Commit | Line | Data |
0daa11f3 |
1 | package Log::Contextual; |
2 | |
dc4fd4b0 |
3 | # ABSTRACT: Simple logging interface with a contextual log |
4 | |
a2777569 |
5 | use strict; |
6 | use warnings; |
2033c911 |
7 | |
ae9785e2 |
8 | my @levels = qw(debug trace warn info error fatal); |
9 | |
675503c7 |
10 | use Exporter::Declare; |
11 | use Exporter::Declare::Export::Generator; |
f11f9542 |
12 | use Data::Dumper::Concise; |
5b094c87 |
13 | use Scalar::Util 'blessed'; |
2033c911 |
14 | |
249b9eb6 |
15 | my @dlog = ((map "Dlog_$_", @levels), (map "DlogS_$_", @levels)); |
16 | |
17 | my @log = ((map "log_$_", @levels), (map "logS_$_", @levels)); |
18 | |
b144ba01 |
19 | eval { |
20 | require Log::Log4perl; |
21 | die if $Log::Log4perl::VERSION < 1.29; |
22 | Log::Log4perl->wrapper_register(__PACKAGE__) |
23 | }; |
24 | |
5fd26f45 |
25 | # ____ is because tags must have at least one export and we don't want to |
26 | # export anything but the levels selected |
6ae293d7 |
27 | sub ____ { } |
5fd26f45 |
28 | |
489f71b2 |
29 | exports('____', @dlog, @log, qw( set_logger with_logger )); |
f11f9542 |
30 | |
5fd26f45 |
31 | export_tag dlog => ('____'); |
32 | export_tag log => ('____'); |
675503c7 |
33 | import_arguments qw(logger package_logger default_logger); |
34 | |
139ded54 |
35 | sub router { |
0092c26a |
36 | our $Router_Instance ||= do { |
37 | require Log::Contextual::Router; |
38 | Log::Contextual::Router->new |
6ae293d7 |
39 | } |
0092c26a |
40 | } |
41 | |
e06303cd |
42 | sub default_import { |
43 | my ($class) = shift; |
44 | |
45 | die 'Log::Contextual does not have a default import list'; |
46 | |
47 | () |
48 | } |
49 | |
6ae293d7 |
50 | sub arg_logger { $_[1] } |
51 | sub arg_levels { $_[1] || [qw(debug trace warn info error fatal)] } |
8112b699 |
52 | sub arg_package_logger { $_[1] } |
53 | sub arg_default_logger { $_[1] } |
54 | |
675503c7 |
55 | sub before_import { |
56 | my ($class, $importer, $spec) = @_; |
6ae293d7 |
57 | my $router = $class->router; |
58 | my $exports = $spec->exports; |
59 | my %router_args = ( |
60 | exporter => $class, |
61 | target => $importer, |
62 | arguments => $spec->argument_info |
63 | ); |
f11f9542 |
64 | |
e06303cd |
65 | my @tags = $class->default_import($spec) |
6ae293d7 |
66 | if $spec->config->{default}; |
675503c7 |
67 | |
e06303cd |
68 | for (@tags) { |
69 | die "only tags are supported for defaults at this time" |
70 | unless $_ =~ /^:(.*)$/; |
71 | |
72 | $spec->config->{$1} = 1; |
73 | } |
74 | |
a5454e75 |
75 | $router->before_import(%router_args); |
8112b699 |
76 | |
84d7d9ee |
77 | if ($exports->{'&set_logger'}) { |
78 | die ref($router) . " does not support set_logger()" |
79 | unless $router->does('Log::Contextual::Role::Router::SetLogger'); |
4d605164 |
80 | |
84d7d9ee |
81 | $spec->add_export('&set_logger', sub { $router->set_logger(@_) }) |
82 | } |
4d605164 |
83 | |
84d7d9ee |
84 | if ($exports->{'&with_logger'}) { |
85 | die ref($router) . " does not support with_logger()" |
86 | unless $router->does('Log::Contextual::Role::Router::WithLogger'); |
4d605164 |
87 | |
84d7d9ee |
88 | $spec->add_export('&with_logger', sub { $router->with_logger(@_) }) |
89 | } |
4d605164 |
90 | |
5fd26f45 |
91 | my @levels = @{$class->arg_levels($spec->config->{levels})}; |
675503c7 |
92 | for my $level (@levels) { |
249b9eb6 |
93 | if ($spec->config->{log} || $exports->{"&log_$level"}) { |
6ae293d7 |
94 | $spec->add_export( |
95 | "&log_$level", |
96 | sub (&@) { |
97 | my ($code, @args) = @_; |
98 | $router->handle_log_request( |
99 | exporter => $class, |
100 | caller_package => scalar(caller), |
101 | caller_level => 1, |
102 | message_level => $level, |
