X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FLog%2FContextual.pm;h=1d0a1dca966de1903ba032dd5c71811c41d98f46;hb=0c180ced3d15f9851c4ae1cf4ea984c026f67b3f;hp=9aa4fb2e62d944db2c0400890a76320b215065c8;hpb=9b8e24d58f78b5d0119c0d166cf4a52584da2140;p=p5sagit%2FLog-Contextual.git

diff --git a/lib/Log/Contextual.pm b/lib/Log/Contextual.pm
index 9aa4fb2..1d0a1dc 100644
--- a/lib/Log/Contextual.pm
+++ b/lib/Log/Contextual.pm
@@ -3,218 +3,172 @@ package Log::Contextual;
 use strict;
 use warnings;
 
-our $VERSION = '0.00100';
+our $VERSION = '0.004202';
 
-require Exporter;
+my @levels = qw(debug trace warn info error fatal);
+
+use Exporter::Declare;
+use Exporter::Declare::Export::Generator;
 use Data::Dumper::Concise;
+use Scalar::Util 'blessed';
+
+my @dlog = ((map "Dlog_$_", @levels), (map "DlogS_$_", @levels));
+
+my @log = ((map "log_$_", @levels), (map "logS_$_", @levels));
+
+eval {
+   require Log::Log4perl;
+   die if $Log::Log4perl::VERSION < 1.29;
+   Log::Log4perl->wrapper_register(__PACKAGE__)
+};
+
+# ____ is because tags must have at least one export and we don't want to
+# export anything but the levels selected
+sub ____ {}
 
-BEGIN { our @ISA = qw(Exporter) }
-
-my @dlog = (qw(
-   Dlog_debug DlogS_debug
-   Dlog_trace DlogS_trace
-   Dlog_warn DlogS_warn
-   Dlog_info DlogS_info
-   Dlog_error DlogS_error
-   Dlog_fatal DlogS_fatal
- ));
-
-my @log = (qw(
-   log_debug
-   log_trace
-   log_warn
-   log_info
-   log_error
-   log_fatal
- ));
-
-our @EXPORT_OK = (
+exports ('____',
    @dlog, @log,
    qw( set_logger with_logger )
 );
 
-our %EXPORT_TAGS = (
-   dlog => \@dlog,
-   log  => \@log,
-   all  => [@dlog, @log],
-);
+export_tag dlog => ('____');
+export_tag log  => ('____');
+import_arguments qw(logger package_logger default_logger);
 
-sub import {
-   my $package = shift;
-   die 'Log::Contextual does not have a default import list'
-      unless @_;
+sub before_import {
+   my ($class, $importer, $spec) = @_;
 
-   for my $idx ( 0 .. $#_ ) {
-      if ( $_[$idx] eq '-logger' ) {
-         set_logger($_[$idx + 1]);
-         splice @_, $idx, 2;
-         last;
+   die 'Log::Contextual does not have a default import list'
+      if $spec->config->{default};
+
+   my @levels = @{$class->arg_levels($spec->config->{levels})};
+   for my $level (@levels) {
+      if ($spec->config->{log}) {
+         $spec->add_export("&log_$level", sub (&@) {
+            _do_log( $level => _get_logger( caller ), shift @_, @_)
+         });
+         $spec->add_export("&logS_$level", sub (&@) {
+            _do_logS( $level => _get_logger( caller ), $_[0], $_[1])
+         });
+      }
+      if ($spec->config->{dlog}) {
+         $spec->add_export("&Dlog_$level", sub (&@) {
+           my ($code, @args) = @_;
+           return _do_log( $level => _get_logger( caller ), sub {
+              local $_ = (@args?Data::Dumper::Concise::Dumper @args:'()');
+              $code->(@_)
+           }, @args );
+         });
+         $spec->add_export("&DlogS_$level", sub (&$) {
+           my ($code, $ref) = @_;
+           _do_logS( $level => _get_logger( caller ), sub {
+              local $_ = Data::Dumper::Concise::Dumper $ref;
+              $code->($ref)
+           }, $ref )
+         });
       }
    }
-   $package->export_to_level(1, $package, @_);
 }
 
