]>
Commit | Line | Data |
---|---|---|
f46dd377 MG |
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 | =head1 NAME | |
9 | ||
10 | Pod::Constants - Include constants from POD | |
11 | ||
12 | =head1 SYNOPSIS | |
13 | ||
14 | use vars qw($myvar $VERSION @myarray $html %myhash); | |
15 | ||
16 | use Pod::Constants -trim => 1, | |
17 | 'Pod Section Name' => \$myvar, | |
18 | 'Version' => sub { eval }, | |
19 | 'Some list' => \@myarray, | |
20 | html => \$html, | |
21 | 'Some hash' => \%myhash; | |
22 | ||
23 | =head2 Pod Section Name | |
24 | ||
25 | This string will be loaded into $myvar | |
26 | ||
27 | =head2 Version | |
28 | ||
29 | # This is an example of using a closure. $_ is set to the | |
30 | # contents of the paragraph. In this example, "eval" is | |
31 | # used to execute this code at run time. | |
32 | $VERSION = 0.17; | |
33 | ||
34 | =head2 Some list | |
35 | ||
36 | Each line from this section of the file | |
e18addae | 37 | will be placed into a separate array element. |
f46dd377 MG |
38 | For example, this is $myarray[2]. |
39 | ||
40 | =head2 Some hash | |
41 | ||
42 | This text will not go into the hash, because | |
43 | it doesn't look like a definition list. | |
44 | key1 => Some value (this will go into the hash) | |
45 | var2 => Some Other value (so will this) | |
46 | wtf = This won't make it in. | |
47 | ||
48 | =head2 %myhash's value after the above: | |
49 | ||
50 | ( key1 => "Some value (this will go into the hash)", | |
51 | var2 => "Some Other value (so will this)" ) | |
52 | ||
53 | =begin html <p>This text will be in $html</p> | |
54 | ||
55 | =cut | |
56 | ||
57 | =head1 DESCRIPTION | |
58 | ||
59 | This module allows you to specify those constants that should be | |
60 | documented in your POD, and pull them out a run time in a fairly | |
61 | arbitrary fashion. | |
62 | ||
63 | Pod::Constants uses Pod::Parser to do the parsing of the source file. | |
64 | It has to open the source file it is called from, and does so directly | |
65 | either by lookup in %INC or by assuming it is $0 if the caller is | |
66 | "main" (or it can't find %INC{caller()}) | |
67 | ||
68 | =head2 ARBITARY DECISIONS | |
69 | ||
70 | I have made this code only allow the "Pod Section Name" to match | |
71 | `headN', `item', `for' and `begin' POD sections. If you have a good | |
72 | reason why you think it should match other POD sections, drop me a | |
73 | line and if I'm convinced I'll put it in the standard version. | |
74 | ||
75 | For `for' and `begin' sections, only the first word is counted as | |
76 | being a part of the specifier, as opposed to `headN' and `item', where | |
77 | the entire rest of the line counts. | |
78 | ||
79 | =cut | |
80 | ||
81 | use 5.004; | |
82 | use strict; | |
83 | ||
84 | use base qw(Pod::Parser Exporter); | |
85 | use Data::Dumper; | |
86 | use Carp; | |
87 | ||
88 | use vars qw($VERSION); | |
89 | $VERSION = 0.17; | |
90 | ||
91 | # An ugly hack to go from caller() to the relevant parser state | |
92 | # variable | |
93 | my %parsers; | |
94 | ||
95 | sub end_input { | |
96 | #my ($parser, $command, $paragraph, $line_num) = (@_); | |
97 | my $parser = shift; | |
98 | ||
99 | return unless $parser->{active}; | |
100 | ||
101 | print "Found end of $parser->{active}\n" if ($parser->{DEBUG}); | |
102 | my $whereto = $parser->{wanted_pod_tags}->{$parser->{active}}; | |
103 | print "\$_ will be set to:\n---\n$parser->{paragraphs}\n---\n" | |
104 | if ($parser->{DEBUG}); | |
105 | ||
106 | $parser->{paragraphs} =~ s/^\s*|\s*$//gs | |