103 | message_sub => $code, |
104 | message_args => \@args, |
105 | ); |
106 | return @args; |
107 | }); |
249b9eb6 |
108 | } |
109 | if ($spec->config->{log} || $exports->{"&logS_$level"}) { |
6ae293d7 |
110 | $spec->add_export( |
111 | "&logS_$level", |
112 | sub (&@) { |
113 | my ($code, @args) = @_; |
114 | $router->handle_log_request( |
115 | exporter => $class, |
116 | caller_package => scalar(caller), |
117 | caller_level => 1, |
118 | message_level => $level, |
119 | message_sub => $code, |
120 | message_args => \@args, |
121 | ); |
122 | return $args[0]; |
123 | }); |
675503c7 |
124 | } |
249b9eb6 |
125 | if ($spec->config->{dlog} || $exports->{"&Dlog_$level"}) { |
6ae293d7 |
126 | $spec->add_export( |
127 | "&Dlog_$level", |
128 | sub (&@) { |
129 | my ($code, @args) = @_; |
130 | my $wrapped = sub { |
131 | local $_ = (@_ ? Data::Dumper::Concise::Dumper @_ : '()'); |
132 | &$code; |
133 | }; |
134 | $router->handle_log_request( |
135 | exporter => $class, |
136 | caller_package => scalar(caller), |
137 | caller_level => 1, |
138 | message_level => $level, |
139 | message_sub => $wrapped, |
140 | message_args => \@args, |
141 | ); |
142 | return @args; |
143 | }); |
249b9eb6 |
144 | } |
145 | if ($spec->config->{dlog} || $exports->{"&DlogS_$level"}) { |
6ae293d7 |
146 | $spec->add_export( |
147 | "&DlogS_$level", |
148 | sub (&$) { |
149 | my ($code, $ref) = @_; |
150 | my $wrapped = sub { |
151 | local $_ = Data::Dumper::Concise::Dumper($_[0]); |
152 | &$code; |
153 | }; |
154 | $router->handle_log_request( |
155 | exporter => $class, |
156 | caller_package => scalar(caller), |
157 | caller_level => 1, |
158 | message_level => $level, |
159 | message_sub => $wrapped, |
160 | message_args => [$ref], |
161 | ); |
162 | return $ref; |
163 | }); |
a2777569 |
164 | } |
165 | } |
675503c7 |
166 | } |
167 | |
a5454e75 |
168 | sub after_import { |
169 | my ($class, $importer, $spec) = @_; |
6ae293d7 |
170 | my %router_args = ( |
171 | exporter => $class, |
172 | target => $importer, |
173 | arguments => $spec->argument_info |
174 | ); |
a5454e75 |
175 | $class->router->after_import(%router_args); |
176 | } |
709d11fe |
177 | |
31285520 |
178 | for (qw(set with)) { |
179 | no strict 'refs'; |
180 | my $sub = "${_}_logger"; |
181 | *{"Log::Contextual::$sub"} = sub { |
489f71b2 |
182 | die "$sub is no longer a direct sub in Log::Contextual. " |
183 | . 'Note that this feature was never tested nor documented. ' |
184 | . "Please fix your code to import $sub instead of trying to use it directly" |
185 | } |
31285520 |
186 | } |
187 | |
0daa11f3 |
188 | 1; |
0a3750e2 |
189 | |
190 | __END__ |
191 | |
2daff231 |
192 | =head1 SYNOPSIS |
193 | |
9b8e24d5 |
194 | use Log::Contextual qw( :log :dlog set_logger with_logger ); |
5b094c87 |
195 | use Log::Contextual::SimpleLogger; |
196 | use Log::Log4perl ':easy'; |
197 | Log::Log4perl->easy_init($DEBUG); |
2daff231 |
198 | |
5b094c87 |
199 | my $logger = Log::Log4perl->get_logger; |
200 | |
201 | set_logger $logger; |
2daff231 |
202 | |
9b8e24d5 |
203 | log_debug { 'program started' }; |
2daff231 |
204 | |
205 | sub foo { |
f9bf084b |
206 | |
207 | my $minilogger = Log::Contextual::SimpleLogger->new({ |
208 | levels => [qw( trace debug )] |
209 | }); |
210 | |
2ae9c121 |
211 | my @args = @_; |
212 | |
f9bf084b |
213 | with_logger $minilogger => sub { |
21431192 |
214 | log_trace { 'foo entered' }; |
2ae9c121 |
215 | my ($foo, $bar) = Dlog_trace { "params for foo: $_" } @args; |
2daff231 |
216 | # ... |
21431192 |
217 | log_trace { 'foo left' }; |
f9bf084b |
218 | }; |
2daff231 |
219 | } |
220 | |
5b094c87 |
221 | foo(); |
222 | |
9fe4eeb3 |