-our $Get_Logger;
-
-sub set_logger {
-   my $logger = $_[0];
-   $logger = do { my $l = $logger; sub { $l } }
-      if ref $logger ne 'CODE';
-   $Get_Logger = $logger;
-}
-
-sub with_logger {
-   my $logger = $_[0];
-   $logger = do { my $l = $logger; sub { $l } }
-      if ref $logger ne 'CODE';
-   local $Get_Logger = $logger;
-   $_[1]->();
-}
-
-sub log_trace (&) {
-   my $log = $Get_Logger->();
-   $log->trace($_[0]->())
-      if $log->is_trace;
-}
-
-sub log_debug (&) {
-   my $log = $Get_Logger->();
-   $log->debug($_[0]->())
-      if $log->is_debug;
-}
-
-sub log_info (&) {
-   my $log = $Get_Logger->();
-   $log->info($_[0]->())
-      if $log->is_info;
-}
-
-sub log_warn (&) {
-   my $log = $Get_Logger->();
-   $log->warn($_[0]->())
-      if $log->is_warn;
-}
-
-sub log_error (&) {
-   my $log = $Get_Logger->();
-   $log->error($_[0]->())
-      if $log->is_error;
-}
-
-sub log_fatal (&) {
-   my $log = $Get_Logger->();
-   $log->fatal($_[0]->())
-      if $log->is_fatal;
-}
+sub arg_logger { $_[1] }
+sub arg_levels { $_[1] || [qw(debug trace warn info error fatal)] }
+sub arg_package_logger { $_[1] }
+sub arg_default_logger { $_[1] }
 
+sub after_import {
+   my ($class, $importer, $specs) = @_;
 
+   if (my $l = $class->arg_logger($specs->config->{logger})) {
+      set_logger($l)
+   }
 
-sub Dlog_trace (&@) {
-  my $code = shift;
-  my @values = @_;
-  log_trace {
-     do { local $_ = Data::Dumper::Concise::Dumper @values; $code->() };
-  };
-  @values
-}
+   if (my $l = $class->arg_package_logger($specs->config->{package_logger})) {
+      _set_package_logger_for($importer, $l)
+   }
 
-sub DlogS_trace (&$) {
-  my $code = $_[0];
-  my $value = $_[1];
-  log_trace {
-     do { local $_ = Data::Dumper::Concise::Dumper $value; $code->() };
-  };
-  $value
+   if (my $l = $class->arg_default_logger($specs->config->{default_logger})) {
+      _set_default_logger_for($importer, $l)
+   }
 }
 
-sub Dlog_debug (&@) {
-  my $code = shift;
-  my @values = @_;
-  log_debug {
-     do { local $_ = Data::Dumper::Concise::Dumper @values; $code->() };
-  };
-  @values
+our $Get_Logger;
+our %Default_Logger;
+our %Package_Logger;
+
+sub _set_default_logger_for {
+   my $logger = $_[1];
+   if(ref $logger ne 'CODE') {
+      die 'logger was not a CodeRef or a logger object.  Please try again.'
+         unless blessed($logger);
+      $logger = do { my $l = $logger; sub { $l } }
+   }
+   $Default_Logger{$_[0]} = $logger
 }
 
-sub DlogS_debug (&$) {
-  my $code = $_[0];
-  my $value = $_[1];
-  log_debug {
-     do { local $_ = Data::Dumper::Concise::Dumper $value; $code->() };
-  };
-  $value
+sub _set_package_logger_for {
+   my $logger = $_[1];
+   if(ref $logger ne 'CODE') {
+      die 'logger was not a CodeRef or a logger object.  Please try again.'
+         unless blessed($logger);
+      $logger = do { my $l = $logger; sub { $l } }
+   }
+   $Package_Logger{$_[0]} = $logger
 }
 
-sub Dlog_info (&@) {
-  my $code = shift;
-  my @values = @_;
-  log_info {
-     do { local $_ = Data::Dumper::Concise::Dumper @values; $code->() };
-  };
-  @values
+sub _get_logger($) {
+   my $package = shift;
+   (
+      $Package_Logger{$package} ||
+      $Get_Logger ||
+      $Default_Logger{$package} ||
+      die q( no logger set!  you can't try to log something without a logger! )
+   )->($package, { caller_level => 2 });
 }
 
