MsiPackage - meaning of attribute "cache"

Question

I am searching for a description, what the attribute "cache" is standing for in the MsiPackage. When I look at http://wix.sourceforge.net/manual-wix3/wix_xsd_msipackage.htm I cannot get some additional information. Is there another link with a description of this attribute or can someone explain me this attribute?

Answer 1

The WiX toolset boostrapper/chainer, Burn, has the ability to acquire (copy or download) and cache the packages it installs. The package cache is very useful to provide the Windows Installer a location to go get the original package if for some reason it's cache (under %WINDIR%) is invalidated. There are a number of reasons the Windows Installer will not trust its cache and many of them will hit at the most innopportune times. In particular, minor upgrading and patching can require the original source.

Anyway, the MsiPackage element Cache attribute can be used to force the Burn engine to cache or not cache the package. The default will provide the best user experience so unless you have an explicit reason to change it, I recommend leaving the Cache attribute absent.