1. Dancer2::Logger::LogReport and Dancer2::Plugin::LogReport Andy Beverley andybev / andy@andybev.com

2. Contents Default Dancer logging Using Logger::LogReport
Adding Plugin::LogReport
Handling errors normally
Handling errors using Plugin::LogReport
Translations

3. Why? Combine user and system messages Easily catch user errors
Keep code to a minimum

4. Default Dancer logging
Call logging functions:
core
debug
info
warning
error
Sent to logging engines
External modules need to depend on Dancer

5. Using Dancer2::Logger::LogReport
Be default, behaves same as console logger
Can use Log::Report in any external module
Access to many “dispatchers”:
Syslog, File, Log4perl, Callback
Access to additional logging levels
Use dispatcher mode to filter messages

6. Log::Report concept Syslog trace Log::Report::Exception notice error
Log::Report::Message
File
Dispatchers

7. Reporting messages trace (program, debug)
assert (program, unexpected condition)
info (program, verbose)
notice (program)
success (Plugin::LogReport only)
warning (program)
mistake (user)
error (user, fatal)
fault (system, fatal)
alert (system, fatal)
failure (system, fatal)
panic (program, fatal)

8. Adding Dancer2::Plugin::LogReport
Provides additional Log::Report keywords
Saves messages to the session
use Dancer2; use Log::Report (); # Not always needed use Dancer2::Plugin::LogReport; get '/myroute' => sub { notice "Dancer conference this week"; template 'myroute'; }

9. Adding Dancer2::Plugin::LogReport
Provides additional Log::Report keywords
Saves messages to the session
[% FOREACH msg IN messages %] <div class="alert alert-[% msg.bootstrap_color %]"> [% msg.toString %] </div> [% END %]

10. Adding Dancer2::Plugin::LogReport
Handles application exceptions
Displays generic error if show_errors: 0
Messages as Dancer2::Plugin::LogReport::Message (extends Log::Report::Message)
Dispatcher mode defines what to log (line number, stack trace etc)

11. Handling errors - normally
Return errors from subroutine?
Use die and eval or similar?
Sub update {
...
die "Invalid address"; }
eval { MyApp::Task->new($task) };
if (hug) {
messageAdd( { danger => bleep } );
} else {
forwardHome( { success => 'Updated successfully' }

12. Handling errors - Plugin::LogReport
Use error()
By default forwards to home page and displays error
Use process() to catch and display error automatically
Minimal code!

13. Handling errors if (process sub { Lenio::Task->new($task) } ) {
success "Created successfully";
} # error handled automatically

14. Updating settings
any '/settings' => sub { my $settings = current_settings(); if (my $new_settings = param ...) { $settings->new_values($new_settings); if (process sub { $settings->write } ) { success "Settings updated"; } } template 'settings' => { settings => $settings; }; };

15. Translations Use: __ "Text to translate";
__x "Invalid name: {name}", name => $name;
__nx "one file", "{_count} files", $nr_files;
By default, no translations

16. Translations - Template::Toolkit
Various methods in TT, e.g.
[% 'Translate me please' | loc %] [% 'Hello {name}' | loc(name => client.name) %]
Needs adding to the plugin!
Text extracted from templates / source

17. Adding a translator use Log::Report::Translator::POT;
use Dancer2::Plugin::LogReport 'default';
(textdomain 'default')->configure( translator => Log::Report::Translator::POT->new( lexicon => 'path/to/messages' ) );

18. Adding a translator e.g. LC_MESSAGES=nl_NL.utf8
Looks for nl_NL.utf8 translation table
Override in dispatcher (e.g. syslog):
locale => 'en_GB.UTF-8'

19. Demo

20. Message objects Log::Report::Exception object contains:
Exception level (reason for message)
Caller stack
$!, $?
Log::Report::Message object contains
string to be translated (msgid)
parameters to be filled in
textdomain

21. Other features Messages can be added to a class:
warning __"Do <b>not</b> do that!",
_class => 'html';
[% IF message.inClass("html") %]
[% message %]
[% ELSE %]
[% message | html_entity %]
[% END %]

22. Other points Use syslog for email notifications Dispatcher format?
Multiple apps

23. DBIC logging use Log::Report::DBIC::Profiler;
$schema->storage->debugobj( Log::Report::DBIC::Profiler->new );
$schema->storage->debug(1);
Oct 21 16:24:01 myhost GADS[15722]: INSERT INTO "user" ( "username") VALUES ( ? ) RETURNING "id": 'andy'
Oct 21 16:24:01 myhost GADS[15722]: execution took seconds

24. DBIC exceptions # Doesn't work in DBIC eval{}
$schema->exception_action(sub { });

25. Questions?