ant-design/components/locale-provider/LocaleReceiver.tsx

import * as React from 'react';
import PropTypes from 'prop-types';

export interface LocaleReceiverProps {
  componentName: string;
  defaultLocale: object | Function;
  children: (locale, localeCode?) => React.ReactElement<any>;
}

export interface LocaleReceiverContext {
  antLocale?: { [key: string]: any };
}

export default class LocaleReceiver extends React.Component<LocaleReceiverProps> {
  static contextTypes = {
    antLocale: PropTypes.object,
  };

  context: LocaleReceiverContext;

  getLocale() {
    const { componentName, defaultLocale } = this.props;
    const { antLocale } = this.context;
    const localeFromContext = antLocale && antLocale[componentName];
    return {
      ...(typeof defaultLocale === 'function' ? defaultLocale() : defaultLocale),
      ...(localeFromContext || {}),
    };
  }

  getLocaleCode() {
    const { antLocale } = this.context;
    const localeCode = antLocale && antLocale.locale;
    // Had use LocaleProvide but didn't set locale
    if (antLocale && antLocale.exist && !localeCode) {
      return 'en-us';
    }
    return localeCode;
  }

  render() {
    return this.props.children(this.getLocale(), this.getLocaleCode());
  }
}