Merge branch 'rob/6583-ensure-latest-file-download-not-older-cached' …

…into rob/release-sprint-2022-11-14-to-2022-11-21-2

sites/all/modules/custom/dwcarchiver/dwcarchiver.pages.inc

@@ -75,7 +75,12 @@ function dwcarchiver_overview_page() {
     }
     $row[] = l('Preview', 'admin/config/content/dwcarchiver/' . $archive->machine_name . '/preview');
     $row[] = l('Rebuild', 'admin/config/content/dwcarchiver/' . $archive->machine_name . '/rebuild');
-    $row[] = l('Download', $archive->machine_name . '.zip');
+
+    // defeat the cache by adding a unique pattern to end, so that the latest archived file is always downloaded
+    // credit: https://www.drupal.org/forum/support/post-installation/2009-05-09/prevent-question-marks-in-autopath-links-from-being#comment-4305604
+    // and: https://stackoverflow.com/a/3055584/227926
+    $timeNow = time();
+    $row[] = l('Download', $archive->machine_name . '.zip', array('query' => array('timestamp' => $timeNow)));
     $rows[] = $row;
   }
   return [

sites/all/modules/custom/dwcarchiver/dwcarchiver.rebuild.inc

@@ -26,6 +26,12 @@ function dwcarchiver_rebuild($dwcarchiver, $deliver = TRUE) {
       drupal_set_message(t('Unable to rebuild the archive, please contact an administrator.'), 'error');
     }
     else {
+      // clear file cached for following path
+      // e.g. https://myriatrix.myspecies.info/gbif-dwca.zip
+      $host = _varnish_get_host();
+      $base = base_path();
+      varnish_purge($host, '^' . $base . '/gbif-dwca.zip*' );
+
       _dwcarchiver_create_xml_and_data_files($dwcarchiver, $zip);
       $zip->close();
       // Move the zip file to the dwcarchiver folder.