Description:

Need to define a custom MSI property and define a value for it. Depending on the property value the installer should conditionally display a custom dialog.

For example:

Define a property BuildType and define a value for it Beta. If the property value is Beta then the installer should display a custom dialog. If the value is something else, such as Release, then the installer should not display a dialog.

Solution:

Basic MSI Project:

Create an MSI property named BuildType with value Beta and use that MSI property in a condition to determine whether to display a dialog.

For example:
Action: Hide; Condition: Not BuildType1
Action: Show; Condition: BuildType1

InstallScript code in the same Basic MSI project:

MsiGetProperty (hMSI, "BuildType", svName, nvSize);
if(svName=="Beta") then
_WinSubShowWindow(hwnds,1);
_WinSubEnableControl(hwndDlg,TXTBOX,1);
else if (svName =="Release")then
_WinSubShowWindow(hwnds,0);
_WinSubEnableControl(hwndDlg,TXTBOX,0);
endif;