- copy ./en.js
- rename it (for example jp.js)
- translate it
- go to server-html.jsx
- add your locale data as it is done in https://cdn.polyfill.io script (add ',Intl.~locale.XX' at the end of url)
- add localeData and newly translated strings as it is done in Translator.jsx (read the comments)
Use lower-snake-case (e.g. 'keep_syntax_lowercase_with_dashes') for all translation string names.
Example: show_password: 'Show Password'
Please keep in mind that none of the strings are bound directly to components to keep them reusable.
For example: 'messages_count' can be used in one page today, but also can be placed in another tomorrow.
Strings must be as close to source as possible.
They must keep proper structure because "change_password" can translate both 'Change Password' and 'Change Account Password'.
Same with "user hasn't started posting" and "user hasn't started posting yet", 'user_hasnt_followed_anything_yet' and 'user_hasnt_followed_anything' are not the same.
Do not use anything to style strings unless you are 100% sure what you are doing.
This is no good: 'LOADING' instead of 'Loading'.
Avoid whitespace styling: ' Loading' - is no good.
Also, try to avoid using syntax signs, unless it's a long ass string which will always end with a dot no matter where you put it. Example: 'Loading...', 'Loading!' is no good, use 'Loading' instead.
If you are not sure which syntax to use and how to write your translations just copy the way the original string has been written.
Plurals are strings which look different depending on which numbers are used.
We use formatJs syntax, read the docs http://formatjs.io/guides/message-syntax/
Pay special attention to '{plural} Format' section. This link shows how they determine which plural to use in different languages (they explain how string falls under 'few', 'many' and 'other' category. If you are completely lost, just look at the other translation files (en.js or ru.js).
IMPORTANT: if you use the wrong rules for pluralization, the translation will fail '{postCount, plural, zero {0 постов} one {# пост} few {# поста} many {# постов}}' instead of using a normal string. In that case, check what kind of rules your language needs. For example: Russian needs "zero", "one", "few", "many". But english only needs 'zero', 'one', 'more than one'.
\n means new line break
\' means ' (single quote sign)
this works: 'hasn\'t', "hasn't" (double quotes != single quotes)
this does not: 'hasn't'
Some languages require certain strings to be empty. For example, Russian in some contexts does not have an equivalent for 'by' (e.g. 'Post created by Misha'). For empty strings use ' ' (empty quotes with single space) instead of '', otherwise you will see string name instead of nothing.