NAME¶
Log::Report::Dispatcher - manage message dispatching, display or logging
INHERITANCE¶
Log::Report::Dispatcher is extended by
Log::Report::Dispatcher::Callback
Log::Report::Dispatcher::File
Log::Report::Dispatcher::Log4perl
Log::Report::Dispatcher::LogDispatch
Log::Report::Dispatcher::Perl
Log::Report::Dispatcher::Syslog
Log::Report::Dispatcher::Try
SYNOPSIS¶
use Log::Report;
# The following will be created for you automatically
dispatcher 'PERL', 'default', accept => 'NOTICE-';
dispatcher close => 'default'; # after deamonize
dispatcher 'FILE', 'log'
, mode => 'DEBUG', to => '/var/log/mydir/myfile';
# Full package name is used, same as 'FILE'
dispatcher Log::Report::Dispatch::File => 'stderr'
, to => \*STDERR, accept => 'NOTICE-';
DESCRIPTION¶
In Log::Report, dispatchers are used to handle (exception) messages which are
created somewhere else. Those message were produced (thrown) by
Log::Report::error() and friends.
This base-class handles the creation of dispatchers, plus the common filtering
rules. See the "DETAILS" section, below.
METHODS¶
Constructors¶
- $obj->close()
- Terminate the dispatcher activities. The dispatcher gets disabled, to
avoid the case that it is accidentally used. Returns "undef"
(false) if the dispatcher was already closed.
- Log::Report::Dispatcher->new($type, $name, %options)
- Create a dispatcher. The $type of back-end to start is required, and
listed in the "DESCRIPTION" part of this manual-page. For
various external back-ends, special wrappers are created.
The $name must be uniquely identifying this dispatcher. When a second
dispatcher is created (via Log::Report::dispatcher()) with the name
of an existing dispatcher, the existing one will get replaced.
All %options which are not consumed by this base constructor are passed to
the wrapped back-end. Some of them will check whether all %options are
understood, other ignore unknown %options.
-Option --Default
accept depend on mode
charset <undef>
format_reason 'LOWERCASE'
locale <system locale>
mode 'NORMAL'
- accept => REASONS
- See Log::Report::Util::expand_reasons() for possible values. If the
initial mode for this dispatcher does not need verbose or debug
information, then those levels will not be accepted.
When the mode equals "NORMAL" (the default) then
"accept"'s default is "NOTICE-". In case of
"VERBOSE"> it will be "INFO-", "ASSERT"
results in "ASSERT-", and "DEBUG" in
"ALL".
- charset => CHARSET
- Convert the messages in the specified character-set (codeset). By default,
no conversion will take place, because the right choice cannot be
determined automatically.
- format_reason => 'UPPERCASE'|'LOWERCASE'|'UCFIRST'|'IGNORE'|CODE
- How to show the reason text which is printed before the message. When a
CODE is specified, it will be called with a translated text and the
returned text is used.
- locale => LOCALE
- Overrules the global setting. Can be overruled by
Log::Report::report(locale).
- mode => 'NORMAL'|'VERBOSE'|'ASSERT'|'DEBUG'|0..3
- Possible values are "NORMAL" (or 0 or "undef"), which
will not show "INFO" or debug messages, "VERBOSE" (1;
shows "INFO" not debug), "ASSERT" (2; only ignores
"TRACE" messages), or "DEBUG" (3) which shows
everything. See section "Run modes" in Log::Report.
You are advised to use the symbolic mode names when the mode is changed
within your program: the numerical values are available for smooth
Getopt::Long integration.
Accessors¶
- $obj->isDisabled()
- $obj->mode()
- Returns the mode in use for the dispatcher as number. See new(mode) and
"Run modes" in Log::Report.
- $obj->name()
- Returns the unique name of this dispatcher.
- $obj->needs( [$reason] )
- Returns the list with all REASONS which are needed to fulfill this
dispatcher's needs. When disabled, the list is empty, but not forgotten.
[0.999] when only one $reason is specified, it is returned if in the
list.
- $obj->type()
- The dispatcher $type, which is usually the same as the class of this
object, but not in case of wrappers like for Log::Dispatch.
Logging¶
- $obj->collectLocation()
- Log::Report::Dispatcher->collectLocation()
- Collect the information to be displayed as line where the error occurred.
Probably, this needs improvement, where carp and die show different
lines.
- $obj->collectStack( [$maxdepth] )
- Log::Report::Dispatcher->collectStack( [$maxdepth] )
- Returns an ARRAY of ARRAYs with text, filename, line-number.
- $obj->log(HASH-$of-%options, $reason, $message, $domain)
- This method is called by Log::Report::report() and should not be
called directly. Internally, it will call translate(), which does
most $of the work.
