Changes to an application during a NAD update

When the WindowViewer node updates an application, it makes every attempt to retain the attributes (read-only, system, hidden, and so on) of the NAD Repository application during the copy process.

WindowViewer also copies all files and subfolders of the NAD Repository application, except for these files: *.WVW, *.DAT, *.LGH, *.IDX, *.LOG, *.LOK, *.FSM, *.STG, *.DBK, *.CBK, *.HBK, *.KBK, *.LBK, *.NBK, *.OBK, *.TBK, *.WBK, *.XBK, *.$$, RETENTIV.X, RETENTIV.D, RETENTIV.A, RETENTIV.S, RETENTIV.H, RETENTIV.T, SSD_, WM.INI, DB.INI, LINKDEFS.INI, TBOX.INI, GROUP.DEF, and ITOCX.CFG.

Note: WindowViewer recursively deletes all files and sub folders in the destination application folder except those required for run-time language switching. This folder should be considered a temporary folder. No other files should be placed in it.

The NAD client starts an update by creating a local list of files and sub-directories that appear in the client application directory. As it looks for updates in the list of NAD Repository files, the NAD client removes the corresponding client file for each NAD Repository file from the local list. The remaining entries in the local list are obsolete files and sub-directories that should be deleted from the application.

All downloaded files are copied to a temporary sub-directory called NAD_Temp. Files are only copied from NAD_Temp to the application directory if all of the new and updated files are copied successfully within the re-try limits. If the NAD client has to abandon an update, the running application is not corrupted by the partial introduction of new or updated files.

If contact with the NAD Repository fails after all new and updated files have been downloaded, the update can still be completed by copying the updates from NAD_Temp and deleting the obsolete files. This ensures that files are not erased simply because a lost connection makes it impossible to confirm their existence on the NAD Repository application.

NAD can detect whether additional changes have been made to the NAD Repository application during application download. If such a situation arises, NAD abandons the download of the application. If you run the Notify Clients command after the latest update, NAD automatically begins downloading the latest application files at the next polling period. Otherwise, it waits until the next Notify Clients command issued before an application download takes place.