NAME
Text::PO - Read and write PO files
SYNOPSIS
use Text::PO;
# Create a parser (include directives enabled by default)
my $po = Text::PO->new;
$po->debug(2);
$po->parse( $poFile ) || die( $po->error );
# Or disable include processing for this parsing
$po->parse( $poFile, include => 0 );
# Retrieve parsed elements
my $hash = $po->as_hash;
my $json = $po->as_json;
# Serialize back to PO text
my $str = $po->as_string;
# Add data:
my $e = $po->add_element(
msgid => 'Hello!',
msgstr => 'Salut !',
);
my $e = $po->add_include(
file => 'include/me.po',
after => 'Hello world!',
);
$po->remove_element( $e );
# Iterate over elements
$po->elements->foreach(sub
{
my $e = shift( @_ ); # $_ is also available
if( $e->msgid_as_text eq 'Hello!' )
{
# do something
}
});
Or, maybe using the object overloading directly:
$po->elements->foreach(sub
{
my $e = shift( @_ ); # $_ is also available
if( $e eq $other )
{
# do something
}
});
# Write in a PO format to STDOUT
$po->dump;
# or to a file handle
$po->dump( $io );
# Synchronise data
$po->sync( '/some/where/com.example.api.po' );
$po->sync( $file_handle );
# or merge
$po->merge( '/some/where/com.example.api.po' );
$po->merge( $file_handle );
VERSION
v0.9.0
DESCRIPTION
This module parse GNU PO (portable object) and POT (portable object
template) files, making it possible to edit the localised text and write
it back to a po file.
Text::PO::MO reads and writes ".mo" (machine object) binary files.
Thus, with those modules, you do not need to install "msgfmt", "msginit"
of GNU. It is better if you have them though.
Also, this distribution provides a way to export the "po" files in json
format to be used from within JavaScript and a JavaScript class to load
and use those files is also provided along with some command line
scripts. See the "share" folder along with its own test units.
Also, there is a script in "scripts" that can be used to transcode ".po"
or "mo" files into json format and vice versa.
For more information on the format of a PO element, check
Text::PO::Element
CONSTRUCTOR
new
Create a new Text::PO object acting as an accessor.
One object should be created per po file, because it stores internally
the po data for that file in the Text::PO object instantiated.
Returns the object.
The following options can be provided:
* "domain"
The PO domain.
* "header"
An array reference of PO file header string. Those are often lines
of comments preceded by a pound sign ("#"), possibly with some
copyright information.
* "encoding"
The content encoding of the file, such as "utf-8"
* "include"
Defaults to true.
A boolean value (1 or 0) to indicate whether the parser should
recognise include directives or not.
* "max_recurse"
Defaults to 32
An unsigned integer value representing the maximum recursion allowed
when "include" is enabled, and when the parser finds include
directives.
* "meta"
An hash reference of meta key-value pairs, with the keys in all
lower case.
* "meta_keys"
An array reference of meta keys found,
* "use_json"
Defaults to true.
A boolean value (1 or 0) to indicate whether to use JSON format.
METHODS
add_element
my $elem = $po->add_element( $element_object,
after => 'Some other text',
);
my $elem = $po->add_element(
msgid => 'Hello world!",
msgstr => 'Salut tout le monde !',
comment => 'No comment',
before => 'Some other text', # Add this new element before this msgid/include directive
);
This takes either of the following parameters, and adds the new element,
if it does not already exist, to the list of elements:
1. Text::PO::Element object + %options
A Text::PO::Element object, possibly followed by an hash or hash
reference of options.
2. %options
An hash or hash ref of options that will be passed to
Text::PO::Element to create a new object.
It returns the newly created element if it did not already exist, or the
existing one found. Thus if you try to add an element data that already
exists, this will prevent it and return the existing element object
found.
If an error occurred, it will set an error object and return "undef" in
scalar context, or an empty list in list context.
