erp5_web_renderjs_ui: do not hammer zope during installation

bt5/erp5_web_renderjs_ui/PathTemplateItem/web_page_module/rjs_gadget_erp5_serviceworker.js

@@ -21,21 +21,27 @@
           var required_file_dict = result_list[0],
             cache = result_list[1],
             key,
-            promise_list = [],
+            promise = Promise.resolve(),
             url;
 
+          function append(url) {
+            promise = promise
+              .then(function () {
+                // Use cache.add because safari does not support cache.addAll.
+                return cache.add(url);
+              });
+          }
+
           for (key in required_file_dict) {
             if (required_file_dict.hasOwnProperty(key)) {
               url = new URL(key, location.toString()).toString();
+              // Add all offline dependencies to the cache
+              // One by one, to not hammer zopes
               required_url_list.push(url);
-              // Use cache.add because safari does not support cache.addAll.
-              // console.log("Install " + CACHE_NAME + " = " + url);
-              promise_list.push(cache.add(url));
+              append(url);
             }
           }
-
-          // Add all offline dependencies to the cache
-          return Promise.all(promise_list);
+          return promise;
         })
         .then(function () {
           // When user accesses ERP5JS web site first time, service worker is

bt5/erp5_web_renderjs_ui/PathTemplateItem/web_page_module/rjs_gadget_erp5_serviceworker.xml

@@ -238,7 +238,7 @@
                   </item>
                   <item>
                       <key> <string>serial</string> </key>
-                      <value> <string>981.48930.15634.60876</string> </value>
+                      <value> <string>981.49192.3036.63283</string> </value>
                   </item>
                   <item>
                       <key> <string>state</string> </key>
@@ -256,7 +256,7 @@
                           </tuple>
                           <state>
                             <tuple>
-                              <float>1581325589.75</float>
+                              <float>1581341953.03</float>
                               <string>UTC</string>
                             </tuple>
                           </state>