Internationalize React apps. Not only for React component but also for Vanilla JS.
npm install react-intl-universal  
``js`
import { injectIntl } from 'react-intl';
class MyComponent extends Component {
render() {
const intl = this.props;
const title = intl.formatMessage({ id: 'title' });
return ({title});
}
};
export default injectIntl(MyComponent);
However, this approach introduces two major issues.
Firstly, Internationalizing can be applied only in view layer such as React.Component. For Vanilla JS file, there's no way to internationalize it. For example, the following snippet is general form validator used by many React.Component in our apps. We definitely will not have such code separated in different React.Component in order to internationalize the warning message. Sadly, react-intl can't be used in Vanilla JS.
`js`
export default const rules = {
noSpace(value) {
if (value.includes(' ')) {
return 'Space is not allowed.';
}
}
};
Secondly, since your React.Component is wrapped by another class, the behavior is not as expected in many way. For example, to get the instance of React.Component, you can't use the normal way like:
`js`
class App {
render() {
}
getMyInstance() {
console.log('getMyInstance', this.refs.my);
}
}
Instead, you need to use the method getWrappedInstance()` to get that.`js
class MyComponent {...}
export default injectIntl(MyComponent, {withRef: true});
class App {
render() {
}
getMyInstance() {
console.log('getMyInstance', this.refs.my.getWrappedInstance());
}
}
`
Furthermore, your React.Component's properties are not inherited in subclass since component is injected by react-intl.
Due to the problem above, we create react-intl-universal to internationalize React app using simple but powerful API.
is substituted directly into the string. In the example below, there are two variables {name} and {where}, the second argument representing the variables in get method are substituted into the string.Locale data:
`json
{ "HELLO": "Hello, {name}. Welcome to {where}!" }
`JS code:
js
intl.get('HELLO', { name: 'Tony', where: 'Alibaba' }) // "Hello, Tony. Welcome to Alibaba!"
`$3
Locale data:
json
{ "PHOTO": "You have {num, plural, =0 {no photos.} =1 {one photo.} other {# photos.}}" }
`
JS code:
js
intl.get('PHOTO', { num: 0 }); // "You have no photos."
intl.get('PHOTO', { num: 1 }); // "You have one photo."
intl.get('PHOTO', { num: 1000000 }); // "You have 1,000,000 photos."
`
Plural label supports standard ICU Message syntax.Number thousands separators also varies according to the user's locale. According to this document, United States use a period to indicate the decimal place. Many other countries use a comma instead.
$3
Locale data:
json
{ "SALE_PRICE": "The price is {price, number, USD}" }
`
JS code:
js
intl.get('SALE_PRICE', { price: 123456.78 }); // The price is $123,456.78
`
As mentioned, the locale data is in ICU Message format.The syntax is {name, type, format}. Here is description:
- name is the variable name in the message. In this case, it's
.
- type is the type of value such as number, date, and time.
- format is optional, and is additional information for the displaying format of the value. In this case, it's USD.if
type is number and format is omitted, the result is formatted number with thousands separators. If format is one of currency code, it will show in corresponding currency format.$3
Locale data:
`json
{
"SALE_START": "Sale begins {start, date}",
"SALE_END": "Sale ends {end, date, long}"
}
`
JS code:
js
intl.get('SALE_START', {start:new Date()}); // Sale begins 4/19/2017
intl.get('SALE_END', {end:new Date()}); // Sale ends April 19, 2017
`
If is date, format has the following values:
- short shows date as shortest as possible
- medium shows short textual representation of the month
- long shows long textual representation of the month
- full shows dates with the most detail$3
Locale data:
`json
{
"COUPON": "Coupon expires at {expires, time, medium}"
}
`
JS code:
js
intl.get('COUPON', {expires:new Date()}); // Coupon expires at 6:45:44 PM
`
if is time, format has the following values:
- short shows times with hours and minutes
- medium shows times with hours, minutes, and seconds
- long shows times with hours, minutes, seconds, and timezone$3
When the specific key does't exist in current locale, you may want to make it return a default message. Use defaultMessage method after get method. For example,Locale data:
`json
{ "HELLO": "Hello, {name}" }
`
JS code:
jsx
const name = 'Tony';
intl.get('HELLO', { name }).defaultMessage(Hello, ${name}); // "Hello, Tony"
`Or using
for short:
`jsx
const name = 'Tony';
intl.get('HELLO', { name }).d(Hello, ${name}); // "Hello, Tony"
`And
also supports default message.
