Locale-Wolowitz

Dead simple localization for web apps with JSON.

Stars
10
Committers
4

NAME Locale::Wolowitz - Dead simple localization with JSON.

SYNOPSIS # in ./i18n/locales.coll.json { "Welcome!": { "he": "ברוכים הבאים!", "es": "Bienvenido!" }, "I'm using %1": { "he": "אני משתמש ב%1", "es": "Estoy usando %1" }, "Linux": { "he": "לינוקס" } }

        # in your app
        use Locale::Wolowitz;

        my $w = Locale::Wolowitz->new( './i18n' );

        print $w->loc('Welcome!', 'es'); # prints 'Bienvenido!'

        print $w->loc("I'm using %1", 'he', $w->loc('Linux', 'he')); # prints "אני משתמש בלינוקס"

        # you can also directly load data (useful if data is not in files, but say in database)
        $w->load_structure({
                hello => {
                        he => 'שלום',
                        fr => 'bonjour'
                }
        });

        print $w->loc('hello', 'he'); # prints "שלום"

DESCRIPTION Locale::Wolowitz is a very simple text localization system. Yes, another localization system.

Frankly, I never realized how to use the standard Perl localization
systems such as Locale::Maketext, Gettext, Data::Localize or whatever.
It seems they are more meant to localize an application to the language
of the system on which its running, which isn't really what I need. Most
of the time, seeing as how I'm mostly writing web applications, I wish
to localize my applications/websites according to the user's wishes, not
by the system. For example, I may create a content management system
where the user can select the interface's language. Also, I grew to hate
the standard .po files, and thought using a JSON format might be more
comfortable.

Locale::Wolowitz allows you to provide different languages to end-users
of your applications. To some extent, when writing RESTful web
applications, this means you can perform language negotiation with
visitors (see Content negotiation on Wikipedia
<https://secure.wikimedia.org/wikipedia/en/w/index.php?title=Content_neg
otiation&oldid=367120431>).

Locale::Wolowitz works with JSON files. Each file can serve one or more
languages. When creating an instance of this module, you are required to
pass a path to a directory where your application's JSON localization
files are present. These are all loaded and merged into one big hash-ref
(unless you tell the module to only load a specific file), which is
stored in memory. A file with only one language has to be named
<lang>.json (where <lang> is the name of the language, you'd probably
want to use the two-letter ISO 639-1 code). A file with multiple
languages must end with .coll.json (this requirement will probably be
lifted in the future).

The basic idea is to write your application in a base language, and use
the JSON files to translate text to other languages. For example, lets
say you're writing your application in English and translating it to
Hebrew, Spanish, and Dutch. You put Spanish and Dutch translations in
one file, and since everybody hates Israel, you put Hebrew translations
alone. The Spanish and Dutch file can look like this:

        # es_and_nl.coll.json
        {
                "Welcome!": {
                        "es": "Bienvenido!",
                        "nl": "Welkom!"
                },
                "I'm using %1": {
                        "es": "Estoy usando %1",
                        "nl": "Ik gebruik %1"
                },
                "Linux": {} // this line can also be missing entirely
        }

While the Hebrew file can look like this:

        # he.json
        {
                "Welcome!": "ברוכים הבאים!",
                "I'm using %1": "אני משתמש ב%1",
                "Linux": "לינוקס"
        }

When loading these files, Locale::Wolowitz internally merges the two
files into one structure:

        {
                "Welcome!" => {
                        "es" => "Bienvenido!",
                        "nl" => "Welkom!",
                        "he" => "ברוכים הבאים!",
                },
                "I'm using %1" => {
                        "es" => "Estoy usando %1",
                        "nl" => "Ik gebruik %1",
                        "he" => "אני משתמש ב%1",
                },
                "Linux" => {
                        "he" => "לינוקס",
                }
        }

Notice the "%1" substrings above. This is a placeholder, just like in
other localization paradigms - they are replaced with content you
provide, usually dynamic content. In Locale::Wolowitz, placeholders are
written with a percent sign, followed by an integer, starting from 1
(e.g. %1, %2, %3). When passing data for the placeholders, make sure
you're passing scalars, or printable objects, otherwise you'll encounter
errors.

We can also see here that Spanish and Dutch have no translation for
"Linux". Since Linux is written "Linux" in these languages, they have no
translation. When attempting to translate a string that has no
translation to the requested language, or has no reference in the JSON
files at all, the string is simply returned as is (but placeholders will
still be replaced as expected).

