I18n.js
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It's a small library to provide the Rails I18n translations on the JavaScript.
Features:
- Pluralization
- Date/Time localization
- Number localization
- Locale fallback
- Asset pipeline support
- Lots more! :)
Version Notice
The master
branch (including this README) is for latest 3.0.0
instead of 2.x
.
Usage
Installation
Rails app
Add the gem to your Gemfile.
gem "i18n-js"
If you're using the asset pipeline,
then you must add the following line to your app/assets/javascripts/application.js
.
First, put this in your application.html
(layout file).
Then get the JS files following the instructions below.
<%# This is just an example, you can put `i18n.js` and `translations.js` anywhere you like %>
<%# Unlike the Asset Pipeline example, you need to require both **in order** %>
<%= javascript_include_tag "i18n" %>
<%= javascript_include_tag "translations", skip_pipeline: true %>
There are two ways to get translations.js
(For Rails app without Asset Pipeline).
- This
translations.js
file can be automatically generated by the I18n::JS::Middleware
.
Just add config.middleware.use I18n::JS::Middleware
to your config/application.rb
file. - If you can't or prefer not to generate this file,
you can move the middleware line to your
config/environments/development.rb
file
and run rake i18n:js:export
before deploying.
This will export all translation files, including the custom scopes
you may have defined on config/i18n-js.yml
.
If I18n.available_locales
is set (e.g. in your Rails config/application.rb
file)
then only the specified locales will be exported.
Current version of i18n.js
will also be exported to avoid version mismatching by downloading.
Export Configuration (For translations)
Exported translation files generated by I18n::JS::Middleware
or rake i18n:js:export
can be customized with config file config/i18n-js.yml
(use rails generate i18n:js:config
to create it).
You can even get more files generated to different folders and with different translations to best suit your needs.
The config file also affects developers using Asset Pipeline to require translations.
Except the option file
, since all translations are required by adding //= require i18n/translations
.
Examples:
translations:
- file: 'public/javascripts/path-to-your-messages-file.js'
only: '*.date.formats'
- file: 'public/javascripts/path-to-your-second-file.js'
only: ['*.activerecord', '*.admin.*.title']
If only
is omitted all the translations will be saved. Also, make sure you add that initial *
; it specifies that all languages will be exported. If you want to export only one language, you can do something like this:
translations:
- file: 'public/javascripts/en.js'
only: 'en.*'
- file: 'public/javascripts/pt-BR.js'
only: 'pt-BR.*'
Optionally, you can auto generate a translation file per available locale if you specify the %{locale}
placeholder.
translations:
- file: "public/javascripts/i18n/%{locale}.js"
only: '*'
- file: "public/javascripts/frontend/i18n/%{locale}.js"
only: ['*.frontend', '*.users.*']
You can also include ERB in your config file.
translations:
<% Widgets.each do |widget| %>
- file: <%= "'#{widget.file}'" %>
only: <%= "'#{widget.only}'" %>
<% end %>
You are able to exclude certain phrases or whole groups of phrases by
specifying the YAML key(s) in the except
configuration option. The outputted
JS translations file (exported or generated by the middleware) will omit any
keys listed in except
configuration param:
translations:
- except: ['*.active_admin', '*.ransack', '*.activerecord.errors']
Export Configuration (For other things)
-
I18n::JS.config_file_path
Expected Type: String
Default: config/i18n-js.yml
Behaviour: Try to read the config file from that location
-
I18n::JS.export_i18n_js_dir_path
Expected Type: String
Default: public/javascripts
Behaviour:
- Any
String
: considered as a relative path for a folder to Rails.root
and export i18n.js
to that folder for rake i18n:js:export
- Any non-
String
(nil
, false
, :none
, etc): Disable i18n.js
exporting
-
I18n::JS.sort_translation_keys
Expected Type: Boolean
Default: true
Behaviour:
- Sets whether or not to deep sort all translation keys in order to generate identical output for the same translations
- Set to true to ensure identical asset fingerprints for the asset pipeline
-
You may also set export_i18n_js
and sort_translation_keys
in your config file, e.g.:
export_i18n_js: false
export_i18n_js: "my/path"
sort_translation_keys: false
translations:
- ...
To find more examples on how to use the configuration file please refer to the tests.
Fallbacks
If you specify the fallbacks
option, you will be able to fill missing translations with those inside fallback locale(s).
Default value is true
.
