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1 | # Copyright (C) 2001, 2002, 2007 Sam Vilain. All Rights Reserved. | |
2 | # This module is free software. It may be used, redistributed and/or | |
3 | # modified under the terms of the Perl Artistic License, version 2 or | |
4 | # later, OR the terms of the GNU General Public License, v3 or later. | |
5 | ||
6 | package Pod::Constants; | |
7 | ||
8 | use 5.004; | |
9 | use strict; | |
10 | ||
11 | use base qw(Pod::Parser Exporter); | |
12 | use Data::Dumper; | |
13 | use Carp; | |
14 | ||
15 | use vars qw($VERSION); | |
16 | $VERSION = 0.17; | |
17 | ||
18 | # An ugly hack to go from caller() to the relevant parser state | |
19 | # variable | |
20 | my %parsers; | |
21 | ||
22 | sub end_input { | |
23 | #my ($parser, $command, $paragraph, $line_num) = (@_); | |
24 | my $parser = shift; | |
25 | ||
26 | return unless $parser->{active}; | |
27 | ||
28 | print "Found end of $parser->{active}\n" if ($parser->{DEBUG}); | |
29 | my $whereto = $parser->{wanted_pod_tags}->{$parser->{active}}; | |
30 | print "\$_ will be set to:\n---\n$parser->{paragraphs}\n---\n" | |
31 | if ($parser->{DEBUG}); | |
32 | ||
33 | $parser->{paragraphs} =~ s/^\s*|\s*$//gs | |
34 | if $parser->{trimmed_tags}->{$parser->{active}}; | |
35 | ||
36 | if (ref $whereto eq "CODE") { | |
37 | print "calling sub\n" if $parser->{DEBUG}; | |
38 | local ($_) = $parser->{paragraphs}; | |
39 | $whereto->(); | |
40 | print "done\n" if $parser->{DEBUG}; | |
41 | } elsif (ref $whereto eq "SCALAR") { | |
42 | print "inserting into scalar\n" if $parser->{DEBUG}; | |
43 | $$whereto = $parser->{paragraphs}; | |
44 | } elsif (ref $whereto eq "ARRAY") { | |
45 | print "inserting into array\n" if $parser->{DEBUG}; | |
46 | @$whereto = split /\n/, $parser->{paragraphs}; | |
47 | } elsif (ref $whereto eq "HASH") { | |
48 | print "inserting into hash\n" if $parser->{DEBUG}; | |
49 | # Oh, sorry, should I be in LISP101? | |
50 | %$whereto = (map { map { s/^\s*|\s*$//g; $_ } | |
51 | split /=>/, $_ } | |
52 | grep m/^ | |
53 | ( (?:[^=]|=[^>])+ ) # scan up to "=>" | |
54 | => | |
55 | ( (?:[^=]|=[^>])+ =? )# don't allow more "=>"'s | |
56 | $/x, | |
57 | split /\n/, $parser->{paragraphs}); | |
58 | } else { die $whereto } | |
59 | $parser->{active} = undef; | |
60 | } | |
61 | ||
62 | # Pod::Parser overloaded command | |
63 | sub command { | |
64 | my ($parser, $command, $paragraph, $line_num) = @_; | |
65 | ||
66 | $paragraph =~ s/(?:\r\n|\n\r)/\n/g; | |
67 | ||
68 | print "Got command =$command, value=$paragraph\n" | |
69 | if $parser->{DEBUG}; | |
70 | ||
71 | $parser->end_input() if $parser->{active}; | |
72 | ||
73 | my $does_she_want_it_sir; | |
74 | ||
75 | my ($lookup); | |
76 | # first check for a catch-all for this command type | |
77 | if ( exists $parser->{wanted_pod_tags}->{"*$command"} ) { | |
78 | $parser->{paragraphs} = $paragraph; | |
79 | $parser->{active} = "*$command"; | |
80 | $does_she_want_it_sir = "oohw"; | |
81 | ||
82 | } elsif ($command =~ m/^(head\d+|item|(for|begin))$/) { | |
83 | if ( $2 ) { | |
84 | # if it's a "for" or "begin" section, the title is the | |
85 | # first word only | |
86 | ($lookup, $parser->{paragraphs}) = | |
87 | ($paragraph =~ m/^\s*(\S*)\s*(.*)/s); | |
88 | } else { | |
89 | # otherwise, it's up to the end of the line | |
90 | ($lookup, $parser->{paragraphs}) | |
91 | = ($paragraph =~ m/^\s*(\S[^\n]*?)\s*\n(.*)$/s); | |
92 | } | |
93 | ||
94 | # Look for a match by name | |
95 | if (defined $lookup | |
96 | and exists $parser->{wanted_pod_tags}->{$lookup}) { | |