107 | if $parser->{trimmed_tags}->{$parser->{active}}; | |
108 | ||
109 | if (ref $whereto eq "CODE") { | |
110 | print "calling sub\n" if $parser->{DEBUG}; | |
111 | local ($_) = $parser->{paragraphs}; | |
112 | $whereto->(); | |
113 | print "done\n" if $parser->{DEBUG}; | |
114 | } elsif (ref $whereto eq "SCALAR") { | |
115 | print "inserting into scalar\n" if $parser->{DEBUG}; | |
116 | $$whereto = $parser->{paragraphs}; | |
117 | } elsif (ref $whereto eq "ARRAY") { | |
118 | print "inserting into array\n" if $parser->{DEBUG}; | |
119 | @$whereto = split /\n/, $parser->{paragraphs}; | |
120 | } elsif (ref $whereto eq "HASH") { | |
121 | print "inserting into hash\n" if $parser->{DEBUG}; | |
122 | # Oh, sorry, should I be in LISP101? | |
123 | %$whereto = (map { map { s/^\s*|\s*$//g; $_ } | |
124 | split /=>/, $_ } | |
125 | grep m/^ | |
126 | ( (?:[^=]|=[^>])+ ) # scan up to "=>" | |
127 | => | |
128 | ( (?:[^=]|=[^>])+ =? )# don't allow more "=>"'s | |
129 | $/x, | |
130 | split /\n/, $parser->{paragraphs}); | |
131 | } else { die $whereto } | |
132 | $parser->{active} = undef; | |
133 | } | |
134 | ||
135 | # Pod::Parser overloaded command | |
136 | sub command { | |
137 | my ($parser, $command, $paragraph, $line_num) = @_; | |
138 | ||
139 | $paragraph =~ s/(?:\r\n|\n\r)/\n/g; | |
140 | ||
141 | print "Got command =$command, value=$paragraph\n" | |
142 | if $parser->{DEBUG}; | |
143 | ||
144 | $parser->end_input() if $parser->{active}; | |
145 | ||
146 | my $does_she_want_it_sir; | |
147 | ||
148 | my ($lookup); | |
149 | # first check for a catch-all for this command type | |
150 | if ( exists $parser->{wanted_pod_tags}->{"*$command"} ) { | |
151 | $parser->{paragraphs} = $paragraph; | |
152 | $parser->{active} = "*$command"; | |
153 | $does_she_want_it_sir = "oohw"; | |
154 | ||
155 | } elsif ($command =~ m/^(head\d+|item|(for|begin))$/) { | |
156 | if ( $2 ) { | |
157 | # if it's a "for" or "begin" section, the title is the | |
158 | # first word only | |
159 | ($lookup, $parser->{paragraphs}) = | |
160 | ($paragraph =~ m/^\s*(\S*)\s*(.*)/s); | |
161 | } else { | |
162 | # otherwise, it's up to the end of the line | |
163 | ($lookup, $parser->{paragraphs}) | |
164 | = ($paragraph =~ m/^\s*(\S[^\n]*?)\s*\n(.*)$/s); | |
165 | } | |
166 | ||
167 | # Look for a match by name | |
168 | if (defined $lookup | |
169 | and exists $parser->{wanted_pod_tags}->{$lookup}) { | |
170 | print "Found $lookup\n" if ($parser->{DEBUG}); | |
171 | $parser->{active} = $lookup; | |
172 | $does_she_want_it_sir = "suits you sir"; | |
173 | } | |
174 | ||
175 | } else { | |
176 | # nothing | |
177 | print "Ignoring =$command (not known)\n" if $parser->{DEBUG}; | |
178 | } | |
179 | ||
180 | { | |
181 | local $^W = 0; | |
182 | print "Ignoring =$command $paragraph (lookup = $lookup)\n" | |
183 | if (!$does_she_want_it_sir and $parser->{DEBUG}) | |
184 | } | |
185 | } | |
186 | ||
187 | # Pod::Parser overloaded verbatim | |
188 | sub verbatim { | |
189 | my ($parser, $paragraph, $line_num) = @_; | |
190 | $paragraph =~ s/(?:\r\n|\n\r)/\n/g; | |
191 | ||
192 | print("Got paragraph: $paragraph (" | |
193 | .($parser->{active}?"using":"ignoring").")\n") | |
194 | if $parser->{DEBUG}; | |
195 | ||
196 | if (defined $parser->{active}) { | |
197 | $parser->{paragraphs} .= $paragraph; | |
198 | } | |
199 | } | |
200 | ||
201 | # Pod::Parser overloaded textblock | |
202 | sub textblock { goto \&verbatim } | |
203 | ||
204 | =head1 FUNCTIONS | |
205 | ||