Examples:
fallbacks: true
translations:
- file: "public/javascripts/i18n/%{locale}.js"
only: '*'
This will enable merging fallbacks into each file. (set to false
to disable).
If you use I18n
with fallbacks, the fallbacks defined there will be used.
Otherwise I18n.default_locale
will be used.
fallbacks: :de
translations:
- file: "public/javascripts/i18n/%{locale}.js"
only: '*'
Here, the specified locale :de
will be used as fallback for all locales.
fallbacks:
fr: ["de", "en"]
de: "en"
translations:
- file: "public/javascripts/i18n/%{locale}.js"
only: '*'
Fallbacks defined will be used, if not defined (e.g. :pl
) I18n.fallbacks
or I18n.default_locale
will be used.
fallbacks: :default_locale
translations:
- file: "public/javascripts/i18n/%{locale}.js"
only: '*'
Setting the option to :default_locale
will enforce the fallback to use the I18n.default_locale
, ignoring I18n.fallbacks
.
Examples:
fallbacks: false
translations:
- file: "public/javascripts/i18n/%{locale}.js"
only: '*'
You must disable this feature by setting the option to false
.
To find more examples on how to use the configuration file please refer to the tests.
Namespace
Setting the namespace
option will change the namespace of the output Javascript file to something other than I18n
.
This can be useful in no-conflict scenarios. Example:
translations:
- file: "public/javascripts/i18n/translations.js"
namespace: "MyNamespace"
will create:
MyNamespace.translations || (MyNamespace.translations = {});
MyNamespace.translations["en"] = { ... }
Adding a line at the beginning of the translations file (useful for imports)
Setting the prefix: "import I18n from 'i18n-js';\n"
option will add the line at the beggining of the resultant translation file.
This can be useful to use this gem with the i18n-js npm package, which is quite useful to use it with webpack.
The user should provide the semi-colon and the newline character if needed.
For example:
translations:
- file: "public/javascripts/i18n/translations.js"
prefix: "import I18n from 'i18n-js';\n"
will create:
import I18n from 'i18n-js';
I18n.translations || (I18n.translations = {});
#### Pretty Print
Set the `pretty_print` option if you would like whitespace and indentation in your output file (default: false)
```yaml
translations:
- file: "public/javascripts/i18n/translations.js"
pretty_print: true
Javascript Deep Merge (:js_extend option)
By default, the output file Javascript will call the I18n.extend
method to ensure that newly loaded locale
files are deep-merged with any locale data already in memory. To disable this either globally or per-file,
set the js_extend
option to false
js_extend: false
translations:
- file: "public/javascripts/i18n/translations.js"
js_extend: false
Vanilla JavaScript
Just add the i18n.js
file to your page. You'll have to build the translations object
by hand or using your favorite programming language. More info below.
Via NPM with webpack and CommonJS
Add the following line to your package.json dependencies
where version is the version you want
"i18n-js": "{version_constraint}"
"i18n-js": "https://github.com/fnando/i18n-js/archive/{tag_name_or_branch_name_or_commit_sha}.tar.gz"
Run npm install then use via
var i18n = require("i18n-js");
Setting up
You don't need to set up a thing. The default settings will work just okay. But if you want to split translations into several files or specify specific contexts, you can follow the rest of this setting up section.
Set your locale is easy as
I18n.defaultLocale = "pt-BR";
I18n.locale = "pt-BR";
I18n.currentLocale();
NOTE: You can now apply your configuration before I18n is loaded like this:
I18n = {}
I18n.defaultLocale = "pt-BR";
I18n.locale = "pt-BR";
I18n.currentLocale();
In practice, you'll have something like the following in your application.html.erb
:
<script type="text/javascript">
I18n.defaultLocale = "<%= I18n.default_locale %>";
I18n.locale = "<%= I18n.locale %>";
</script>
You can use translate your messages:
I18n.t("some.scoped.translation");
I18n.t("some.scoped.translation", {locale: "fr"});
You can also interpolate values:
I18n.translations["en"] = {
greeting: "Hello %{name}"
}
I18n.t("greeting", {name: "John Doe"});
You can set default values for missing scopes:
I18n.t("some.missing.scope", {defaultValue: "A default message"});
I18n.t("noun", {defaultValue: "I'm a {{noun}}", noun: "Mac"});
You can also provide a list of default fallbacks for missing scopes:
I18n.t("some.missing.scope", {defaults: [{scope: "some.existing.scope"}]});
I18n.t("some.missing.scope", {defaults: [{message: "Some message"}]});
Default values must be provided as an array of hashs where the key is the
type of translation desired, a scope
or a message
. The translation returned
will be either the first scope recognized, or the first message defined.