97 | print "Found $lookup\n" if ($parser->{DEBUG}); | |
98 | $parser->{active} = $lookup; | |
99 | $does_she_want_it_sir = "suits you sir"; | |
100 | } | |
101 | ||
102 | } else { | |
103 | # nothing | |
104 | print "Ignoring =$command (not known)\n" if $parser->{DEBUG}; | |
105 | } | |
106 | ||
107 | { | |
108 | local $^W = 0; | |
109 | print "Ignoring =$command $paragraph (lookup = $lookup)\n" | |
110 | if (!$does_she_want_it_sir and $parser->{DEBUG}) | |
111 | } | |
112 | } | |
113 | ||
114 | # Pod::Parser overloaded verbatim | |
115 | sub verbatim { | |
116 | my ($parser, $paragraph, $line_num) = @_; | |
117 | $paragraph =~ s/(?:\r\n|\n\r)/\n/g; | |
118 | ||
119 | print("Got paragraph: $paragraph (" | |
120 | .($parser->{active}?"using":"ignoring").")\n") | |
121 | if $parser->{DEBUG}; | |
122 | ||
123 | if (defined $parser->{active}) { | |
124 | $parser->{paragraphs} .= $paragraph; | |
125 | } | |
126 | } | |
127 | ||
128 | # Pod::Parser overloaded textblock | |
129 | sub textblock { goto \&verbatim } | |
130 | ||
131 | sub import { | |
132 | my $class = shift; | |
133 | ||
134 | # if no args, just return | |
135 | return unless (@_); | |
136 | ||
137 | # try to guess the source file of the caller | |
138 | my $source_file; | |
139 | if (caller ne "main") { | |
140 | (my $module = caller().".pm") =~ s|::|/|g; | |
141 | $source_file = $INC{$module}; | |
142 | } | |
143 | $source_file ||= $0; | |
144 | ||
145 | ( -f $source_file ) | |
146 | or croak ("Cannot find source file (guessed $source_file) for" | |
147 | ." package ".caller()); | |
148 | ||
149 | # nasty tricks with the stack so we don't have to be silly with | |
150 | # caller() | |
151 | unshift @_, $source_file; | |
152 | goto \&import_from_file; | |
153 | } | |
154 | ||
155 | use IO::Handle; | |
156 | ||
157 | sub import_from_file { | |
158 | my $filename = shift; | |
159 | ||
160 | my $parser = __PACKAGE__->new(); | |
161 | ||
162 | $parser->{wanted_pod_tags} = {}; | |
163 | $parser->{trimmed_tags} = {}; | |
164 | $parser->{trim_next} = 0; | |
165 | $parser->{DEBUG} = 0; | |
166 | $parser->{active} = undef; | |
167 | $parsers{caller()} = $parser; | |
168 | ||
169 | $parser->add_hook(@_); | |
170 | ||
171 | print "Pod::Parser: DEBUG: Opening $filename for reading\n" | |
172 | if $parser->{DEBUG}; | |
173 | my $fh = new IO::Handle; | |
174 | open $fh, "<$filename" | |
175 | or die ("cannot open $filename for reading; $!"); | |
176 | ||
177 | $parser->parse_from_filehandle($fh, \*STDOUT); | |
178 | ||
179 | close $fh; | |
180 | } | |
181 | ||
182 | sub add_hook { | |
183 | my $parser; | |
184 | if ( UNIVERSAL::isa($_[0], __PACKAGE__) ) { | |
185 | $parser = shift; | |
186 | } else { | |
187 | $parser = $parsers{caller()} | |
188 | or die("add_hook called, but don't know what for - " | |
189 | ."caller = ".caller()); | |
190 | } | |
191 | while (my ($pod_tag, $var) = splice @_, 0, 2) { | |
192 | #print "$pod_tag: $var\n"; | |
193 | if (lc($pod_tag) eq "-trim") { | |
194 | $parser->{trim_next} = $var; | |
195 | } elsif ( lc($pod_tag) eq "-debug" ) { | |
196 | $parser->{DEBUG} = $var; | |
197 | } elsif (lc($pod_tag) eq "-usage") { | |
198 | # an idea for later - automatic "usage" | |
199 | #%wanted_pod_tags{@tags} | |
200 | } else { | |
201 | if ((ref $var) =~ /^(?:SCALAR|CODE|ARRAY|HASH)$/) { | |
202 | print "Will look for $pod_tag.\n" | |
203 | if ($parser->{DEBUG}); | |
204 | $parser->{wanted_pod_tags}->{$pod_tag} = $var; | |
205 | $parser->{trimmed_tags}->{$pod_tag} = 1 | |
206 | if $parser->{trim_next}; | |
