Just a Theory

I’ve just uploaded SVN::Notify 2.56 to CPAN. Check a mirror near you! There have been a lot of changes since I last posted about SVN::Notify (for the 2.50 release), not least of which is that SourceForge has standardized on it for their Subversion roll out. W00t! The result was a couple of patches from SourceForge’s David Burley to add headers and footers and to truncate diffs over a certain size. See the sample output for how it looks. Thanks, David!

The change I’m most pleased with in 2.56 is the addition of SVN::Notify::Alternative, based on a submission from Jukka Zitting. This new subclass allows you to actually combine a number of other subclasses into a single activity notification message. Why? Well, mainly because, though you might like to get HTML messages with colorized diffs, some mail clients might not care for the HTML. They would much prefer the plain text version.

SVN::Notify::Alternative allows you to have your cake and eat it too: send a single message with multipart/alternative sections for both HTML output and plain text. Plain text will always be used; to use HTML::ColorDiff with it, just do this:

svnnotify —repos-path "$1" —revision "$2" \
  —to developers@example.com —handler Alternative \
  —alternative HTML::ColorDiff —with-diff

This incantation will send an email with both the plain text and HTML::ColorDiff formats. If you look at it in Mail.app, you’ll see the nice colorized format, and if you look at it in pine, you’ll see the plain text.

For the curious, here are all of the changes since 2.50:

2.56 2006-04-04T23:16:37

• Abstracted creation of the diff file handle into the new diff_handle() method.
• Documented use of diff_handle() in the output() method.
• Added optional second argument to output() to optionally suppress the output of the email headers. This argument is used by the new Alternative subclass.
• Added SVN::Notify::Alternative, which allows multiple versions of a commit email to be sent, such as text/plain plus HTML. The multiple versions are assembled into a single email message using the multipart/alternative media type. For those who want HTML messages but must support users that can only read plain text or rely on archives that ignore HTML messages, this can be very useful. Based on an implementation by Jukka Zitting.
• Fixed use_ok() tests that weren’t running at all.
• Added an extra newline to separate the file list from an inline diff in the plain text format where —with-diff has been specified.
• Moved the multipart/mixed content-type header generation from output_headers() to output_content_type(), not only because this makes more sense, but also because it makes attachments behave better when using SVN::Notify::Alternative.
• Documented accessors in SVN::Notify::HTML.

2.55 2006-04-03T23:11:11

• Added the io-layer option to specify an alternate IO layer. Will be most useful for those with repositories containing text in multiple encodings, where it should be set to raw.
• Fixed the context output in the subject for the —subject-cx option so that it’s smarter about determining the longest common path. Reported by Max Horn.
• No longer modifying the values of the to_regex_map hash, so as not to mess with folks who might be passing it as a hash to more than one call to new(). Reported by Darby Felton.
• Added a meta http-equiv="content-type" tag to HTML output that includes the character set to help some clients in the proper display of the characters in an HTML email. I’m not sure if any clients actually need this help, but it certainly can’t hurt!
• Added the —css-url option to specify an alternate style sheet for HTML emails. SVN::Notify::HTML’s own CSS is left in the email, as well, so the specified style sheet can just override the default, rather than have to style everything itself. Yes, it takes advantage of the cascading feature of cascading style sheets! Based on a suggestion by Steve James.

2.54 2006-03-06T00:33:42

• Added /usr/bin to the list of paths searched for executables. Suggested by Nacho Barrientos.
• Added —max-diff-length option. Patch from David Burley/SourceForge.

2.53 2006-02-24T21:30:48

• Added header and footer attributes and command-line options to specify text to be put at the head and foot of each message. For HTML messages, the text will be escaped, unless it starts with <, in which case it will be assumed to be valid HTML and will therefore not be escaped. Either way, it will be output between <div> tags with the IDs header or footer as appropriate. Based on a patch from David Burley/SourceForge.
• Fixed the executable-searching algorithm added in 2.52 to add .exe to the name of the executable being searched for if $^O eq 'MSWin32'.
• Fixed encoding issues so that, under Perl 5.8 and later, the IO layer is set on file handles so as to encode input and decode output in the character set specified by the charset attribute. CPAN # 16050, reported by Michael Zehrer.
• Added a second argument to all calls to encode_entities() in SVN::Notify::HTML and SVN::Notify::HTML::ColorDiff so that only '>'. '<', '&', and '"' are escaped.
• Fixed a bug in the _find_exe() function that was attempting to modify a constant variable. Patch from John Peacock.
• Turned the _find_exe() function into the find_exe() class method, since subclasses (such as SVN::Notify::Mirror) might want to use it.

2.52 2006-02-19T18:50:24

• Now uses File::Spec->path to search for a validate sendmail or svnlook when they’re not specified via their respective command-line options or environment variables. Suggested by Andreas Koenig. Not that they should probably be explicitly set anyway, as the $PATH environment variable tends to be non-existent when running under Apache.

2.51 2006-01-02T23:28:11

• Fixed ColorDiff HTML to once again be valid XHTML 1.1.

Enjoy!