new¶

  my $logger = Log::Dispatchouli->new(\%arg);

This returns a new logger, a Log::Dispatchouli object.

Valid arguments are:

  ident       - the name of the thing logging (mandatory)
  to_self     - log to the logger object for testing; default: false
  to_stdout   - log to STDOUT; default: false
  to_stderr   - log to STDERR; default: false
  facility    - to which syslog facility to send logs; default: none
  to_file     - log to PROGRAM_NAME.YYYYMMDD in the log path; default: false
  log_file    - a leaf name for the file to log to with to_file
  log_path    - path in which to log to file; defaults to DISPATCHOULI_PATH
                environment variable or, failing that, to your system's tmpdir
  file_format - this optional coderef is passed the message to be logged
                and returns the text to write out
  log_pid     - if true, prefix all log entries with the pid; default: true
  fail_fatal  - a boolean; if true, failure to log is fatal; default: true
  muted       - a boolean; if true, only fatals are logged; default: false
  debug       - a boolean; if true, log_debug method is not a no-op
                defaults to the truth of the DISPATCHOULI_DEBUG env var
  quiet_fatal - 'stderr' or 'stdout' or an arrayref of zero, one, or both
                fatal log messages will not be logged to these
                (default: stderr)
  config_id   - a name for this logger's config; rarely needed!
  syslog_socket - a value for Sys::Syslog's "socket" arg; default: "native"

The log path is either /tmp or the value of the DISPATCHOULI_PATH env var.

If the DISPATCHOULI_NOSYSLOG env var is true, we don't log to syslog.

log¶

  $logger->log(@messages);
  $logger->log(\%arg, @messages);

This method uses String::Flogger on the input, then unconditionally logs the result. Each message is flogged individually, then joined with spaces.

If the first argument is a hashref, it will be used as extra arguments to logging. It may include a "prefix" entry to preprocess the message by prepending a string (if the prefix is a string) or calling a subroutine to generate a new message (if the prefix is a coderef).

log_fatal¶

This behaves like the "log" method, but will throw the logged string as an exception after logging.

This method can also be called as "fatal", to match other popular logging interfaces. If you want to override this method, you must override "log_fatal" and not "fatal".

log_debug¶

This behaves like the "log" method, but will only log (at the debug level) if the logger object has its debug property set to true.

This method can also be called as "debug", to match other popular logging interfaces. If you want to override this method, you must override "log_debug" and not "debug".

log_event¶

This method is like "log", but is used for structured logging instead of free form text. It's invoked like this:

  $logger->log($event_type => $data_ref);

$event_type should be a simple string, probably a valid identifier, that identifies the kind of event being logged. It is suggested, but not required, that all events of the same type have the same kind of structured data in them.

$data_ref is a set of key/value pairs of data to log in this event. It can be an arrayref (in which case the ordering of pairs is preserved) or a hashref (in which case they are sorted by key).

The logged string will be in logfmt format, meaning a series of key=value pairs separated by spaces and following these rules:

• an "identifier" is a string of printable ASCII characters between "!" and "~", excluding "\" and "="
• keys must be valid identifiers
• if a key is empty, "~" is used instead
• if a key contains characters not permitted in an identifier, they are replaced by "?"
• values must either be valid identifiers, or be quoted
• quoted value start and end with """
• in a quoted value, """ becomes "\"", "\" becomes "\\", newline and carriage return become "\n" and "\r" respectively, and other control characters are replaced with "\u{....}" where the contents of the braces are the hex value of the control character

When values are undef, they are represented as "~".

When values are array references, the index/values are mapped over, so that:

  key => [ 'a', 'b' ]

becomes

  key.0=a key.1=b

When values are hash references, the key/values are mapped, with keys sorted, so that:

  key => { b => 2, a => 1 }

becomes

  key.a=1 key.b=2

This expansion is performed recursively. If a value itself recurses, appearances of a reference after the first time will be replaced with a string like "&foo.bar", pointing to the first occurrence. This is not meant to be a robust serialization mechanism. It's just here to help you be a little lazy. Don't push the limits.