207 | } else { | |
208 | die ("Sorry - need a reference to import POD " | |
209 | ."sections into, not the scalar value $var" | |
210 | ." importing $pod_tag into ".caller()); | |
211 | } | |
212 | } | |
213 | } | |
214 | } | |
215 | ||
216 | sub delete_hook { | |
217 | my $parser; | |
218 | if ( UNIVERSAL::isa($_[0], __PACKAGE__) ) { | |
219 | $parser = shift; | |
220 | } else { | |
221 | $parser = $parsers{caller()} | |
222 | or die("delete_hook called, but don't know what for - " | |
223 | ."caller = ".caller()); | |
224 | } | |
225 | while ( my $label = shift ) { | |
226 | delete $parser->{wanted_pod_tags}->{$label}; | |
227 | delete $parser->{trimmed_tags}->{$label}; | |
228 | } | |
229 | } | |
230 | ||
231 | BEGIN { | |
232 | Pod::Constants->import | |
233 | ( | |
234 | SYNOPSIS => sub { | |
235 | eval pop @{[ grep /^\s*\$VERSION/, split /\n/, $_ ]} | |
236 | } | |
237 | ) | |
238 | }; | |
239 | ||
240 | 1.4142; | |
241 | __END__ | |
242 | ||
243 | =encoding utf-8 | |
244 | ||
245 | =head1 NAME | |
246 | ||
247 | Pod::Constants - Include constants from POD | |
248 | ||
249 | =head1 SYNOPSIS | |
250 | ||
251 | use vars qw($myvar $VERSION @myarray $html %myhash); | |
252 | ||
253 | use Pod::Constants -trim => 1, | |
254 | 'Pod Section Name' => \$myvar, | |
255 | 'Version' => sub { eval }, | |
256 | 'Some list' => \@myarray, | |
257 | html => \$html, | |
258 | 'Some hash' => \%myhash; | |
259 | ||
260 | =head2 Pod Section Name | |
261 | ||
262 | This string will be loaded into $myvar | |
263 | ||
264 | =head2 Version | |
265 | ||
266 | # This is an example of using a closure. $_ is set to the | |
267 | # contents of the paragraph. In this example, "eval" is | |
268 | # used to execute this code at run time. | |
269 | $VERSION = 0.17; | |
270 | ||
271 | =head2 Some list | |
272 | ||
273 | Each line from this section of the file | |
274 | will be placed into a separate array element. | |
275 | For example, this is $myarray[2]. | |
276 | ||
277 | =head2 Some hash | |
278 | ||
279 | This text will not go into the hash, because | |
280 | it doesn't look like a definition list. | |
281 | key1 => Some value (this will go into the hash) | |
282 | var2 => Some Other value (so will this) | |
283 | wtf = This won't make it in. | |
284 | ||
285 | =head2 %myhash's value after the above: | |
286 | ||
287 | ( key1 => "Some value (this will go into the hash)", | |
288 | var2 => "Some Other value (so will this)" ) | |
289 | ||
290 | =begin html <p>This text will be in $html</p> | |
291 | ||
292 | =cut | |
293 | ||
294 | =head1 DESCRIPTION | |
295 | ||
296 | This module allows you to specify those constants that should be | |
297 | documented in your POD, and pull them out a run time in a fairly | |
298 | arbitrary fashion. | |
299 | ||
300 | Pod::Constants uses Pod::Parser to do the parsing of the source file. | |
301 | It has to open the source file it is called from, and does so directly | |
302 | either by lookup in %INC or by assuming it is $0 if the caller is | |
303 | "main" (or it can't find %INC{caller()}) | |
304 | ||
305 | =head2 ARBITARY DECISIONS | |
306 | ||
307 | I have made this code only allow the "Pod Section Name" to match | |
308 | `headN', `item', `for' and `begin' POD sections. If you have a good | |
309 | reason why you think it should match other POD sections, drop me a | |
310 | line and if I'm convinced I'll put it in the standard version. | |
311 | ||
312 | For `for' and `begin' sections, only the first word is counted as | |
313 | being a part of the specifier, as opposed to `headN' and `item', where | |