223 | Beginning with version 1.008 L<Log::Dispatchouli> also works out of the box |
224 | with C<Log::Contextual>: |
225 | |
226 | use Log::Contextual qw( :log :dlog set_logger ); |
227 | use Log::Dispatchouli; |
228 | my $ld = Log::Dispatchouli->new({ |
229 | ident => 'slrtbrfst', |
230 | to_stderr => 1, |
231 | debug => 1, |
232 | }); |
233 | |
234 | set_logger $ld; |
235 | |
236 | log_debug { 'program started' }; |
237 | |
2daff231 |
238 | =head1 DESCRIPTION |
239 | |
30d7027a |
240 | Major benefits: |
241 | |
242 | =over 2 |
243 | |
244 | =item * Efficient |
245 | |
246 | The logging functions take blocks, so if a log level is disabled, the |
247 | block will not run: |
248 | |
249 | # the following won't run if debug is off |
250 | log_debug { "the new count in the database is " . $rs->count }; |
251 | |
252 | Similarly, the C<D> prefixed methods only C<Dumper> the input if the level is |
253 | enabled. |
254 | |
255 | =item * Handy |
256 | |
257 | The logging functions return their arguments, so you can stick them in |
258 | the middle of expressions: |
259 | |
260 | for (log_debug { "downloading:\n" . join qq(\n), @_ } @urls) { ... } |
261 | |
262 | =item * Generic |
263 | |
264 | C<Log::Contextual> is an interface for all major loggers. If you log through |
265 | C<Log::Contextual> you will be able to swap underlying loggers later. |
266 | |
267 | =item * Powerful |
268 | |
39cd2f65 |
269 | C<Log::Contextual> chooses which logger to use based on L<< user defined C<CodeRef>s|/LOGGER CODEREF >>. |
30d7027a |
270 | Normally you don't need to know this, but you can take advantage of it when you |
271 | need to later |
272 | |
273 | =item * Scalable |
274 | |
275 | If you just want to add logging to your extremely basic application, start with |
276 | L<Log::Contextual::SimpleLogger> and then as your needs grow you can switch to |
277 | L<Log::Dispatchouli> or L<Log::Dispatch> or L<Log::Log4perl> or whatever else. |
278 | |
279 | =back |
280 | |
281 | This module is a simple interface to extensible logging. It exists to |
282 | abstract your logging interface so that logging is as painless as possible, |
283 | while still allowing you to switch from one logger to another. |
3dc9bd3c |
284 | |
30d7027a |
285 | It is bundled with a really basic logger, L<Log::Contextual::SimpleLogger>, |
286 | but in general you should use a real logger instead of that. For something |
287 | more serious but not overly complicated, try L<Log::Dispatchouli> (see |
288 | L</SYNOPSIS> for example.) |
a2af6976 |
289 | |
e36f2183 |
290 | =head1 A WORK IN PROGRESS |
291 | |
292 | This module is certainly not complete, but we will not break the interface |
293 | lightly, so I would say it's safe to use in production code. The main result |
294 | from that at this point is that doing: |
295 | |
296 | use Log::Contextual; |
297 | |
298 | will die as we do not yet know what the defaults should be. If it turns out |
299 | that nearly everyone uses the C<:log> tag and C<:dlog> is really rare, we'll |
300 | probably make C<:log> the default. But only time and usage will tell. |
301 | |
302 | =head1 IMPORT OPTIONS |
303 | |
304 | See L</SETTING DEFAULT IMPORT OPTIONS> for information on setting these project |
305 | wide. |
3dc9bd3c |
306 | |
c154d18a |
307 | =head2 -logger |
308 | |
3dc9bd3c |
309 | When you import this module you may use C<-logger> as a shortcut for |
436c4b82 |
310 | L</set_logger>, for example: |
3dc9bd3c |
311 | |
312 | use Log::Contextual::SimpleLogger; |
9b8e24d5 |
313 | use Log::Contextual qw( :dlog ), |
314 | -logger => Log::Contextual::SimpleLogger->new({ levels => [qw( debug )] }); |
3dc9bd3c |
315 | |
