PPI::Transform(3) User Contributed Perl Documentation PPI::Transform(3)
NAME
PPI::Transform - Abstract base class for document transformation
classes
DESCRIPTION
"PPI::Transform" provides an API for the creation of classes and
objects that modify or transform PPI documents.
METHODS
new
my $transform = PPI::Transform->new(
param1 => 'value1',
param2 => 'value2',
);
The "new" constructor creates a new object for your "PPI::Transform"
subclass. A default constructor is provided for you which takes no
params and creates a basic, empty, object.
If you wish to have your transform constructor take params, these must
be in the form of a list of key/value pairs.
Returns a new "PPI::Transform"-compatible object, or returns "undef" on
error.
document
The "document" method should be implemented by each subclass, and takes
a single argument of a PPI::Document object, modifying it in place as
appropriate for the particular transform class.
That's right, this method will not clone and should not clone the
document object. If you do not want the original to be modified, you
need to clone it yourself before passing it in.
Returns the numbers of changes made to the document. If the transform
is unable to track the quantity (including the situation where it
cannot tell IF it made a change) it should return 1. Returns zero if no
changes were made to the document, or "undef" if an error occurs.
By default this error is likely to only mean that you passed in
something that wasn't a PPI::Document, but may include additional
errors depending on the subclass.
apply
The "apply" method is used to apply the transform to something. The
argument must be a PPI::Document, or something which can be turned into
one and then be written back to again.
Currently, this list is limited to a "SCALAR" reference, although a
handler registration process is available for you to add support for
additional types of object should you wish (see the source for this
module).
Returns true if the transform was applied, false if there is an error
in the transform process, or may die if there is a critical error in
the apply handler.
file
# Read from one file and write to another
$transform->file( 'Input.pm' => 'Output.pm' );
# Change a file in place
$transform->file( 'Change.pm' );
The "file" method modifies a Perl document by filename. If passed a
single parameter, it modifies the file in-place. If provided a second
parameter, it will attempt to save the modified file to the alternative
filename.
Returns true on success, or "undef" on error.
SUPPORT
See the support section in the main module.
AUTHOR
Adam Kennedy <adamk@cpan.org>
COPYRIGHT
Copyright 2001 - 2011 Adam Kennedy.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
The full text of the license can be found in the LICENSE file included
with this module.
perl v5.28.2 2019-04-28 PPI::Transform(3)
ppi 1.264.0 - Generated Fri May 3 15:02:02 CDT 2019