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Revision history for Perl extension GraphViz2.

2.14  Mon Jul  1 10:09:00 2013
	- Patch push_subgraph() to correctly handle the case of an unnamed subgraph.
		The code was outputting 'subgraph "" {...}'. The extra "" are now suppressed.
		The code also handles the case of the name being undef.
		There are no doc changes because the docs described precisely what should have happened, thusly:
			So, without $name, 'subgraph {' is written to the output stream.
			With $name, 'subgraph "$name" {' is written to the output stream.
		Many thanx (again) to Larry Marso for reporting this, with sample code.
	- Add scripts/unnamed.sub.graph.pl.

2.13  Fri Jun 28 12:02:00 2013
	- Oops - Patch scripts/record.1.pl as was allegedly done for V 2.11.

2.12  Thu Jun 27 14:40:00 2013
	- Add scripts/plaintext.pl, which generates a 'Use of uninitialized value...' error under V 2.11 and,
		after the fix, does not do so under V 2.12. Many thanx to Larry Marso for the (private email) report.

2.11  Thu Jun 27 09:21:00 2013
	- Correct spelling of Kent Fredric's name below, with apologies.
	- Patch scripts/record.1.pl and scripts/record.2.pl to use '\\n' to get a literal '\n' in the output dot
		file. The original works my Debian machine, but needs fixing in case there's someone out there not
		using Debian :-).
	- Remove debug log message from add_edge().

2.10  Mon Jun 24 11:05:00 2013
	- Overview: Re-work the label and port handing code.
	- Note: the global graph attribute 'record_orientation' no longer does anything. The new label syntax,
		(next, and in detail in the FAQ (https://metacpan.org/module/GraphViz2#How-labels-interact-with-ports) ),
		is now the recommended way of using labels to specify both ports and orientation.
		Using 'record_orientation' will not cause parameter validation to fail, it just won't have any effect.
		The attribute will be removed in a future version, so prepare now by deleting it from your code.
	- Labels can be a string, an arrayref of strings, or an arrayref of hashrefs. The latter alternative
		is new. The keys to the hashrefs are 'text' and 'port', with the latter being optional.
		See the FAQ topic mentioned above. See scripts/record.2.pl for sample code.
		Many thanx to Kent Fredric for the report (RT#85976), and the list of suggestions.
	- Add scripts/record.3.pl and add it to the demo generating code scripts/generate.*.sh.
		It demonstrates deeply nested record structures using a string as a label. The same effect could be
		achieved by using an arrayref of hashrefs, of course. scripts/record.2.pl shows how.
	- Stop escaping the 2 label characters { and }, since they are used to orient fields within records.
		On the demo page http://savage.net.au/Perl-modules/html/graphviz2/, see scripts/record.*.pl.
		Expand the FAQ discussion of escaping to cover this issue.
	- Remove restriction that port names in calls to add_edge() had to start with 'port'.
		This was due to my misreading of the Graphviz docs, where all examples used a 'port' prefix.
		The code also now checks for '*::*', in case the program is using Perl classes for node names,
		in which case we don't want the first ':' to be taken as the introduction for a port name.
	- Update words/tokens (arrow shapes etc) stored within the source code, by running scripts/extract.*.pl
		and storing the output in lib/GraphViz2.pm after the __DATA__ token. Yes, I know this is hard-coding.
		See the amazing module Data::Section::Simple for details.
		The set of words/tokens matches Graphviz 2.30.1, as of today, 2013-06-24.
	- Rename CHANGES to Changes as per CPAN::Changes::SPEC.
	- Reformat the POD in lib/GraphViz2.pm slightly.
	- Remove scripts/parse.marpa.pl and t/sample.marpa.1.dat, as a step in removing all Marpa-related material,
		because it uses the deprecated NAIF interface. All new Marpa work should use the scanless interface (SCIF).
	- Change Build.PL and Makefile.PL to check for Perl being at least V 5.14.0. If you are using an earlier
		version, you can forgo utf8 support by editing the files to relax this restriction.
		Some tests (utf8.pl, utf8.test.pl) will presumably fail as a consequence.
		Lastly, my attention has been drawn to Unicode::Semantics::up(), but I've chosen not to use it.