206 | =head2 import(@args) | |
207 | ||
208 | This function is called when we are "use"'d. It determines the source | |
209 | file by inspecting the value of caller() or $0. | |
210 | ||
211 | The form of @args is HOOK => $where. | |
212 | ||
213 | $where may be a scalar reference, in which case the contents of the | |
214 | POD section called "HOOK" will be loaded into $where. | |
215 | ||
216 | $where may be an array reference, in which case the contents of the | |
217 | array will be the contents of the POD section called "HOOK", split | |
218 | into lines. | |
219 | ||
220 | $where may be a hash reference, in which case any lines with a "=>" | |
221 | symbol present will have everything on the left have side of the => | |
222 | operator as keys and everything on the right as values. You do not | |
223 | need to quote either, nor have trailing commas at the end of the | |
224 | lines. | |
225 | ||
226 | $where may be a code reference (sub { }), in which case the sub is | |
227 | called when the hook is encountered. $_ is set to the value of the | |
228 | POD paragraph. | |
229 | ||
230 | You may also specify the behaviour of whitespace trimming; by default, | |
231 | no trimming is done except on the HOOK names. Setting "-trim => 1" | |
232 | turns on a package "global" (until the next time import is called) | |
233 | that will trim the $_ sent for processing by the hook processing | |
234 | function (be it a given function, or the built-in array/hash | |
235 | splitters) for leading and trailing whitespace. | |
236 | ||
237 | The name of HOOK is matched against any "=head1", "=head2", "=item", | |
238 | "=for", "=begin" value. If you specify the special hooknames "*item", | |
239 | "*head1", etc, then you will get a function that is run for every | |
240 | ||
241 | Note that the supplied functions for array and hash splitting are | |
242 | exactly equivalent to fairly simple Perl blocks: | |
243 | ||
244 | Array: | |
245 | ||
246 | HOOK => sub { @array = split /\n/, $_ } | |
247 | ||
248 | Hash: | |
249 | ||
250 | HOOK => sub { | |
251 | %hash = | |
252 | (map { map { s/^\s+|\s+$//g; $_ } split /=>/, $_ } | |
253 | (grep m/^ | |
254 | ( (?:[^=]|=[^>])+ ) # scan up to "=>" | |
255 | => | |
256 | ( (?:[^=]|=[^>])+ =? )# don't allow more "=>"'s | |
257 | $/x, split /\n/, $_)); | |
258 | } | |
259 | ||
260 | Well, they're simple if you can grok map, a regular expression like | |
261 | that and a functional programming style. If you can't I'm sure it is | |
262 | probably voodoo to you. | |
263 | ||
264 | Here's the procedural equivalent: | |
265 | ||
266 | HOOK => sub { | |
267 | for my $line (split /\n/, $_) { | |
268 | my ($key, $value, $junk) = split /=>/, $line; | |
269 | next if $junk; | |
270 | $key =~ s/^\s+|\s+$//g | |
271 | $value =~ s/^\s+|\s+$//g | |
272 | $hash{$key} = $value; | |
273 | } | |
274 | }, | |
275 | ||
276 | =cut | |
277 | ||
278 | sub import { | |
279 | my $class = shift; | |
280 | ||
281 | # if no args, just return | |
282 | return unless (@_); | |
283 | ||
284 | # try to guess the source file of the caller | |
285 | my $source_file; | |
286 | if (caller ne "main") { | |
287 | (my $module = caller().".pm") =~ s|::|/|g; | |
288 | $source_file = $INC{$module}; | |
289 | } | |
290 | $source_file ||= $0; | |
291 | ||
292 | ( -f $source_file ) | |
293 | or croak ("Cannot find source file (guessed $source_file) for" | |
294 | ." package ".caller()); | |
295 | ||
296 | # nasty tricks with the stack so we don't have to be silly with | |