Say you write your application in English (and thus 'en' is your base
language). Since Locale::Wolowitz doesn't really know what your base
language is, you can translate texts within the same language. This is
more useful when you want to give some of your strings an identifier.
For example:

        "copyrights": {
                "en": "Copyrights, 2010 Ido Perlmuter",
                "he": "כל הזכויות שמורות, 2010 עידו פרלמוטר"
        }

CONSTRUCTOR new( [ $path / $filename, %options ] ) Creates a new instance of this module. A path to a directory in which JSON localization files exist, or a path to a specific localization file, may be supplied. If you pass a directory, all JSON localization files in it will be loaded and merged as described above. If you pass one file, only that file will be loaded.

Note that "Locale::Wolowitz" will ignore dotfiles in the provided path
(e.g. hidden files, backups files, etc.).

A hash-ref of options can also be provided. The only option currently
supported is "utf8", which is on by default. If on, all JSON files are
assumed to be in UTF-8 character set and will be automatically decoded.
Provide a false value if your files are not UTF-8 encoded, for example:

        Locale::Wolowitz->new( '/path/to/files', { utf8 => 0 } );

OBJECT METHODS load_path( $path / $filename ) Receives a path to a directory in which JSON localization files exist, or a path to a specific localization file, and loads (and merges) the localization data from the file(s). If localization data was already loaded previously, the structure will be merged, with the new data taking precedence.

You can call this method and load_structure() as much as you want, the
data from each call will be merged with existing data.

load_structure( %structure, [ $lang ] ) Receives a hash-ref of localization data similar to that in the JSON files and loads it into the object (possibly merging with existing data, if any). If $lang is supplied, a one-to-one structure will be assumed, like so:

        load_structure(
                { "hello" => "שלום", "world" => "עולם" },
                'he'
        )

Or, if $lang is not provided, the structure must be the multiple
language structure, like so:

        load_structure({
                "hello" => {
                        "he" => "שלום",
                        "fr" => "bonjour"
                },
                "world" => {
                        "he" => "עולם",
                        "fr" => "monde",
                        "it" => "mondo"
                }
        })

You can call this method and load_path() as much as you want, the data
from each call will be merged with existing data.

loc( $msg, $lang, [ @args ] ) Returns the string $msg, translated to the requested language (if such a translation exists, otherwise no traslation occurs). Any other parameters passed to the method (@args) are injected to the placeholders in the string (if present).

If an argument is an array ref, it'll be replaced with a recursive call
to "loc" with its elements, with the $lang argument automatically added.
In other words, the following two statements are equivalent:

    print $w->loc("I'm using %1", 'he', $w->loc('Linux', 'he'));
    # same result as
    print $w->loc("I'm using %1", 'he', [ 'Linux' ]);

loc_for( $lang ) Returns a function ref that is like "loc", but with the $lang curried away.

    use Locale::Wolowitz;

    my $w = Locale::Wolowitz->new( './i18n' );

    my $french_loc  = $w->loc_for('fr');
    my $german_loc  = $w->loc_for('de');

    print $french_loc->('Welcome!'); # equivalent to $w->loc( 'Welcome!', 'fr' )

DIAGNOSTICS The following exceptions are thrown by this module:

"You must provide a path to localization directory."
    This exception is thrown if you haven't provided the "new()"
    subroutine a path to a localization file, or a directory of
    localization files. Read the documentation for the "new()"
    subroutine above.

"Can't open localization directory: %s" and "Can't close localization
directory: %s"
    This exception is thrown if Locale::Wolowitz failed to open/close
    the directory of the localization files. This will probably happen
    due to permission problems. The error message should include the
    actual reason for the failure.

"Path must be to a directory or a JSON file."
    This exception is thrown if you passed a wrong value to the "new()"
    subroutine as the path to the localization directory/file. Either
    the path is wrong and thus does not exist, or the path does exist,
    but is not a directory and not a file.

"Can't open localization file %s: %s" and "Can't close localization file
%s: %s"
    This exception is thrown if Locale::Wolowitz fails to open/close a
    specific localization file. This will usually happen because of
    permission problems. The error message will include both the name of
    the file, and the actual reason for the failure.

CONFIGURATION AND ENVIRONMENT "Locale::Wolowitz" requires no configuration files or environment variables.

DEPENDENCIES "Locale::Wolowitz" depends on the following CPAN modules:

*   Carp

*   JSON::MaybeXS

"Locale::Wolowitz" recommends Cpanel::JSON::XS or JSON::XS for faster
parsing of JSON files.

INCOMPATIBILITIES WITH OTHER MODULES None reported.

BUGS AND LIMITATIONS No bugs have been reported.

Please report any bugs or feature requests to
"[email protected]", or through the web interface at
<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Locale-Wolowitz>.

AUTHOR Ido Perlmuter [email protected]

LICENSE AND COPYRIGHT Copyright 2017 Ido Perlmuter

Licensed under the Apache License, Version 2.0 (the "License"); you may
not use this file except in compliance with the License. You may obtain
a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.