2.09  Fri May 31 09:57:00 2013
	- Re-write the code in Build.PL and Makefile.PL which checks for Graphviz (dot) being installed,
		since the previous code, using a pipe, was failing on some versions of Windows.
	- Assume Config.pm is installed, and hence remove it from the pre-reqs.
		This also stops a warning message generated because Config's version # is undef.
	- Likewise assume File::Spec and File::Temp are installed, and 'recent enough'.
		This is because the new code uses these 3 modules before specifying the pre-reqs.
	- Bump the pre-req for Perl from 5.10.0 to 5.14, since we 'use feature qw/unicode_strings/.
	- Re-write the code in Build.PL and Makefile.PL which checks for Perl being 'recent enough',
		since the previous code, using a pre-req of "perl => '5.10.0'" generates a warning message
		when using Makefile.PL (for my current Perl V 5.14.2). Now we analyze $Config{version}.
	- One CPAN Tester found tests failing even though Graphviz was installed.
		The problem was that the Times font was missing. The new code should fail during 'perl Build.PL',
		or 'perl Makefile.PL', rather than during testing, which is good.

2.08  Thu Mar 21 13:16:00 2013
	- Add $ENV{DBI_SCHEMA} to scripts/dbi.schema.pl.
	- For the MusicBrainz database, use DBI_SCHEMA=musicbrainz,cover_art_archive,report,statistics.
		See http://musicbrainz.org/doc/MusicBrainz_Database for details.
		Users of cpanm will want 'cpanm Carton' instead of 'sudo cpan Carton' in Perl dependencies.
		See https://github.com/metabrainz/musicbrainz-server/blob/master/INSTALL.md for details.

2.07  Wed Mar 13 13:24:00 2013
	- Extend GraphViz2::DBI to handle SQLite using pragma foreign_key_list($table_name).
	- Add scripts/sqlite.foreign.keys.pl to help analyze that pragma's output.
	- Remove the string 'App-Office-CMS' from scripts/dbi.schema.pl. That is, the create() method is
		called as $g -> create(name => ''). This has the effect of removing the global node from the
		resultant graph. All tables were descendents of this node, but with schemas of dozens or hundreds
		of tables, it became confusing.
	- Patch dbi.schema.pl to set the DBI connect attr sqlite_unicode and foreign_keys pragma if using SQLite.

2.06  Thu Nov  8 12:38:00 2012
	- No code changes.
	- For pre-reqs such as strict, warnings, etc, which ship with Perl, set the version # to 0.
		Reported as RT#80663 by Father Chrysostomos for Tree::DAG_Node.

2.05  Tue Oct  2 10:20:00 2012
	- No fundamental code changes, so no need to upgrade, unless you need the following new features.
	- After a request from Jack Maney, author of the Perl module Hypatia:
		o Document the mutator node_hash(), which returns a hashref keyed by node name.
			Use this to get a list of all nodes and their attributes.
		o Add a new mutator, edge_hash(), which also returns a hashref keyed by node name.
			The node is the one at the arrow/tail/ end of the edge, i.e. where the edge starts from.
			Use this to learn all sorts of things about the edge.
		o Add scripts/report.nodes.and.edges.pl (a version of scripts/html.labels.pl) to demonstrate
			how to access this data.
		o Update to POD to match.

2.04  Fri Aug 17 10:48:00 2012
	- Add Perl V 5.14.2 to the pre-reqs, for the utf8 stuff.
	- Re-write the subgraph handling code, which was broken up to V 2.03.
		Add samples, script/rank.sub.graph.[1234].pl, to demonstrate subgraph name effects and node rankings.
		script/rank.sub.graph.[12].pl use subgraphs to force a set of nodes to be horizontally aligned.
		script/rank.sub.graph.[34].pl show the effects of subgraph name changes on the same data.

2.03  Mon Jun 18  9:47:00 2012
	- Switch from double to single quotes in line 22 of GraphViz2::Parse::Regexp, so the resultant string,
		treated as Perl code, runs on Windows. Reported by Max Maischein as RT#77869.
	- Also, slightly reformat line 39 of that module.

2.02  Thu Apr 19 11:51:00 2012
	- Accept patch from Lee as in RT#76459, to replace the code which writes the dot input file to
		a file with binmode, and just pass the data to dot via IPC::Run.
		Happily, this allows me to eliminate 'use open qw/:encoding(UTF-8) :std/;' in t/test.t.
	- Update the pre-reqs in Build.PL and Makefile.PL.
	- Add scripts/utf8.test.pl to the list of scripts shipped with this module.
	- Add scripts/utf8* to scripts/generate.*.sh.
	- Make scripts/generate.*.sh emit a warning when DBI_DSN is not set.

