Commit | Line | Data |
0daa11f3 |
1 | package Log::Contextual; |
2 | |
a2777569 |
3 | use strict; |
4 | use warnings; |
2033c911 |
5 | |
8ccaf9fb |
6 | our $VERSION = '0.005001'; |
b42fe5d2 |
7 | $VERSION = eval $VERSION if $VERSION =~ /_/; # numify for warning-free dev releases |
2033c911 |
8 | |
ae9785e2 |
9 | my @levels = qw(debug trace warn info error fatal); |
10 | |
675503c7 |
11 | use Exporter::Declare; |
12 | use Exporter::Declare::Export::Generator; |
f11f9542 |
13 | use Data::Dumper::Concise; |
5b094c87 |
14 | use Scalar::Util 'blessed'; |
2033c911 |
15 | |
249b9eb6 |
16 | my @dlog = ((map "Dlog_$_", @levels), (map "DlogS_$_", @levels)); |
17 | |
18 | my @log = ((map "log_$_", @levels), (map "logS_$_", @levels)); |
19 | |
b144ba01 |
20 | eval { |
21 | require Log::Log4perl; |
22 | die if $Log::Log4perl::VERSION < 1.29; |
23 | Log::Log4perl->wrapper_register(__PACKAGE__) |
24 | }; |
25 | |
5fd26f45 |
26 | # ____ is because tags must have at least one export and we don't want to |
27 | # export anything but the levels selected |
6ae293d7 |
28 | sub ____ { } |
5fd26f45 |
29 | |
249b9eb6 |
30 | exports ('____', |
31 | @dlog, @log, |
32 | qw( set_logger with_logger ) |
33 | ); |
f11f9542 |
34 | |
5fd26f45 |
35 | export_tag dlog => ('____'); |
36 | export_tag log => ('____'); |
675503c7 |
37 | import_arguments qw(logger package_logger default_logger); |
38 | |
139ded54 |
39 | sub router { |
0092c26a |
40 | our $Router_Instance ||= do { |
41 | require Log::Contextual::Router; |
42 | Log::Contextual::Router->new |
6ae293d7 |
43 | } |
0092c26a |
44 | } |
45 | |
e06303cd |
46 | sub default_import { |
47 | my ($class) = shift; |
48 | |
49 | die 'Log::Contextual does not have a default import list'; |
50 | |
51 | () |
52 | } |
53 | |
6ae293d7 |
54 | sub arg_logger { $_[1] } |
55 | sub arg_levels { $_[1] || [qw(debug trace warn info error fatal)] } |
8112b699 |
56 | sub arg_package_logger { $_[1] } |
57 | sub arg_default_logger { $_[1] } |
58 | |
675503c7 |
59 | sub before_import { |
60 | my ($class, $importer, $spec) = @_; |
6ae293d7 |
61 | my $router = $class->router; |
62 | my $exports = $spec->exports; |
63 | my %router_args = ( |
64 | exporter => $class, |
65 | target => $importer, |
66 | arguments => $spec->argument_info |
67 | ); |
f11f9542 |
68 | |
e06303cd |
69 | my @tags = $class->default_import($spec) |
6ae293d7 |
70 | if $spec->config->{default}; |
675503c7 |
71 | |
e06303cd |
72 | for (@tags) { |
73 | die "only tags are supported for defaults at this time" |
74 | unless $_ =~ /^:(.*)$/; |
75 | |
76 | $spec->config->{$1} = 1; |
77 | } |
78 | |
a5454e75 |
79 | $router->before_import(%router_args); |
8112b699 |
80 | |
84d7d9ee |
81 | if ($exports->{'&set_logger'}) { |
82 | die ref($router) . " does not support set_logger()" |
83 | unless $router->does('Log::Contextual::Role::Router::SetLogger'); |
4d605164 |
84 | |
84d7d9ee |
85 | $spec->add_export('&set_logger', sub { $router->set_logger(@_) }) |
86 | } |
4d605164 |
87 | |
84d7d9ee |
88 | if ($exports->{'&with_logger'}) { |
89 | die ref($router) . " does not support with_logger()" |
90 | unless $router->does('Log::Contextual::Role::Router::WithLogger'); |
4d605164 |
91 | |
84d7d9ee |
92 | $spec->add_export('&with_logger', sub { $router->with_logger(@_) }) |
93 | } |
4d605164 |
94 | |
5fd26f45 |
95 | my @levels = @{$class->arg_levels($spec->config->{levels})}; |
675503c7 |
96 | for my $level (@levels) { |
249b9eb6 |
97 | if ($spec->config->{log} || $exports->{"&log_$level"}) { |
6ae293d7 |
98 | $spec->add_export( |
99 | "&log_$level", |
100 | sub (&@) { |
101 | my ($code, @args) = @_; |
102 | $router->handle_log_request( |