The translation will fallback to the defaultValue
translation if no scope
in defaults
matches and if no default of type message
is found.
Translation fallback can be enabled by enabling the I18n.fallbacks
option:
<script type="text/javascript">
I18n.fallbacks = true;
</script>
By default missing translations will first be looked for in less
specific versions of the requested locale and if that fails by taking
them from your I18n.defaultLocale
.
I18n.t("some.missing.scope");
Custom fallback rules can also be specified for a particular language. There
are three different ways of doing it so:
I18n.locales.no = ["nb", "en"];
I18n.locales.no = "nb";
I18n.locales.no = function(locale){ return ["nb"]; };
By default a missing translation will be displayed as
[missing "name of scope" translation]
While you are developing or if you do not want to provide a translation
in the default language you can set
I18n.missingBehaviour='guess';
this will take the last section of your scope and guess the intended value.
Camel case becomes lower cased text and underscores are replaced with space
questionnaire.whatIsYourFavorite_ChristmasPresent
becomes "what is your favorite Christmas present"
In order to still detect untranslated strings, you can
i18n.missingTranslationPrefix to something like:
I18n.missingTranslationPrefix = 'EE: ';
And result will be:
"EE: what is your favorite Christmas present"
This will help you doing automated tests against your localisation assets.
Some people prefer returning null
for missing translation:
I18n.missingTranslation = function () { return undefined; };
Pluralization is possible as well and by default provides English rules:
I18n.t("inbox.counting", {count: 10});
The sample above expects the following translation:
en:
inbox:
counting:
one: You have 1 new message
other: You have {{count}} new messages
zero: You have no messages
NOTE: Rails I18n recognizes the zero
option.
If you need special rules just define them for your language, for example Russian, just add a new pluralizer:
I18n.pluralization["ru"] = function (count) {
var key = count % 10 == 1 && count % 100 != 11 ? "one" : [2, 3, 4].indexOf(count % 10) >= 0 && [12, 13, 14].indexOf(count % 100) < 0 ? "few" : count % 10 == 0 || [5, 6, 7, 8, 9].indexOf(count % 10) >= 0 || [11, 12, 13, 14].indexOf(count % 100) >= 0 ? "many" : "other";
return [key];
};
You can find all rules on http://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html.
If you're using the same scope over and over again, you may use the scope
option.
var options = {scope: "activerecord.attributes.user"};
I18n.t("name", options);
I18n.t("email", options);
I18n.t("username", options);
You can also provide an array as scope.
I18n.t(["greetings", "hello"]);
Number formatting
Similar to Rails helpers, you have localized number and currency formatting.
I18n.l("currency", 1990.99);
I18n.l("number", 1990.99);
I18n.l("percentage", 123.45);
To have more control over number formatting, you can use the
I18n.toNumber
, I18n.toPercentage
, I18n.toCurrency
and I18n.toHumanSize
functions.
I18n.toNumber(1000);
I18n.toCurrency(1000);
I18n.toPercentage(100);
The toNumber
and toPercentage
functions accept the following options:
precision
: defaults to 3
separator
: defaults to .
delimiter
: defaults to ,
strip_insignificant_zeros
: defaults to false
See some number formatting examples:
I18n.toNumber(1000, {precision: 0});
I18n.toNumber(1000, {delimiter: ".", separator: ","});
I18n.toNumber(1000, {delimiter: ".", precision: 0});
The toCurrency
function accepts the following options:
precision
: sets the level of precisionseparator
: sets the separator between the unitsdelimiter
: sets the thousands delimiterformat
: sets the format of the output stringunit
: sets the denomination of the currencystrip_insignificant_zeros
: defaults to false
sign_first
: defaults to true
You can provide only the options you want to override:
I18n.toCurrency(1000, {precision: 0});
The toHumanSize
function accepts the following options:
precision
: defaults to 1
separator
: defaults to .