Supported options are:
* all the ones used in Text::PO::Element
* "before" / "after"
A "msgid" or "include" directive value to add this element before or
after.
add_include
my $elem = $po->add_include( $element_object,
after => 'Some other text',
);
my $elem = $po->add_include(
file => 'include/me.po",
comment => 'No comment',
before => 'Some other text', # Add this new element before this msgid/include directive
);
This takes either of the following parameters, and adds the new include
directive, if it does not already exist, to the list of elements:
1. Text::PO::Element object + %options
A Text::PO::Element object, possibly followed by an hash or hash
reference of options.
2. %options
An hash or hash ref of options that will be passed to
Text::PO::Element to create a new object.
Note that the "file" parameter must be set in the element passed, or
provided among the options used to create a new element.
It returns the newly created element if it did not already exist, or the
existing one found. Thus if you try to add an include directive that
already exists, this will prevent it and return the existing element
object found.
If an error occurred, it will set an error object and return "undef" in
scalar context, or an empty list in list context.
Supported options are:
* all the ones used in Text::PO::Element
* "before" / "after"
A "msgid" or "include" directive value to add this element before or
after.
added
Returns an array object (Module::Generic::Array) of Text::PO::Element
objects added during synchronisation.
as_json
This takes an optional hash reference of option parameters and return a
json formatted string.
All options take a boolean value. Possible options are:
* "indent"
If true, JSON will indent the data.
Default to false.
* "pretty"
If true, this will return a human-readable json data.
* "sort"
If true, this will instruct JSON to sort the keys. This makes it
slower to generate.
It defaults to false, which will use a pseudo random order set by
perl.
* "utf8"
If true, JSON will utf8 encode the data.
as_hash
Return the data parsed as an hash reference.
as_string
Serializes the current PO object into a single string containing valid
GNU ".po" syntax. This is equivalent to calling "dump" into an in-memory
scalar, but more convenient for tests or further processing.
my $string = $po->as_string;
This always returns a plain Perl string (not a blessed scalar or IO
object) to avoid issues with string overloading.
charset
Sets or gets the character encoding for the po data. This will affect
the "charset" parameter in "Content-Type" meta information.
content_encoding
Sets or gets the meta field value for "Content-Encoding"
content_type
Sets or gets the meta field value for "Content-Type"
current_lang
Returns the current language environment variable set, trying "LANGUAGE"
and "LANG"
decode
Given a string, this will decode it using the character set specified
with "encoding"
domain
Sets or gets the domain (or namespace) for this PO. Something like
"com.example.api"
dump
Given an optional filehandle, or STDOUT by default, it will print to
that filehandle in a format suitable to the po file.
Thus, one could create a perl script, read a po file, then redirect the
output of the dump back to another po file like
./po_script.pl en_GB.po > new_en_GB.po
It returns the Text::PO object used.
elements
Returns the array reference of all the Text::PO::Element objects
encoding
Sets or gets the character set encoding for the GNU PO file. Typically
this should be "utf-8"
exists
Given a Text::PO::Element object, it will check if this object exists in
its current stack. To achieve this, it will check if both the "msgid"
and the "msgstr" exists and match. If you only want to check if the
"msgid" exists, use the "msgid_only" option as explained below.
It takes an optional hash or hash reference of options as follows:
* "msgid_only"
Boolean. If true, this will check only if the "msgid" already
exists, and not the corresponding "msgstr"
It returns true of false accordingly.
hash
Returns the data of the po file as an hash reference with each key
representing a string and its value the localised version.
header
Access the headers data for this po file. The data is an array
reference.
include
$po->include(1); # enable include directives
$po->include(0); # disable include directives
my $bool = $po->include;
Controls whether "$include "file.po"" directives are recognised during
parsing.
Include support is enabled by default.
Include directives may appear in comments, using one of the following
forms:
# $include "other.po"
#. $include 'relative/path.po'
# $include "shared/common.po"
When include processing is enabled, any referenced file is parsed
recursively. Only valid PO entries
("msgid"/"msgstr"/"msgid_plural"/"msgctxt" blocks and special comments)
from included files are merged into the caller’s namespace; header
blocks and meta sections of include files are ignored.