316 | sometimes you might want to have the logger handy for other stuff, in which |
317 | case you might try something like the following: |
318 | |
319 | my $var_log; |
320 | BEGIN { $var_log = VarLogger->new } |
9b8e24d5 |
321 | use Log::Contextual qw( :dlog ), -logger => $var_log; |
3dc9bd3c |
322 | |
5fd26f45 |
323 | =head2 -levels |
324 | |
325 | The C<-levels> import option allows you to define exactly which levels your |
326 | logger supports. So the default, |
327 | C<< [qw(debug trace warn info error fatal)] >>, works great for |
328 | L<Log::Log4perl>, but it doesn't support the levels for L<Log::Dispatch>. But |
329 | supporting those levels is as easy as doing |
330 | |
331 | use Log::Contextual |
332 | -levels => [qw( debug info notice warning error critical alert emergency )]; |
333 | |
e2b4b29c |
334 | =head2 -package_logger |
335 | |
336 | The C<-package_logger> import option is similar to the C<-logger> import option |
44d86a53 |
337 | except C<-package_logger> sets the logger for the current package. |
e2b4b29c |
338 | |
339 | Unlike L</-default_logger>, C<-package_logger> cannot be overridden with |
340 | L</set_logger>. |
341 | |
342 | package My::Package; |
343 | use Log::Contextual::SimpleLogger; |
344 | use Log::Contextual qw( :log ), |
345 | -package_logger => Log::Contextual::WarnLogger->new({ |
346 | env_prefix => 'MY_PACKAGE' |
347 | }); |
348 | |
349 | If you are interested in using this package for a module you are putting on |
350 | CPAN we recommend L<Log::Contextual::WarnLogger> for your package logger. |
351 | |
c154d18a |
352 | =head2 -default_logger |
353 | |
354 | The C<-default_logger> import option is similar to the C<-logger> import option |
44d86a53 |
355 | except C<-default_logger> sets the B<default> logger for the current package. |
c154d18a |
356 | |
357 | Basically it sets the logger to be used if C<set_logger> is never called; so |
358 | |
359 | package My::Package; |
360 | use Log::Contextual::SimpleLogger; |
361 | use Log::Contextual qw( :log ), |
362 | -default_logger => Log::Contextual::WarnLogger->new({ |
ae59bbe3 |
363 | env_prefix => 'MY_PACKAGE' |
c154d18a |
364 | }); |
365 | |
e36f2183 |
366 | =head1 SETTING DEFAULT IMPORT OPTIONS |
3dc9bd3c |
367 | |
e36f2183 |
368 | Eventually you will get tired of writing the following in every single one of |
369 | your packages: |
3dc9bd3c |
370 | |
e36f2183 |
371 | use Log::Log4perl; |
372 | use Log::Log4perl ':easy'; |
373 | BEGIN { Log::Log4perl->easy_init($DEBUG) } |
3dc9bd3c |
374 | |
e36f2183 |
375 | use Log::Contextual -logger => Log::Log4perl->get_logger; |
376 | |
377 | You can set any of the import options for your whole project if you define your |
378 | own C<Log::Contextual> subclass as follows: |
379 | |
380 | package MyApp::Log::Contextual; |
381 | |
382 | use base 'Log::Contextual'; |
383 | |
384 | use Log::Log4perl ':easy'; |
385 | Log::Log4perl->easy_init($DEBUG) |
386 | |
2b40dee5 |
387 | sub arg_default_logger { $_[1] || Log::Log4perl->get_logger } |
e36f2183 |
388 | sub arg_levels { [qw(debug trace warn info error fatal custom_level)] } |
e06303cd |
389 | sub default_import { ':log' } |
e36f2183 |
390 | |
2b40dee5 |
391 | # or maybe instead of default_logger |
e36f2183 |
392 | sub arg_package_logger { $_[1] } |
e36f2183 |
393 | |
2b40dee5 |
394 | # and almost definitely not this, which is only here for completeness |
395 | sub arg_logger { $_[1] } |
e36f2183 |
396 | |
2b40dee5 |
397 | Note the C<< $_[1] || >> in C<arg_default_logger>. All of these methods are |
398 | passed the values passed in from the arguments to the subclass, so you can |