- $obj->stackTraceLine(%options)
- Log::Report::Dispatcher->stackTraceLine(%options)
-
-Option --Default
abstract 1
call <required>
filename <required>
linenr <required>
max_line undef
max_params 8
package <required>
params <required>
- abstract => INTEGER
- The higher the abstraction value, the less details are given about the
caller. The minimum abstraction is specified, and then increased
internally to make the line fit within the "max_line"
margin.
- call => STRING
- filename => STRING
- linenr => INTEGER
- max_line => INTEGER
- max_params => INTEGER
- package => CLASS
- params => ARRAY
- $obj->translate(HASH-$of-%options, $reason, $message)
- See "Processing the message", which describes the actions taken
by this method. A string is returned, which ends on a new-line, and may be
multi-line (in case a stack trace is produced).
DETAILS¶
Available back-ends¶
When a dispatcher is created (via
new() or
Log::Report::dispatcher()), you must specify the TYPE of the
dispatcher. This can either be a class name, which extends a
Log::Report::Dispatcher, or a pre-defined abbreviation of a class name.
Implemented are:
- Log::Report::Dispatcher::Perl (abbreviation 'PERL')
- Use Perl's own "print()", "warn()" and
"die()" to ventilate reports. This is the default
dispatcher.
- Log::Report::Dispatcher::File (abbreviation 'FILE')
- Logs the message into a file, which can either be opened by the class or
be opened before the dispatcher is created.
- Log::Report::Dispatcher::Syslog (abbreviation 'SYSLOG')
- Send messages into the system's syslog infrastructure, using
Sys::Syslog.
- Log::Report::Dispatcher::Callback (abbreviation 'CALLBACK')
- Calls any CODE reference on receipt of each selected message, for instance
to send important message as email or SMS.
- "Log::Dispatch::*"
- All of the Log::Dispatch::Output extensions can be used directly. The
Log::Report::Dispatcher::LogDispatch will wrap around that back-end.
- "Log::Log4perl"
- Use the Log::Log4perl main object to write to dispatchers. This
infrastructure uses a configuration file.
- Log::Report::Dispatcher::Try (abbreviation 'TRY')
- Used by function Log::Report::try(). It collects the exceptions and
can produce them on request.
Processing the message¶
Addition information
The modules which use "Log::Report" will only specify the base of the
message string. The base dispatcher and the back-ends will extend this message
with additional information:
- . the reason
- . the filename/line-number where the problem appeared
- . the filename/line-number where it problem was reported
- . the error text in $!
- . a stack-trace
- . a trailing new-line
When the message is a translatable object (Log::Report::Message, for instance
created with Log::Report::__()), then the added components will get translated
as well. Otherwise, all will be in English.
Exactly what will be added depends on the actual mode of the dispatcher (change
it with
mode(), initiate it with new(mode)).
mode mode mode mode
REASON SOURCE TE! NORM VERB ASSE DEBUG
trace program ... S
assert program ... SL SL
info program T.. S S S
notice program T.. S S S S
mistake user T.. S S S SL
warning program T.. S S SL SL
error user TE. S S SL SC
fault system TE! S S SL SC
alert system T.! SL SL SC SC
failure system TE! SL SL SC SC
panic program .E. SC SC SC SC
T - usually translated
E - exception (execution interrupted)
! - will include $! text at display
L - include filename and linenumber
S - show/print when accepted
C - stack trace (like Carp::confess())
Filters
With a filter, you can block or modify specific messages before translation.
There may be a wish to change the REASON of a report or its content. It is not
possible to avoid the exit which is related to the original message, because a
module's flow depends on it to happen.
When there are filters defined, they will be called in order of definition. For
each of the dispatchers which are called for a certain REASON (which
"accept" that REASON), it is checked whether its name is listed for
the filter (when no names where specified, then the filter is applied to all
dispatchers).
When selected, the filter's CODE reference is called with four arguments: the
dispatcher object (a Log::Report::Dispatcher), the HASH-of-OPTIONS passed as
optional first argument to
Log::Report::report(), the REASON, and the
MESSAGE. Returned is the new REASON and MESSAGE. When the returned REASON is
"undef", then the message will be ignored for that dispatcher.
Be warned about processing the MESSAGE: it is a Log::Report::Message object
which may have a "prepend" string and "append" string or
object. When the call to
Log::Report::report() contained multiple
comma-separated components, these will already have been joined together using
concatenation (see
Log::Report::Message::concat().
SEE ALSO¶
This module is part of Log-Report distribution version 1.05, built on June 24,
2014. Website:
http://perl.overmeer.net/log-report/
LICENSE¶
Copyrights 2007-2014 by [Mark Overmeer]. For other contributors see ChangeLog.
This program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself. See
http://www.perl.com/perl/misc/Artistic.html