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CLI

Installation​

npm i -D @formatjs/cli

Add the following command to your package.json scripts:

{
  "scripts": {
    "extract": "formatjs extract",
    "compile": "formatjs compile"
  }
}

We've built this CLI that helps you extract messages from a list of files. It uses @formatjs/ts-transformer under the hood and should be able to extract messages if you're declaring using 1 of the mechanisms below:

import {defineMessages, defineMessage} from 'react-intl'

defineMessages({
  foo: {
    id: 'foo',
    defaultMessage: 'foo',
    description: 'bar',
  },
})

defineMessage({
  id: 'single',
  defaultMessage: 'single message',
  description: 'header',
})
import {FormattedMessage} from 'react-intl'
;<FormattedMessage id="foo" defaultMessage="foo" description="bar" />
function Comp(props) {
  const {intl} = props
  return intl.formatMessage({
    // The whole `intl.formatMessage` is required so we can extract
    id: 'foo',
    defaultMessage: 'foo',
    description: 'bar',
  })
}

Extraction​

npm run extract -- --help
# Usage: formatjs extract [options] [files...]

# Extract string messages from React components that use react-intl.
# The input language is expected to be TypeScript or ES2017 with JSX.

For example:

npm run extract -- "src/**/*.{ts,tsx,vue}" --out-file lang.json
caution

You should always quote (" or ') your glob pattern (like "src/**/*") to avoid auto shell expansion of those glob, which varies depending on your shell (zsh vs fish vs bash).

--format [path]​

Path to a formatter file that controls the shape of JSON file from --out-file. The formatter file must export a function called format with the signature.

type FormatFn = <T = Record<string, MessageDescriptor>>(
  msgs: Record<string, MessageDescriptor>
) => T

This is especially useful to convert from our extracted format to a TMS-specific format.

See our builtin formatters for examples.

--out-file [path]​

The target file path where the plugin will output an aggregated .json file of allthe translations from the files supplied. This flag will ignore --messages-dir

--id-interpolation-pattern [pattern]​

If certain message descriptors don't have id, this pattern will be used to automatically generate IDs for them. Default to [sha512:contenthash:base64:6]. See nodejs crypto createHash for hash algorithms & nodejs buffer docs for digest encodings.

--extract-source-location​

Whether the metadata about the location of the message in the source file should be extracted. If true, then file, start, and end fields will exist for each extracted message descriptors. (default: false)

--additional-component-names [comma-separated-names]​

Additional component names to extract messages from, e.g: ['FormattedFooBarMessage']. NOTE: By default we check for the fact that FormattedMessage is imported from moduleSourceName to make sure variable alias works. This option does not do that so it's less safe.

--additional-function-names [comma-separated-names]​

Additional function names to extract messages from, e.g: ['$t'].

--ignore [files]​

List of glob paths to not extract translations from.

--throws​

Whether to throw an exception when we fail to process any file in the batch.

--pragma [pragma]​

Parse specific additional custom pragma. This allows you to tag certain file with metadata such as project. For example with this file:

// @intl-meta project:my-custom-project
import {FormattedMessage} from 'react-intl'
;<FormattedMessage defaultMessage="foo" id="bar" />

and with option {pragma: "intl-meta"}, we'll parse out // @intl-meta project:my-custom-project into {project: 'my-custom-project'} in the result file.

--flatten​

Whether to hoist selectors & flatten sentences as much as possible. E.g:

I have {count, plural, one{a dog} other{many dogs}}

becomes

{count, plural, one{I have a dog} other{I have many dogs}}

The goal is to provide as many full sentences as possible since fragmented sentences are not translator-friendly.

Compilation​

Compile extracted files from formatjs extract to a react-intl consumable JSON file. This also does ICU message verification. See Message Distribution for more details.

npm run compile -- --help

--format [path]​

Path to a formatter file that converts <translation_file> to Record<string, string> so we can compile. The file must export a function named compile with the signature:

type CompileFn = <T = Record<string, MessageDescriptor>>(
  msgs: T
) => Record<string, string>

This is especially useful to convert from a TMS-specific format back to react-intl format.

See our builtin formatters for examples.

--out-file <output>​

The target file that contains compiled messages.

--ast​

Whether to compile message into AST instead of just string. See Advanced Usage

--pseudo-locale <pseudoLocale>​

Whether we should compile messages into pseudo locales instead. Available pseudo-locales:

Given the English message my name is {name}

LocaleMessage
xx-LSmy name is {name}SSSSSSSSSSSSSSSSSSSSSSSSS
xx-ACMY NAME IS {name}
xx-HA[javascript]my name is {name}
en-XA[ḿẏ ƞȧȧḿḗḗ īş {name}]
en-XB‮ɯʎ uɐɯǝ ıs {name}‬
caution

Requires --ast

Extraction and compilation with a single script​

In some environments you may want to simply extract your messages to a file ready for use with react-intl without using an intermediary extracted message file format. This could be useful for quickly and easily creating the file for the original language that uses the default messages. This could also be useful if you use a Translation Management System (TMS) that is best suited to working with the compiled files. Keep in mind that the compiled file does not contain message descriptions so it is harder to work with for translators. Ideally you want to find or write a custom formatter you can use to extract messages into a file format that works with your TMS.

