# NAME

Catalyst::Plugin::ErrorCatcher - Catch application errors and emit them somewhere

# VERSION

version 0.0.8.21

# SYNOPSIS

    use Catalyst qw/-Debug StackTrace ErrorCatcher/;

# DESCRIPTION

This plugin allows you to do More Stuff with the information that would
normally only be seen on the Catalyst Error Screen courtesy of the
[Catalyst::Plugin::StackTrace](https://metacpan.org/pod/Catalyst::Plugin::StackTrace) plugin.

## setup($c, $@)

Prepare the plugin for use.

## finalize\_error($c)

If configured, and needed, deal with raised errors.

## my\_finalize\_error($c)

This is the method that's called by `finalize_error` when we do want to use ErrorCatcher
to format and emit some information.

## emitters\_init($c)

This routine initialises the emitters enabled in the configuration for the plugin.

## append\_feedback($stringref, $data)

This is a small utility method that simplifies some of the work needed to
add some data to a string-reference, including some basic checks and initialisation.

## append\_feedback\_emptyline

Add an empty-line to the string-reference of data being built.

## append\_feedback\_keyvalue($ref, $key, $value, $keypadding)

Add:

    {key}: value

to the feedback data being prepared.

`$keypadding` is optional. If omitted, defaults to 8.

## sanitise\_param($value)

Local implementation of ["qquote" in Data::Dumper](https://metacpan.org/pod/Data::Dumper#qquote) and general sanity checks and
transformations of the data in a given piece of data.

## append\_output\_params($ref, $label, $params)

Given a hashref of related items, `$params`, and a `$label` for the grouping,
add sensibly formatted output to the feedback data being constructed.

# CONFIGURATION

The plugin is configured in a similar manner to other Catalyst plugins:

    <Plugin::ErrorCatcher>
        enable                1
        context               5
        always_log            0
        include_session       0
        user_identified_by    username

        emit_module           A::Module
    </Plugin::ErrorCatcher>

- **enable**

    Setting this to _true_ forces the module to work its voodoo.

    It's also enabled if the value is unset and you're running Catalyst in
    debug-mode.

- **context**

    When there is stack-trace information to share, how many lines of context to
    show around the line that caused the error.

- **emit\_module**

    This specifies which module to use for custom output behaviour.

    You can chain multiple modules by specifying a line in the config for each
    module you'd like used:

        emit_module A::Module
        emit_module Another::Module
        emit_module Yet::Another::Module

    If none are specified, or all that are specified fail, the default behaviour
    is to log the prepared message at the INFO level via `$c->log()`.

    For details on how to implement a custom emitter see ["CUSTOM EMIT CLASSES"](#custom-emit-classes)
    in this documentation.

- **always\_log**

    The default plugin behaviour when using one or more emitter modules is to
    suppress the _info_ log message if one or more of them succeeded.

    If you wish to log the information, via `$c->log()` then set this value
    to 1.

- **include\_session**

    The default behaviour is to suppress potentially sensitive and revealing
    session-data in the error report.

    If you feel that this information is useful in your investigations set the
    value to _true_.

    When set to 1 the report will include a `Data::Dump::pp()` representation of
    the request's session. 

- **user\_identified\_by**

    If there's a logged-in user use the specified value as the method to identify
    the user.

    If the specified value is invalid the module defaults to using _id_.

    If unspecified the value defaults to _id_.

# STACKTRACE IN REPORTS WHEN NOT RUNNING IN DEBUG MODE

It is possible to run your application in non-Debug mode, and still have
errors reported with a stack-trace.

Include the StackTrace and ErrorCatcher plugins in MyApp.pm:

    use Catalyst qw<
      ErrorCatcher
      StackTrace
    >;

Set up your `myapp.conf` to include the following:

    <stacktrace>
      enable      1
    </stacktrace>

    <Plugin::ErrorCatcher>
      enable      1
      # include other options here
    <Plugin::ErrorCatcher>

Any exceptions should now show your user the _"Please come back later"_
screen whilst still capturing and emitting a report with stack-trace.

# PROVIDED EMIT CLASSES

## Catalyst::Plugin::ErrorCatcher::Email

This module uses [MIME::Lite](https://metacpan.org/pod/MIME::Lite) to send the prepared output to a specified
email address.

See [Catalyst::Plugin::ErrorCatcher::Email](https://metacpan.org/pod/Catalyst::Plugin::ErrorCatcher::Email) for usage and configuration
details.

# CUSTOM EMIT CLASSES

A custom emit class takes the following format:

    package A::Module;
    # vim: ts=8 sts=4 et sw=4 sr sta
    use strict;
    use warnings;
    
    sub emit {
      my ($class, $c, $output) = @_;
    
      $c->log->info(
        'IGNORING OUTPUT FROM Catalyst::Plugin::ErrorCatcher'
      );
    
      return;
    }
    
    1;
    __END__

The only requirement is that you have a sub called `emit`.

`Catalyst::Plugin::ErrorCatcher` passes the following parameters in the call
to `emit()`:

- **$class**

    The package name

- **$c**

    A [Context](https://metacpan.org/pod/Catalyst::Manual::Intro#Context) object

- **$output**

    The processed output from `Catalyst::Plugin::ErrorCatcher`

If you want to use the original error message you should use:

    my @error = @{ $c->error };

You may use and abuse any Catalyst methods, or other Perl modules as you see
fit.

# KNOWN ISSUES

- BODY tests failing (Catalyst >=5.90008)

    Summary: https://github.com/chiselwright/catalyst-plugin-errorcatcher/pull/1

    Bug report: https://rt.cpan.org/Public/Bug/Display.html?id=75607

# SEE ALSO

[Catalyst](https://metacpan.org/pod/Catalyst),
[Catalyst::Plugin::StackTrace](https://metacpan.org/pod/Catalyst::Plugin::StackTrace)

# THANKS

The authors of [Catalyst::Plugin::StackTrace](https://metacpan.org/pod/Catalyst::Plugin::StackTrace), from which a lot of
code was used.

Ash Berlin for guiding me in the right direction after a known hacky first
implementation.

\# vim: ts=8 sts=4 et sw=4 sr sta

# AUTHOR

Chisel <chisel@chizography.net>

# COPYRIGHT AND LICENSE

This software is copyright (c) 2015 by Chisel Wright.

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

# CONTRIBUTORS

- Chisel Wright <chisel@chizography.net>
- Fitz Elliott <fitz.elliott@gmail.com>
- Mohammad S Anwar <mohammad.anwar@yahoo.com>
- Tim Bunce <tim@tigerlms.com>