`jsx
const name = 'Tony';
intl.getHTML('HELLO', { name }).d(Hello, {name}) // React.Element with "Hello, Tony"
`
$3
The method returns string message. For HTML message, use getHTML instead. For example,Locale data:
`json
{ "TIP": "This is HTML" }
`
JS code:
js
intl.getHTML('TIP'); // {React.Element}
`$3
react-intl-universal provides a utility helping developer determine the user's . As the running examples, when user select a new locale, it redirect user new location like http://localhost:3000?lang=en-US. Then, we can use intl.determineLocale to get the locale from URL. It can also support determine user's locale via cookie, localStorage, and browser default language. Refer to the APIs section for more detail.
Debugger mode
When developing a website with multiple languages (i18n), translators are usually responsible for translating the content instead of the web developer. However, translators often struggle to find the specific message they need to edit on the webpage because they don't know its key. This leads to them having to ask the developer for the key, resulting in a lot of time wasted on communication.To solve this issue, a solution is proposed: When the debugger mode in
react-intl-universal is enabled, each message on the webpage will be wrapped in a special span element with the key "data-i18n-key". This way, translators can easily see the key of the message and make the necessary edits themselves using some message management system, without needing to ask the developer.Enabling debugger mode:
`js
intl.init({
// ...
debug: true
})
`Message will be wrapped in a span element with the key "data-i18n-key":
Component Internationalization
When internationalizing a React component, you don't need to again.
You could make it as peerDependency, then just load the locale data in the compoent.APIs Definition
`js
/**
* Initialize properties and load CLDR locale data according to currentLocale
* @param {Object} options
* @param {string} options.escapeHtml To escape html. Default value is true.
* @param {string} options.currentLocale Current locale such as 'en-US'
* @param {Object} options.locales App locale data like {"en-US":{"key1":"value1"},"zh-CN":{"key1":"值1"}}
* @param {Object} options.warningHandler Ability to accumulate missing messages using third party services. See https://github.com/alibaba/react-intl-universal/releases/tag/1.11.1
* @param {string} options.fallbackLocale Fallback locale such as 'zh-CN' to use if a key is not found in the current locale
* @param {boolean} options.debug If debugger mode is on, the message will be wrapped by a span with data key
* @param {string} options.dataKey If debugger mode is on, the message will be wrapped by a span with this data key. Default value 'data-i18n-key'
* @returns {Promise}
*/
init(options)
/**
* Load more locales after init
* @param {Object} locales App locale data
*/
load(locales)
/**
* Get the formatted message by key
* @param {string} key The string representing key in locale data file
* @param {Object} variables Variables in message
* @returns {string} message
*/
get(key, variables)
/**
* Get the formatted html message by key.
* @param {string} key The string representing key in locale data file
* @param {Object} variables Variables in message
* @returns {React.Element} message
*/
getHTML(key, options)
/**
* Helper: determine user's locale via URL, cookie, and browser's language.
* You may not need this API, if you have other rules to determine user's locale.
* @param {string} options.urlLocaleKey URL's query Key to determine locale. Example: if URL=http://localhost?lang=en-US, then set it 'lang'
* @param {string} options.cookieLocaleKey Cookie's Key to determine locale. Example: if cookie=lang:en-US, then set it 'lang'
* @param {string} options.localStorageLocaleKey LocalStorage's Key to determine locale such as 'lang'
* @returns {string} determined locale such as 'en-US'
*/
determineLocale(options)
/**
* Change current locale
* @param {string} newLocale Current locale such as 'en-US'
*/
changeCurrentLocale(newLocale)
/**
* Get the inital options
* @returns {Object} options includes currentLocale and locales
*/
getInitOptions()
/**
* Formats a list of React nodes for proper internationalized formatting.
* @param {React.ReactNode[]} nodeList - Array of React nodes to format.
* @param {Intl.ListFormatOptions} options - Intl.ListFormat options.
* @returns {React.ReactNode[]} Array of React nodes formatted with locale-appropriate separators.
