I ran into this problem last year. You aren't doing anything wrong. The reason for this happening is simple. Apache (and IIS) do not sent an updated etag value with the response to the PUT request (webdav save method) because you can add post-processing to the PUT request that would change the file (common with things like GIT where change headers are added). This means that the Apache (and IIS) can't be positive that the file that would be sent for a subsequent GET request would be identical to what was sent with the PUT request. So, it is inappropriate for the web server to include the etag header in the response to the PUT request.
The client application (tiddlywiki running in your browser) should follow-up the PUT request with a GET request to get an update to the tiddlywiki file after the PUT finishes to ensure that all affected changes are reflected in what you have in your browser. This would also provide an updated etag value and solve the 412 issue. I have tested the above with Firefox, Chrome, IE, and Safari on Windows, Linux, and OSX (where the software was available to me) with the Apache web server (version 2.4) running on Linux, FreeBSD, Windows 7, and Windows 10 as well as IIS running on both Windows 7 and Windows 10. They all behave the same way. There was discussion of this many months ago on groups. https://groups.google.com/forum/#!searchin/tiddlywiki/webdav$20etag$20thelostadmin%7Csort:date/tiddlywiki/8HB0R_ADYac/AMyHtqO2AAAJ The only reliable work-around I've found to-date is to reload the web page after each save of tiddlywiki. My Apache web server uses WebDav for tiddlywiki and I use the post-processing to make a backup (similar to how tiddlyspot has a backup directory) of changes to the files. It's not available for general use because of the etag issue. On Monday, April 2, 2018 at 2:20:25 PM UTC-4, Kevin Kleinfelter wrote: > > I'm trying TW from an Apache WebDAV server. I'm getting > Error while saving: > XMLHttpRequest error code: 412 > > All I did was to load a brand new TW file into my browser via > http://192.168.1.2/webdav/testfile.html, add a new tiddler, and let the > auto-save do its thing. I did no concurrent updating from another browser > or on the server. I tried 3 times (starting with a new browser each time). > > I *think* my WebDAV is configured correctly: > > - I connected to it via Mac Finder, and added/deleted/renamed files > without error. > - I was able to retrieve a file via: curl --user "userid:password" > http://myserver/webdav/testfile.html --digest -o testfile.html > - I was able to put a file via: curl --user "userid:password" > http://myserver/webdav/ --upload-file testfile.html --digest > > When I look at the Apache access log I notice these two PUTs (first is the > TW put; second is the curl put): > > - "PUT /webdav/testfile.html HTTP/1.1" 412 558 " > http://192.168.1.2/webdav/testfile.html" "Mozilla/5.0 blah-blah" > - "PUT /webdav/testfile.html HTTP/1.1" 204 289 "-" "curl/7.54.0" > > Clearly, the difference in the PUT request formats triggers a 412 error > when TW PUTs the data. > > The Apache webdav and DavLock folders are owned and writable by www-data. > The DavLock db and the document files are owned and writable by www-data. > > What am I doing wrong? > TIA > > -- You received this message because you are subscribed to the Google Groups "TiddlyWiki" group. To unsubscribe from this group and stop receiving emails from it, send an email to tiddlywiki+unsubscr...@googlegroups.com. To post to this group, send email to email@example.com. Visit this group at https://groups.google.com/group/tiddlywiki. To view this discussion on the web visit https://groups.google.com/d/msgid/tiddlywiki/e79d38a1-82b7-49e7-a6f9-271b293e9fc8%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.