399 | either throw them away, honor them, die on usage, or whatever. To be clear, |
400 | if you define your subclass, and someone uses it as follows: |
e36f2183 |
401 | |
2b40dee5 |
402 | use MyApp::Log::Contextual -default_logger => $foo, |
403 | -levels => [qw(bar baz biff)]; |
404 | |
405 | Your C<arg_default_logger> method will get C<$foo> and your C<arg_levels> |
e36f2183 |
406 | will get C<[qw(bar baz biff)]>; |
2daff231 |
407 | |
e06303cd |
408 | Additionally, the C<default_import> method is what happens if a user tries to |
409 | use your subclass with no arguments. The default just dies, but if you'd like |
410 | to change the default to import a tag merely return the tags you'd like to |
411 | import. So the following will all work: |
412 | |
413 | sub default_import { ':log' } |
414 | |
415 | sub default_import { ':dlog' } |
416 | |
417 | sub default_import { qw(:dlog :log ) } |
418 | |
436c4b82 |
419 | See L<Log::Contextual::Easy::Default> for an example of a subclass of |
420 | C<Log::Contextual> that makes use of default import options. |
421 | |
2daff231 |
422 | =head1 FUNCTIONS |
423 | |
424 | =head2 set_logger |
425 | |
426 | my $logger = WarnLogger->new; |
21431192 |
427 | set_logger $logger; |
428 | |
27141a7a |
429 | Arguments: L</LOGGER CODEREF> |
2daff231 |
430 | |
21431192 |
431 | C<set_logger> will just set the current logger to whatever you pass it. It |
432 | expects a C<CodeRef>, but if you pass it something else it will wrap it in a |
06e908c3 |
433 | C<CodeRef> for you. C<set_logger> is really meant only to be called from a |
434 | top-level script. To avoid foot-shooting the function will warn if you call it |
435 | more than once. |
2daff231 |
436 | |
437 | =head2 with_logger |
438 | |
439 | my $logger = WarnLogger->new; |
21431192 |
440 | with_logger $logger => sub { |
2daff231 |
441 | if (1 == 0) { |
442 | log_fatal { 'Non Logical Universe Detected' }; |
443 | } else { |
444 | log_info { 'All is good' }; |
445 | } |
80c3e48b |
446 | }; |
2daff231 |
447 | |
27141a7a |
448 | Arguments: L</LOGGER CODEREF>, C<CodeRef $to_execute> |
2daff231 |
449 | |
21431192 |
450 | C<with_logger> sets the logger for the scope of the C<CodeRef> C<$to_execute>. |
0e13e261 |
451 | As with L</set_logger>, C<with_logger> will wrap C<$returning_logger> with a |
21431192 |
452 | C<CodeRef> if needed. |
2daff231 |
453 | |
21431192 |
454 | =head2 log_$level |
2daff231 |
455 | |
0e13e261 |
456 | Import Tag: C<:log> |
3dc9bd3c |
457 | |
0e13e261 |
458 | Arguments: C<CodeRef $returning_message, @args> |
2daff231 |
459 | |
a4d67519 |
460 | C<log_$level> functions all work the same except that a different method |
21431192 |
461 | is called on the underlying C<$logger> object. The basic pattern is: |
2daff231 |
462 | |
0e13e261 |
463 | sub log_$level (&@) { |
21431192 |
464 | if ($logger->is_$level) { |
0e13e261 |
465 | $logger->$level(shift->(@_)); |
21431192 |
466 | } |
0e13e261 |
467 | @_ |
21431192 |
468 | } |
2daff231 |
469 | |
0e13e261 |
470 | Note that the function returns it's arguments. This can be used in a number of |
471 | ways, but often it's convenient just for partial inspection of passthrough data |
472 | |
473 | my @friends = log_trace { |
474 | 'friends list being generated, data from first friend: ' . |
475 | Dumper($_[0]->TO_JSON) |
476 | } generate_friend_list(); |
477 | |
478 | If you want complete inspection of passthrough data, take a look at the |
479 | L</Dlog_$level> functions. |
480 | |
a4d67519 |
481 | Which functions are exported depends on what was passed to L</-levels>. The |
482 | default (no C<-levels> option passed) would export: |
2daff231 |
483 | |
a4d67519 |
484 | =over 2 |
2daff231 |
485 | |
