package Alzabo::Exceptions;
use strict;
use vars qw($VERSION);
use Alzabo::Utils;
$VERSION = 2.0;
my %e;
BEGIN
{
%e = ( 'Alzabo::Exception' =>
{ description =>
'Generic exception within the Alzabo API. Should only be used as a base class.',
alias => 'exception',
},
'Alzabo::Exception::Driver' =>
{ description => 'An attempt to eval a string failed',
fields => [ 'sql', 'bind' ],
isa => 'Alzabo::Exception',
alias => 'driver_exception',
},
'Alzabo::Exception::Eval' =>
{ description => 'An attempt to eval a string failed',
isa => 'Alzabo::Exception',
alias => 'eval_exception',
},
'Alzabo::Exception::Logic' =>
{ description =>
'An internal logic error occurred (presumably, Alzabo was asked to do something that cannot be done)',
isa => 'Alzabo::Exception',
alias => 'logic_exception',
},
'Alzabo::Exception::NoSuchRow' =>
{ description => 'An attempt to fetch data from the database for a primary key that did not exist in the specified table',
isa => 'Alzabo::Exception',
alias => 'no_such_row_exception',
},
'Alzabo::Exception::Params' =>
{ description => 'An exception generated when there is an error in the parameters passed in a method of function call',
isa => 'Alzabo::Exception',
alias => 'params_exception',
},
'Alzabo::Exception::NotNullable' =>
{ description => 'An exception generated when there is an attempt is made to set a non-nullable column to NULL',
isa => 'Alzabo::Exception::Params',
fields => [ 'column_name', 'table_name', 'schema_name' ],
alias => 'not_nullable_exception',
},
'Alzabo::Exception::Panic' =>
{ description => 'An exception generated when something totally unexpected happens',
isa => 'Alzabo::Exception',
alias => 'panic_exception',
},
'Alzabo::Exception::RDBMSRules' =>
{ description => 'An RDBMS rule check failed',
isa => 'Alzabo::Exception',
alias => 'rdbms_rules_exception',
},
'Alzabo::Exception::RDBMSRules::RecreateTable' =>
{ description =>
'An exception generated to indicate the a table needs to be recreated as part of a schema SQL diff',
isa => 'Alzabo::Exception',
alias => 'recreate_table_exception',
},
'Alzabo::Exception::ReferentialIntegrity' =>
{ description =>
'An operation was attempted that would violate referential integrity',
isa => 'Alzabo::Exception',
alias => 'referential_integrity_exception',
},
'Alzabo::Exception::SQL' =>
{ description =>
'An exception generated when there a logical error in a set of operation on an Alzabo::SQLMaker object',
isa => 'Alzabo::Exception',
alias => 'sql_exception',
},
'Alzabo::Exception::Storable' =>
{ description => 'An attempt to call a function from the Storable module failed',
isa => 'Alzabo::Exception',
alias => 'storable_exception',
},
'Alzabo::Exception::System' =>
{ description => 'An attempt to interact with the system failed',
isa => 'Alzabo::Exception',
alias => 'system_exception',
},
'Alzabo::Exception::VirtualMethod' =>
{ description =>
'Indicates that the method called must be subclassed in the appropriate class',
isa => 'Alzabo::Exception',
alias => 'virtual_method_exception',
},
);
}
use Exception::Class (%e);
Alzabo::Exception->Trace(1);
sub import
{
my ($class, %args) = @_;
my $caller = caller;
if ( $args{abbr} )
{
foreach my $name ( ref $args{abbr} ? @{ $args{abbr} } : $args{abbr} )
{
no strict 'refs';
die "Unknown exception abbreviation '$name'" unless defined &{$name};
*{"${caller}::$name"} = \&{$name};
}
}
{
no strict 'refs';
*{"${caller}::isa_alzabo_exception"} = \&isa_alzabo_exception;
*{"${caller}::rethrow_exception"} = \&rethrow_exception;
}
}
sub isa_alzabo_exception
{
my ($err, $name) = @_;
return unless defined $err;
my $class =
! $name
? 'Alzabo::Exception'
: $name =~ /^Alzabo::Exception/
? $name
: "Alzabo::Exception::$name";
{
no strict 'refs';
die "no such exception class $class"
unless defined(${"${class}::VERSION"});
}
return Alzabo::Utils::safe_isa($err, $class);
}
sub rethrow_exception
{
my $err = shift;
return unless $err;
if ( Alzabo::Utils::safe_can( $err, 'rethrow' ) )
{
$err->rethrow;
}
