On the "Installer->Update Options" step, you can configure how an installer should behave in the event of an update. An update occurs when the user installs an application into a directory where an installation with the same application ID already exists.
Typically, minor upgrades of an application should be installed into the same directory as earlier installations. The default behavior of install4j is to suggest the previous installation directory and program group, so that the user is guided into installing the application into the same directory. If this behavior is not desired, you can switch off these suggestions or change the application ID on the "Installer->Update Options" step.
The following points are of interest with respect to updates into the same installation directory:
If you would like to uninstall the previous installation before installing any new files, you can add the "Execute previous uninstaller" action before the "Install files" action. In this context, the uninstallation policies that exclude updates are important. With these uninstallation policies you can preserve certain files for updates, but uninstall them when the user manually invokes the uninstaller. The uninstaller invoked by the "Execute previous uninstaller" action is running in unattended mode. You can use
to exclude certain actions for an update uninstaller.
install4j offers two types of installers that can be selected on the "Installer->Update options" step:
Regular installersThis option generates standalone installers. If the "Detect previous installation directory" check box is selected and a previous installation can be detected on the computer, the installer will suggest the directory of that previous installation. In that case, the "Update alert" form component on the "Welcome" screen will ask the user if the previous installation should be updated.
This generates an installer that can only be installed on top of an installation of a certain installation. An add-on installer does not have a separate uninstaller. This is useful to distribute additional files that do not change the version number of the installation.
If the add-on installer type is selected, you have to specify the application ID for the base application.