-sub DlogS_info (&$) {
-  my $code = $_[0];
-  my $value = $_[1];
-  log_info {
-     do { local $_ = Data::Dumper::Concise::Dumper $value; $code->() };
-  };
-  $value
-}
+sub set_logger {
+   my $logger = $_[0];
+   if(ref $logger ne 'CODE') {
+      die 'logger was not a CodeRef or a logger object.  Please try again.'
+         unless blessed($logger);
+      $logger = do { my $l = $logger; sub { $l } }
+   }
 
-sub Dlog_warn (&@) {
-  my $code = shift;
-  my @values = @_;
-  log_warn {
-     do { local $_ = Data::Dumper::Concise::Dumper @values; $code->() };
-  };
-  @values
+   warn 'set_logger (or -logger) called more than once!  This is a bad idea!'
+      if $Get_Logger;
+   $Get_Logger = $logger;
 }
 
-sub DlogS_warn (&$) {
-  my $code = $_[0];
-  my $value = $_[1];
-  log_warn {
-     do { local $_ = Data::Dumper::Concise::Dumper $value; $code->() };
-  };
-  $value
+sub with_logger {
+   my $logger = $_[0];
+   if(ref $logger ne 'CODE') {
+      die 'logger was not a CodeRef or a logger object.  Please try again.'
+         unless blessed($logger);
+      $logger = do { my $l = $logger; sub { $l } }
+   }
+   local $Get_Logger = $logger;
+   $_[1]->();
 }
 
-sub Dlog_error (&@) {
-  my $code = shift;
-  my @values = @_;
-  log_error {
-     do { local $_ = Data::Dumper::Concise::Dumper @values; $code->() };
-  };
-  @values
-}
+sub _do_log {
+   my $level  = shift;
+   my $logger = shift;
+   my $code   = shift;
+   my @values = @_;
 
-sub DlogS_error (&$) {
-  my $code = $_[0];
-  my $value = $_[1];
-  log_error {
-     do { local $_ = Data::Dumper::Concise::Dumper $value; $code->() };
-  };
-  $value
+   $logger->$level($code->(@_))
+      if $logger->${\"is_$level"};
+   @values
 }
 
-sub Dlog_fatal (&@) {
-  my $code = shift;
-  my @values = @_;
-  log_fatal {
-     do { local $_ = Data::Dumper::Concise::Dumper @values; $code->() };
-  };
-  @values
-}
+sub _do_logS {
+   my $level  = shift;
+   my $logger = shift;
+   my $code   = shift;
+   my $value  = shift;
 
-sub DlogS_fatal (&$) {
-  my $code = $_[0];
-  my $value = $_[1];
-  log_fatal {
-     do { local $_ = Data::Dumper::Concise::Dumper $value; $code->() };
-  };
-  $value
+   $logger->$level($code->($value))
+      if $logger->${\"is_$level"};
+   $value
 }
 
 1;
@@ -227,34 +181,118 @@ Log::Contextual - Simple logging interface with a contextual log
 
 =head1 SYNOPSIS
 
- use Log::Log4perl;
  use Log::Contextual qw( :log :dlog set_logger with_logger );
+ use Log::Contextual::SimpleLogger;
+ use Log::Log4perl ':easy';
+ Log::Log4perl->easy_init($DEBUG);
 
- my $logger  = sub { Log::Log4perl->get_logger };
+ my $logger  = Log::Log4perl->get_logger;
 
- set_logger { $logger };
+ set_logger $logger;
 
  log_debug { 'program started' };
 
  sub foo {
-   with_logger(Log::Contextual::SimpleLogger->new({
-       levels => [qw( trace debug )]
-     }) => sub {
+
+   my $minilogger = Log::Contextual::SimpleLogger->new({
+     levels => [qw( trace debug )]
+   });
+
+   with_logger $minilogger => sub {
      log_trace { 'foo entered' };
      my ($foo, $bar) = Dlog_trace { "params for foo: $_" } @_;
      # ...
      log_trace { 'foo left' };
-   });
+   };
  }
 