*
* @example
* For en-US locale: formatList(["str1", "str2"]) => Returns: ["str1", ", ", "str2"] => Render as: "str1, str2" in React.js
* For zh-CN locale: formatList(["str1", "str2"]) => Returns: ["str1", "、", "str2"] => Render as: "str1、str2" in React.js
*/
formatList(nodeList, options)
/**
* Returns locale-specific parentheses format for the current language.
* @param {React.ReactNode} node - The content to be wrapped in parentheses.
* @returns {ReactNode[]} An array containing left parenthesis, content, and right parenthesis.
*
* @example
* For en-US locale: formatParentheses("str1") => Returns ["(", "str1", ")"] => Render as "(str1)" in React.js
* For zh-CN locale: formatParentheses("str1") => Returns ["（", "str1", "）"] => Render as "（str1）" in React.js
*/
formatParentheses(node)
/**
* Returns locale-specific colon character for the current language.
* @returns {string} The locale-appropriate colon character.
*
* @example
* For en-US locale: <>{intl.get("LABEL_NAME")}{intl.getColon()}{intl.get("VALUE")} => Returns "label: value"
* For zh-CN locale: <>{intl.get("LABEL_NAME")}{intl.getColon()}{intl.get("VALUE")} => Returns "label：value"
*/
getColon()
/**
* Formats a number according to the current locale.
* @param {number} number - The number to format.
* @returns {string} The formatted number.
*
* @example
* For en-US locale: formatNumber(1234.56) => Returns "1,234.56"
* For de-DE locale: formatNumber(1234.56) => Returns "1.234,567"
* For fr-FR locale: formatNumber(1234.56) => Returns "1 234,567"
*/
formatNumber(number)
`
Compatibility with react-intl
As mentioned in the issue Mirror react-intl API, to make people switch their existing React projects from react-intl to react-intl-universal. We provide two compatible APIs as following.js
/**
* As same as get(...) API
* @param {Object} options
* @param {string} options.id
* @param {string} options.defaultMessage
* @param {Object} variables Variables in message
* @returns {string} message
*/
formatMessage(options, variables)
`
js
/**
* As same as getHTML(...) API
* @param {Object} options
* @param {string} options.id
* @param {React.Element} options.defaultMessage
* @param {Object} variables Variables in message
* @returns {React.Element} message
*/
formatHTMLMessage(options, variables)
`For example, the
API`js
const name = 'Tony';
intl.formatMessage({ id:'hello', defaultMessage: Hello, ${name}}, {name});
`
is equivalent to API
`js
const name = 'Tony';
intl.get('hello', {name}).d(Hello, ${name});
`And the
API
`js
const name = 'Tony';
intl.formatHTMLMessage({ id:'hello', defaultMessage: Hello}, {name});
`
is equivalent to API
`js
const name = 'Tony';
intl.getHTML('hello', {name}).d(Hello);
`
FAQ
$3
If constants are defined outside of a React component, the message in
may get loaded before intl.init(...). This can cause a warning to be displayed, such as react-intl-universal locales data "null" not exists.`jsx
// Wrong: the message in constants.fruits is loaded before intl.init(...)
const constants = {
fruits : [
{ label: intl.get('banana'), value: 'banana' },
{ label: intl.get('apple'), value: 'apple' },
]
}
function MyComponent() {
return
}
To fix this, you should call
before render.#### Solution 1
Make the message object as a function, and call it at render function.
`jsx
const constants = {
fruits : () => [ // as arrow function
{ label: intl.get('banana'), value: 'banana' },
{ label: intl.get('apple'), value: 'apple' },
]
}
function MyComponent() {
// fruits is a function which returns message when rendering
return
}
`#### Solution 2
Use getter syntax to make a function call when that property is looked up
jsx
const constants = {
fruits: [
{
get label() {
return intl.get("banana");
},
value: "banana",
},
{
get label() {
return intl.get("apple");
},
value: "apple",
},
],
};
function MyComponent() {
// When "label" property is looked up, it actually make a function call
return ;
}
`
$3
jsx
const MyComp = (props) => {
const onClick = (e) => {
if (e.target.tagName === 'A') {
// event handler for "A" tag in the message
}
};
return (
// Wrap the message in a container and listen for the children's events.
{intl.getHTML('more_detail').d(Please refer to the document for more detail.)}
)
}
``