This feature allows modular PO files, shared error message bundles, and
structured localisation domains without a separate preprocessing step.
language
Sets or gets the meta field value for "Language"
language_team
Sets or gets the meta field value for "Language-Team"
last_translator
Sets or gets the meta field value for "Last-Translator"
max_recurse
$po->max_recurse(20);
my $limit = $po->max_recurse;
Sets or gets the maximum recursion depth allowed when processing include
directives.
The default is 32.
If the recursion limit is exceeded (for example because of accidental
self-inclusion or a circular include chain), parsing will abort and
"error" will contain a descriptive message including the file path and
line number where recursion overflow occurred.
This protects users from infinite loops and malicious PO input.
merge
This takes the same parameters as "sync" and will merge the current data
with the target data and return the newly created Text::PO object
meta
This sets or return the given meta information. The meta field name
provided is case insensitive and you can replace dashes ("-") with
underscore (<_>)
$po->meta( 'Project-Id-Version' => 'MyProject 1.0' );
# or this will also work
$po->meta( project_id_version => 'MyProject 1.0' );
It can take a hash ref, a hash, or a single element. If a single element
is provided, it return its corresponding value.
This returns its internal hash of meta information.
meta_keys
This is an hash reference of meta information.
mime_version
Sets or gets the meta field value for "MIME-Version"
new_element
Provided with an hash or hash reference of property-value pairs, and
this will pass those information to Text::PO::Element and return the new
object.
normalise_meta
Given a meta field, this will return a normalised version of it, ie a
field name with the right case and dash instead of underscore
characters.
parse
$po->parse( $filepath );
$po->parse( $filepath, include => 0 );
$po->parse( $fh, max_recurse => 20 );
Parses a GNU ".po" file or a filehandle and loads its entries into the
current object. Returns the current Text::PO instance on success. Upon
error, it sets an error object and returns "undef" in scalar context,
and an empty list in list context.
Include processing
If include processing is enabled (see "include"), the parser recognises
the following non-standard directives:
# $include "path.po"
#.$include "relative.po"
Relative paths are resolved against the directory of the parent file.
When an include directive is seen:
1. A new Text::PO object is created for the included file.
2. The effective "include" and "max_recurse" settings are passed to the
child parser.
3. Only PO elements ("msgid"/"msgstr"/"msgctl"/"msgid_plural" entries,
and special comments) from the included file are merged into the
parent’s "elements" list. Header metadata from included files is
ignored.
4. Circular references are detected. A descriptive error is attached to
the directive line and parsing continues for the parent file.
5. If the included file has some header meta information containing the
header "Language" and if it does not match that of the parent, a
warning is emitted if warnings are enabled.
Options
parse() accepts the following options:
* "include" (boolean)
Override the parser’s include behaviour for this parse call.
* "max_recurse" (unsigned integer)
Override the maximum include depth for this parse call.
parse_date_to_object
Provided with a date string and this returns a DateTime object
parse_header_value
Takes a header value such as "text/plain; charset="utf-8"" and this
returns a "Text::PO::HeaderValue" object
parse2hash
Whether the pod file is stored as standard GNU po data or as json data,
this method will read its data and return an hash reference of it.
parse2object
Takes a file path, parse the po file and loads its data onto the current
object. It returns the current object.
plural
Sets or gets the plurality definition for this domain and locale used in
the current object.
If set, this will expect 2 parameters: 1) an integer representing the
possible plurality for the given locale and 2) the expression that will
be evaluated to assess which plural form to use.
It returns an array reference representing those 2 values.
If you want to find out the proper plural form for a given "locale", you
should refer to the Unicode CLDR <https://cldr.unicode.org/> data, which
can be accessed and queries via the module Locale::Unicode::Data:
my $cldr = Locale::Unicode::Data->new;
say $cldr->plural_forms( 'fr' ); # nplurals=2; plural=(n > 1);
plural_forms
Sets or gets the meta field value for "Plural-Forms"
po_revision_date
Sets or gets the meta field value for "PO-Revision-Date"
pot_creation_date
Sets or gets the meta field value for "POT-Creation-Date"
project_id_version
Sets or gets the meta field value for "Project-Id-Version"
quote
Given a string, it will escape carriage return, double quote and return
it,
remove_duplicates
Takes a boolean value to enable or disable the removal of duplicates in
the po file.
remove_element
Given a Text::PO::Element and this will remove it from the object
elements list.