a4d67519 |
486 | =item log_trace |
2daff231 |
487 | |
a4d67519 |
488 | =item log_debug |
2daff231 |
489 | |
a4d67519 |
490 | =item log_info |
2daff231 |
491 | |
a4d67519 |
492 | =item log_warn |
2daff231 |
493 | |
a4d67519 |
494 | =item log_error |
2daff231 |
495 | |
a4d67519 |
496 | =item log_fatal |
2daff231 |
497 | |
a4d67519 |
498 | =back |
2daff231 |
499 | |
0e13e261 |
500 | =head2 logS_$level |
501 | |
502 | Import Tag: C<:log> |
503 | |
504 | Arguments: C<CodeRef $returning_message, Item $arg> |
505 | |
506 | This is really just a special case of the L</log_$level> functions. It forces |
507 | scalar context when that is what you need. Other than that it works exactly |
508 | same: |
509 | |
510 | my $friend = logS_trace { |
511 | 'I only have one friend: ' . Dumper($_[0]->TO_JSON) |
512 | } friend(); |
513 | |
514 | See also: L</DlogS_$level>. |
515 | |
21431192 |
516 | =head2 Dlog_$level |
517 | |
0e13e261 |
518 | Import Tag: C<:dlog> |
3dc9bd3c |
519 | |
0e13e261 |
520 | Arguments: C<CodeRef $returning_message, @args> |
2daff231 |
521 | |
0e13e261 |
522 | All of the following six functions work the same as their L</log_$level> |
9b8e24d5 |
523 | brethren, except they return what is passed into them and put the stringified |
21431192 |
524 | (with L<Data::Dumper::Concise>) version of their args into C<$_>. This means |
525 | you can do cool things like the following: |
526 | |
527 | my @nicks = Dlog_debug { "names: $_" } map $_->value, $frew->names->all; |
528 | |
529 | and the output might look something like: |
530 | |
531 | names: "fREW" |
532 | "fRIOUX" |
533 | "fROOH" |
534 | "fRUE" |
535 | "fiSMBoC" |
536 | |
a4d67519 |
537 | Which functions are exported depends on what was passed to L</-levels>. The |
538 | default (no C<-levels> option passed) would export: |
21431192 |
539 | |
a4d67519 |
540 | =over 2 |
21431192 |
541 | |
a4d67519 |
542 | =item Dlog_trace |
21431192 |
543 | |
a4d67519 |
544 | =item Dlog_debug |
21431192 |
545 | |
a4d67519 |
546 | =item Dlog_info |
21431192 |
547 | |
a4d67519 |
548 | =item Dlog_warn |
21431192 |
549 | |
a4d67519 |
550 | =item Dlog_error |
2daff231 |
551 | |
a4d67519 |
552 | =item Dlog_fatal |
2daff231 |
553 | |
a4d67519 |
554 | =back |
2daff231 |
555 | |
83b33eb5 |
556 | =head2 DlogS_$level |
557 | |
0e13e261 |
558 | Import Tag: C<:dlog> |
3dc9bd3c |
559 | |
0e13e261 |
560 | Arguments: C<CodeRef $returning_message, Item $arg> |
83b33eb5 |
561 | |
0e13e261 |
562 | Like L</logS_$level>, these functions are a special case of L</Dlog_$level>. |
563 | They only take a single scalar after the C<$returning_message> instead of |
564 | slurping up (and also setting C<wantarray>) all the C<@args> |
83b33eb5 |
565 | |
566 | my $pals_rs = DlogS_debug { "pals resultset: $_" } |
567 | $schema->resultset('Pals')->search({ perlers => 1 }); |
568 | |
27141a7a |
569 | =head1 LOGGER CODEREF |
570 | |
571 | Anywhere a logger object can be passed, a coderef is accepted. This is so |
572 | that the user can use different logger objects based on runtime information. |
573 | The logger coderef is passed the package of the caller the caller level the |
574 | coderef needs to use if it wants more caller information. The latter is in |
575 | a hashref to allow for more options in the future. |
576 | |
37a8266a |
577 | Here is a basic example of a logger that exploits C<caller> to reproduce the |
578 | output of C<warn> with a logger: |
579 | |
580 | my @caller_info; |
581 | my $var_log = Log::Contextual::SimpleLogger->new({ |
582 | levels => [qw(trace debug info warn error fatal)], |
583 | coderef => sub { chomp($_[0]); warn "$_[0] at $caller_info[1] line $caller_info[2].\n" } |