103 | exporter => $class, |
104 | caller_package => scalar(caller), |
105 | caller_level => 1, |
106 | message_level => $level, |
107 | message_sub => $code, |
108 | message_args => \@args, |
109 | ); |
110 | return @args; |
111 | }); |
249b9eb6 |
112 | } |
113 | if ($spec->config->{log} || $exports->{"&logS_$level"}) { |
6ae293d7 |
114 | $spec->add_export( |
115 | "&logS_$level", |
116 | sub (&@) { |
117 | my ($code, @args) = @_; |
118 | $router->handle_log_request( |
119 | exporter => $class, |
120 | caller_package => scalar(caller), |
121 | caller_level => 1, |
122 | message_level => $level, |
123 | message_sub => $code, |
124 | message_args => \@args, |
125 | ); |
126 | return $args[0]; |
127 | }); |
675503c7 |
128 | } |
249b9eb6 |
129 | if ($spec->config->{dlog} || $exports->{"&Dlog_$level"}) { |
6ae293d7 |
130 | $spec->add_export( |
131 | "&Dlog_$level", |
132 | sub (&@) { |
133 | my ($code, @args) = @_; |
134 | my $wrapped = sub { |
135 | local $_ = (@_ ? Data::Dumper::Concise::Dumper @_ : '()'); |
136 | &$code; |
137 | }; |
138 | $router->handle_log_request( |
139 | exporter => $class, |
140 | caller_package => scalar(caller), |
141 | caller_level => 1, |
142 | message_level => $level, |
143 | message_sub => $wrapped, |
144 | message_args => \@args, |
145 | ); |
146 | return @args; |
147 | }); |
249b9eb6 |
148 | } |
149 | if ($spec->config->{dlog} || $exports->{"&DlogS_$level"}) { |
6ae293d7 |
150 | $spec->add_export( |
151 | "&DlogS_$level", |
152 | sub (&$) { |
153 | my ($code, $ref) = @_; |
154 | my $wrapped = sub { |
155 | local $_ = Data::Dumper::Concise::Dumper($_[0]); |
156 | &$code; |
157 | }; |
158 | $router->handle_log_request( |
159 | exporter => $class, |
160 | caller_package => scalar(caller), |
161 | caller_level => 1, |
162 | message_level => $level, |
163 | message_sub => $wrapped, |
164 | message_args => [$ref], |
165 | ); |
166 | return $ref; |
167 | }); |
a2777569 |
168 | } |
169 | } |
675503c7 |
170 | } |
171 | |
a5454e75 |
172 | sub after_import { |
173 | my ($class, $importer, $spec) = @_; |
6ae293d7 |
174 | my %router_args = ( |
175 | exporter => $class, |
176 | target => $importer, |
177 | arguments => $spec->argument_info |
178 | ); |
a5454e75 |
179 | $class->router->after_import(%router_args); |
180 | } |
709d11fe |
181 | |
0daa11f3 |
182 | 1; |
0a3750e2 |
183 | |
184 | __END__ |
185 | |
2daff231 |
186 | =head1 NAME |
187 | |
8bc568d2 |
188 | Log::Contextual - Simple logging interface with a contextual log |
2daff231 |
189 | |
190 | =head1 SYNOPSIS |
191 | |
9b8e24d5 |
192 | use Log::Contextual qw( :log :dlog set_logger with_logger ); |
5b094c87 |
193 | use Log::Contextual::SimpleLogger; |
194 | use Log::Log4perl ':easy'; |
195 | Log::Log4perl->easy_init($DEBUG); |
2daff231 |
196 | |
5b094c87 |
197 | my $logger = Log::Log4perl->get_logger; |
198 | |
199 | set_logger $logger; |
2daff231 |
200 | |
9b8e24d5 |
201 | log_debug { 'program started' }; |
2daff231 |
202 | |
203 | sub foo { |
f9bf084b |
204 | |
205 | my $minilogger = Log::Contextual::SimpleLogger->new({ |
206 | levels => [qw( trace debug )] |
207 | }); |
208 | |
2ae9c121 |
209 | my @args = @_; |
210 | |
f9bf084b |
211 | with_logger $minilogger => sub { |
21431192 |
212 | log_trace { 'foo entered' }; |
2ae9c121 |
213 | my ($foo, $bar) = Dlog_trace { "params for foo: $_" } @args; |
2daff231 |
214 | # ... |
21431192 |
215 | log_trace { 'foo left' }; |
f9bf084b |
216 | }; |
2daff231 |
217 | } |
218 | |
5b094c87 |
219 | foo(); |
220 | |
9fe4eeb3 |
221 | Beginning with version 1.008 L<Log::Dispatchouli> also works out of the box |
222 | with C<Log::Contextual>: |
223 | |
224 | use Log::Contextual qw( :log :dlog set_logger ); |
