ function leaflet_library_info() {
  *   A renderable array.
  */
 function leaflet_build_map(array $map, array $features = array(), $height = '400px') {
-  $map_id = backdrop_html_id('leaflet_map');
+  // Function backdrop_html_id() is unreliable when creating unique IDs.
+  // We attach a pseudo random number instead to make multiple maps on a page
+  // work properly with maps in blocks.
+  $map_id = 'leaflet-map-' . rand();
   $build = array(
     '#theme' => 'head_tag',
     '#tag' => 'div',