delimiter
: defaults to ""
strip_insignificant_zeros
: defaults to false
format
: defaults to %n%u
I18n.toHumanSize(1234);
I18n.toHumanSize(1234 * 1024);
Date formatting
I18n.l("date.formats.short", "2009-09-18");
I18n.l("time.formats.short", "2009-09-18 23:12:43");
I18n.l("time.formats.short", "2009-11-09T18:10:34");
I18n.l("time.formats.short", "2009-11-09T18:10:34Z");
I18n.l("date.formats.short", 1251862029000);
I18n.l("date.formats.short", "09/18/2009");
I18n.l("date.formats.short", (new Date()));
You can also add placeholders to the date format:
I18n.translations["en"] = {
date: {
formats: {
ordinal_day: "%B %{day}"
}
}
}
I18n.l("date.formats.ordinal_day", "2009-09-18", { day: '18th' });
If you prefer, you can use the I18n.toTime
and I18n.strftime
functions to format dates.
var date = new Date();
I18n.toTime("date.formats.short", "2009-09-18");
I18n.toTime("date.formats.short", date);
I18n.strftime(date, "%d/%m/%Y");
The accepted formats for I18n.strftime
are:
%a - The abbreviated weekday name (Sun)
%A - The full weekday name (Sunday)
%b - The abbreviated month name (Jan)
%B - The full month name (January)
%c - The preferred local date and time representation
%d - Day of the month (01..31)
%-d - Day of the month (1..31)
%H - Hour of the day, 24-hour clock (00..23)
%-H/%k - Hour of the day, 24-hour clock (0..23)
%I - Hour of the day, 12-hour clock (01..12)
%-I/%l - Hour of the day, 12-hour clock (1..12)
%m - Month of the year (01..12)
%-m - Month of the year (1..12)
%M - Minute of the hour (00..59)
%-M - Minute of the hour (0..59)
%p - Meridian indicator (AM or PM)
%P - Meridian indicator (am or pm)
%S - Second of the minute (00..60)
%-S - Second of the minute (0..60)
%w - Day of the week (Sunday is 0, 0..6)
%y - Year without a century (00..99)
%-y - Year without a century (0..99)
%Y - Year with century
%z/%Z - Timezone offset (+0545)
Check out spec/*.spec.js
files for more examples!
Using pluralization and number formatting together
Sometimes you might want to display translation with formatted number, like adding thousand delimiters to displayed number
You can do this:
{
"en": {
"point": {
"one": "1 Point",
"other": "{{formatted_number}} Points",
"zero": "0 Points"
}
}
}
var point_in_number = 1000;
I18n.t('point', { count: point_in_number, formatted_number: I18n.toNumber(point_in_number) });
Output should be 1,000 points
Using multiple exported translation files on a page.
This method is useful for very large apps where a single contained translations.js file is not desirable. Examples would be a global translations file and a more specific route translation file.
Rails without asset pipeline
- Setup your
config/i18n-js.yml
to have multiple files and try to minimize any overlap.
sort_translation_keys: true
fallbacks: false
translations:
+ file: "app/assets/javascript/nls/welcome.js"
only:
+ '*.welcome.*'
+ file: "app/assets/javascript/nls/albums.js"
only:
+ '*.albums.*'
+ file: "app/assets/javascript/nls/global.js"
only:
+ '*'
except:
+ '*.welcome.*'
+ '*.albums.*'
When rake i18n:js:export
is executed it will create 3 translations files that can be loaded via the javascript_include_tag
- Add the
javascript_include_tag
to your layout and to any route specific files that will require it.
<%= javascript_include_tag(
"i18n"
"nls/global"
) %>
and in the route specific
<%= javascript_include_tag(
"nls/welcome"
) %>
- Make sure that you add these files to your
config/application.rb
config.assets.precompile += %w(
i18n
nls/*
)
Using require.js / r.js
To use this with require.js we are only going to change a few things from above.
- In your
config/i18n-js.yml
we need to add a better location for the i18n to be exported. You want to use this location so that it can be properly precompiled by r.js.
export_i18n_js: "app/assets/javascript/nls"
- In your
config/require.yml
we need to add a map, shim all the translations, and include them into the appropriate modules
map:
'*':
i18n: 'nls/i18n'
shims:
nls/welcome:
deps:
+ i18n
nls/global:
deps:
+ i18n
modules:
+ name: 'application'
include:
+ i18n
+ 'nls/global'
+ name: 'welcome'
exclude:
+ application
include:
+ 'nls/welcome'
- When
rake assets:precompile
is executed it will optimize the translations into the correct modules so they are loaded with their assigned module, and loading them with requirejs is as simple as requiring any other shim.
define(['welcome/other_asset','nls/welcome'], function (otherAsset){
});
- (optional) As an additional configuration we can make a task to be run before the requirejs optimizer. This will allow any automated scripts that run the requirejs optimizer to export the strings before we run r.js
# lib/tasks/i18n.rake
Rake::Task[:'i18n:js:export'].prerequisites.clear
task :'i18n:js:export' => :'i18n:js:before_export'
task :'requirejs:precompile:external' => :'i18n:js:export'
namespace :i18n do
namespace :js do
task :before_export => :'assets:environment' do
I18n.load_path += Dir[Rails.root.join('config', 'locales', '*.{yml,rb}')]
I18n.backend.load_translations
end
end
end
Using I18n.js with other languages (Python, PHP, ...)