297 | # caller() | |
298 | unshift @_, $source_file; | |
299 | goto \&import_from_file; | |
300 | } | |
301 | ||
302 | =head2 import_from_file($filename, @args) | |
303 | ||
304 | Very similar to straight "import", but you specify the source filename | |
305 | explicitly. | |
306 | ||
307 | =cut | |
308 | ||
309 | use IO::Handle; | |
310 | ||
311 | sub import_from_file { | |
312 | my $filename = shift; | |
313 | ||
314 | my $parser = __PACKAGE__->new(); | |
315 | ||
316 | $parser->{wanted_pod_tags} = {}; | |
317 | $parser->{trimmed_tags} = {}; | |
318 | $parser->{trim_next} = 0; | |
319 | $parser->{DEBUG} = 0; | |
320 | $parser->{active} = undef; | |
321 | $parsers{caller()} = $parser; | |
322 | ||
323 | $parser->add_hook(@_); | |
324 | ||
325 | print "Pod::Parser: DEBUG: Opening $filename for reading\n" | |
326 | if $parser->{DEBUG}; | |
327 | my $fh = new IO::Handle; | |
328 | open $fh, "<$filename" | |
329 | or die ("cannot open $filename for reading; $!"); | |
330 | ||
331 | $parser->parse_from_filehandle($fh, \*STDOUT); | |
332 | ||
333 | close $fh; | |
334 | } | |
335 | ||
336 | =head2 add_hook(NAME => value) | |
337 | ||
338 | This function adds another hook, it is useful for dynamic updating of | |
339 | parsing through the document. | |
340 | ||
341 | For an example, please see t/01-constants.t in the source | |
342 | distribution. More detailed examples will be added in a later | |
343 | release. | |
344 | ||
345 | =cut | |
346 | ||
347 | sub add_hook { | |
348 | my $parser; | |
349 | if ( UNIVERSAL::isa($_[0], __PACKAGE__) ) { | |
350 | $parser = shift; | |
351 | } else { | |
352 | $parser = $parsers{caller()} | |
353 | or die("add_hook called, but don't know what for - " | |
354 | ."caller = ".caller()); | |
355 | } | |
356 | while (my ($pod_tag, $var) = splice @_, 0, 2) { | |
357 | #print "$pod_tag: $var\n"; | |
358 | if (lc($pod_tag) eq "-trim") { | |
359 | $parser->{trim_next} = $var; | |
360 | } elsif ( lc($pod_tag) eq "-debug" ) { | |
361 | $parser->{DEBUG} = $var; | |
362 | } elsif (lc($pod_tag) eq "-usage") { | |
363 | # an idea for later - automatic "usage" | |
364 | #%wanted_pod_tags{@tags} | |
365 | } else { | |
366 | if ((ref $var) =~ /^(?:SCALAR|CODE|ARRAY|HASH)$/) { | |
367 | print "Will look for $pod_tag.\n" | |
368 | if ($parser->{DEBUG}); | |
369 | $parser->{wanted_pod_tags}->{$pod_tag} = $var; | |
370 | $parser->{trimmed_tags}->{$pod_tag} = 1 | |
371 | if $parser->{trim_next}; | |
372 | } else { | |
373 | die ("Sorry - need a reference to import POD " | |
374 | ."sections into, not the scalar value $var" | |
375 | ." importing $pod_tag into ".caller()); | |
376 | } | |
377 | } | |
378 | } | |
379 | } | |
380 | ||
381 | =head2 delete_hook(@list) | |
382 | ||
383 | Deletes the named hooks. Companion function to add_hook | |
384 | ||
385 | =cut | |
386 | ||
387 | sub delete_hook { | |
388 | my $parser; | |
389 | if ( UNIVERSAL::isa($_[0], __PACKAGE__) ) { | |
390 | $parser = shift; | |
391 | } else { | |
392 | $parser = $parsers{caller()} | |
393 | or die("delete_hook called, but don't know what for - " | |
394 | ."caller = ".caller()); | |
395 | } | |
396 | while ( my $label = shift ) { | |
397 | delete $parser->{wanted_pod_tags}->{$label}; | |
398 | delete $parser->{trimmed_tags}->{$label}; | |
399 | } | |
400 | } | |
401 | ||
402 | =head2 CLOSURES AS DESTINATIONS | |
403 | ||
404 | If the given value is a ref CODE, then that function is called, with | |
405 | $_ set to the value of the paragraph. This can be very useful for | |
