How to conditionally show the "UpgradeDlg" dialog

The following article uses options that are available starting with the Enterprise edition and project type.

The feature explained in this How-To can only be used if the installation package is created by following the steps mentioned in the Upgrades page for side by side installations.

When using side by side installation packages, you can add the "UpgradeDlg" dialog from the Dialogs page. This dialog allows the user to choose if the old versions of the installation package will be removed or the current version will be installed side by side with them.

Since the installation package can also be installed on a clean machine (there is no older version present), this dialog should be showed only if an older version of the installation package is found. For this, you can follow these steps:

1. make sure that the original package has the "Allow side by side installs of different product versions" option set in the Upgrades page
2. create the upgraded package by following the steps in the Upgrade page
3. go to the "Dialogs" page and add the "UpgradeDlg" dialog after "FolderDlg"
4. with the "UpgradeDlg" dialog still selected use the "Show only if..." option from the context menu
5. in the "Expression" field from the Edit Condition Dialog write OLDPRODUCTS
6. build and run the project