2.01  Wed Mar  7 08:50:00 2012
	  - I only tested V 2.00 by outputting to SVG (a text format), but outputting to a binary format such as PNG was broken.
	  	So, remove the 'use open qw/:encoding(UTF-8) :std/;', and restore binmode, in GraphViz2.pm.
	  - Remove log to screen in utf8.pl, since Log::Handler doesn't accept utf8 as a logger option.
	  - Copy scripts/utf8.pl to scripts/utf8.test.pl and edit to display just 5 delta characters. See html/utf8.test.svg. PNG is ok too.
		This demonstrates (hopefully) we can get the correct output on a binary format despite the 'Wide character in print...' message.
	  - Add FAQ topic regarding this 'Wide character in print...' problem.

2.00  Tue Mar  6 16:02:00 2012
	  - Support utf8 in labels. This required changes to GraphViz2.pm. See scripts/utf8.pl and html/utf8.svg. I'm using Perl V 5.14.2.
	  	Sample output is online at http://savage.net.au/Perl-modules/html/graphviz2/utf8.svg.
	  - Add an item to the FAQ about how to write scripts using utf8.
	  - Re-write GraphViz2::Parse::ISA to draw multiple class hierarchies on 1 graph. This means the API for that class has changed.
	  	Specifically, create() no longer exists. Call add() 1 or more times instead. Then, call generate_graph(). See the docs for details.
		Sample output is online at http://savage.net.au/Perl-modules/html/graphviz2/parse.isa.svg.

1.13  Sun Dec 25 10:33:00 2011
	  - Change <img...> to <object...> in the demo creation code, to keep poor old FireFox happy.
	  - Change various things in html/graphviz2.index.tx to we validate as XHTML 1.0 Strict.
	  - Unreleased.

1.12  Wed Dec 14 11:22:00 2011
	  - Add 5 scripts, scripts/macro.*.pl, to demonstrate using a Perl sub as a macro to generate both cluster and non-cluster sub-graphs.
	  - Update the TODO in GraphViz2.pm, since it erroneously gave the impression the current code did not handle compound clusters.
	  - Re-generate the demo. See: http://savage.net.au/Perl-modules/html/graphviz2/.
	  - Adopt Flavio Poletti's suggestion of trying to pipe to dot, in Build.PL/Makefile.PL, rather than using File::Which,
	  	to see if dot (Graphviz) is installed. This (hopefully) solves the problem of using File::Which on systems where it is
		not installed, before Build.PL/Makefile.PL has a chance to tell the user that File::Which is required. See: RT#73077.
	  - No code changes in *.pm files.

1.11  Tue Nov  8 10:21:00 2011
	  - Fix bug where double quotes in HTML labels were being escaped and should not have been.
	  	Many thanx to Fitz Elliott for the report and initial patch. See https://rt.cpan.org/Ticket/Display.html?id=72259.
	  - Patched scripts/html.labels.pl as per Fitz's suggested test code.
	  - Rename t/lib/Parent.pm to t/lib/Adult.pm to avoid a reported problem with "use parent 'Parent';" under Windows.
	  	This affect various files. See https://rt.cpan.org/Public/Bug/Display.html?id=69076.

1.10  Thu Sep  1 10:45:00 2011
	  - Fix bug in GraphViz in handling of nodes whose shape is none or plaintext, and whose label is HTML.
	  - Fix bug in scripts/generate.png.sh to add png parameter to 'perl -Ilib scripts/generate.demo.pl png'.
	  - HTML labels work without any code changes, so references to them not working have been removed from the docs.
	  - GraphViz2 is called by the now-released Graph::Easy::Marpa, so remove that item from the TODO list.
	  - Fix doc referring to scripts/generate.index.pl. It now refers to scripts/generate.demo.pl.
	  - Add DOCTYPE and Content-type to html/graphviz.index.tx. Output by scripts/generate.demo.pl, html/index.html, now handles UTF-8 properly.
	  - Add alt to the <img ...> tags output by scripts/generate.demo.pl.
	  - Add scripts/html.labels.pl. This code includes a demo of using ports.
	  - Reorder methods in GraphViz2::Utils to be in alphabetical order.

1.09  Thu Jul 21 14:13:00 2011
	  - Patch parameter validation to allow for output image types such as png:gd etc.
	  	Only the prefix before the first ':' is validated.

