Caching

Mobile Reach Apps download data from the database server to a cache on the client device. When the device connects to the server and does not have a database table that it needs, the device asks the server for the fieldmap of that table. The fieldmap defines the structure of the database table (fields and datatypes of those fields) and contains option lists for database fields where necessary.

When data is downloaded, the device uses the fieldmap to create a table on the device that has the same structure as the database table. The downloaded data is stored in this table and is used as the source data for the App. The data in this table is referred to as the data cache. The data cache allows the device to operate completely offline.

Clearing cache

Clearing the cache for one or more Apps deletes the data stored in the table on the device and reloads the data from the database server. Clearing the cache is different from updating recordsets because all of the cached data is deleted and reloaded, not just the changed data. Clearing the cache also picks up any changes to the table structure that occurred on the database server (add field, change a data type, etc).

NOTE: If the data in your App doesn’t seem to be current, try clearing the cache and re-starting the App.

Any modified records on the device that have not been uploaded to the database server are discarded as part of a clear cache operation. Changes to records can be discarded without clearing cache. See the appropriate User Guide for more information.

You can perform a clear cache operation at any time. You SHOULD perform a clear cache operation when:

  • Network preferences are changed on the device.

    NOTE: You will receive an error message if you change the network preferences and attempt to open an App without clearing cache. This message only displays if you are set to private or shared encryption because the network preference settings are used to generate the encryption key.

  • The SQL qualifier for a Group or secondary Recordset component in AppStudio is changed.
  • The table structure is changed on the database server.

    NOTE: When using a ServiceNow database, cache does not have to be cleared when non-structural changes, such as adding an option to a list or changing the name of a column, are made to the database table. To download these changes, open the App and touch the sync icon. If you are in the App, exit to the launcher window, re-open the App and touch the sync icon.

    If structural changes were made to the database table, opening the App and touching the sync icon will generate an error message that states cache must be cleared for the App.

You can clear cache for all Apps or an individual App in the launcher window. Data for each App is reloaded when the App is opened.

Clear Cache: individual App

Clearing cache for an individual App differs, depending on the device being used. All actions are performed in the launcher window.

  • Android: Touch and hold on the App. Touch Yes when asked if you want to delete the cache database for the App.
  • iOS: Swipe from right to left across the App. A Clear Cache button displays. Touch the button. Touch Yes when asked if you want to delete the cache database for the App.

  • Windows 10: Right-click or Touch/Hold on the App. Touch Yes when asked if you want to delete the cache database for the App.

Clear Cache: all Apps

For iOS/Android/Windows 10 devices, clear cache for all Apps by touching the trashcan icon in the launcher window. Touch Yes when asked if you want to delete the cache for all applications.

Clear Cache: Windows Mobile

To clear cache for an individual App on a Windows Mobile device, select the App in the launcher window and select Clear App Cache from the Actions or Touch/Hold menu. Touch Yes when asked if you want to delete the cache database for the application.

To clear the cache for all Apps on a Windows Mobile device, in the launcher window, select Clear Cache from the Tools or Touch/Hold menu. Touch Yes when asked if you want to close all windows and delete all cache databases for all MRT applications.

Hiding the Clear Cache icon

On iOS/Android/Windows 10 devices, the Clear Cache icon can be hidden in the launcher window or on a specified Table or Related List.

If the icon is hidden in the launcher window, you cannot to clear cache for individual Apps or for all Apps running on the device.

If the device is hidden for a table or related list, you can discard individual new records or changes for an individual record. You cannot discard all new records/changes and reload the records from the server.