[Paraview] Extending Broken in 2.6.0

[David C Thompson]

First of all, I have to apologize... I did commit a fix to stop the
LS-Dyna reader from printing crud out from within CanReadFile, but it
apparently did not make it into the 2.6 branch. I've just sent a patch
to Amy to be included if there are any more 2.6 releases.

> > <rant>So basically you have to hack up paraview because someone can
> > not put a file extension on a data file and we all get to incur that
> > performance penalty.</rant>
Yes, although I could make a similar rant along the lines of "You mean
there are still applications that have to determine a file's type by its
extension?" or "You mean there are still file selection dialogs that
won't let you choose a file because it happens to be a directory?"

> Actually, the right way of dealing with this is assigning priorities
> to readers and have paraview try readers in the order of priority.
> LSDyna would have a priority of -infinity :-) I cannot guarantee we
> would implement it quickly but I suggest putting in a feature request
> for it.
I would like to suggest an alternative: have readers register mime types
as well as file extensions. Then libmagic (see
ftp://ftp.astron.com/pub/file/file-4.20.tar.gz) or other OS-specific
utilities (i.e., file attributes on MacOS X) could be used to find the
proper reader without instantiating any readers and without the overhead
of calling many CanReadFile implementations on many files.

	David