NAME
File::Sticker::Derive - derive values from existing meta-data
VERSION
version 4.9
SYNOPSIS
use File::Sticker::Derive;
my $deriver = File::Sticker::Derive->new(%args);
my $derived_meta = $deriver->derive(filename=>$filename,meta=>$meta);DESCRIPTION
This will derive values from existing meta-data.
This is a plug-in, different plug-ins will do different derivations.
DEBUGGING
whoami
Used for debugging info
METHODS
new
Create a new object, setting global values for the object.
my $obj = File::Sticker::Derive->new();init
Initialize the object.
$deriver->init(%args);name
The name of the deriver; this is basically the last component of the module name. This works as either a class function or a method.
$name = $self->name();
$name = File::Sticker::Derive::name($class);
order
The order of this deriver, ranging from 0 to 99. This makes sure that the deriver is applied in order; useful because a later deriver may depend on data created by an earlier deriver.
This must be overridden by the specific deriver class.
derive
Derive common values from the existing meta-data. This UPDATES the passed-in meta hash.
This must be overridden by the specific deriver class.
my $newmeta = $deriver->derive(filename=>$filename, meta=>$meta, overwrite=>\%overwrite);Helper Functions
Private interface.
_overwrite_allowed
Check whether the given field is allowed to be overwritten. This is true when the value of the field is empty, or if the field name is in the passed-in "overwrite" hash.
my $okay = $deriver->_overwrite_allowed(meta=>$meta,field=>$field,overwrite=>\%overwrite);_set_field
Set the value of the given field in the meta hash, checking whether it is allowed to be overwritten.
my $meta = $deriver->_set_field(meta=>$meta,field=>$field,value=>$value,overwrite=>\%overwrite);BUGS
Please report any bugs or feature requests to the author.