225 | use Log::Dispatchouli; |
226 | my $ld = Log::Dispatchouli->new({ |
227 | ident => 'slrtbrfst', |
228 | to_stderr => 1, |
229 | debug => 1, |
230 | }); |
231 | |
232 | set_logger $ld; |
233 | |
234 | log_debug { 'program started' }; |
235 | |
2daff231 |
236 | =head1 DESCRIPTION |
237 | |
30d7027a |
238 | Major benefits: |
239 | |
240 | =over 2 |
241 | |
242 | =item * Efficient |
243 | |
244 | The logging functions take blocks, so if a log level is disabled, the |
245 | block will not run: |
246 | |
247 | # the following won't run if debug is off |
248 | log_debug { "the new count in the database is " . $rs->count }; |
249 | |
250 | Similarly, the C<D> prefixed methods only C<Dumper> the input if the level is |
251 | enabled. |
252 | |
253 | =item * Handy |
254 | |
255 | The logging functions return their arguments, so you can stick them in |
256 | the middle of expressions: |
257 | |
258 | for (log_debug { "downloading:\n" . join qq(\n), @_ } @urls) { ... } |
259 | |
260 | =item * Generic |
261 | |
262 | C<Log::Contextual> is an interface for all major loggers. If you log through |
263 | C<Log::Contextual> you will be able to swap underlying loggers later. |
264 | |
265 | =item * Powerful |
266 | |
39cd2f65 |
267 | C<Log::Contextual> chooses which logger to use based on L<< user defined C<CodeRef>s|/LOGGER CODEREF >>. |
30d7027a |
268 | Normally you don't need to know this, but you can take advantage of it when you |
269 | need to later |
270 | |
271 | =item * Scalable |
272 | |
273 | If you just want to add logging to your extremely basic application, start with |
274 | L<Log::Contextual::SimpleLogger> and then as your needs grow you can switch to |
275 | L<Log::Dispatchouli> or L<Log::Dispatch> or L<Log::Log4perl> or whatever else. |
276 | |
277 | =back |
278 | |
279 | This module is a simple interface to extensible logging. It exists to |
280 | abstract your logging interface so that logging is as painless as possible, |
281 | while still allowing you to switch from one logger to another. |
3dc9bd3c |
282 | |
30d7027a |
283 | It is bundled with a really basic logger, L<Log::Contextual::SimpleLogger>, |
284 | but in general you should use a real logger instead of that. For something |
285 | more serious but not overly complicated, try L<Log::Dispatchouli> (see |
286 | L</SYNOPSIS> for example.) |
a2af6976 |
287 | |
e36f2183 |
288 | =head1 A WORK IN PROGRESS |
289 | |
290 | This module is certainly not complete, but we will not break the interface |
291 | lightly, so I would say it's safe to use in production code. The main result |
292 | from that at this point is that doing: |
293 | |
294 | use Log::Contextual; |
295 | |
296 | will die as we do not yet know what the defaults should be. If it turns out |
297 | that nearly everyone uses the C<:log> tag and C<:dlog> is really rare, we'll |
298 | probably make C<:log> the default. But only time and usage will tell. |
299 | |
300 | =head1 IMPORT OPTIONS |
301 | |
302 | See L</SETTING DEFAULT IMPORT OPTIONS> for information on setting these project |
303 | wide. |
3dc9bd3c |
304 | |
c154d18a |
305 | =head2 -logger |
306 | |
3dc9bd3c |
307 | When you import this module you may use C<-logger> as a shortcut for |
308 | L<set_logger>, for example: |
309 | |
310 | use Log::Contextual::SimpleLogger; |
9b8e24d5 |
311 | use Log::Contextual qw( :dlog ), |
312 | -logger => Log::Contextual::SimpleLogger->new({ levels => [qw( debug )] }); |
3dc9bd3c |
313 | |
314 | sometimes you might want to have the logger handy for other stuff, in which |
315 | case you might try something like the following: |
316 | |
317 | my $var_log; |
