Translate a Ruby on Rails app into Simplified Chinese

What changes when a Rails app goes Chinese

Simplified Chinese breaks three assumptions built into most Rails interfaces: plurals, word order and punctuation.

There is no plural. CLDR gives Chinese a single category, other. A pair such as one: \"%{count} comment\" / other: \"%{count} comments\" becomes one form, other: \"%{count} 条评论\", with a measure word (条, 个, 件, 位…) chosen to suit the noun. Mind how I18n behaves: with the default backend, count: 1 looks for one, and a missing key raises I18n::InvalidPluralizationData unless a Chinese plural rule is loaded (the rails-i18n gem provides one). Check this before release.

Variables move. “Welcome back, %{name}” becomes %{name}，欢迎回来. As long as the whole sentence sits in one value, the translation can reorder it. If your code glues pieces together, e.g. t('.hello') + user.name, the Chinese will read awkwardly: merge it into a single value with interpolation.

No spaces, full-width punctuation. Chinese uses ，。：？！ and does not separate words. The error format errors.format: \"%{attribute} %{message}\" is usually written \"%{attribute}%{message}\", giving 邮箱不能为空 rather than “邮箱 不能为空”.

What Manuce returns, and what it does not do

You get the same YAML file, in the same format. The root locale key (en:, fr: or whatever your source is) becomes the target's; indentation, key order, quotes, comments, line endings, encoding and BOM are preserved. Only the values change.

• Every translated value is compared with the source: a %{count} interpolation or a tag inside an _html key must come back intact. 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 the strings translated and those left as they were, with the reason.

What Manuce does not do: it does not touch views or controllers, does not extract text hard-coded in your ERB templates, does not edit config.i18n.available_locales, and leaves formats such as \"%m/%d/%Y\" as they are. Traditional Chinese (Taiwan, Hong Kong) is a separate language, ordered on its own. Manuce does not produce sworn or certified translations either: if your terms of service need certification, use an accredited translator.

Chinese carries a surcharge (×1.6 on the per-word rate), applied only to words in values, with keys and tags excluded.

Preparing the files before upload

• Collect every source-language file: the main locale file, per-model or per-view files, and any gem locale files you have copied into the project, such as devise.en.yml. A forgotten file means half-translated screens.
• Get sentences out of the code. Look for strings hard-coded in views and for concatenated translations; turn them into one value with %{variable}.
• Move punctuation into the values. A view that renders <%= t('.email') %>: will show 邮箱: with a Latin colon. Put the colon in the value so it can become ：.
• Match the locale code. Check that the returned root key matches the code your app declares. If the project uses zh-CN (the rails-i18n convention), align the key and the file name.
• Prune dead keys: they add to the word count and serve no one.

Checking the Chinese interface once integrated

Fonts. A Latin web font has no Chinese characters, so the browser falls back to whatever it finds. Declare an explicit stack, for example font-family: \"PingFang SC\", \"Microsoft YaHei\", \"Noto Sans SC\", sans-serif;.

Length. Chinese text is two to three times shorter in characters, but each character is wider, so the space taken changes little and buttons usually fit. However, truncate(text, length: 40) counts characters: 40 hanzi carry far more meaning than 40 letters. Revisit those limits.

Dates and numbers. Formats are not translated. Set date.formats.default yourself, for instance \"%Y年%-m月%-d日\", and the unit in number.currency.format if you show prices in yuan.

Testing. Switch to I18n.locale = :zh (or your code), render a counter at 0, 1 and 2 to exercise pluralisation, trigger a few validation errors and read the emails sent by ActionMailer. A tool such as i18n-tasks will flag keys missing between the source and Chinese.

In practice

1. Collect all source-language config/locales/*.yml files, including gem files copied into the project.
2. Upload them to Manuce, choose Simplified Chinese and read the free sample.
3. Download the translated files and the report, then align the root key with your locale code (zh or zh-CN).
4. Set fonts, date formats and the plural rule, then test counters and error messages.