Log::Report::Dispatcher::Try(3)

NAME
Log::Report::Dispatcher::Try - capture all reports as exceptions

INHERITANCE
 Log::Report::Dispatcher::Try
   is a Log::Report::Dispatcher

SYNOPSIS
  try { ... };       # mind the ';' !!
  if($@) {           # signals something went wrong

  if(try {...}) {    # block ended normally

  my $x = try { read_temperature() };
  my @x = try { read_lines_from_file() };

  try { ... }        # no comma!!
     mode => 'DEBUG', accept => 'ERROR-';

  try sub { ... },   # with comma
     mode => 'DEBUG', accept => 'ALL';

  try \&myhandler, accept => 'ERROR-';
  try { ... } hide => 'TRACE';

  print ref $@;      # Log::Report::Dispatcher::Try

  $@->reportFatal;   # re-dispatch result of try block
  $@->reportAll;     # ... also warnings etc
  if($@) {...}       # if errors
  if($@->failed) {   # same       # }
  if($@->success) {  # no errors  # }

  try { # something causes an error report, which is caught
        failure 'no network';
      };
  $@->reportFatal(to => 'syslog');  # overrule destination

  print $@->exceptions; # no re-cast, just print

DESCRIPTION
The try works like Perl's build-in eval(), but implements real exception handling which Perl core lacks.

The Log::Report::try() function creates this "::Try" dispatcher object with name 'try'. After the try() is over, you can find the object in $@. The $@ as "::Try" object behaves exactly as the $@ produced by "eval", but has many added features.

The try() function catches fatal errors happening inside the BLOCK (CODE reference which is just following the function name) into the "::Try" object $@. The errors are not automatically progressed to active dispatchers. However, non-fatal exceptions (like info or notice) are also collected (unless not accepted, see new(accept), but also immediately passed to the active dispatchers (unless the reason is hidden, see new(hide))

After the try() has run, you can introspect the collected exceptions. Typically, you use wasFatal() to get the exception which terminated the run of the BLOCK.

Extends "DESCRIPTION" in Log::Report::Dispatcher.

OVERLOADED

overload: "" stringify
    When $@ is used the traditional way, it is checked to have a string content. In this case, stringify into the fatal error or nothing.

overload: bool boolean
    Returns "true" if the previous try block did produce a terminal error. This "try" object is assigned to $@, and the usual perl syntax is "if($@) {...error-handler...}".

METHODS
Extends "METHODS" in Log::Report::Dispatcher.

  Constructors
Extends "Constructors" in Log::Report::Dispatcher.

$obj->close()
    Inherited, see "Constructors" in Log::Report::Dispatcher

$class->new($type, $name, %options)
    Inherited, see "Constructors" in Log::Report::Dispatcher

     -Option       --Defined in             --Default
      accept         Log::Report::Dispatcher  depend on mode
      charset        Log::Report::Dispatcher  <C<undef>>
      died                                    undef
      exceptions                              []
      format_reason  Log::Report::Dispatcher  'LOWERCASE'
      hide                                    'NONE'
      locale         Log::Report::Dispatcher  <system locale>
      mode           Log::Report::Dispatcher  'NORMAL'
      on_die                                  'ERROR'

    accept => REASONS
    charset => CHARSET
    died => STRING
        The exit string or object ($@) of the eval'ed block, in its unprocessed state.

    exceptions => \@objects
        ARRAY of Log::Report::Exception objects.

    format_reason => 'UPPERCASE'|'LOWERCASE'|'UCFIRST'|'IGNORE'|CODE
    hide => $reasons|\@reasons|'ALL'|'NONE'
        [1.09] see hide()

    locale => LOCALE
    mode => 'NORMAL'|'VERBOSE'|'ASSERT'|'DEBUG'|0..3
    on_die => 'ERROR'|'PANIC'
        When code which runs in this block exits with a die(), it will get translated into a Log::Report::Exception using Log::Report::Die::die_decode(). How serious are we about these errors?

  Accessors
Extends "Accessors" in Log::Report::Dispatcher.