1.08  Thu Jul 21 11:53:00 2011
	  - Change the behaviour of sub log() in GraphViz.pm. Now if called with $level eq 'error', it dies with $message.
	  - Change references to the color darkblue to blue, so it's compatible with both the X11 and SVG color schemes.
	  - Likewise change chartreuse to lawngreen.
	  - Rename scripts/generate.index.pl to scripts/generate.demo.pl, as a more meaningful name.
	  - Patch scripts/generate.demo.pl to accept the output image type as a command line parameter.
	  - Use this new feature to generate png files, and upload them to the demo site
	  	http://savage.net.au/Perl-modules/html/graphviz2/ even though png is often uglier than svg.
		I did this because Iceweasel (Firefox) V 3.5.16 was not displaying svgs within the index file,
		even though they are fine when displayed directly.
	  - Add scripts/generate.png.sh.
	  - Note: scripts/jointed.edges.pl must call dot with -Tpng:gd and not -Tpng, for unknown reasons.
	  - Make both scripts/generate.png.sh and scripts/generate.svg.sh redirect their log files to /tmp,
	  	so that we don't have to ship the logs, and also so they don't keep changing and hence need checking in.
	  - Remove ./dbi.schema.log from the distro.

1.07  Mon Jul  4 15:46:00 2011
	  - Use Date::Format to add a date stamp at the end of html/index.html, as output by generate.index.pl.

1.06  Tue Jun 28 11:10:00 2011
	  - Change usage of File::Temp -> newdir to fix problems testing on BSD-based systems.
	  - Add scripts/jointed.edges.pl.
	  	This demo - in Graph::Easy syntax - ships with Graph::Easy::Marpa.
	  - Re-write generate.index.pl to put all demo data (where available) and images on 1 page.
	  - Upload demo to (new location) http://savage.net.au/Perl-modules/html/graphviz2/index.html.

1.05  Fri Jun 24 12:40:00 2011
	  - Implement GraphViz2::Parse::Marpa, along with scripts/parse.marpa.pl and t/sample.marpa.1.dat.
	  	The output is html/parse.marpa.svg.
	  - Implement GraphViz2::Parse::STT, along with scripts/parse.stt.pl and t/sample.stt.1.dat.
	  	The output is html/parse.stt.svg.
	  - Add use File::Spec to t/test.t

1.04  Wed Jun 22  9:36:00 2011
	  - Reduce required version of File::Basename to 2.77, which came with Perl 5.10.1.
	  - Stop trying to write to t/html/, and use File::Temp for a directory instead.
	  	That way, it doesn't matter who owns t/html/, nor whether or not it's writable.

1.03  Sun Jun 19 16:27:00 2011
	  - Tweak File::Temp -> new to be File::Temp ->new(EXLOCK => 0) for BSD-based systems.

1.02  Fri Jun 17  8:36:00 2011
	  - Add the pre-requisite Log::Handler to Build.PL and Makefile.PL.
	  - Release HTML::Entities::Interpolate V 1.04 and Set::Array V 0.23 to CPAN.
	  - Add README file.
	  - Clean up TODO list.

1.01  Wed Jun 15 15:00:00 2011
	  - Quote cluster/subgraph names so they may contain weird characters.
	  - Add method dependency(data => $depend) to GraphViz2.pm, which accepts an object of type
	  	Algorithm::Dependency. See scripts/dependency.pl and html/dependency.svg.
	  - Add GraphViz2::Parse::ISA, and scripts/parse.isa.pl, and the t/lib/Parent hierarchy.

1.00  Wed Jun 15 14:26:00 2011
	  - This is a re-write of GraphViz. The method parameter lists are incompatible.
	  	Sorry, but it now supports all options and attributes in Graphviz V 2.23.6.
	  - Rewrite GraphViz, GraphViz::Data::Grapher, GraphViz::Parse::RecDescent, GraphViz::Parse::Yacc and GraphViz::Parse::Yapp.
	  	The core code of *::RecDescent, *::Yacc and *::Yapp has been copied from GraphViz, with tiny changes.
	  - GraphViz2::Data::Grapher uses Tree::DAG_Node to hold information, before calling external plotting programs.
	  	The tree is available for you to process whether or not you actually plot the graph.
	  - GraphViz::Regex renamed GraphViz2::Parse::Regexp.
	  - GraphViz::XML renamed GraphViz2::Parse::XML. And it uses XML::Tiny by default.
	  	One demo shows how to use XML::Bare instead.
	  - All new documentation.
	  - All new demos, in scripts/*.pl. These are documented in GraphViz's POD.
	  - All demo output included, in html/*.html and html/*.svg.