liblog-report-perl 1.18-1 / usr / share / perl5 / Log / Report / Dispatcher / Try.pod

=encoding utf8

=head1 NAME

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

=head1 INHERITANCE

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

=head1 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

=head1 DESCRIPTION

The L<Log::Report::try()|Log::Report/"Report Production and Configuration"> catches errors in the block (CODE
reference) which is just following the function name.  All
dispatchers are temporarily disabled by C<try>, and messages
which are reported are collected within a temporary dispatcher
named C<try>.  When the CODE has run, that C<try> dispatcher
is returned in C<$@>, and all original dispatchers reinstated.

Then, after the C<try> has finished, the routine which used
the "try" should decide what to do with the collected reports.
These reports are collected as L<Log::Report::Exception|Log::Report::Exception> objects.
They can be ignored, or thrown to a higher level try... causing
an exit of the program if there is none.

Extends L<"DESCRIPTION" in Log::Report::Dispatcher|Log::Report::Dispatcher/"DESCRIPTION">.
 
=head1 METHODS

Extends L<"METHODS" in Log::Report::Dispatcher|Log::Report::Dispatcher/"METHODS">.
 
=head2 Constructors

Extends L<"Constructors" in Log::Report::Dispatcher|Log::Report::Dispatcher/"Constructors">.
 
=over 4

=item $obj-E<gt>B<close>()

Only when initiated with a FILENAME, the file will be closed.  In any
other case, nothing will be done.

=item Log::Report::Dispatcher::Try-E<gt>B<new>($type, $name, %options)

 -Option       --Defined in             --Default
  accept         Log::Report::Dispatcher  depend on mode
  charset        Log::Report::Dispatcher  <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'

=over 2

=item accept => REASONS

=item charset => CHARSET

=item died => STRING

The exit string ($@) of the eval'ed block.

=item exceptions => ARRAY

ARRAY of L<Log::Report::Exception|Log::Report::Exception> objects.

=item format_reason => 'UPPERCASE'|'LOWERCASE'|'UCFIRST'|'IGNORE'|CODE

=item hide => REASON|ARRAY|'ALL'|'NONE'

[1.09] see L<hide()|Log::Report::Dispatcher::Try/"Accessors">

=item locale => LOCALE

=item mode => 'NORMAL'|'VERBOSE'|'ASSERT'|'DEBUG'|0..3

=item on_die => 'ERROR'|'PANIC'

When code which runs in this block exits with a die(), it will get
translated into a L<Log::Report::Exception|Log::Report::Exception> using
L<Log::Report::Die::die_decode()|Log::Report::Die/"FUNCTIONS">.  How serious are we about these
errors?

=back

=back

=head2 Accessors

Extends L<"Accessors" in Log::Report::Dispatcher|Log::Report::Dispatcher/"Accessors">.
 
=over 4

=item $obj-E<gt>B<die2reason>()

Returns the value of C<new(on_die)>.

=item $obj-E<gt>B<died>( [STRING] )

The message which was reported by C<eval>, which is used internally
to catch problems in the try block.

=item $obj-E<gt>B<exceptions>()

Returns all collected C<Log::Report::Exceptions>.  The last of
them may be a fatal one.  The other are non-fatal.

=item $obj-E<gt>B<hide>(REASON|REASONS|ARRAY|'ALL'|'NONE')

[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 parent try blocks, if none than to the dispatchers.

This option gives the opportunity to block, for instance, trace messages.
Those messages are still collected inside the try object, so may get
passed-on later via L<reportAll()|Log::Report::Dispatcher::Try/"Logging"> if you like.

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

example: change the setting of the running block

  my $parent_try = dispatcher 'active-try';
  parent_try->hide('NONE');

=item $obj-E<gt>B<hides>(REASON)

=item $obj-E<gt>B<isDisabled>()

Inherited, see L<Log::Report::Dispatcher/"Accessors">

=item $obj-E<gt>B<mode>()

Inherited, see L<Log::Report::Dispatcher/"Accessors">

=item $obj-E<gt>B<name>()

Inherited, see L<Log::Report::Dispatcher/"Accessors">

=item $obj-E<gt>B<needs>( [$reason] )

Inherited, see L<Log::Report::Dispatcher/"Accessors">

=item $obj-E<gt>B<type>()

Inherited, see L<Log::Report::Dispatcher/"Accessors">

=back

=head2 Logging

Extends L<"Logging" in Log::Report::Dispatcher|Log::Report::Dispatcher/"Logging">.
 
=over 4

=item $obj-E<gt>B<addSkipStack>(@CODE)

=item Log::Report::Dispatcher::Try-E<gt>B<addSkipStack>(@CODE)

Inherited, see L<Log::Report::Dispatcher/"Logging">

=item $obj-E<gt>B<collectLocation>()

=item Log::Report::Dispatcher::Try-E<gt>B<collectLocation>()

Inherited, see L<Log::Report::Dispatcher/"Logging">

=item $obj-E<gt>B<collectStack>( [$maxdepth] )

=item Log::Report::Dispatcher::Try-E<gt>B<collectStack>( [$maxdepth] )

Inherited, see L<Log::Report::Dispatcher/"Logging">

=item $obj-E<gt>B<log>($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 L<Log::Report::Message|Log::Report::Message>.

=item $obj-E<gt>B<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 L<Log::Report::report()|Log::Report/"Report Production and Configuration">; see
L<Log::Report::Exception::throw()|Log::Report::Exception/"Processing"> which does the job.

=item $obj-E<gt>B<reportFatal>()

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 L<Log::Report::report()|Log::Report/"Report Production and Configuration">; see
L<Log::Report::Exception::throw()|Log::Report::Exception/"Processing"> which does the job.

=item $obj-E<gt>B<skipStack>()

Inherited, see L<Log::Report::Dispatcher/"Logging">

=item $obj-E<gt>B<stackTraceLine>(%options)

=item Log::Report::Dispatcher::Try-E<gt>B<stackTraceLine>(%options)

Inherited, see L<Log::Report::Dispatcher/"Logging">

=item $obj-E<gt>B<translate>(HASH-$of-%options, $reason, $message)

Inherited, see L<Log::Report::Dispatcher/"Logging">

=back

=head2 Status

=over 4

=item $obj-E<gt>B<failed>()

Returns true if the block was left with an fatal message.

=item $obj-E<gt>B<showStatus>()

If this object is kept in C<$@>, 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 C<$@>, but wish for a re-cast of the message
using L<reportAll()|Log::Report::Dispatcher::Try/"Logging"> or L<reportFatal()|Log::Report::Dispatcher::Try/"Logging">.

=item $obj-E<gt>B<success>()

Returns true if the block exited normally.

=item $obj-E<gt>B<wasFatal>(%options)

Returns the L<Log::Report::Exception|Log::Report::Exception> which caused the "try" block to
die, otherwise an empty LIST (undef).

 -Option--Default
  class   undef

=over 2

=item 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 L<Log::Report::Message::inClass()|Log::Report::Message/"Processing">

=back

=back

=head1 DETAILS

Extends L<"DETAILS" in Log::Report::Dispatcher|Log::Report::Dispatcher/"DETAILS">.
 
=head1 OVERLOADING

=over 4

=item overload: B<boolean>

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

=item overload: B<stringify>

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

=back

=head1 SEE ALSO

This module is part of Log-Report distribution version 1.18,
built on October 21, 2016. Website: F<http://perl.overmeer.net/log-report/>

=head1 LICENSE

Copyrights 2007-2016 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 F<http://www.perl.com/perl/misc/Artistic.html>