Nightly Patch Machine


    0.4.0 • Public • Published


    Converts hiearachical objects into messageformat-compatible JSON. More specifically, it:

    • Detects two-letter locale keys and parses their contents according to that locale's pluralisation rules
    • Converts #{var} and %{var} variable replacements into their messageformat equivalents, while properly escaping other {} characters.
    • Detects objects encoding pluralisation choices (using the locale-specific set of CLDR categories, i.e. zero|one|two|few|many|aother) and converts them to their messageformat equivalents.

    With these conversions, messages stored according to the Rails i18n spec may be used together with messageformat.


    npm install messageformat-convert

    If using in an environment that does not natively support ES6 features such as object destructuring and arrow functions, you'll want to use a transpiler for this.


    const convert = require('messageformat-convert');
    const { locales, translations } = convert({
      en: {
        format: '%{attribute} %{message}',
        errors: {
          confirmation: "doesn't match %{attribute}",
          accepted: 'must be accepted',
          wrong_length: {
            one: 'is the wrong length (should be 1 character)',
            other: 'is the wrong length (should be %{count} characters)'
          equal_to: 'must be equal to %{count}'
    const MessageFormat = require('messageformat');
    const mf = new MessageFormat(locales);
    const messages = mf.compile(translations);
    // 'must be accepted'
      attribute: 'Problem',
      message: messages.en.errors.confirmation({ attribute: 'your style' })
    // 'Problem doesn\'t match your style'
    messages.en.errors.wrong_length({ count: 42 });
    // 'is the wrong length (should be 42 characters)'

    API: convert(data, options)

    data should be a hierarchical object of strings; options is an optional set of configuration:

    • defaultLocale (string, default 'en') – Sets the initial locale.

    • includeLocales (array of strings, default null) – By default any key in the input data that matches the two-letter code of a CLDR pluralisation language switches the language used for determining the pluralisation rules. Set this to some limited set of languages (or even an empty array) to limit that.

    • verbose (boolean, default false) – If set to true, some logging and warnings will be printed to the console.

    For more options, take a look at the source.

    The object returned by the function contains the following fields:

    • locales (array of strings) – The actual locales encountered in the data

    • translations (object) – An object containing the MessageFormat strings, matching the shape of the input data

    Messageformat is an OpenJS Foundation project, and we follow its Code of Conduct.

    OpenJS Foundation


    npm i messageformat-convert

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    • eemeli