If the value in $data_ref is a code reference, it will be called and its result logged. If its result is also a code reference, you get whatever garbage that code reference stringifies to.

If the value in $data_ref is a reference reference, then the referenced scalar will be passed to String::Flogger, and the resulting string will be used as the value to log. That string will be quoted as described above, if needed.

log_debug_event¶

This method is just like "log_event", but will log nothing unless the logger has its "debug" property set to true.

set_debug¶

  $logger->set_debug($bool);

This sets the logger's debug property, which affects the behavior of "log_debug".

get_debug¶

This gets the logger's debug property, which affects the behavior of "log_debug".

clear_debug¶

This method does nothing, and is only useful for Log::Dispatchouli::Proxy objects. See Methods for Proxy Loggers, below.

set_muted¶

  $logger->set_muted($bool);

This sets the logger's muted property, which affects the behavior of "log".

get_muted¶

This gets the logger's muted property, which affects the behavior of "log".

clear_muted¶

This method does nothing, and is only useful for Log::Dispatchouli::Proxy objects. See Methods for Proxy Loggers, below.

get_prefix¶

  my $prefix = $logger->get_prefix;

This method returns the currently-set prefix for the logger, which may be a string or code reference or undef. See Logger Prefix.

set_prefix¶

  $logger->set_prefix( $new_prefix );

This method changes the prefix. See Logger Prefix.

clear_prefix¶

This method clears any set logger prefix. (It can also be called as "unset_prefix", but this is deprecated. See Logger Prefix.

ident¶

This method returns the logger's ident.

config_id¶

This method returns the logger's configuration id, which defaults to its ident. This can be used to make two loggers equivalent in Log::Dispatchouli::Global so that trying to reinitialize with a new logger with the same "config_id" as the current logger will not throw an exception, and will simply do no thing.

dispatcher¶

This returns the underlying Log::Dispatch object. This is not the method you're looking for. Move along.

stdio_dispatcher_class¶

This method is an experimental feature to allow you to pick an alternate dispatch class for stderr and stdio. By default, Log::Dispatch::Screen is used. This feature may go away at any time.

string_flogger¶

This method returns the thing on which flog will be called to format log messages. By default, it just returns "String::Flogger"

env_prefix¶

This method should return a string used as a prefix to find environment variables that affect the logger's behavior. For example, if this method returns "XYZZY" then when checking the environment for a default value for the "debug" parameter, Log::Dispatchouli will first check "XYZZY_DEBUG", then "DISPATCHOULI_DEBUG".

By default, this method returns "()", which means no extra environment variable is checked.

env_value¶

  my $value = $logger->env_value('DEBUG');

This method returns the value for the environment variable suffix given. For example, the example given, calling with "DEBUG" will check "DISPATCHOULI_DEBUG".

new_tester¶

  my $logger = Log::Dispatchouli->new_tester( \%arg );

This returns a new logger that logs only "to_self". It's useful in testing. If no "ident" arg is provided, one will be generated. "log_pid" is off by default, but can be overridden.

"\%arg" is optional.

events¶

This method returns the arrayref of events logged to an array in memory (in the logger). If the logger is not logging "to_self" this raises an exception.

clear_events¶

This method empties the current sequence of events logged into an array in memory. If the logger is not logging "to_self" this raises an exception.

proxy¶

  my $proxy_logger = $logger->proxy( \%arg );

This method returns a new proxy logger -- an instance of Log::Dispatchouli::Proxy -- which will log through the given logger, but which may have some settings localized.

%arg is optional. It may contain the following entries:

proxy_prefix

This is a prefix that will be applied to anything the proxy logger logs, and cannot be changed.

proxy_ctx

This is data to be inserted in front of event data logged through the proxy. It will appear after the "event" key but before the logged event data. It can be in the same format as the $data_ref argument to "log_event".

debug

This can be set to true or false to change the proxy's "am I in debug mode?" setting. It can be changed or cleared later on the proxy.

parent¶

logger¶

These methods return the logger itself. (They're more useful when called on proxy loggers.)