318 | BEGIN { $var_log = VarLogger->new } |
9b8e24d5 |
319 | use Log::Contextual qw( :dlog ), -logger => $var_log; |
3dc9bd3c |
320 | |
5fd26f45 |
321 | =head2 -levels |
322 | |
323 | The C<-levels> import option allows you to define exactly which levels your |
324 | logger supports. So the default, |
325 | C<< [qw(debug trace warn info error fatal)] >>, works great for |
326 | L<Log::Log4perl>, but it doesn't support the levels for L<Log::Dispatch>. But |
327 | supporting those levels is as easy as doing |
328 | |
329 | use Log::Contextual |
330 | -levels => [qw( debug info notice warning error critical alert emergency )]; |
331 | |
e2b4b29c |
332 | =head2 -package_logger |
333 | |
334 | The C<-package_logger> import option is similar to the C<-logger> import option |
335 | except C<-package_logger> sets the the logger for the current package. |
336 | |
337 | Unlike L</-default_logger>, C<-package_logger> cannot be overridden with |
338 | L</set_logger>. |
339 | |
340 | package My::Package; |
341 | use Log::Contextual::SimpleLogger; |
342 | use Log::Contextual qw( :log ), |
343 | -package_logger => Log::Contextual::WarnLogger->new({ |
344 | env_prefix => 'MY_PACKAGE' |
345 | }); |
346 | |
347 | If you are interested in using this package for a module you are putting on |
348 | CPAN we recommend L<Log::Contextual::WarnLogger> for your package logger. |
349 | |
c154d18a |
350 | =head2 -default_logger |
351 | |
352 | The C<-default_logger> import option is similar to the C<-logger> import option |
e2b4b29c |
353 | except C<-default_logger> sets the the B<default> logger for the current package. |
c154d18a |
354 | |
355 | Basically it sets the logger to be used if C<set_logger> is never called; so |
356 | |
357 | package My::Package; |
358 | use Log::Contextual::SimpleLogger; |
359 | use Log::Contextual qw( :log ), |
360 | -default_logger => Log::Contextual::WarnLogger->new({ |
ae59bbe3 |
361 | env_prefix => 'MY_PACKAGE' |
c154d18a |
362 | }); |
363 | |
e36f2183 |
364 | =head1 SETTING DEFAULT IMPORT OPTIONS |
3dc9bd3c |
365 | |
e36f2183 |
366 | Eventually you will get tired of writing the following in every single one of |
367 | your packages: |
3dc9bd3c |
368 | |
e36f2183 |
369 | use Log::Log4perl; |
370 | use Log::Log4perl ':easy'; |
371 | BEGIN { Log::Log4perl->easy_init($DEBUG) } |
3dc9bd3c |
372 | |
e36f2183 |
373 | use Log::Contextual -logger => Log::Log4perl->get_logger; |
374 | |
375 | You can set any of the import options for your whole project if you define your |
376 | own C<Log::Contextual> subclass as follows: |
377 | |
378 | package MyApp::Log::Contextual; |
379 | |
380 | use base 'Log::Contextual'; |
381 | |
382 | use Log::Log4perl ':easy'; |
383 | Log::Log4perl->easy_init($DEBUG) |
384 | |
2b40dee5 |
385 | sub arg_default_logger { $_[1] || Log::Log4perl->get_logger } |
e36f2183 |
386 | sub arg_levels { [qw(debug trace warn info error fatal custom_level)] } |
e06303cd |
387 | sub default_import { ':log' } |
e36f2183 |
388 | |
2b40dee5 |
389 | # or maybe instead of default_logger |
e36f2183 |
390 | sub arg_package_logger { $_[1] } |
e36f2183 |
391 | |
2b40dee5 |
392 | # and almost definitely not this, which is only here for completeness |
393 | sub arg_logger { $_[1] } |
e36f2183 |
394 | |
2b40dee5 |
395 | Note the C<< $_[1] || >> in C<arg_default_logger>. All of these methods are |
396 | passed the values passed in from the arguments to the subclass, so you can |
397 | either throw them away, honor them, die on usage, or whatever. To be clear, |
398 | if you define your subclass, and someone uses it as follows: |
e36f2183 |
399 | |
2b40dee5 |
400 | use MyApp::Log::Contextual -default_logger => $foo, |