$obj->die2reason()
    Returns the value of new(on_die).

$obj->died( [STRING] )
    The exit string or object ($@) of the eval'ed block, in its unprocessed state. They will always return "true" when they where deadly, and it always stringifies into something useful.

$obj->exceptions()
    Returns all collected "Log::Report::Exceptions". The last of them may be a fatal one. The other are non-fatal.

$obj->hide(@reasons)
    [1.09] By default, the try will only catch messages which stop the execution of the block (errors etc, internally a 'die'). Other messages are passed to the parent dispatchers.

    This option gives the opportunity to stop, for instance, trace messages. Those messages are still collected inside the try object (unless excluded by new(accept)), so may get passed-on later via reportAll() if you like.

    Be warned: Using this method will reset the whole 'hide' configuration: it's a set not an add.

    example: change the setting of the running block

      my $parent_try = dispatcher 'active-try';
      $parent_try->hide('ALL');

$obj->hides($reason)
    Check whether the try stops message which were produced for $reason.

$obj->isDisabled()
    Inherited, see "Accessors" in Log::Report::Dispatcher

$obj->mode()
    Inherited, see "Accessors" in Log::Report::Dispatcher

$obj->name()
    Inherited, see "Accessors" in Log::Report::Dispatcher

$obj->needs( [$reason] )
    Inherited, see "Accessors" in Log::Report::Dispatcher

$obj->type()
    Inherited, see "Accessors" in Log::Report::Dispatcher

  Logging
Extends "Logging" in Log::Report::Dispatcher.

$any->addSkipStack(@CODE)
    Inherited, see "Logging" in Log::Report::Dispatcher

$any->collectLocation()
    Inherited, see "Logging" in Log::Report::Dispatcher

$any->collectStack( [$maxdepth] )
    Inherited, see "Logging" in Log::Report::Dispatcher

$obj->log($opts, $reason, $message)
    Other dispatchers translate the message here, and make it leave the program. However, messages in a "try" block are only captured in an intermediate layer: they may never be presented to an end-users. And for sure, we do not know the language yet.

    The $message is either a STRING or a Log::Report::Message. Improves base, see "Logging" in Log::Report::Dispatcher

$obj->reportAll(%options)
    Re-cast the messages in all collect exceptions into the defined dispatchers, which were disabled during the try block. The %options will end-up as HASH of %options to Log::Report::report(); see Log::Report::Exception::throw() which does the job.

$obj->reportFatal(%options)
    Re-cast only the fatal message to the defined dispatchers. If the block was left without problems, then nothing will be done. The %options will end-up as HASH of %options to Log::Report::report(); see Log::Report::Exception::throw() which does the job.

$obj->skipStack()
    Inherited, see "Logging" in Log::Report::Dispatcher

$any->stackTraceLine(%options)
    Inherited, see "Logging" in Log::Report::Dispatcher

$obj->translate(HASH-$of-%options, $reason, $message)
    Inherited, see "Logging" in Log::Report::Dispatcher

  Status

$obj->failed()
    Returns "true" if the block was left with an fatal message.

$obj->showStatus()
    If this object is kept in $@, and someone uses this as string, we want to show the fatal error message.

    The message is not very informative for the good cause: we do not want people to simply print the $@, but wish for a re-cast of the message using reportAll() or reportFatal().

$obj->success()
    Returns "true" if the block exited normally.

$obj->wasFatal(%options)
    Returns the Log::Report::Exception which caused the "try" block to die, otherwise an empty LIST ("undef").

     -Option--Default
      class   undef

    class => CLASS|REGEX
        Only return the exception if it was fatal, and in the same time in the specified CLASS (as string) or matches the REGEX. See Log::Report::Message::inClass()

DETAILS
Extends "DETAILS" in Log::Report::Dispatcher.

SEE ALSO
This module is part of Log-Report version 1.41, built on September 11, 2025. Website: http://perl.overmeer.net/CPAN/

LICENSE
For contributors see file ChangeLog.

This software is copyright (c) 2007-2025 by Mark Overmeer.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.