elsif ( ref $err )
{
die $err;
}
Alzabo::Exception->throw( error => $err );
}
package Alzabo::Exception;
sub format
{
my $self = shift;
if (@_)
{
$self->{format} = shift eq 'html' ? 'html' : 'text';
}
return $self->{format} || 'text';
}
sub as_string
{
my $self = shift;
my $stringify_function = "as_" . $self->format;
return $self->$stringify_function();
}
sub as_text
{
return $_[0]->full_message . "\n\n" . $_[0]->trace->as_string;
}
sub as_html
{
my $self = shift;
my $msg = $self->full_message;
require HTML::Entities;
$msg = HTML::Entities::encode_entities($msg);
$msg =~ s/\n/<br>/;
my $html = <<"EOF";
<html><body>
<p align="center"><font face="Verdana, Arial, Helvetica, sans-serif"><b>System error</b></font></p>
<table border="0" cellspacing="0" cellpadding="1">
<tr>
<td nowrap align="left" valign="top"><b>error:</b> </td>
<td align="left" valign="top" nowrap>$msg</td>
</tr>
<tr>
<td align="left" valign="top" nowrap><b>code stack:</b> </td>
<td align="left" valign="top" nowrap>
EOF
foreach my $frame ( $self->trace->frames )
{
my $filename = HTML::Entities::encode_entities( $frame->filename );
my $line = $frame->line;
$html .= "$filename: $line<br>\n";
}
$html .= <<'EOF';
</td>
</tr>
</table>
</body></html>
EOF
return $html;
}
package Alzabo::Exception::Driver;
sub full_message
{
my $self = shift;
my $msg = $self->error;
$msg .= "\nSQL: " . $self->sql if $self->sql;
if ( $self->bind )
{
my @bind = map { defined $_ ? $_ : '<undef>' } @{ $self->bind };
$msg .= "\nBIND: @bind" if @bind;
}
return $msg;
}
1;
=head1 NAME
Alzabo::Exceptions - Creates all exception subclasses used in Alzabo.
=head1 SYNOPSIS
use Alzabo::Exceptions;
=head1 DESCRIPTION
Using this class creates all the exceptions classes used by Alzabo
(via the L<C<Exception::Class>|Exception::Class> class).
See L<C<Exception::Class>|Exception::Class> for more information on
how this is done.
=head1 EXCEPTION CLASSES
=over 4
=item * Alzabo::Exception
This is the base class for all exceptions generated within Alzabo (all
exceptions should return true for C<< $@->isa('Alzabo::Exception') >>
except those that are generated via internal Perl errors).
=item * Alzabo::Exception::Driver
An error occured while accessing a database. See
L<C<Alzabo::Driver>|Alzabo::Driver> for more details.
=item * Alzabo::Exception::Eval
An attempt to eval something returned an error.
=item * Alzabo::Exception::Logic
Alzabo was asked to do something logically impossible, like retrieve
rows for a table without a primary key.
=item * Alzabo::Exception::NoSuchRow
An attempt was made to fetch data from the database with a primary key
that does not actually exist in the specified table.
=item * Alzabo::Exception::NotNullable
An attempt was made to set a non-nullable column to C<NULL>. The
"column_name", "table_name", and "schema_name" fields can be used to
identify the exact column.
=item * Alzabo::Exception::Panic
This exception is thrown when something completely unexpected happens
(think Monty Python).
=item * Alzabo::Exception::Params
This exception is thrown when there is a problem with the parameters
passed to a method or function. These problems can include missing
parameters, invalid values, etc.
=item * Alzabo::Exception::RDBMSRules
A rule for the relevant RDBMS was violated (bad schema name, table
name, column attribute, etc.)
=item * Alzabo::Exception::ReferentialIntegrity
An insert/update/delete was attempted that would violate referential
integrity constraints.
=item * Alzabo::Exception::SQL
An error thrown when there is an attempt to generate invalid SQL via
the Alzabo::SQLMaker module.
=item * Alzabo::Exception::Storable
A error when trying to freeze, thaw, or clone an object using
Storable.
=item * Alzabo::Exception::System
Some sort of system call (file read/write, stat, etc.) failed.
=item * Alzabo::Exception::VirtualMethod
A virtual method was called. This indicates that this method should
be subclassed.
=back
=head1 AUTHOR
Dave Rolsky, <autarch@urth.org>
=cut