Re: [xwiki-devs] [Proposal] XWiki's Permanent Directory Strategy for Installations

Hi devs, Since I'm working on making XE work in Windows7 I've thought more about XWiki's install and configuration. Actually this is not a new topic, I remember starting a discussion about it a few years ago on the devs list but we didn't act on it so here it comes again ;) Rationale ======== The idea is to separate XWiki's binaries from its data. There are several reasons for wanting this: * Some OSes require this and don't allow writing in the binary directory. Windows 7 for example won't allow writing data in \Program Files. * It makes upgrading simpler since you don't need to fish for configuration data and copy them somewhere before unpacking a new distribution over. Or if you unpack in a new directory you don't need to copy the data from the old directory to the new one. * As a consequence of the previous point It allows easier auto upgrades of XE * It makes it simpler to know what to backup: all you need to back is the data directory. Proposal ======= This is the simplest I've found (I've imagine a lot of more complex options which offer other small possibilities but in the end I went for the simpler one for now). So here goes the process when starting up XE: * XE looks for a XWIKI_DATA environment variable and if found it uses it as its environment.permanentDirectory value * If not found, XE looks in the user home directory for an XWiki directory. Now the name of this directory is environment-dependent. On non windows systems it looks for ".xwiki" directory and on Windows systems it looks for a "XWiki" directory. * If not found, then XE stops and prints a message in the console explaining that it couldn't find the location of the XWiki Data dir with explanations on how to set it. The recommendation is thus that users set  the XWIKI_DATA environment property.