ajv-ftl-i18n

Internationalized error messages for Ajv - superfast JSON validator for JSON Schema and JSON Type Definition. A drop in replacement for ajv-i18n with some extra features.

Features

• Based off of Fluent (.ftl)
• Allows overriding messages
• Supports multi-lingual errorMessages
• Supports English (en), Arabic (ar), Catalan (ca), Czech (cs), German (de), Spanish (es), Finnish (fi), French (fr), Hungarian (hu), Indonesian (id), Italian (it), Japanese (ja), Korean (ko), Norwegian bokmål (nb), Dutch (nl), Polish (pl), Português - Brasil (pt-BR), Russian (ru), Slovak (sk), Swedish (sv), Thai (th), Chinese (zh), Chinese - Taiwan (zh-TW). PR to correct or add new locales welcome.

AJV Differences

• ar will return Arabic numerals, based on locale
• en uses lower case NOT
• fr uses «,» instead of "
• Fixed quote/space inconsistencies between locales
• Added in computer translation when missing
• Merged schema and jtd together

Install

1npm i -D ajv-ftl-i18n

Usage

1import _ajv from 'ajv/dist/2020.js'
2import localize from 'ajv-ftl-i18n'
3import errorMessage from 'ajv-errors'
4
5const Ajv = _ajv.default // esm workaround
6
7const ajv = Ajv({
8  allErrors: true,
9  messages: true // must be `true` for `errorMessages` support
10})
11errorMessage(ajv)
12const validate = ajv.compile(schema)
13const valid = validate(data)
14
15if (!valid) {
16  localize.fr(validate.errors)
17  // string with all errors and data paths
18  console.log(ajv.errorsText(validate.errors, { separator: '\n' }))
19}

Transpile

Used to transpile custom ftl files into ajv localizations.

CLI

1Usage: ajv-ftl [options] <input>
2
3Transpile Fluent (.ftl) files to JavaScript (.js or .mjs) for ajv
4
5Arguments:
6  input                  Path to the Fluent file to compile
7
8Options:
9  --locale <locale...>   What locale(s) to be used. Multiple can be set to allow for fallback. i.e. en-CA
10  -o, --output <output>  Path to store the resulting JavaScript file. Will be in ESM.
11  -h, --help             display help for command

NodeJS

1import { readFile, writeFile } from 'node:fs/promises'
2import { transpile } from 'ajv-ftl-i18n'
3
4const ftl = await readFile('./path/to/en.ftl', { encoding: 'utf8' })
5const js = transpile(ftl, { locale: 'en-CA' })
6await writeFile('./path/to/en.mjs', js, 'utf8')

errorMessage

All functionality of ajv-errors are supported. To not introduce new complexity to the errorMessage structure, you'll need to pull your errorMessages into a centralized ftl file for the schema.

${messageId}[, ${key}:${jsonPointer}][...]

Replace with message identifier in Fluent file

schema.ftl

1...
2dimensions = The dimensions are invalid

schema.json

1{
2  "type": "object",
3  "properties": {
4    "height": {
5      "type": "number",
6      "minimum": 4
7    },
8    "width": {
9      "type": "number",
10      "minimum": 4
11    }
12  },
13  "errorMessage": "dimensions"
14}

Use JSON-pointers

schema.ftl

1...
2dimensions = The dimensions ({$h}x{$w}) are invalid

schema.json

1{
2  "type": "object",
3  "properties": {
4    "height": {
5      "type": "number",
6      "minimum": 4
7    },
8    "width": {
9      "type": "number",
10      "minimum": 4
11    }
12  },
13  "errorMessage": {
14    "properties": {
15      "height": "dimensions, h:${/height}, w:${/width}"
16    }
17  }
18}