+ foo();
+
+Beginning with version 1.008 L<Log::Dispatchouli> also works out of the box
+with C<Log::Contextual>:
+
+ use Log::Contextual qw( :log :dlog set_logger );
+ use Log::Dispatchouli;
+ my $ld = Log::Dispatchouli->new({
+    ident     => 'slrtbrfst',
+    to_stderr => 1,
+    debug     => 1,
+ });
+
+ set_logger $ld;
+
+ log_debug { 'program started' };
+
 =head1 DESCRIPTION
 
-This module is a simple interface to extensible logging.  It is bundled with a
-really basic logger, L<Log::Contextual::SimpleLogger>, but in general you
-should use a real logger instead of that.  For something more serious but not
-overly complicated, take a look at L<Log::Dispatchouli>.
+Major benefits:
+
+=over 2
+
+=item * Efficient
+
+The logging functions take blocks, so if a log level is disabled, the
+block will not run:
+
+ # the following won't run if debug is off
+ log_debug { "the new count in the database is " . $rs->count };
+
+Similarly, the C<D> prefixed methods only C<Dumper> the input if the level is
+enabled.
+
+=item * Handy
+
+The logging functions return their arguments, so you can stick them in
+the middle of expressions:
+
+ for (log_debug { "downloading:\n" . join qq(\n), @_ } @urls) { ... }
+
+=item * Generic
+
+C<Log::Contextual> is an interface for all major loggers.  If you log through
+C<Log::Contextual> you will be able to swap underlying loggers later.
+
+=item * Powerful
 
-=head1 OPTIONS
+C<Log::Contextual> chooses which logger to use based on L<< user defined C<CodeRef>s|/LOGGER CODEREF >>.
+Normally you don't need to know this, but you can take advantage of it when you
+need to later
+
+=item * Scalable
+
+If you just want to add logging to your extremely basic application, start with
+L<Log::Contextual::SimpleLogger> and then as your needs grow you can switch to
+L<Log::Dispatchouli> or L<Log::Dispatch> or L<Log::Log4perl> or whatever else.
+
+=back
+
+This module is a simple interface to extensible logging.  It exists to
+abstract your logging interface so that logging is as painless as possible,
+while still allowing you to switch from one logger to another.
+
+It is bundled with a really basic logger, L<Log::Contextual::SimpleLogger>,
+but in general you should use a real logger instead of that.  For something
+more serious but not overly complicated, try L<Log::Dispatchouli> (see
+L</SYNOPSIS> for example.)
+
+=head1 A WORK IN PROGRESS
+
+This module is certainly not complete, but we will not break the interface
+lightly, so I would say it's safe to use in production code.  The main result
+from that at this point is that doing:
+
+ use Log::Contextual;
+
+will die as we do not yet know what the defaults should be.  If it turns out
+that nearly everyone uses the C<:log> tag and C<:dlog> is really rare, we'll
+probably make C<:log> the default.  But only time and usage will tell.
+
+=head1 IMPORT OPTIONS
+
+See L</SETTING DEFAULT IMPORT OPTIONS> for information on setting these project
+wide.
+
+=head2 -logger
 
 When you import this module you may use C<-logger> as a shortcut for
 L<set_logger>, for example:
@@ -270,17 +308,89 @@ case you might try something like the following:
  BEGIN { $var_log = VarLogger->new }
  use Log::Contextual qw( :dlog ), -logger => $var_log;
 
-=head1 A WORK IN PROGRESS
+=head2 -levels
 
-This module is certainly not complete, but we will not break the interface
-lightly, so I would say it's safe to use in production code.  The main result
-from that at this point is that doing:
+The C<-levels> import option allows you to define exactly which levels your
+logger supports.  So the default,
+C<< [qw(debug trace warn info error fatal)] >>, works great for
+L<Log::Log4perl>, but it doesn't support the levels for L<Log::Dispatch>.  But
+supporting those levels is as easy as doing
 
