PPI::Document(3) User Contributed Perl Documentation PPI::Document(3)
NAME
PPI::Document - Object representation of a Perl document
INHERITANCE
PPI::Document
isa PPI::Node
isa PPI::Element
SYNOPSIS
use PPI;
# Load a document from a file
my $Document = PPI::Document->new('My/Module.pm');
# Strip out comments
$Document->prune('PPI::Token::Comment');
# Find all the named subroutines
my $sub_nodes = $Document->find(
sub { $_[1]->isa('PPI::Statement::Sub') and $_[1]->name }
);
my @sub_names = map { $_->name } @$sub_nodes;
# Save the file
$Document->save('My/Module.pm.stripped');
DESCRIPTION
The "PPI::Document" class represents a single Perl "document". A
"PPI::Document" object acts as a root PPI::Node, with some additional
methods for loading and saving, and working with the line/column
locations of Elements within a file.
The exemption to its PPI::Node-like behavior this is that a
"PPI::Document" object can NEVER have a parent node, and is always the
root node in a tree.
Storable Support
"PPI::Document" implements the necessary "STORABLE_freeze" and
"STORABLE_thaw" hooks to provide native support for Storable, if you
have it installed.
However if you want to clone a Document, you are highly recommended to
use the "$Document->clone" method rather than Storable's "dclone"
function (although "dclone" should still work).
METHODS
Most of the things you are likely to want to do with a Document are
probably going to involve the methods from PPI::Node class, of which
this is a subclass.
The methods listed here are the remaining few methods that are truly
Document-specific.
new
# Simple construction
$doc = PPI::Document->new( $filename );
$doc = PPI::Document->new( \$source );
# With the readonly attribute set
$doc = PPI::Document->new( $filename,
readonly => 1,
);
The "new" constructor takes as argument a variety of different sources
of Perl code, and creates a single cohesive Perl "PPI::Document" for
it.
If passed a file name as a normal string, it will attempt to load the
document from the file.
If passed a reference to a "SCALAR", this is taken to be source code
and parsed directly to create the document.
If passed zero arguments, a "blank" document will be created that
contains no content at all.
In all cases, the document is considered to be "anonymous" and not tied
back to where it was created from. Specifically, if you create a
PPI::Document from a filename, the document will not remember where it
was created from.
The constructor also takes attribute flags.
At this time, the only available attribute is the "readonly" flag.
Setting "readonly" to true will allow various systems to provide
additional optimisations and caching. Note that because "readonly" is
an optimisation flag, it is off by default and you will need to
explicitly enable it.
Returns a "PPI::Document" object, or "undef" if parsing fails.
PPI::Exception objects can also be thrown if there are parsing
problems.
set_cache $cache
As of PPI 1.100, "PPI::Document" supports parser caching.
The default cache class PPI::Cache provides a Storable-based caching or
the parsed document based on the MD5 hash of the document as a string.
The static "set_cache" method is used to set the cache object for
"PPI::Document" to use when loading documents. It takes as argument a
PPI::Cache object (or something that "isa" the same).
If passed "undef", this method will stop using the current cache, if
any.
For more information on caching, see PPI::Cache.
Returns true on success, or "undef" if not passed a valid param.
get_cache
If a document cache is currently set, the "get_cache" method will
return it.
Returns a PPI::Cache object, or "undef" if there is no cache currently
set for "PPI::Document".
readonly
The "readonly" attribute indicates if the document is intended to be
read-only, and will never be modified. This is an advisory flag, that
writers of PPI-related systems may or may not use to enable
optimisations and caches for your document.
Returns true if the document is read-only or false if not.
tab_width [ $width ]
In order to handle support for "location" correctly, "Documents" need
to understand the concept of tabs and tab width. The "tab_width" method
is used to get and set the size of the tab width.
At the present time, PPI only supports "naive" (width 1) tabs, but we
do plan on supporting arbitrary, default and auto-sensing tab widths
later.
Returns the tab width as an integer, or "die"s if you attempt to set
the tab width.
save
$document->save( $file )
The "save" method serializes the "PPI::Document" object and saves the
resulting Perl document to a file. Returns "undef" on failure to open
or write to the file.
serialize
Unlike the "content" method, which shows only the immediate content
within an element, Document objects also have to be able to be written
out to a file again.
When doing this we need to take into account some additional factors.
Primarily, we need to handle here-docs correctly, so that are written
to the file in the expected place.
The "serialize" method generates the actual file content for a given
Document object. The resulting string can be written straight to a
file.
Returns the serialized document as a string.
hex_id
The "hex_id" method generates an unique identifier for the Perl
document.
This identifier is basically just the serialized document, with Unix-
specific newlines, passed through MD5 to produce a hexadecimal string.
This identifier is used by a variety of systems (such as PPI::Cache and
Perl::Metrics) as a unique key against which to store or cache
information about a document (or indeed, to cache the document itself).
Returns a 32 character hexadecimal string.
index_locations
Within a document, all PPI::Element objects can be considered to have a
"location", a line/column position within the document when considered
as a file. This position is primarily useful for debugging type
activities.
The method for finding the position of a single Element is a bit
laborious, and very slow if you need to do it a lot. So the
"index_locations" method will index and save the locations of every
Element within the Document in advance, making future calls to
<PPI::Element::location> virtually free.
Please note that this index should always be cleared using
"flush_locations" once you are finished with the locations. If content
is added to or removed from the file, these indexed locations will be
wrong.
flush_locations
When no longer needed, the "flush_locations" method clears all location
data from the tokens.
normalized
The "normalized" method is used to generate a "Layer 1"
PPI::Document::Normalized object for the current Document.
A "normalized" Perl Document is an arbitrary structure that removes any
irrelevant parts of the document and refactors out variations in style,
to attempt to approach something that is closer to the "true meaning"
of the Document.
See PPI::Normal for more information on document normalization and the
tasks for which it is useful.
Returns a PPI::Document::Normalized object, or "undef" on error.
complete
The "complete" method is used to determine if a document is cleanly
structured, all braces are closed, the final statement is fully
terminated and all heredocs are fully entered.
Returns true if the document is complete or false if not.
errstr
For error that occur when loading and saving documents, you can use
"errstr", as either a static or object method, to access the error
message.
If a Document loads or saves without error, "errstr" will return false.
TO DO
- May need to overload some methods to forcefully prevent Document
objects becoming children of another Node.
SUPPORT
See the support section in the main module.
AUTHOR
Adam Kennedy <adamk@cpan.org>
SEE ALSO
PPI(3), <http://ali.as/>
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 2019-04-25 PPI::Document(3)
ppi 1.250.0 - Generated Fri Apr 26 07:17:51 CDT 2019