@instructure/canvas-rce/doc/I18n.md

A component wrapping Canvas's usage of Tinymce

# I18n
## Overview
Each locale has two I18n files that are needed: A Canvas-managed JSON file that contains translations for our custom text, and a Tiny-managed JavaScript file for native TinyMCE menus and content:

### Canvas-manged JSON I18n files
- Live in `canvas-lms/packages/translations/lib/canvas-rce`
- Added to `formatMessage` via `formatMessage.addLocale({<locale code>: <translation keys/values>})`

### Tiny-managed JavaScript Translation files
- Manually pulled down from [this page](https://www.tiny.cloud/get-tiny/language-packages)
- Live in `canvas-rce/src/translations/tinymce`
- Added to `tinymce.I18n` via `tinymce.addI18n(<locale code>, <translation keys/values>`

## Building
Rather than import these two files into RCE individually, canvas-rce has some build tooling to copy the Canvas-managed translations over to JavaScript files (located in `canvas-rce/src/translations/locales`) and then mix in the Tiny-managed translations (via an `import`).

In the end, this results in a single JavaScript file per locale that can be imported into RCE. To handle importing the correct "combined" locale file, the build tooling also generates a helper function called `getTranslations()` (located at `canvas-rce/src/getTranslations.js`)

The "combined" locale files live in `canvas-rce/src/translations/locales`

For more details on the build process see `canvas-rce/scripts/installTranslations.js`

## Adding new Locales
Adding a new locale takes a few steps to ensure things work with the I18n build tooling and runtime importing.

1. Download the new Locale from [this page](https://www.tiny.cloud/get-tiny/language-packages)
2. Unzip the language pack and move the locale .js file to `canvas-rce/src/translations/tinymce`
3. Add the new locale to the mapping of Canvas locale codes to TinyMCE locale codes in `canvas-rce/src/rce/editorLanguage.js`
4. Add the new locale to the `recognized` array in `canvas-rce/src/rce/normalizeLocale.js`
5. Run `yarn installTranslations` to generate the "combined" locale file
6. `git add` the new Tiny-managed locale file added in step 2
7. `git add` the new generated "combined" locale file found in `canvas-rce/src/translations/locales`
8. `git add` the rest of the modified files, commit, and push \o/