- use Log::Contextual;
+ use Log::Contextual
+   -levels => [qw( debug info notice warning error critical alert emergency )];
 
-will die as we do not yet know what the defaults should be.  If it turns out
-that nearly everyone uses the C<:log> tag and C<:dlog> is really rare, we'll
-probably make C<:log> the default.  But only time and usage will tell.
+=head2 -package_logger
+
+The C<-package_logger> import option is similar to the C<-logger> import option
+except C<-package_logger> sets the the logger for the current package.
+
+Unlike L</-default_logger>, C<-package_logger> cannot be overridden with
+L</set_logger>.
+
+ package My::Package;
+ use Log::Contextual::SimpleLogger;
+ use Log::Contextual qw( :log ),
+   -package_logger => Log::Contextual::WarnLogger->new({
+      env_prefix => 'MY_PACKAGE'
+   });
+
+If you are interested in using this package for a module you are putting on
+CPAN we recommend L<Log::Contextual::WarnLogger> for your package logger.
+
+=head2 -default_logger
+
+The C<-default_logger> import option is similar to the C<-logger> import option
+except C<-default_logger> sets the the B<default> logger for the current package.
+
+Basically it sets the logger to be used if C<set_logger> is never called; so
+
+ package My::Package;
+ use Log::Contextual::SimpleLogger;
+ use Log::Contextual qw( :log ),
+   -default_logger => Log::Contextual::WarnLogger->new({
+      env_prefix => 'MY_PACKAGE'
+   });
+
+=head1 SETTING DEFAULT IMPORT OPTIONS
+
+Eventually you will get tired of writing the following in every single one of
+your packages:
+
+ use Log::Log4perl;
+ use Log::Log4perl ':easy';
+ BEGIN { Log::Log4perl->easy_init($DEBUG) }
+
+ use Log::Contextual -logger => Log::Log4perl->get_logger;
+
+You can set any of the import options for your whole project if you define your
+own C<Log::Contextual> subclass as follows:
+
+ package MyApp::Log::Contextual;
+
+ use base 'Log::Contextual';
+
+ use Log::Log4perl ':easy';
+ Log::Log4perl->easy_init($DEBUG)
+
+ sub arg_default_logger { $_[1] || Log::Log4perl->get_logger }
+ sub arg_levels { [qw(debug trace warn info error fatal custom_level)] }
+
+ # or maybe instead of default_logger
+ sub arg_package_logger { $_[1] }
+
+ # and almost definitely not this, which is only here for completeness
+ sub arg_logger { $_[1] }
+
+Note the C<< $_[1] || >> in C<arg_default_logger>.  All of these methods are
+passed the values passed in from the arguments to the subclass, so you can
+either throw them away, honor them, die on usage, or whatever.  To be clear,
+if you define your subclass, and someone uses it as follows:
+
+ use MyApp::Log::Contextual -default_logger => $foo,
+                            -levels => [qw(bar baz biff)];
+
+Your C<arg_default_logger> method will get C<$foo> and your C<arg_levels>
+will get C<[qw(bar baz biff)]>;
 
 =head1 FUNCTIONS
 
@@ -289,11 +399,13 @@ probably make C<:log> the default.  But only time and usage will tell.
  my $logger = WarnLogger->new;
  set_logger $logger;
 
-Arguments: Ref|CodeRef $returning_logger
+Arguments: L</LOGGER CODEREF>
 
 C<set_logger> will just set the current logger to whatever you pass it.  It
 expects a C<CodeRef>, but if you pass it something else it will wrap it in a
-C<CodeRef> for you.
+C<CodeRef> for you.  C<set_logger> is really meant only to be called from a
+top-level script.  To avoid foot-shooting the function will warn if you call it
+more than once.
 
 =head2 with_logger
 
@@ -306,58 +418,81 @@ C<CodeRef> for you.
     }
  };
 
-Arguments: Ref|CodeRef $returning_logger, CodeRef $to_execute
+Arguments: L</LOGGER CODEREF>, C<CodeRef $to_execute>
 
 C<with_logger> sets the logger for the scope of the C<CodeRef> C<$to_execute>.
-As with L<set_logger>, C<with_logger> will wrap C<$returning_logger> with a
+As with L</set_logger>, C<with_logger> will wrap C<$returning_logger> with a
 C<CodeRef> if needed.
 