406 | applying your own custom mutations to the POD to change it from human | |
407 | readable text into something your program can use. | |
408 | ||
409 | After I added this function, I just kept on thinking of cool uses for | |
410 | it. The nice, succinct code you can make with it is one of | |
411 | Pod::Constant's strongest features. | |
412 | ||
413 | Below are some examples. | |
414 | ||
415 | =head1 EXAMPLES | |
416 | ||
417 | =head2 Module Makefile.PL maintenance | |
418 | ||
419 | Tired of keeping those module Makefile.PL's up to date? Note: This | |
420 | method seems to break dh-make-perl. | |
421 | ||
422 | =head2 Example Makefile.PL | |
423 | ||
424 | eval "use Pod::Constants"; | |
425 | ($Pod::Constants::VERSION >= 0.11) | |
426 | or die <<EOF | |
427 | #### | |
428 | #### ERROR: This module requires Pod::Constants 0.11 or | |
429 | #### higher to be installed. | |
430 | #### | |
431 | EOF | |
432 | ||
433 | my ($VERSION, $NAME, $PREREQ_PM, $ABSTRACT, $AUTHOR); | |
434 | Pod::Constants::import_from_file | |
435 | ( | |
436 | 'MyTestModule.pm', | |
437 | 'MODULE RELEASE' => sub { ($VERSION) = m/(\d+\.\d+)/ }, | |
e18addae | 438 | 'DEPENDENCIES' => ($PREREQ_PM = { }), |
f46dd377 MG |
439 | -trim => 1, |
440 | 'NAME' => sub { $ABSTRACT=$_; ($NAME) = m/(\S+)/ }, | |
441 | 'AUTHOR' => \$AUTHOR, | |
442 | ); | |
443 | ||
444 | WriteMakefile | |
445 | ( | |
446 | 'NAME' => $NAME, | |
447 | 'PREREQ_PM' => $PREREQ_PM, | |
448 | 'VERSION' => $VERSION, | |
449 | ($] >= 5.005 ? ## Add these new keywords supported since 5.005 | |
450 | (ABSTRACT => $ABSTRACT, | |
451 | AUTHOR => $AUTHOR) : ()), | |
452 | ); | |
453 | ||
454 | =head2 Corresponding Module | |
455 | ||
456 | =head1 NAME | |
457 | ||
458 | MyTestModule - Demonstrate Pod::Constant's Makefile.PL usefulness | |
459 | ||
460 | =head2 MODULE RELEASE | |
461 | ||
462 | This is release 1.05 of this module. | |
463 | ||
e18addae | 464 | =head2 DEPENDENCIES |
f46dd377 MG |
465 | |
466 | The following modules are required to make this module: | |
467 | ||
468 | Some::Module => 0.02 | |
469 | ||
470 | =head2 AUTHOR | |
471 | ||
472 | Ima Twat <ima@twat.name> | |
473 | ||
474 | =cut | |
475 | ||
476 | use vars qw($VERSION); | |
477 | use Pod::Constants -trim => 1, | |
478 | 'MODULE RELEASE' => sub { ($VERSION) = m/(\d+\.\d+) or die }; | |
479 | ||
480 | =head1 AUTHOR | |
481 | ||
482 | Sam Vilain, <samv@cpan.org> | |
483 | ||
484 | =head1 BUGS/TODO | |
485 | ||
486 | I keep thinking it would be nice to be able to import an =item list | |
487 | into an array or something, eg for a program argument list. But I'm | |
488 | not too sure how it would be all that useful in practice; you'd end up | |
489 | putting the function names for callbacks in the pod or something | |
490 | (perhaps not all that bad). | |
491 | ||
492 | Would this be useful? | |
493 | ||
494 | Pod::Constants::import(Foo::SECTION => \$myvar); | |
495 | ||
496 | Debug output is not very readable | |
497 | ||
498 | =head1 PATCHES WELCOME | |
499 | ||
500 | If you have any suggestions for enhancements, they are much more likely | |
501 | to happen if you submit them as a patch to the distribution. | |
502 | ||
503 | Source is kept at | |
504 | ||
505 | git://utsl.gen.nz/Pod-Constants | |
506 | ||
507 | =cut | |
508 | ||
509 | BEGIN { | |
510 | Pod::Constants->import | |
511 | ( | |
512 | SYNOPSIS => sub { | |
513 | eval pop @{[ grep /^\s*\$VERSION/, split /\n/, $_ ]} | |
514 | } | |
515 | ) | |
516 | }; | |
517 | ||
518 | 1.4142; |