Client-Side Caching of SAPUI5 Flexibility Changes

Validity token in the URL notifies the browser whether SAPUI5 flexibility changes exist and validation requests to the server are required or whether the data can be fetched directly from the browser's cache

The validity token is calculated per application and user, as each user can have a different set of changes per application. These unique URLs are calculated at startup of the SAP Fiori launchpad (FLP) for all applications. For a fast token calculation per component name or application variant ID, the ID is used.

If no changes for an application exist, a predefined token notifies the client that no validation request to the server is required.

At start of an SAPUI5 app, a hook is provided that is called directly after loading the application descriptor. The hook contains the async hints section of the FLP application information, in which the unique and cacheable URLs with the SAPUI5 flexibility changes are provided. The async hints also provide information about the library dependency. This ensures that the SAPUI5 flexibility library is loaded if SAPUI5 flexibility changes for an application exist.

Example

"asyncHints": {
              "libs": [
                   { "name": "sap.ui.table" },
                   { "name": "sap.ui.fl" },

              ],
              "components": [
                       {
                              "name": "sap.ushell.test.AppDepTest1",
                              "url": {
                                   "url": "/sap/bc/ui5_ui5/ui3/app_dep_test_1/+BB1F635803B5E14BAA49FEF0BC1113CB+5",
                                   "final": true
                              }
                        }
              ],
              "requests" : [
                     {
                            "name": "sap.ui.fl.changes",
                            "url" : "/sap/bc/lrep/flex/data/fin.gl.lineitembrowser.display.Component/+QTOLJQLAYP6QXHVSZ58RNGLM8NY~",
                      }
               ] 
}

To avoid slowing down the startup time of the FLP due to the calculation of the validity token, a global validity token indicates changes of the SAPUI5 flexibility token. For this, a set of global cache tokens per user are precalculated:

A token for tenant-independant changes
A token for tenant-dependent changes
A token for user-dependent changes

The precalculation is done whenever changes occur that influence the global token. On request, they are combined to one user-specific global validity token for SAPUI5 flexibility changes.