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6 Log::Any::Adapter::Development - Manual for developing new Log::Any
7 adapters
8
10 version 1.710
11
13 The adapter module:
14 package Log::Any::Adapter::YAL;
16 use strict;
17 use warnings;
18 use Log::Any::Adapter::Util ();
19 use base qw(Log::Any::Adapter::Base);
20 # Optionally initialize object, e.g. for delegation
22 #
23 sub init {
24 my ($self) = @_;
25 $self->{attr} = ...;
27 }
28 # Create logging methods: debug, info, etc.
30 #
31 foreach my $method ( Log::Any::Adapter::Util::logging_methods() ) {
32 no strict 'refs';
33 *$method = sub { ... };
34 }
35 # or, support structured logging instead
37 sub structured {
38 my ($self, $level, $category, @args) = @_;
39 # ... process and log all @args
40 }
41 # Create detection methods: is_debug, is_info, etc.
44 #
45 foreach my $method ( Log::Any::Adapter::Util::detection_methods() ) {
46 no strict 'refs';
47 *$method = sub { ... };
48 }
49 and the application:
51 Log::Any->set_adapter('YAL');
53
55 This document describes how to implement a new Log::Any adapter.
56 The easiest way to start is to look at the source of existing adapters,
58 such as Log::Any::Adapter::Log4perl and Log::Any::Adapter::Dispatch.
59
61 If you are going to publicly release your adapter, call it
62 'Log::Any::Adapter::something' so that users can use it with
63 Log::Any->set_adapter(I<something>);
65 If it's an internal driver, you can call it whatever you like and use
67 it like
68 Log::Any->set_adapter('+My::Log::Adapter');
70
72 All adapters must directly or indirectly inherit from
73 Log::Any::Adapter::Base.
74
76 Log::Any supports the following log levels:
77 If the logging mechanism used by your adapter supports different
79 levels, it's your responsibility to map them appropriately when you
80 implement the logging and detection methods described below. For
81 example, if your mechanism only supports "debug", "normal" and "fatal"
82 levels, you might map the levels like this:
83
85 Constructor
86 The constructor ("new") is provided by Log::Any::Adapter::Base. It
87 will:
88 At this point, overriding the default constructor is not supported.
90 Hopefully it will not be needed.
91 The constructor is called whenever a log object is requested. e.g. If
93 the application initializes Log::Any like so:
94 Log::Any->set_adapter('Log::YAL', yal_object => $yal, depth => 3);
96 and then a class requests a logger like so:
98 package Foo;
100 use Log::Any qw($log);
101 Then $log will be populated with the return value of:
103 Log::Any::Adapter::Yal->new(yal_object => $yal, depth => 3, category => 'Foo');
105 This is memoized, so if the same category should be requested again
107 (e.g. through a separate "get_logger" call, the same object will be
108 returned. Therefore, you should try to avoid anything non-
109 deterministic in your "init" function.
110 Logging methods
112 The following methods have no default implementation, and MUST be
113 defined by your subclass, unless your adapter supports "Structured
114 logging":
115 These methods must log a message at the specified level.
117 To help generate these methods programmatically, you can get a list of
119 the sub names with the Log::Any::Adapter::Util::logging_methods
120 function.
121 Log-level detection methods (required)
123 The following methods have no default implementation, and MUST be
124 defined by your subclass:
125 These methods must return a boolean indicating whether the specified
127 level is active, i.e. whether the adapter is listening for messages of
128 that level.
129 To help generate these methods programmatically, you can get a list of
131 the sub names with the Log::Any::Adapter::Util::detection_methods
132 function.
133 Structured logging
135 Your adapter can choose to receive structured data instead of a string.
136 In this case, instead of implementing all the "Logging methods", you
137 define a single method called "structured". The method receives the log
138 level, the category, and all arguments that were passed to the logging
139 function, so be prepared to not only handle strings, but also hashrefs,
140 arrayrefs, coderefs, etc.
141 Aliases
143 Aliases (e.g. "err" for "error") are handled by Log::Any::Proxy and
144 will call the corresponding real name in your adapter class. You do
145 not need to implement them in your adapter.
146 Optional methods
148 The following methods have no default implementation but MAY be
149 provided by your subclass:
150 init
152 This is called after the adapter object is created and blessed into
153 your class. Perform any necessary validation or initialization
154 here. For example, you would use "init" to create a logging object
155 for delegation, or open a file or socket, etc.
156 Support methods
158 The following Log::Any::Adapter::Base method may be useful for defining
159 adapters via delegation:
160 delegate_method_to_slot ($slot, $method, $adapter_method)
162 Handle the specified $method by calling $adapter_method on the
163 object contained in "$self->{$slot}".
164 See Log::Any::Adapter::Dispatch and Log::Any::Adapter::Log4perl for
166 examples of usage.
167 The following Log::Any::Adapter::Util functions give you a list of
169 methods that you need to implement. You can get logging methods,
170 detection methods or both:
171
173 • Jonathan Swartz <swartz@pobox.com>
174 • David Golden <dagolden@cpan.org>
176 • Doug Bell <preaction@cpan.org>
178 • Daniel Pittman <daniel@rimspace.net>
180 • Stephen Thirlwall <sdt@cpan.org>
182
184 This software is copyright (c) 2017 by Jonathan Swartz, David Golden,
185 and Doug Bell.
186 This is free software; you can redistribute it and/or modify it under
188 the same terms as the Perl 5 programming language system itself.
189perl v5.34.0 2021-08-04 Log::Any::Adapter::Development(3)