createNavigationContainer.js

/* @flow */

import React from 'react';
import invariant from './utils/invariant';
import { BackHandler, Linking } from './PlatformHelpers';
import NavigationActions from './NavigationActions';
import addNavigationHelpers from './addNavigationHelpers';

import type {
  NavigationRoute,
  NavigationAction,
  NavigationState,
  NavigationScreenProp,
  NavigationNavigatorProps,
  NavigationNavigator,
} from './TypeDefinition';

type NavigationContainerProps = {
  uriPrefix?: string | RegExp,
  onNavigationStateChange?: (
    NavigationState,
    NavigationState,
    NavigationAction
  ) => void,
};

type Props<O, S> = NavigationContainerProps & NavigationNavigatorProps<O, S>;

type State = {
  nav: ?NavigationState,
};

/**
 * Create an HOC that injects the navigation and manages the navigation state
 * in case it's not passed from above.
 * This allows to use e.g. the StackNavigator and TabNavigator as root-level
 * components.
 */
export default function createNavigationContainer<S: *, O>(
  Component: NavigationNavigator<*, S, *, O>
) {
  class NavigationContainer extends React.Component<void, Props<O, S>, State> {
    state: State;
    props: Props<O, S>;

    subs: ?{
      remove: () => void,
    } = null;

    static router = Component.router;

    constructor(props: Props<O, S>) {
      super(props);

      this._validateProps(props);

      this.state = {
        nav: this._isStateful()
          ? Component.router.getStateForAction(NavigationActions.init())
          : null,
      };
    }

    _isStateful(): boolean {
      return !this.props.navigation;
    }

    _validateProps(props: Props<O, S>) {
      if (this._isStateful()) {
        return;
      }

      const { navigation, screenProps, ...containerProps } = props;

      const keys = Object.keys(containerProps);

      invariant(
        keys.length === 0,
        'This navigator has both navigation and container props, so it is ' +
          `unclear if it should own its own state. Remove props: "${keys.join(
            ', '
          )}" ` +
          'if the navigator should get its state from the navigation prop. If the ' +
          'navigator should maintain its own state, do not pass a navigation prop.'
      );
    }

    _urlToPathAndParams(url: string) {
      const params = {};
      const delimiter = this.props.uriPrefix || '://';
      let path = url.split(delimiter)[1];
      if (typeof path === 'undefined') {
        path = url;
      }
      return {
        path,
        params,
      };
    }

    _handleOpenURL = ({ url }: { url: string }) => {
      const parsedUrl = this._urlToPathAndParams(url);
      if (parsedUrl) {
        const { path, params } = parsedUrl;
        const action = Component.router.getActionForPathAndParams(path, params);
        if (action) {
          this.dispatch(action);
        }
      }
    };

    _onNavigationStateChange(
      prevNav: NavigationState,
      nav: NavigationState,
      action: NavigationAction
    ) {
      if (
        typeof this.props.onNavigationStateChange === 'undefined' &&
        this._isStateful() &&
        !!process.env.REACT_NAV_LOGGING
      ) {
        /* eslint-disable no-console */
        if (console.group) {
          console.group('Navigation Dispatch: ');
          console.log('Action: ', action);
          console.log('New State: ', nav);
          console.log('Last State: ', prevNav);
          console.groupEnd();
        } else {
          console.log('Navigation Dispatch: ', {
            action,
            newState: nav,
            lastState: prevNav,
          });
        }
        /* eslint-enable no-console */
        return;
      }

      if (typeof this.props.onNavigationStateChange === 'function') {
        this.props.onNavigationStateChange(prevNav, nav, action);
      }
    }

    componentWillReceiveProps(nextProps: *) {
      this._validateProps(nextProps);
    }

    componentDidMount() {
      if (!this._isStateful()) {
        return;
      }

      this.subs = BackHandler.addEventListener('hardwareBackPress', () =>
        this.dispatch(NavigationActions.back())
      );

      Linking.addEventListener('url', this._handleOpenURL);

      Linking.getInitialURL().then(
        (url: ?string) => url && this._handleOpenURL({ url })
      );
    }

    componentWillUnmount() {
      Linking.removeEventListener('url', this._handleOpenURL);
      this.subs && this.subs.remove();
    }

    dispatch = (action: NavigationAction) => {
      const { state } = this;
      if (!this._isStateful()) {
        return false;
      }
      const nav = Component.router.getStateForAction(action, state.nav);
      if (nav && nav !== state.nav) {
        this.setState({ nav }, () =>
          this._onNavigationStateChange(state.nav, nav, action)
        );
        return true;
      }
      return false;
    };

    _navigation: ?NavigationScreenProp<NavigationRoute, NavigationAction>;

    render() {
      let navigation = this.props.navigation;
      if (this._isStateful()) {
        if (!this._navigation || this._navigation.state !== this.state.nav) {
          this._navigation = addNavigationHelpers({
            dispatch: this.dispatch,
            state: this.state.nav,
          });
        }
        navigation = this._navigation;
      }
      return <Component {...this.props} navigation={navigation} />;
    }
  }

  return NavigationContainer;
}