Issue #2571481 by slydevil, Dom.: Locally cached file is not gzipped

googleanalytics.module

@@ -262,7 +262,7 @@ function googleanalytics_preprocess_layout() {
     $library_tracker_url = 'https://www.google-analytics.com/' . ($debug ? 'analytics_debug.js' : 'analytics.js');
 
     // Should a local cached copy of analytics.js be used?
-    if (variable_get('googleanalytics_cache', 0) && $url = _googleanalytics_cache($library_tracker_url)) {
+    if ($config->get('cache') && $url = _googleanalytics_cache($library_tracker_url)) {
       // A dummy query-string is added to filenames, to gain control over
       // browser-caching. The string changes on every update or full cache
       // flush, forcing browsers to load a new copy of the files, as the
@@ -533,6 +533,10 @@ function _googleanalytics_cache($location, $synchronize = FALSE) {
         if ($data_hash_local != $data_hash_remote && file_prepare_directory($path)) {
           // Save updated tracking code file to disk.
           file_unmanaged_save_data($result->data, $file_destination, FILE_EXISTS_REPLACE);
+          // Based on Backdrop Core backdrop_build_css_cache().
+          if (settings_get('css_gzip_compression', TRUE) && config_get('system.core', 'clean_url') && extension_loaded('zlib')) {
+            file_unmanaged_save_data(gzencode($result->data, 9, FORCE_GZIP), $file_destination . '.gz', FILE_EXISTS_REPLACE);
+          }
           watchdog('googleanalytics', 'Locally cached tracking code file has been updated.', array(), WATCHDOG_INFO);
 
           // Change query-strings on css/js files to enforce reload for all users.
@@ -545,6 +549,10 @@ function _googleanalytics_cache($location, $synchronize = FALSE) {
           // There is no need to flush JS here as core refreshes JS caches
           // automatically, if new files are added.
           file_unmanaged_save_data($result->data, $file_destination, FILE_EXISTS_REPLACE);
+          // Based on Backdrop Core backdrop_build_css_cache().
+          if (settings_get('css_gzip_compression', TRUE) && config_get('system.core', 'clean_url') && extension_loaded('zlib')) {
+            file_unmanaged_save_data(gzencode($result->data, 9, FORCE_GZIP), $file_destination . '.gz', FILE_EXISTS_REPLACE);
+          }
           watchdog('googleanalytics', 'Locally cached tracking code file has been saved.', array(), WATCHDOG_INFO);
 
           // Return the local JS file path.