Migrating to install4j 8

In nearly all cases, migrating to install4j 8 just means opening and saving your project with the install4j 8 IDE. Nevertheless, there are some considerations with respect to backwards compatibility and a couple of behavioral changes.

• The unattended installer does not ignore file installation failures anymore but fails at the first file installation failure. To get the old behavior, start the installer with the -nofilefailures argument. To permanently set this mode, add -Dinstall4j.noFileFailures=true to the "VM parameters" property of the installer.
• When using the VM parameters -Dinstall4j.alternativeLogFile=<path> and its new alias -Dinstallj4.log=<path>
  now imply -Dinstall4j.keepLog=true, meaning that the log file is no longer deleted in case of a successful execution of the installer application.
• The default file name of the error log for Windows installers has changed from error.log to ${compiler:sys.mediaFileName}_error.log. You can restore the old file name with the new "Log file for stderr" property of the installer.
• In bean properties with an array type, installer variables with collection values are expanded as separate array elements. Previously this was only implemented if the installer variables had array values. In the API, this new behavior affects the AbstractBean.replaceVariables(...) methods with array parameters. If you rely on the toString() replacement of collections, you have to change the types of the related installer variables.
• Variable names for all built-in variable systems can no longer contain the character sequence ?: which is now used for specifying default values for missing variables.
• FormEnvironment.getId(...) now returns the display ID of the form component rather than the automatic ID. If you were checking for an explicit automatic ID and also defined a custom ID for a form component, that code will now fail.
• The "Read text from file" action will now fail if an error occurred. Previously it always succeeded.
• The compiler variable sys.platform now contains the value windows-x32 for 32-bit Windows media files instead of windows. For 64-bit Windows media files it remains windows-x64.
• The "Customize project defaults->Installer custom script" step of the Unix/Linux GUI installer media wizard has been removed. The custom script is now configured on the installer in the "Installer->Screens & Actions" step. The simple case where there is only one Unix/Linux GUI installer is migrated correctly. However, if you used different customizations for different Unix/Linux GUI installers, the migration will be incomplete and you have to solve it with compiler variables.
• For Linux/Unix installers, the umask is now set to 0022 to allow execution by all users. This can be changed by setting the compiler variable sys.ext.installerUmask to another mask value or to false to prevent executing any umask command in the installer script.