Add patch

doc/todo/automatic_use_of_syntax_plugin_on_source_code_files/discussion.mdwn

@@ -0,0 +1,159 @@
+Here is another [[patch]] for this.  It is more up to date than either of the patches linked on the previous page.  It is most similar to [[plugins/contrib/sourcehighlight]].
+
+Note that if this is being used with `c` or `c++` then you'll probably want to wait until [[bugs/multiple_pages_with_same_name]] is fixed.
+
+-- [[Will]]
+
+----
+
+    #!/usr/bin/perl
+    # markup source files
+    package IkiWiki::Plugin::sourcecode;
+    
+    use warnings;
+    use strict;
+    use IkiWiki 2.00;
+    use open qw{:utf8 :std};
+    
+    my %metaheaders;
+    
+    sub import { #{{{
+    	hook(type => "getsetup", id => "sourcecode", call => \&getsetup);
+    	hook(type => "checkconfig", id => "sourcecode", call => \&checkconfig);
+    	hook(type => "pagetemplate", id => "sourcecode", call => \&pagetemplate);
+    } # }}}
+    
+    sub getsetup () { #{{{
+    	return 
+    		plugin => {
+    			safe => 1,
+    			rebuild => 1, # format plugin
+    		},
+    		sourcecode_command => {
+    			type => "string",
+    			example => "/usr/bin/source-highlight",
+    			description => "The command to execute to run source-highlight",
+    			safe => 0,
+    			rebuild => 1,
+    		},
+    		sourcecode_lang => {
+    			type => "string",
+    			example => "c,cpp,h,java",
+    			description => "Comma separated list of suffixes to recognise as source code",
+    			safe => 1,
+    			rebuild => 1,
+    		},
+    		sourcecode_linenumbers => {
+    			type => "boolean",
+    			example => 1,
+    			description => "Should we add line numbers to the source code",
+    			safe => 1,
+    			rebuild => 1,
+    		},
+    		sourcecode_css => {
+    			type => "string",
+    			example => "sourcecode_style",
+    			description => "page to use as css file for source",
+    			safe => 1,
+    			rebuild => 1,
+    		},
+    } #}}}
+    
+    sub checkconfig () { #{{{
+    	if (! $config{sourcecode_lang}) {
+    		error("The sourcecode plugin requires a list of suffixes in the 'sourcecode_lang' config option");
+    	}
+    	
+    	if (! $config{sourcecode_command}) {
+    		$config{sourcecode_command} = "source-highlight";
+    	}
+    	
+    	if (! length `which $config{sourcecode_command} 2>/dev/null`) {
+    		error("The sourcecode plugin is unable to find the $config{sourcecode_command} command");
+    	}
+    
+    	if (! $config{sourcecode_css}) {
+    		$config{sourcecode_css} = "sourcecode_style";
+    	}
+    	
+    	if (! defined $config{sourcecode_linenumbers}) {
+    		$config{sourcecode_linenumbers} = 1;
+    	}
+    	
+    	my %langs = ();
+    	
+    	open(LANGS, "$config{sourcecode_command} --lang-list|");
+    	while (<LANGS>) {
+    		if ($_ =~ /(\w+) = .+\.lang/) {
+    			$langs{$1} = 1;
+    		}
+    	}
+    	close(LANGS);
+    	
+    	foreach my $lang (split(/[, ]+/, $config{sourcecode_lang})) {
+    		if ($langs{$lang}) {
+    			hook(type => "htmlize", id => $lang, call => \&htmlize);
+    		} else {
+    			error("Your installation of source-highlight cannot handle sourcecode language $lang!");
+    		}
+    	}
+    } #}}}
+    
+    sub htmlize (@) { #{{{
+    	my %params=@_;
+    
+    	my $page = $params{page};
+    
+    	eval q{use FileHandle};
+    	error($@) if $@;
+    	eval q{use IPC::Open2};
+    	error($@) if $@;
+    
+    	local(*SPS_IN, *SPS_OUT);  # Create local handles
+    
+    	my @args;
+    
+    	if ($config{sourcecode_linenumbers}) {
+    		push @args, '--line-number= ';
+    	}
+    
+    	my $pid = open2(*SPS_IN, *SPS_OUT, $config{sourcecode_command},
+    					'-s', IkiWiki::pagetype($pagesources{$page}),
+    					'-c', $config{sourcecode_css}, '--no-doc',
+    					'-f', 'xhtml',
+    					@args);
+    
+    	error("Unable to open $config{sourcecode_command}") unless $pid;
+    
+    	print SPS_OUT $params{content};
+    	close SPS_OUT;
+    
+    	my @html = <SPS_IN>;
+    	close SPS_IN;
+    	
+    	waitpid $pid, 0;
+    
+    	my $stylesheet=bestlink($page, $config{sourcecode_css}.".css");
+    	if (length $stylesheet) {
+    		push @{$metaheaders{$page}}, '<link href="'.urlto($stylesheet, $page).'"'.
+    			' rel="stylesheet"'.
+    			' type="text/css" />';
+    	}
+    
+    	return '<div id="sourcecode">'."\r\n".join("\r\n",@html)."\r\n</div>\n";
+    } # }}}
+    
+    sub pagetemplate (@) { #{{{
+    	my %params=@_;
+    
+    	my $page=$params{page};
+    	my $template=$params{template};
+    
+    	if (exists $metaheaders{$page} && $template->query(name => "meta")) {
+    		# avoid duplicate meta lines
+    		my %seen;
+    		$template->param(meta => join("\n", grep { (! $seen{$_}) && ($seen{$_}=1) } @{$metaheaders{$page}}));
+    	}
+    } # }}}
+    
+    1