messageformat

Class: Messages

Accessor for compiled MessageFormat functions

import Messages from 'messageformat/messages'

new Messages(locales [, defaultLocale])

Parameters:
Name Type Argument Description
locales object

A map of locale codes to their function objects
defaultLocale string | null <optional>

If not defined, default and initial locale is the first entry of locales
Source:
Example
var fs = require('fs');
var MessageFormat = require('messageformat');
var mf = new MessageFormat(['en', 'fi']);
var msgSet = {
  en: {
    a: 'A {TYPE} example.',
    b: 'This has {COUNT, plural, one{one user} other{# users}}.',
    c: {
      d: 'We have {P, number, percent} code coverage.'
    }
  },
  fi: {
    b: 'Tällä on {COUNT, plural, one{yksi käyttäjä} other{# käyttäjää}}.',
    e: 'Minä puhun vain suomea.'
  }
};
var cfStr = mf.compile(msgSet).toString('module.exports');
fs.writeFileSync('messages.js', cfStr);

...

var Messages = require('messageformat/messages');
var msgData = require('./messages');
var messages = new Messages(msgData, 'en');

messages.hasMessage('a')                // true
messages.hasObject('c')                 // true
messages.get('b', { COUNT: 3 })         // 'This has 3 users.'
messages.get(['c', 'd'], { P: 0.314 })  // 'We have 31% code coverage.'

messages.get('e')                       // 'e'
messages.setFallback('en', ['foo', 'fi'])
messages.get('e')                       // 'Minä puhun vain suomea.'

messages.locale = 'fi'
messages.hasMessage('a')                // false
messages.hasMessage('a', 'en')          // true
messages.hasMessage('a', null, true)    // true
messages.hasObject('c')                 // false
messages.get('b', { COUNT: 3 })         // 'Tällä on 3 käyttäjää.'
messages.get('c').d({ P: 0.628 })       // 'We have 63% code coverage.'

Members

<static, readonly> availableLocales :Array.<string>

List of available locales

Type:
  • Array.<string>
Source:

<static> defaultLocale :string|null

Default fallback locale

One of Messages#availableLocales or null. Partial matches of language tags are supported, so e.g. with an en locale defined, it will be selected by messages.defaultLocale = 'en-US' and vice versa.

Type:
  • string | null
Source:

<static> locale :string|null

Current locale

One of Messages#availableLocales or null. Partial matches of language tags are supported, so e.g. with an en locale defined, it will be selected by messages.locale = 'en-US' and vice versa.

Type:
  • string | null
Source:

Methods

addMessages(data [, lc] [, keypath])

Add new messages to the accessor; useful if loading data dynamically

The locale code lc should be an exact match for the locale being updated, or empty to default to the current locale. Use #resolveLocale for resolving partial locale strings.

If keypath is empty, adds or sets the complete message object for the corresponding locale. If any keys in keypath do not exist, a new object will be created at that key.

Parameters:
Name Type Argument Description
data function | object

Hierarchical map of keys to functions, or a single message function
lc string <optional>

If empty or undefined, defaults to this.locale
keypath Array.<string> <optional>

The keypath being added
Source:
Returns:

The Messages instance, to allow for chaining

Type
Messages

get(key [, props] [, lc])

Get the message or object corresponding to key

key may be a string for functions at the root level, or string[] for accessing hierarchical objects. If an exact match is not found, the fallback locales are checked for the first match.

If key maps to a message function, it will be called with props. If it maps to an object, the object is returned directly.

Parameters:
Name Type Argument Description
key string | Array.<string>

The key or keypath being sought
props object <optional>

Optional properties passed to the function
lc string <optional>

If empty or undefined, defaults to this.locale
Source:
Returns:
Type
string | Object.<string, (function()|object)>

getFallback( [lc])

Get the list of fallback locales

Parameters:
Name Type Argument Description
lc string <optional>

If empty or undefined, defaults to this.locale
Source:
Returns:
Type
Array.<string>

hasMessage(key [, lc] [, fallback])

Check if key is a message function for the locale

key may be a string for functions at the root level, or string[] for accessing hierarchical objects. If an exact match is not found and fallback is true, the fallback locales are checked for the first match.

Parameters:
Name Type Argument Default Description
key string | Array.<string>

The key or keypath being sought
lc string <optional>

If empty or undefined, defaults to this.locale
fallback boolean <optional>
 false

If true, also checks fallback locales
Source:
Returns:
Type
boolean

hasObject(key [, lc] [, fallback])

Check if key is a message object for the locale

key may be a string for functions at the root level, or string[] for accessing hierarchical objects. If an exact match is not found and fallback is true, the fallback locales are checked for the first match.

Parameters:
Name Type Argument Default Description
key string | Array.<string>

The key or keypath being sought
lc string <optional>

If empty or undefined, defaults to this.locale
fallback boolean <optional>
 false

If true, also checks fallback locales
Source:
Returns:
Type
boolean

resolveLocale(lc)

Resolve lc to the key of an available locale or null, allowing for partial matches. For example, with an en locale defined, it will be selected by messages.defaultLocale = 'en-US' and vice versa.

Parameters:
Name Type Description
lc string

Locale code
Source:
Returns:
Type
string | null

setFallback(lc, fallback)

Set the fallback locale or locales for lc

To disable fallback for the locale, use setFallback(lc, []). To use the default fallback, use setFallback(lc, null).

Parameters:
Name Type Description
lc string
fallback Array.<string> | null
Source:
Returns:

The Messages instance, to allow for chaining

Type
Messages