401 | -levels => [qw(bar baz biff)]; |
402 | |
403 | Your C<arg_default_logger> method will get C<$foo> and your C<arg_levels> |
e36f2183 |
404 | will get C<[qw(bar baz biff)]>; |
2daff231 |
405 | |
e06303cd |
406 | Additionally, the C<default_import> method is what happens if a user tries to |
407 | use your subclass with no arguments. The default just dies, but if you'd like |
408 | to change the default to import a tag merely return the tags you'd like to |
409 | import. So the following will all work: |
410 | |
411 | sub default_import { ':log' } |
412 | |
413 | sub default_import { ':dlog' } |
414 | |
415 | sub default_import { qw(:dlog :log ) } |
416 | |
2daff231 |
417 | =head1 FUNCTIONS |
418 | |
419 | =head2 set_logger |
420 | |
421 | my $logger = WarnLogger->new; |
21431192 |
422 | set_logger $logger; |
423 | |
27141a7a |
424 | Arguments: L</LOGGER CODEREF> |
2daff231 |
425 | |
21431192 |
426 | C<set_logger> will just set the current logger to whatever you pass it. It |
427 | expects a C<CodeRef>, but if you pass it something else it will wrap it in a |
06e908c3 |
428 | C<CodeRef> for you. C<set_logger> is really meant only to be called from a |
429 | top-level script. To avoid foot-shooting the function will warn if you call it |
430 | more than once. |
2daff231 |
431 | |
432 | =head2 with_logger |
433 | |
434 | my $logger = WarnLogger->new; |
21431192 |
435 | with_logger $logger => sub { |
2daff231 |
436 | if (1 == 0) { |
437 | log_fatal { 'Non Logical Universe Detected' }; |
438 | } else { |
439 | log_info { 'All is good' }; |
440 | } |
80c3e48b |
441 | }; |
2daff231 |
442 | |
27141a7a |
443 | Arguments: L</LOGGER CODEREF>, C<CodeRef $to_execute> |
2daff231 |
444 | |
21431192 |
445 | C<with_logger> sets the logger for the scope of the C<CodeRef> C<$to_execute>. |
0e13e261 |
446 | As with L</set_logger>, C<with_logger> will wrap C<$returning_logger> with a |
21431192 |
447 | C<CodeRef> if needed. |
2daff231 |
448 | |
21431192 |
449 | =head2 log_$level |
2daff231 |
450 | |
0e13e261 |
451 | Import Tag: C<:log> |
3dc9bd3c |
452 | |
0e13e261 |
453 | Arguments: C<CodeRef $returning_message, @args> |
2daff231 |
454 | |
a4d67519 |
455 | C<log_$level> functions all work the same except that a different method |
21431192 |
456 | is called on the underlying C<$logger> object. The basic pattern is: |
2daff231 |
457 | |
0e13e261 |
458 | sub log_$level (&@) { |
21431192 |
459 | if ($logger->is_$level) { |
0e13e261 |
460 | $logger->$level(shift->(@_)); |
21431192 |
461 | } |
0e13e261 |
462 | @_ |
21431192 |
463 | } |
2daff231 |
464 | |
0e13e261 |
465 | Note that the function returns it's arguments. This can be used in a number of |
466 | ways, but often it's convenient just for partial inspection of passthrough data |
467 | |
468 | my @friends = log_trace { |
469 | 'friends list being generated, data from first friend: ' . |
470 | Dumper($_[0]->TO_JSON) |
471 | } generate_friend_list(); |
472 | |
473 | If you want complete inspection of passthrough data, take a look at the |
474 | L</Dlog_$level> functions. |
475 | |
a4d67519 |
476 | Which functions are exported depends on what was passed to L</-levels>. The |
477 | default (no C<-levels> option passed) would export: |
2daff231 |
478 | |
a4d67519 |
479 | =over 2 |
2daff231 |
480 | |
a4d67519 |
481 | =item log_trace |
2daff231 |
482 | |
a4d67519 |
483 | =item log_debug |
2daff231 |
484 | |
a4d67519 |
485 | =item log_info |
2daff231 |
486 | |
a4d67519 |
487 | =item log_warn |
2daff231 |
488 | |
a4d67519 |
489 | =item log_error |
2daff231 |
490 | |
a4d67519 |
491 | =item log_fatal |
2daff231 |
492 | |
a4d67519 |