If the value provided is not an Text::PO::Element object it will return
an error.
It returns a true value representing the number of elements removed or 0
if none could be found.
removed
Sets or gets this boolean value.
report_bugs_to
Sets or gets the meta field value for "Report-Msgid-Bugs-To"
quote
Takes a string and escape the characters that needs to be and returns
it.
remove_duplicates
Takes a boolean value and if true, this will remove duplicate msgid.
removed
Returns an array object (Module::Generic::Array) of Text::PO::Element
removed during synchronisation.
source
Sets or gets an hash reference of parameters providing information about
the source of the data.
It could have an attribute "handle" with a glob as value or an attribute
"file" with a filepath as value.
sync
$po->sync( '/some/where/com.example.api.po' );
# or
$po->sync({ file => '/some/where/com.example.api.po' });
# or
$po->sync({ handle => $file_handle });
# or, if source of data has been set previously by parse()
$po->parse( '/some/where/com.example.api.po' );
# Do some change to the data, then:
$po->sync;
Given a file or a file handle, it will read the po file, and our current
object will synchronise against it.
It takes an hash or hash reference passed as argument, as optional
parameters with the following properties:
* "file"
File path
* "handle"
Opened file handle
This means that our object is the source and the file or filehandle
representing the target po file is the recipient of the synchronisation.
This method will return an error a file is provided, already exists, but
is either a symbolic link or not a regular file ("-f" test), or a file
handle is provided, but not currently opened.
If a file path is provided, and the file does not yet exist, it will
attempt to create it or return an error if it cannot. In this case, it
will use "dump" to write all its data to file.
If the target file was created, it will return the current object,
otherwise it returns the newly created Text::PO representing the data
synchronised.
sync_fh
Takes a file handle as its unique argument and synchronise the object
data with the file handle. This means, the file handle provided must be
opened in both read and write mode.
What it does is that, after creating a new Text::PO object, it will
first call "parse" on the file handle to load its data, and then add all
of the current object data to the newly created object, and finally dump
all back to the file handle using "dump"
It will set two array of data: one for the elements that did not exist
in the recipient data and thus were added and one for those elements in
the target data that did not exist in the source object and thus were
removed.
If the option *append* is specified, however, it will not remove those
elements in the target that doe not exist in the source one. You can get
the same result by calling the method "merge" instead of "sync"
You can get the data of each of those 2 arrays by calling the methods
"added" and "removed" respectively.
It returns the newly created Text::PO object containing the synchronised
data.
unquote
Takes a string, unescape it and returns it.
use_json
Takes a boolean value and if true, this will save the data as json
instead of regular po format.
Saving data as json makes it quicker to load, but also enable the data
to be used by JavaScript.
PRIVATE METHODS
_can_write_fh
Given a filehandle, returns true if it can be written to it or false
otherwise.
_set_get_meta_date
Takes a meta field name for a date-type field and sets its value, if one
is provided, or returns a DateTime object.
If a value is provided, even a string, it will be converted to a
DateTime object and a DateTime::Format::Strptime will be attached to it
as a formatter so the stringification of the object produces a date
compliant with PO format.
_set_get_meta_value
Takes a meta field name and sets or gets its value.
THREAD-SAFETY
This module is thread-safe. All state is stored on a per-object basis,
and the underlying file operations and data structures do not share
mutable global state.
AUTHOR
Jacques Deguest <jack@deguest.jp>
SEE ALSO
Text::PO::Element, Text::PO::MO, Text::PO::Gettext
<https://www.gnu.org/software/gettext/manual/html_node/PO-Files.html>,
<https://en.wikipedia.org/wiki/Gettext>
GNU documentation on header format
<https://www.gnu.org/software/gettext/manual/html_node/Header-Entry.html
>
COPYRIGHT & LICENSE
Copyright (c) 2020-2025 DEGUEST Pte. Ltd.
You can use, copy, modify and redistribute this package and associated
files under the same terms as Perl itself.