 =head2 log_$level
 
-Import Tag: ":log"
+Import Tag: C<:log>
 
-Arguments: CodeRef $returning_message
+Arguments: C<CodeRef $returning_message, @args>
 
-All of the following six functions work the same except that a different method
+C<log_$level> functions all work the same except that a different method
 is called on the underlying C<$logger> object.  The basic pattern is:
 
- sub log_$level (&) {
+ sub log_$level (&@) {
    if ($logger->is_$level) {
-     $logger->$level(shift->());
+     $logger->$level(shift->(@_));
    }
+   @_
  }
 
-=head3 log_trace
+Note that the function returns it's arguments.  This can be used in a number of
+ways, but often it's convenient just for partial inspection of passthrough data
+
+ my @friends = log_trace {
+   'friends list being generated, data from first friend: ' .
+     Dumper($_[0]->TO_JSON)
+ } generate_friend_list();
+
+If you want complete inspection of passthrough data, take a look at the
+L</Dlog_$level> functions.
+
+Which functions are exported depends on what was passed to L</-levels>.  The
+default (no C<-levels> option passed) would export:
 
- log_trace { 'entered method foo with args ' join q{,}, @args };
+=over 2
 
-=head3 log_debug
+=item log_trace
 
- log_debug { 'entered method foo' };
+=item log_debug
 
-=head3 log_info
+=item log_info
 
- log_info { 'started process foo' };
+=item log_warn
 
-=head3 log_warn
+=item log_error
 
- log_warn { 'possible misconfiguration at line 10' };
+=item log_fatal
 
-=head3 log_error
+=back
 
- log_error { 'non-numeric user input!' };
+=head2 logS_$level
 
-=head3 log_fatal
+Import Tag: C<:log>
 
- log_fatal { '1 is never equal to 0!' };
+Arguments: C<CodeRef $returning_message, Item $arg>
+
+This is really just a special case of the L</log_$level> functions.  It forces
+scalar context when that is what you need.  Other than that it works exactly
+same:
+
+ my $friend = logS_trace {
+   'I only have one friend: ' .  Dumper($_[0]->TO_JSON)
+ } friend();
+
+See also: L</DlogS_$level>.
 
 =head2 Dlog_$level
 
-Import Tag: ":dlog"
+Import Tag: C<:dlog>
 
-Arguments: CodeRef $returning_message, @args
+Arguments: C<CodeRef $returning_message, @args>
 
-All of the following six functions work the same as their L<log_$level>
+All of the following six functions work the same as their L</log_$level>
 brethren, except they return what is passed into them and put the stringified
 (with L<Data::Dumper::Concise>) version of their args into C<$_>.  This means
 you can do cool things like the following:
@@ -372,68 +507,100 @@ and the output might look something like:
  "fRUE"
  "fiSMBoC"
 
-=head3 Dlog_trace
-
- my ($foo, $bar) = Dlog_trace { "entered method foo with args: $_" } @_;
-
-=head3 Dlog_debug
+Which functions are exported depends on what was passed to L</-levels>.  The
+default (no C<-levels> option passed) would export:
 
- Dlog_debug { "random data structure: $_" } { foo => $bar };
+=over 2
 
-=head3 Dlog_info
+=item Dlog_trace
 
- return Dlog_info { "html from method returned: $_" } "<html>...</html>";
+=item Dlog_debug
 
-=head3 Dlog_warn
+=item Dlog_info
 
- Dlog_warn { "probably invalid value: $_" } $foo;
+=item Dlog_warn
 
-=head3 Dlog_error
+=item Dlog_error
 
- Dlog_error { "non-numeric user input! ($_)" } $port;
+=item Dlog_fatal
 
-=head3 Dlog_fatal
-
- Dlog_fatal { '1 is never equal to 0!' } 'ZOMG ZOMG' if 1 == 0;
+=back
 
