Translate a Ruby on Rails app into English

What changes when a Rails locale file moves to English

A Rails locale file starts with the language’s root key. The delivered file starts with en: instead; everything beneath keeps the same tree, so t('.title') lazy lookups and t('users.index.title') calls still resolve.

• Plurals. English has only two CLDR categories, one and other. If your source is Polish or Russian, with few and many, those forms collapse into other. If it is French, note that French one covers 0 as well as 1, whereas in English count: 0 selects other: ‘0 comments’. So other: "%{count} comments" must read naturally for zero too. An explicit zero: key, if you have one, is kept and translated (‘No comments yet’).
• Validation messages. Rails builds %{attribute} %{message}, so the message must follow the attribute name: ‘Email can’t be blank’. Gender agreement markers found in Romance-language sources, such as ‘rempli(e)’, simply disappear.
• Punctuation. French spacing before colons goes: "Total :" becomes "Total:"; German „…“ or French « » quotes become English quotation marks.
• Length. From French, English text usually runs 10 to 15% shorter, so buttons and form labels rarely need layout changes.

British or American English: decide before uploading

The root key produced is en:, but spelling and vocabulary should follow one variety across the whole app. Typical differences in a Rails interface:

• colour / color, organisation / organization, cancelled / canceled;
• basket / cart, postcode / ZIP code in address forms;
• Sign in versus Log in: pick one and keep it in every view and mailer.

Date formats are not translated: date.formats.default: "%d/%m/%Y" stays as it is. That suits a UK audience; for the US, change it yourself to "%m/%d/%Y", and consider %I:%M %p instead of %H:%M in time.formats. Check number.format too: many European sources use a comma as decimal separator and a space or full stop for thousands, while English expects 1,250.50.

If your app serves en-GB and en-US separately, rename the root key and file accordingly after delivery.

What Manuce returns, and what it does not do

The file returned is the one you uploaded: indentation, key order, quoting style, comments, line endings, encoding and BOM are all preserved. Only the values change, which keeps your Git diff readable line by line.

• Each translated value is compared with the source for variables and tags. welcome_html: "Bonjour %{name}" must come back as "Hello %{name}", same placeholder, same tag. If a mismatch persists, the source value is kept and the report says so.
• Not translated: keys, empty values, URLs, email addresses, numbers, colours, date formats, identifiers and anything marked as non-translatable.
• The report lists translated strings and those left as they were, with the reason.

What Manuce does not do: it only sees locale files. A string hard-coded in an ERB view or a controller, such as notice: "Profil enregistré", is not in the YAML and stays in the source language. Nor does it touch config/application.rb or your initialisers. Pricing is based on the words in the values, with keys and tags excluded; for a customer-facing interface, the Professional level, handled by the domain specialist, is the sensible choice.

Preparing your files and checking the result

Before uploading:

• Move any hard-coded strings out of views, mailers and flash messages into YAML; a tool such as the i18n-tasks gem helps spot missing or unused keys.
• Gather every relevant file: the main locale file, but also devise.fr.yml or similar gem files, and per-model files holding activerecord.models.user or activerecord.attributes.user.email.
• Make sure the YAML loads cleanly: a badly indented source file will still be badly indented.

After delivery:

1. Save the file as config/locales/en.yml and add :en to config.i18n.available_locales.
2. Set I18n.locale = :en and render a counter with 0, 1 and 2 items to check one and other.
3. Look for concatenation in code, such as t('label') + " :", which reintroduces foreign punctuation.
4. Adjust date and number formats for your chosen variety, then work through the report for any strings left untranslated.

In practice

1. Collect the locale files from config/locales, including gem files such as Devise’s.
2. Upload them: the quote appears at once, based on the words in the values, and a free extract shows the result.
3. Choose a level and pay; a typical file is translated in minutes.
4. Put en.yml in config/locales, add :en to available locales and adjust date and number formats.
5. Read the report and test plurals with count set to 0, 1 and 2.