493 | =back |
2daff231 |
494 | |
0e13e261 |
495 | =head2 logS_$level |
496 | |
497 | Import Tag: C<:log> |
498 | |
499 | Arguments: C<CodeRef $returning_message, Item $arg> |
500 | |
501 | This is really just a special case of the L</log_$level> functions. It forces |
502 | scalar context when that is what you need. Other than that it works exactly |
503 | same: |
504 | |
505 | my $friend = logS_trace { |
506 | 'I only have one friend: ' . Dumper($_[0]->TO_JSON) |
507 | } friend(); |
508 | |
509 | See also: L</DlogS_$level>. |
510 | |
21431192 |
511 | =head2 Dlog_$level |
512 | |
0e13e261 |
513 | Import Tag: C<:dlog> |
3dc9bd3c |
514 | |
0e13e261 |
515 | Arguments: C<CodeRef $returning_message, @args> |
2daff231 |
516 | |
0e13e261 |
517 | All of the following six functions work the same as their L</log_$level> |
9b8e24d5 |
518 | brethren, except they return what is passed into them and put the stringified |
21431192 |
519 | (with L<Data::Dumper::Concise>) version of their args into C<$_>. This means |
520 | you can do cool things like the following: |
521 | |
522 | my @nicks = Dlog_debug { "names: $_" } map $_->value, $frew->names->all; |
523 | |
524 | and the output might look something like: |
525 | |
526 | names: "fREW" |
527 | "fRIOUX" |
528 | "fROOH" |
529 | "fRUE" |
530 | "fiSMBoC" |
531 | |
a4d67519 |
532 | Which functions are exported depends on what was passed to L</-levels>. The |
533 | default (no C<-levels> option passed) would export: |
21431192 |
534 | |
a4d67519 |
535 | =over 2 |
21431192 |
536 | |
a4d67519 |
537 | =item Dlog_trace |
21431192 |
538 | |
a4d67519 |
539 | =item Dlog_debug |
21431192 |
540 | |
a4d67519 |
541 | =item Dlog_info |
21431192 |
542 | |
a4d67519 |
543 | =item Dlog_warn |
21431192 |
544 | |
a4d67519 |
545 | =item Dlog_error |
2daff231 |
546 | |
a4d67519 |
547 | =item Dlog_fatal |
2daff231 |
548 | |
a4d67519 |
549 | =back |
2daff231 |
550 | |
83b33eb5 |
551 | =head2 DlogS_$level |
552 | |
0e13e261 |
553 | Import Tag: C<:dlog> |
3dc9bd3c |
554 | |
0e13e261 |
555 | Arguments: C<CodeRef $returning_message, Item $arg> |
83b33eb5 |
556 | |
0e13e261 |
557 | Like L</logS_$level>, these functions are a special case of L</Dlog_$level>. |
558 | They only take a single scalar after the C<$returning_message> instead of |
559 | slurping up (and also setting C<wantarray>) all the C<@args> |
83b33eb5 |
560 | |
561 | my $pals_rs = DlogS_debug { "pals resultset: $_" } |
562 | $schema->resultset('Pals')->search({ perlers => 1 }); |
563 | |
27141a7a |
564 | =head1 LOGGER CODEREF |
565 | |
566 | Anywhere a logger object can be passed, a coderef is accepted. This is so |
567 | that the user can use different logger objects based on runtime information. |
568 | The logger coderef is passed the package of the caller the caller level the |
569 | coderef needs to use if it wants more caller information. The latter is in |
570 | a hashref to allow for more options in the future. |
571 | |
37a8266a |
572 | Here is a basic example of a logger that exploits C<caller> to reproduce the |
573 | output of C<warn> with a logger: |
574 | |
575 | my @caller_info; |
576 | my $var_log = Log::Contextual::SimpleLogger->new({ |
577 | levels => [qw(trace debug info warn error fatal)], |
578 | coderef => sub { chomp($_[0]); warn "$_[0] at $caller_info[1] line $caller_info[2].\n" } |
579 | }); |
580 | my $warn_faker = sub { |
581 | my ($package, $args) = @_; |
582 | @caller_info = caller($args->{caller_level}); |
583 | $var_log |
584 | }; |
585 | set_logger($warn_faker); |
586 | log_debug { 'test' }; |
587 | |
27141a7a |
588 | The following is an example that uses the information passed to the logger |
