问题
I'm trying to figure out how to change language using React-Intl. This is my first React App and it has been made with create-react-app, I'm not using Redux nor Flux.
In my index.js I have the following code:
import React from 'react';
import ReactDOM from 'react-dom';
import TodoApp from './components/TodoApp';
import registerServiceWorker from './registerServiceWorker';
import './index.css';
// Bootstrap CSS libraries
import 'bootstrap/dist/css/bootstrap.css';
import 'bootstrap/dist/css/bootstrap-theme.css';
import { IntlProvider, addLocaleData } from 'react-intl';
import intlEN from 'react-intl/locale-data/en';
import intlES from 'react-intl/locale-data/es';
import intlMessagesES from './i18n/locales/es.json';
import intlMessagesEN from './i18n/locales/en.json';
addLocaleData([...intlEN, ...intlES]);
/* Define your translations */
let i18nConfig = {
locale: 'es',
messages: intlMessagesES
};
let changeLanguage = (lang) => {
i18nConfig = { locale: lang, messages: intlMessagesEN };
return i18nConfig;
}
ReactDOM.render(
<IntlProvider locale={ i18nConfig.locale } key={ i18nConfig.locale } messages={ i18nConfig.messages }>
<TodoApp onChangeLanguage={changeLanguage} />
</IntlProvider>,
document.getElementById('root'));
registerServiceWorker();
TodoApp is sending a string on 'lang' parameter by props (i.e.: 'es' or 'en'), when I change i18nConfig nothing seems to change with IntlProvider. My thought was that change my i18nConfig variable then all my app would change language as well.
I have FormattedMessages in TodoApp and my two JSON messages are filled like this:
// i18n/locales/en.json
{
"footer.add.placeholder": "Enter a name ...",
"footer.add.priority0.text": "No priority",
"footer.add.priority1.text": "Priority 1",
...
}
Do you know what am I missing on my code ?? Maybe I have not understand something right about React-Intl. Any advice will be helpful, thank you.
回答1:
It works if you remove all from root:
ReactDOM.render(<TodoApp />, document.getElementById('root'));
But now we change TodoApp component like this:
1) We add 'locale' as component state and import React-Intl:
import { IntlProvider, addLocaleData } from 'react-intl';
import intlEN from 'react-intl/locale-data/en';
import intlES from 'react-intl/locale-data/es';
import intlMessagesES from './../i18n/locales/es.json';
import intlMessagesEN from './../i18n/locales/en.json';
addLocaleData([...intlEN, ...intlES]);
/* Define your default translations */
let i18nConfig = {
locale: 'en',
messages: intlMessagesEN
};
2) Change our changeLanguage function (this time called 'onChangeLanguage'), this function receives 'lang' from a subComponent language selector:
onChangeLanguage(lang) {
switch (lang) {
case 'ES': i18nConfig.messages = intlMessagesES; break;
case 'EN': i18nConfig.messages = intlMessagesEN; break;
default: i18nConfig.messages = intlMessagesEN; break;
}
this.setState({ locale: lang });
i18nConfig.locale = lang;
}
And finally render:
render() {
return (
<IntlProvider key={ i18nConfig.locale } locale={ i18nConfig.locale } messages={ i18nConfig.messages }>
<div>
<Header onChangeLanguage={this.onChangeLanguage} />
// Other components ...
</div>
</IntlProvider>
);
}
If someone doesn't understand at all, ask in comments! Thanks to @TomásEhrich
回答2:
With a new React Context API it is quite easy to do. Create a wrapper:
import React from "react";
import Types from "prop-types";
import { IntlProvider, addLocaleData } from "react-intl";
import en from "react-intl/locale-data/en";
import de from "react-intl/locale-data/de";
import deTranslation from "../../lang/de";
import enTranslation from "../../lang/en";
addLocaleData([...en, ...de]);
const Context = React.createContext();
class IntlProviderWrapper extends React.Component {
constructor(...args) {
super(...args);
this.switchToEnglish = () =>
this.setState({ locale: "en", messages: enTranslation });
this.switchToDeutsch = () =>
this.setState({ locale: "de", messages: deTranslation });
// pass everything in state to avoid creating object inside render method (like explained in the documentation)
this.state = {
locale: "en",
messages: enTranslation,
switchToEnglish: this.switchToEnglish,
switchToDeutsch: this.switchToDeutsch
};
}
render() {
const { children } = this.props;
const { locale, messages } = this.state;
return (
<Context.Provider value={this.state}>
<IntlProvider
key={locale}
locale={locale}
messages={messages}
defaultLocale="en"
>
{children}
</IntlProvider>
</Context.Provider>
);
}
}
export { IntlProviderWrapper, Context as IntlContext };
And then use that Provider and Consumer:
import { Provider } from "react-redux";
import { IntlProviderWrapper } from "./IntlContext";
class App extends Component {
render() {
return (
<Provider store={store}>
<IntlProviderWrapper>
...
</IntlProviderWrapper>
</Provider>
);
}
}
somewhere in the app:
import React from "react";
import { Text, Button } from "native-base";
import { IntlContext } from "../IntlContext";
const LanguageSwitch = () => (
<IntlContext.Consumer>
{({ switchToEnglish, switchToDeutsch }) => (
<React.Fragment>
<button onClick={switchToEnglish}>
English
</button>
<button onClick={switchToDeutsch}>
Deutsch
</button>
</React.Fragment>
)}
</IntlContext.Consumer>
);
// with hooks
const LanguageSwitch2 = () => {
const { switchToEnglish, switchToDeutsch } = React.useContext(IntlContext);
return (
<>
<button onClick={switchToEnglish}>English</button>
<button onClick={switchToDeutsch}>Deutsch</button>
</>
);
};
export default LanguageSwitch;
Example on CodeSandbox
Here is the relevant repository with a more general solution.
Note: at the moment react-intl is still using an old context API but in the future solution like this might work out-of-the-box.
回答3:
you can use redux manage your locale and localeMessage. just add a key in IntlProvider.
import React, { Component } from 'react';
import { IntlProvider } from 'react-intl';
class Inter extends Component {
render() {
let { locale, localeMessage, children } = this.props;
return (
<IntlProvider key={locale} locale={locale} messages={localeMessage}>
{children}
</IntlProvider>
)
}
};
export default Inter;
来源:https://stackoverflow.com/questions/44635584/react-intl-how-to-switch-locale-and-messages-from-variable