In order to achieve extraction and compilation in a single script, you can simply set up a script for that in package.json like in this example:

"scripts": {
  "extract": "formatjs extract",
  "compile": "formatjs compile",
  "extract-compile": "formatjs extract 'src/**/*.ts*' --out-file temp.json --flatten --id-interpolation-pattern '[sha512:contenthash:base64:6]' && formatjs compile 'temp.json' --out-file lang/en.json && rm temp.json"
}

Breakdown of the script​

The extract-compile example script consists of three operations performed one after the other.

formatjs extract 'src/**/*.ts*' --out-file temp.json --flatten --id-interpolation-pattern '[sha512:contenthash:base64:6]'

The first script extracts messages from all typescript files that are located in subfolders of src. You may need to ignore certain files that could trigger errors or warnings in the script, such as --ignore myFolder/myFile.ts

formatjs compile 'temp.json' --out-file lang/en.json

The second script compiles the messages from temp.json into the file lang/en.json. This file is ready to be consumed by react-intl.

rm temp.json

The last script deletes the temp.json extracted file. Feel free remove this from the script if you wish to keep this file around.

The resulting files​

Here you can see the difference between the extracted (using the default formatter) and the compiled file formats. In the script above, temp.json is the extracted file and en.json is the compiled file.

{
  "hak27d": {
    "defaultMessage": "Control Panel",
    "description": "title of control panel section"
  },
  "haqsd": {
    "defaultMessage": "Delete user {name}",
    "description": "delete button"
  },
  "19hjs": {
    "defaultMessage": "New Password",
    "description": "placeholder text"
  },
  "explicit-id": {
    "defaultMessage": "Confirm Password",
    "description": "placeholder text"
  }
}

Folder Compilation​

Batch compile a folder with extracted files from formatjs extract to a folder containing react-intl consumable JSON files. This also does ICU message verification. See Message Distribution for more details.

npm run formatjs compile-folder [options] <folder> <outFolder>

Folder structure should be in the form of <folder>/<locale>.json and the output would be <outFolder>/<locale>.json.

--format [path]​

Path to a formatter file that converts <translation_file> to Record<string, string> so we can compile. The file must export a function named compile with the signature:

type CompileFn = <T = Record<string, MessageDescriptor>>(
  msgs: T
) => Record<string, string>

This is especially useful to convert from a TMS-specific format back to react-intl format

--ast​

Whether to compile message into AST instead of just string. See Advanced Usage

--skip-errors​

Whether to continue compiling messages after encountering an error parsing one of them. Any keys with errors will not be included in the output file.

Builtin Formatters​

We provide the following built-in formatters to integrate with 3rd party TMSes:

TMS--format
BabelEditsimple
Crowdin Chrome JSONcrowdin
Lingohubsimple
Localize's Simple JSONsimple
locizesimple
Lokalise Structured JSONlokalise
Phrasesimple
POEditor Key-Value JSONsimple
SimpleLocalizesimple
Smartling ICU JSONsmartling
Transifex's Structured JSONtransifex
caution

The formats of extract & compile have to be the same, which means if you extract --format smartling, you have to compile --format smartling as well & vice versa.

Custom Formatters​

You can provide your own formatter by using our interfaces:

import {FormatFn, CompileFn, Comparator} from '@formatjs/cli'

interface VendorJson {}

// [Optional] Format @formatjs/cli structure to vendor's structure
export const format: FormatFn<VendorJson> = () => {}
// [Optional] Format vendor's structure to @formatjs/cli structure
export const compile: CompileFn<VendorJson> = () => {}
// [Optional] Sort the messages in a specific order during serialization
export const compareMessages: Comparator = () => {}

Take a look at our builtin formatter code for some examples.

Node API​

Install @formatjs/cli-lib instead to use programmatically

npm i -D @formatjs/cli-lib

Extraction​

import {extract} from '@formatjs/cli-lib'

const resultAsString: Promise<string> = extract(files, {
  idInterpolationPattern: '[sha512:contenthash:base64:6]',
})

Compilation​

import {compile} from '@formatjs/cli-lib'

const resultAsString: Promise<string> = compile(files, {
  ast: true,
})

Custom Formatter​

import {FormatFn, CompileFn, Comparator} from '@formatjs/cli-lib'

export const format: FormatFn = msgs => msgs

// Sort key reverse alphabetically
export const compareMessages = (el1, el2) => {
  return el1.key < el2.key ? 1 : -1
}

export const compile: CompileFn = msgs => {
  const results: Record<string, string> = {}
  for (const k in msgs) {
    results[k] = msgs[k].defaultMessage!
  }
  return results
}