Re: [matplotlib-devel] switching to PS/SVG backends

[Jochen V. <vo...@se...>]

Hello Steve,

On Thu, Nov 18, 2004 at 11:38:10PM +0800, Steve Chaplin wrote:
> At the moment the PS backend does
>   try:
>       fh =3D file(outfile, 'w')
>   except IOError:
>       error_msg_ps('Could not open %s for writing' % outfile)
>=20
> which translates into
>   try:
>       fh =3D file(outfile, 'w')
>   except IOError:
>       verbose.report_error('Error: Could not open %s for writing' %
> outfile)
>       sys.exit()
>=20
> The backend does not do any cleanup after the exception, so I think it
> could be changed to just
>       fh =3D file(outfile, 'w')
As I understood John, the plan is to report error messages via the
verbose.report_error function.  Where would this be called with
the modified code (especially when there is no GUI backend active)?

> allowing the exception terminate the program with the error message
> appearing at the end of the traceback.
This looks really ugly to me.  But maybe it is the script author's
responsibility to catch this if he cares about this.

> Then the GUI backends can then do
>     from backend_svg import FigureCanvasSVG as FigureCanvas
>     try:
>         fc =3D self.switch_backends(FigureCanvas)
>         fc.print_figure(filename, dpi, facecolor, edgecolor,
> orientation)
>     except IOError, exc:
>         error_msg("%s: %s" % (exc.filename, exc.strerror), parent=3Dself)
What about other exceptions thrown by the backend?

I see that passing the original exception to the caller is cleaner
and I would be happy to change the PostScript backend to do this.
The only question for me is: how and when is the "report_error" function
to be used?

All the best,
Jochen
--=20
http://seehuhn.de/