The JavaScript library is language agnostic; so you can use it with PHP, Python, [your favorite language here].
The only requirement is that you need to set the translations
attribute like following:
I18n.translations = {};
I18n.translations["en"] = {
message: "Some special message for you"
}
I18n.translations["pt-BR"] = {
message: "Uma mensagem especial para você"
}
Known Issues
Missing translations in precompiled file(s) after adding any new locale file
Due to the design of sprockets
:
depend_on
only takes file paths, not directory paths- registered
preprocessors
are only run when the fingerprint of any asset file, including .erb
files, is changed
This means that new locale files will not be detected, and so they will not trigger a i18n-js refresh. There are a few approaches to work around this:
- You can force i18n-js to update its translations by completely clearing the assets cache. Use one of the following:
$ rake assets:clobber
$ rake tmp:cache:clear
These commands will remove all fingerprinted assets, and you will have to recompile them with
$ rake assets:precompile
or similar commands. If you are precompiling assets on the target machine(s), cached pages may be broken by this, so they will need to be refreshed.
-
You can change something in a different locale file.
-
Finally, you can change config.assets.version
.
Note: See issue #213 for more details and discussion of this issue.
Translations in JS are not updated when Sprockets not loaded before this gem
The "rails engine" declaration will try to detect existence of "sprockets" before adding the initailizer
If sprockets is loaded after this gem, the preprocessor for
making JS translations file cache to depend on content of locale files will not be hooked.
So ensure sprockets is loaded before this gem like moving entry of sprockets in Gemfile or adding "require" statements for sprockets somewhere.
Note: See issue #404 for more details and discussion of this issue.
JS I18n.toCurrency
& I18n.toNumber
cannot handle large integers
The above methods use toFixed
and it only supports 53 bit integers.
Ref: http://2ality.com/2012/07/large-integers.html
Feel free to find & discuss possible solution(s) at issue #511
Only works with Simple
backend
If you set I18n.backend
to something other than the default Simple
backend, you will likely get an exception like this:
Undefined method 'initialized?' for <your backend class>
For now, i18n-js is only compatible with the Simple
backend.
If you need a more sophisticated backend for your rails application, like I18n::Backend::ActiveRecord
, you can setup i18n-js to get translations from a separate Simple
backend, by adding the following in an initializer:
I18n::JS.backend = I18n.backend
I18n.backend = I18n::Backend::Chain.new(<your other backend(s)>, I18n.backend)
This will use your backend with the default Simple
backend as fallback, while i18n-js only sees and uses the simple backend.
This means however, that only translations from your static locale files will be present in JavaScript.
If you do cannot use a Chain
-Backend for some reason, you can also set
I18n::JS.backend = I18n::Backend::Simple.new
I18n.backend = <something different>
However, the automatic reloading of translations in developement will not work in this case.
This is because Rails calls I18n.reload!
for each request in development, but reload!
will not be called on I18n::JS.backend
, since it is a different object.
One option would be to patch I18n.reload!
in an initializer:
module I18n
def self.reload!
I18n::JS.backend.reload!
super
end
end
See issue #428 for more details and discussion of this issue.
Maintainer
Contributing
Once you've made your great commits:
- Fork I18n.js
- Create a branch with a clear name
- Make your changes (Please also add/change spec, README and CHANGELOG if applicable)
- Push changes to the created branch
- Create an Pull Request
- That's it!
Please respect the indentation rules and code style.
And use 2 spaces, not tabs. And don't touch the versioning thing.
Running tests
You can run I18n tests using Node.js or your browser.
To use Node.js, install the jasmine-node
library:
$ npm install jasmine-node
Then execute the following command from the lib's root directory:
$ npm test
To run using your browser, just open the spec/js/specs.html
file.
You can run both Ruby and JavaScript specs with rake spec
.
License
(The MIT License)
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
'Software'), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.