NAME

Module::Generic::Null - Null Value Chaining Object Class

SYNOPSIS

    # In your code:
    sub customer
    {
        my $self = shift( @_ );
        return( $self->error( "No customer id was provided" ) ) if( !scalar( @_ ) );
        return( $self->customer_info_to_object( @_ ) );
    }

    # And this method is called without providing an id, thus triggering an error,
    # but is chained. Upon error triggered by method "error", a Module::Generic::Null
    # object is returned
    my $name = $object->customer->name;

DESCRIPTION

Normally this call would have triggered a perl error like Cannot call method name on an undefined value, but since "error" in Module::Generic returns a Module::Generic::Null object, the method name here is called without triggering an error, and of course returns an Module::Generic::Null object when being chained, or undef otherwise. Undefined value is the typical response one gets when an error occurred, so you can check like this :

    my $name = $object->customer->name || die( $object->error );

Module::Generic::Null use AUTOLOAD to allow any method to work, but contains the original error within its object.

Apart from that, this does not do anything meaningful.

METHODS

There is only 1 method. This module makes it possible to call it with any method to fake original data flow.

new

This takes an error object and an optional hash reference of key-value pairs and return the object.

AUTHOR

Jacques Deguest <jack@deguest.jp>

COPYRIGHT & LICENSE

Copyright (c) 2000-2020 DEGUEST Pte. Ltd.

You can use, copy, modify and redistribute this package and associated files under the same terms as Perl itself.