 =head2 DlogS_$level
 
-Import Tag: ":dlog"
+Import Tag: C<:dlog>
 
-Arguments: CodeRef $returning_message, Item $arg
+Arguments: C<CodeRef $returning_message, Item $arg>
 
-All of the following six functions work the same as the related L<Dlog_$level>
-functions, except they only take a single scalar after the
-C<$returning_message> instead of slurping up (and also setting C<wantarray>)
-all the C<@args>
+Like L</logS_$level>, these functions are a special case of L</Dlog_$level>.
+They only take a single scalar after the C<$returning_message> instead of
+slurping up (and also setting C<wantarray>) all the C<@args>
 
  my $pals_rs = DlogS_debug { "pals resultset: $_" }
    $schema->resultset('Pals')->search({ perlers => 1 });
 
-=head3 DlogS_trace
-
- my ($foo, $bar) =
-   DlogS_trace { "entered method foo with first arg $_" } $_[0], $_[1];
-
-=head3 DlogS_debug
-
- DlogS_debug { "random data structure: $_" } { foo => $bar };
-
-=head3 DlogS_info
-
- return DlogS_info { "html from method returned: $_" } "<html>...</html>";
-
-=head3 DlogS_warn
-
- DlogS_warn { "probably invalid value: $_" } $foo;
-
-=head3 DlogS_error
-
- DlogS_error { "non-numeric user input! ($_)" } $port;
-
-=head3 DlogS_fatal
+=head1 LOGGER CODEREF
+
+Anywhere a logger object can be passed, a coderef is accepted.  This is so
+that the user can use different logger objects based on runtime information.
+The logger coderef is passed the package of the caller the caller level the
+coderef needs to use if it wants more caller information.  The latter is in
+a hashref to allow for more options in the future.
+
+Here is a basic example of a logger that exploits C<caller> to reproduce the
+output of C<warn> with a logger:
+
+ my @caller_info;
+ my $var_log = Log::Contextual::SimpleLogger->new({
+    levels  => [qw(trace debug info warn error fatal)],
+    coderef => sub { chomp($_[0]); warn "$_[0] at $caller_info[1] line $caller_info[2].\n" }
+ });
+ my $warn_faker = sub {
+    my ($package, $args) = @_;
+    @caller_info = caller($args->{caller_level});
+    $var_log
+ };
+ set_logger($warn_faker);
+ log_debug { 'test' };
+
+The following is an example that uses the information passed to the logger
+coderef.  It sets the global logger to C<$l3>, the logger for the C<A1>
+package to C<$l1>, except the C<lol> method in C<A1> which uses the C<$l2>
+logger and lastly the logger for the C<A2> package to C<$l2>.
+
+Note that it increases the caller level as it dispatches based on where
+the caller of the log function, not the log function itself.
+
+ my $complex_dispatcher = do {
+
+    my $l1 = ...;
+    my $l2 = ...;
+    my $l3 = ...;
+
+    my %registry = (
+       -logger => $l3,
+       A1 => {
+          -logger => $l1,
+          lol     => $l2,
+       },
+       A2 => { -logger => $l2 },
+    );
+
+    sub {
+       my ( $package, $info ) = @_;
+
+       my $logger = $registry{'-logger'};
+       if (my $r = $registry{$package}) {
+          $logger = $r->{'-logger'} if $r->{'-logger'};
+          my (undef, undef, undef, $sub) = caller($info->{caller_level} + 1);
+          $sub =~ s/^\Q$package\E:://g;
+          $logger = $r->{$sub} if $r->{$sub};
+       }
+       return $logger;
+    }
+ };
 
- DlogS_fatal { '1 is never equal to 0!' } 'ZOMG ZOMG' if 1 == 0;
+ set_logger $complex_dispatcher;
 
 =head1 LOGGER INTERFACE
 
@@ -469,7 +636,7 @@ mst - Matt S. Trout <mst@shadowcat.co.uk>
 
 =head1 COPYRIGHT
 
-Copyright (c) 2010 the Log::Contextual L</AUTHOR> and L</DESIGNER> as listed
+Copyright (c) 2012 the Log::Contextual L</AUTHOR> and L</DESIGNER> as listed
 above.
 
 =head1 LICENSE