The most common library for internationalizing and localizing Ruby on Rails applications is rails-i18n. A detailed guide on using it in your Rails applications can be found here: Rails I18n API.

Besides other file formats, YAML is the most commonly used format for internationalizing Rails applications.
YAML is a human-readable data serialization format with a well-defined standard.

Format

Key-value pairs are delimited with a colon :.
Values can be surrounded by single or double quotes.
YAML has many other rules for marking value blocks, such as using key: | for multi-line values.
Rails I18n uses the hierarchical style to structure your file (see example below).
Multiple languages are allowed in one Rails I18n YAML file. However, this approach is rarely used, and we recommend using one file per language.
The first level must always define the language of the following translations according to ISO_639-1. Lingohub will use the language information from the file content.
Comments start with a hash sign # and are ignored by all known parsers. But in the Lingohub context, all comment lines are parsed directly preceding a key-value pair (with no blank lines in between) and are treated as segment descriptions or LingoCheck rules belonging to that line.
The placeholder syntax is %{name}, where “name” can consist of multiple non-whitespace characters.
Lingohub is aware of parsing array structures.
UTF-8 is the default encoding for Rails I18n YAML files.
Lingohub can parse both array syntax types (see the example below) but cannot guarantee that the same syntax is used when exporting the file.
Lingohub cannot guarantee that it will use the same quoting and escaping as imported when exporting a file, but it will always produce a syntactically correct file.

Examples

Additional example files can be accessed here.

# this comment is ignored because it is not directly followed by a key-value pair
en:
  # this comment is also ignored, 
  # because it is followed by a key that has children nodes
  header:
    hello_user : Hello %{username}
    # comments are treated as translation descriptions 
    # belonging to the key-value pair that follows
    # lingochecks as well
    # lh-check {placeholders:true, terms: Lingohub, min: -5, max:+5}
    welcome: Welcome to Lingohub! this is your %{visit_count} visit.
  about:
    # example of an array in YAML
    features_array:
      - Reach billions with your apps!
      - Android, iOS & Co!
      - Clever Github integration!
    another_array: ['one', 'two', 'three'] 
    multi_line: |
      A multi 
      line value

Format

Examples

References