314 | the entire rest of the line counts. | |
315 | ||
316 | =head1 FUNCTIONS | |
317 | ||
318 | =head2 import(@args) | |
319 | ||
320 | This function is called when we are "use"'d. It determines the source | |
321 | file by inspecting the value of caller() or $0. | |
322 | ||
323 | The form of @args is HOOK => $where. | |
324 | ||
325 | $where may be a scalar reference, in which case the contents of the | |
326 | POD section called "HOOK" will be loaded into $where. | |
327 | ||
328 | $where may be an array reference, in which case the contents of the | |
329 | array will be the contents of the POD section called "HOOK", split | |
330 | into lines. | |
331 | ||
332 | $where may be a hash reference, in which case any lines with a "=>" | |
333 | symbol present will have everything on the left have side of the => | |
334 | operator as keys and everything on the right as values. You do not | |
335 | need to quote either, nor have trailing commas at the end of the | |
336 | lines. | |
337 | ||
338 | $where may be a code reference (sub { }), in which case the sub is | |
339 | called when the hook is encountered. $_ is set to the value of the | |
340 | POD paragraph. | |
341 | ||
342 | You may also specify the behaviour of whitespace trimming; by default, | |
343 | no trimming is done except on the HOOK names. Setting "-trim => 1" | |
344 | turns on a package "global" (until the next time import is called) | |
345 | that will trim the $_ sent for processing by the hook processing | |
346 | function (be it a given function, or the built-in array/hash | |
347 | splitters) for leading and trailing whitespace. | |
348 | ||
349 | The name of HOOK is matched against any "=head1", "=head2", "=item", | |
350 | "=for", "=begin" value. If you specify the special hooknames "*item", | |
351 | "*head1", etc, then you will get a function that is run for every | |
352 | ||
353 | Note that the supplied functions for array and hash splitting are | |
354 | exactly equivalent to fairly simple Perl blocks: | |
355 | ||
356 | Array: | |
357 | ||
358 | HOOK => sub { @array = split /\n/, $_ } | |
359 | ||
360 | Hash: | |
361 | ||
362 | HOOK => sub { | |
363 | %hash = | |
364 | (map { map { s/^\s+|\s+$//g; $_ } split /=>/, $_ } | |
365 | (grep m/^ | |
366 | ( (?:[^=]|=[^>])+ ) # scan up to "=>" | |
367 | => | |
368 | ( (?:[^=]|=[^>])+ =? )# don't allow more "=>"'s | |
369 | $/x, split /\n/, $_)); | |
370 | } | |
371 | ||
372 | Well, they're simple if you can grok map, a regular expression like | |
373 | that and a functional programming style. If you can't I'm sure it is | |
374 | probably voodoo to you. | |
375 | ||
376 | Here's the procedural equivalent: | |
377 | ||
378 | HOOK => sub { | |
379 | for my $line (split /\n/, $_) { | |
380 | my ($key, $value, $junk) = split /=>/, $line; | |
381 | next if $junk; | |
382 | $key =~ s/^\s+|\s+$//g | |
383 | $value =~ s/^\s+|\s+$//g | |
384 | $hash{$key} = $value; | |
385 | } | |
386 | }, | |
387 | ||
388 | =head2 import_from_file($filename, @args) | |
389 | ||
390 | Very similar to straight "import", but you specify the source filename | |
391 | explicitly. | |
392 | ||
393 | =head2 add_hook(NAME => value) | |
394 | ||
395 | This function adds another hook, it is useful for dynamic updating of | |
396 | parsing through the document. | |
397 | ||
398 | For an example, please see t/01-constants.t in the source | |
399 | distribution. More detailed examples will be added in a later | |
400 | release. | |
401 | ||
402 | =head2 delete_hook(@list) | |