584 | }); |
585 | my $warn_faker = sub { |
586 | my ($package, $args) = @_; |
587 | @caller_info = caller($args->{caller_level}); |
588 | $var_log |
589 | }; |
590 | set_logger($warn_faker); |
591 | log_debug { 'test' }; |
592 | |
27141a7a |
593 | The following is an example that uses the information passed to the logger |
594 | coderef. It sets the global logger to C<$l3>, the logger for the C<A1> |
595 | package to C<$l1>, except the C<lol> method in C<A1> which uses the C<$l2> |
596 | logger and lastly the logger for the C<A2> package to C<$l2>. |
597 | |
37a8266a |
598 | Note that it increases the caller level as it dispatches based on where |
599 | the caller of the log function, not the log function itself. |
600 | |
27141a7a |
601 | my $complex_dispatcher = do { |
602 | |
603 | my $l1 = ...; |
604 | my $l2 = ...; |
605 | my $l3 = ...; |
606 | |
607 | my %registry = ( |
608 | -logger => $l3, |
609 | A1 => { |
610 | -logger => $l1, |
611 | lol => $l2, |
612 | }, |
613 | A2 => { -logger => $l2 }, |
614 | ); |
615 | |
616 | sub { |
617 | my ( $package, $info ) = @_; |
618 | |
619 | my $logger = $registry{'-logger'}; |
620 | if (my $r = $registry{$package}) { |
621 | $logger = $r->{'-logger'} if $r->{'-logger'}; |
37a8266a |
622 | my (undef, undef, undef, $sub) = caller($info->{caller_level} + 1); |
27141a7a |
623 | $sub =~ s/^\Q$package\E:://g; |
624 | $logger = $r->{$sub} if $r->{$sub}; |
625 | } |
626 | return $logger; |
627 | } |
628 | }; |
629 | |
630 | set_logger $complex_dispatcher; |
631 | |
3dc9bd3c |
632 | =head1 LOGGER INTERFACE |
633 | |
634 | Because this module is ultimately pretty looking glue (glittery?) with the |
635 | awesome benefit of the Contextual part, users will often want to make their |
636 | favorite logger work with it. The following are the methods that should be |
637 | implemented in the logger: |
638 | |
639 | is_trace |
640 | is_debug |
641 | is_info |
642 | is_warn |
643 | is_error |
644 | is_fatal |
645 | trace |
646 | debug |
647 | info |
648 | warn |
649 | error |
650 | fatal |
651 | |
652 | The first six merely need to return true if that level is enabled. The latter |
653 | six take the results of whatever the user returned from their coderef and log |
654 | them. For a basic example see L<Log::Contextual::SimpleLogger>. |
655 | |
eab2ca3c |
656 | =head1 LOG ROUTING |
657 | |
a5454e75 |
658 | In between the loggers and the log functions is a log router that is responsible for |
eab2ca3c |
659 | finding a logger to handle the log event and passing the log information to the |
a5454e75 |
660 | logger. This relationship is described in the documentation for C<Log::Contextual::Role::Router>. |
eab2ca3c |
661 | |
a5454e75 |
662 | C<Log::Contextual> and packages that extend it will by default share a router singleton that |
663 | implements the with_logger() and set_logger() functions and also respects the -logger, |
664 | -package_logger, and -default_logger import options with their associated default value |
665 | functions. The router singleton is available as the return value of the router() function. Users |
666 | of Log::Contextual may overload router() to return instances of custom log routers that |
667 | could for example work with loggers that use a different interface. |
eab2ca3c |
668 | |
a5454e75 |
669 | =head1 CONTRIBUTORS |
670 | |
436c4b82 |
671 | =encoding utf8 |
672 | |
eab2ca3c |
673 | triddle - Tyler Riddle <t.riddle@shadowcat.co.uk> |
674 | |
436c4b82 |
675 | voj - Jakob Voß <voss@gbv.de> |
676 | |
2daff231 |
677 | =head1 DESIGNER |
678 | |
679 | mst - Matt S. Trout <mst@shadowcat.co.uk> |
680 | |
2daff231 |
681 | =cut |
682 | |