Checking for an Automatic Download

When JADE thin client mode checks whether an automatic download is required, the following actions occur.

The patch numbers of the required libraries and the release version of the jade.exe and jaddinst programs are passed to the application server during the initial connection. If there is a mismatch:

If the AutomaticDownLoad parameter (on both the application server and the presentation client) is set to true, a download is invoked to copy the files from the binary directory on the application server.
If the automatic download is not in effect, a version error is returned to the jade.exe program and the download process terminates.

If the application server and presentation client are running different environments, the release version and patch numbers of common libraries are compared. If they are different or the module is a presentation client module only, the files in the environment directory relevant to the presentation client are obtained (that is, loaded and retained).

If the patch number of any common module differs from that of the application server, a message is logged (in the jommsg.log file on the application server) and the automatic download continues.

If the required executable (that is, jade.exe) is not available in the JADE work directory and library modules are not available in the binary directory on the application server, an automatic download does not apply and the appropriate entry is logged (in the jommsg.log file on the application server).

If the DownLoadVersion parameter value in the JADE initialization file on the application server differs from the value of the DownLoadVersion parameter passed from the presentation client during the initial connection of the presentation client to the application server or a version mismatch occurs, a download is initiated. (This download version is not case-sensitive.)

The DownLoadVersion, DownLoadDescription, and PreDownLoadDescription parameters in the [JadeAppServer] section of the JADE initialization file are global to the application server. Changing the version causes all thin clients that attach and have a different local version to compare their file set with that of the environment type on the application server.

In all other situations, automatic download version checking and update occurs only if one of the JADE libraries used by the presentation client has a different version to that being run by the application server or the JADE executable in use by the presentation client has a different version from the file in the download directory.

If a version mismatch download was not required during the initial connection, the value of the PreDownLoadVersion parameter in the JADE initialization file on the application server is compared with that of the value passed from the presentation client. (This download version is not case-sensitive.) If these versions match, if the PreDownLoadDirectory or PreDownLoadProgramDataDirectory parameter is empty, or if the maximum number of downloads that is allowed is already in progress, the pre-download does not occur and the application initiation continues as normal. If a pre-download situation is found, a download is initiated.

To enable the pre-download process to work, the pre-download directories must have the same subdirectory structure as the corresponding download directories. For details about the directories that are required for each environment type, see "Overview", earlier in this appendix.