403 | ||
404 | Deletes the named hooks. Companion function to add_hook | |
405 | ||
406 | =head2 CLOSURES AS DESTINATIONS | |
407 | ||
408 | If the given value is a ref CODE, then that function is called, with | |
409 | $_ set to the value of the paragraph. This can be very useful for | |
410 | applying your own custom mutations to the POD to change it from human | |
411 | readable text into something your program can use. | |
412 | ||
413 | After I added this function, I just kept on thinking of cool uses for | |
414 | it. The nice, succinct code you can make with it is one of | |
415 | Pod::Constant's strongest features. | |
416 | ||
417 | Below are some examples. | |
418 | ||
419 | =head1 EXAMPLES | |
420 | ||
421 | =head2 Module Makefile.PL maintenance | |
422 | ||
423 | Tired of keeping those module Makefile.PL's up to date? Note: This | |
424 | method seems to break dh-make-perl. | |
425 | ||
426 | =head2 Example Makefile.PL | |
427 | ||
428 | eval "use Pod::Constants"; | |
429 | ($Pod::Constants::VERSION >= 0.11) | |
430 | or die <<EOF | |
431 | #### | |
432 | #### ERROR: This module requires Pod::Constants 0.11 or | |
433 | #### higher to be installed. | |
434 | #### | |
435 | EOF | |
436 | ||
437 | my ($VERSION, $NAME, $PREREQ_PM, $ABSTRACT, $AUTHOR); | |
438 | Pod::Constants::import_from_file | |
439 | ( | |
440 | 'MyTestModule.pm', | |
441 | 'MODULE RELEASE' => sub { ($VERSION) = m/(\d+\.\d+)/ }, | |
442 | 'DEPENDENCIES' => ($PREREQ_PM = { }), | |
443 | -trim => 1, | |
444 | 'NAME' => sub { $ABSTRACT=$_; ($NAME) = m/(\S+)/ }, | |
445 | 'AUTHOR' => \$AUTHOR, | |
446 | ); | |
447 | ||
448 | WriteMakefile | |
449 | ( | |
450 | 'NAME' => $NAME, | |
451 | 'PREREQ_PM' => $PREREQ_PM, | |
452 | 'VERSION' => $VERSION, | |
453 | ($] >= 5.005 ? ## Add these new keywords supported since 5.005 | |
454 | (ABSTRACT => $ABSTRACT, | |
455 | AUTHOR => $AUTHOR) : ()), | |
456 | ); | |
457 | ||
458 | =head2 Corresponding Module | |
459 | ||
460 | =head1 NAME | |
461 | ||
462 | MyTestModule - Demonstrate Pod::Constant's Makefile.PL usefulness | |
463 | ||
464 | =head2 MODULE RELEASE | |
465 | ||
466 | This is release 1.05 of this module. | |
467 | ||
468 | =head2 DEPENDENCIES | |
469 | ||
470 | The following modules are required to make this module: | |
471 | ||
472 | Some::Module => 0.02 | |
473 | ||
474 | =head2 AUTHOR | |
475 | ||
476 | Ima Twat <ima@twat.name> | |
477 | ||
478 | =cut | |
479 | ||
480 | use vars qw($VERSION); | |
481 | use Pod::Constants -trim => 1, | |
482 | 'MODULE RELEASE' => sub { ($VERSION) = m/(\d+\.\d+) or die }; | |
483 | ||
484 | =head1 AUTHOR | |
485 | ||
486 | Sam Vilain, <samv@cpan.org> | |
487 | ||
488 | =head1 BUGS/TODO | |
489 | ||
490 | I keep thinking it would be nice to be able to import an =item list | |
491 | into an array or something, eg for a program argument list. But I'm | |
492 | not too sure how it would be all that useful in practice; you'd end up | |
493 | putting the function names for callbacks in the pod or something | |
494 | (perhaps not all that bad). | |
495 | ||
496 | Would this be useful? | |
497 | ||
498 | Pod::Constants::import(Foo::SECTION => \$myvar); | |
499 | ||
500 | Debug output is not very readable | |
501 | ||
502 | =head1 PATCHES WELCOME | |
503 | ||
504 | If you have any suggestions for enhancements, they are much more likely | |
505 | to happen if you submit them as a patch to the distribution. | |
506 | ||
507 | Source is kept at | |
508 | ||
509 | git://utsl.gen.nz/Pod-Constants | |
510 | ||
511 | ||
512 | =cut |