589 | coderef. It sets the global logger to C<$l3>, the logger for the C<A1> |
590 | package to C<$l1>, except the C<lol> method in C<A1> which uses the C<$l2> |
591 | logger and lastly the logger for the C<A2> package to C<$l2>. |
592 | |
37a8266a |
593 | Note that it increases the caller level as it dispatches based on where |
594 | the caller of the log function, not the log function itself. |
595 | |
27141a7a |
596 | my $complex_dispatcher = do { |
597 | |
598 | my $l1 = ...; |
599 | my $l2 = ...; |
600 | my $l3 = ...; |
601 | |
602 | my %registry = ( |
603 | -logger => $l3, |
604 | A1 => { |
605 | -logger => $l1, |
606 | lol => $l2, |
607 | }, |
608 | A2 => { -logger => $l2 }, |
609 | ); |
610 | |
611 | sub { |
612 | my ( $package, $info ) = @_; |
613 | |
614 | my $logger = $registry{'-logger'}; |
615 | if (my $r = $registry{$package}) { |
616 | $logger = $r->{'-logger'} if $r->{'-logger'}; |
37a8266a |
617 | my (undef, undef, undef, $sub) = caller($info->{caller_level} + 1); |
27141a7a |
618 | $sub =~ s/^\Q$package\E:://g; |
619 | $logger = $r->{$sub} if $r->{$sub}; |
620 | } |
621 | return $logger; |
622 | } |
623 | }; |
624 | |
625 | set_logger $complex_dispatcher; |
626 | |
3dc9bd3c |
627 | =head1 LOGGER INTERFACE |
628 | |
629 | Because this module is ultimately pretty looking glue (glittery?) with the |
630 | awesome benefit of the Contextual part, users will often want to make their |
631 | favorite logger work with it. The following are the methods that should be |
632 | implemented in the logger: |
633 | |
634 | is_trace |
635 | is_debug |
636 | is_info |
637 | is_warn |
638 | is_error |
639 | is_fatal |
640 | trace |
641 | debug |
642 | info |
643 | warn |
644 | error |
645 | fatal |
646 | |
647 | The first six merely need to return true if that level is enabled. The latter |
648 | six take the results of whatever the user returned from their coderef and log |
649 | them. For a basic example see L<Log::Contextual::SimpleLogger>. |
650 | |
eab2ca3c |
651 | =head1 LOG ROUTING |
652 | |
a5454e75 |
653 | In between the loggers and the log functions is a log router that is responsible for |
eab2ca3c |
654 | finding a logger to handle the log event and passing the log information to the |
a5454e75 |
655 | logger. This relationship is described in the documentation for C<Log::Contextual::Role::Router>. |
eab2ca3c |
656 | |
a5454e75 |
657 | C<Log::Contextual> and packages that extend it will by default share a router singleton that |
658 | implements the with_logger() and set_logger() functions and also respects the -logger, |
659 | -package_logger, and -default_logger import options with their associated default value |
660 | functions. The router singleton is available as the return value of the router() function. Users |
661 | of Log::Contextual may overload router() to return instances of custom log routers that |
662 | could for example work with loggers that use a different interface. |
eab2ca3c |
663 | |
a5454e75 |
664 | =head1 AUTHOR |
2daff231 |
665 | |
666 | frew - Arthur Axel "fREW" Schmidt <frioux@gmail.com> |
667 | |
a5454e75 |
668 | =head1 CONTRIBUTORS |
669 | |
eab2ca3c |
670 | triddle - Tyler Riddle <t.riddle@shadowcat.co.uk> |
671 | |
2daff231 |
672 | =head1 DESIGNER |
673 | |
674 | mst - Matt S. Trout <mst@shadowcat.co.uk> |
675 | |
676 | =head1 COPYRIGHT |
677 | |
a6e29e27 |
678 | Copyright (c) 2012 the Log::Contextual L</AUTHOR> and L</DESIGNER> as listed |
2daff231 |
679 | above. |
680 | |
681 | =head1 LICENSE |
682 | |
683 | This library is free software and may be distributed under the same terms as |
684 | Perl 5 itself. |
685 | |
686 | =cut |
687 | |