动态更新父状态

Question

我试图根据孩子的组件输入值更新父组件的状态，然后再次渲染组件。

我有App，Map和ListPlaces组件。 地图组件显示地图和标记，并以App组件中的标记为道具。

ListPlaces组件具有自己的状态（searchQuery）和一个方法（updateQuery）。基本上，它使用regexp并根据输入过滤结果，并在 list元素中显示过滤后的值。很好，但是，我需要的还不止这些。我想在这里做什么？根据输入值的更改，我想更新我的标记（App组件中的状态），然后再次重新渲染地图组件以在地图上仅显示相关的标记。想法是基本的，但我无法实现。

当我尝试更改实际上是数组的标记时，它将为0。我将共享我的所有代码，但我需要说 我认为问题可能与输入中的onChange方法有关元素（ListPlaces）

App.js

class App extends Component {
    constructor(props) {
        super(props);
        this.state = {
            places: [],
            markers: [],
            markerID: -1,
            newmarkers: []
        };

        this.changeMarkers = this.changeMarkers.bind(this);
    }

    componentDidMount() {
        fetch(
            "api_url"
        )
            .then(response => response.json())
            .then(data => {
                this.setState({
                    places: data.response.venues,
                    markers: data.response.venues
                });
            })
            .catch(error => {
                console.log("Someting went wrong ", error);
            });
    }

    openInfo = (e, id) => {
        this.setState({
            markerID: id
        });
    };

    closeInfo = () => {
        this.setState({
            markerID: -1
        });
    };

    changeMarkers = newValue => {
        const newmarkers = this.state.places.filter(
            place => place.name === newValue
        );
        this.setState({
            markers: newmarkers
        });
    };

    toggleListPlaces = () => {
        const nav = document.getElementById("nav-toggle");
        const body = document.getElementsByTagName("body")[0];

        nav.classList.toggle("active");

        if (body.classList.contains("show-nav")) {
            body.classList.remove("show-nav");
        } else {
            // If sidebar is hidden:
            body.classList.add("show-nav");
        }
    };

    render() {
        return (
            <div className="App">
                <Map
                    role="application"
                    places={this.state.places}
                    markers={this.state.markers}
                    openInfoHandler={this.openInfo}
                    closeInfoHandler={this.closeInfo}
                    markerID={this.state.markerID}
                    googleMapURL="map_url"
                    loadingElement={<div style={{ height: "100%" }} />}
                    containerElement={<div style={{ height: "100%" }} />}
                    mapElement={<div style={{ height: "100%" }} />}
                />
                <ListPlaces
                    toggleListHandler={this.toggleListPlaces}
                    locations={this.state.places}
                    openInfoHandler={this.openInfo}
                    changeMarkersHandler={this.changeMarkers}
                />
            </div>
        );
    }
}

export default App;

ListPlaces

class ListPlaces extends Component {
    state = {
        searchQuery: ""
    };

    updateQuery = query => {
        this.setState({ searchQuery: query});
    };

    render() {
        const { toggleListHandler, locations, openInfoHandler, changeMarkersHandler} = this.props;
        let showLocations;
        if (this.state.searchQuery) {
            const match = new RegExp(escapeRegExp(this.state.searchQuery), "i");
            showLocations = locations.filter(location =>match.test(location.name));
        } else {
            showLocations = locations;
        }

        return (
            <div>
                <aside>
                    <h2>Restaurants</h2>
                    <nav>
                        <div className="search-area">
                            <input
                                className="search-input"
                                type="text"
                                placeholder="Search Restaurant"
                                value={this.state.searchQuery}
                                onChange={e => {this.updateQuery(e.target.value); changeMarkersHandler(e.target.value)}}
                            />
                        </div>
                        <ul>
                            {showLocations.map(location => {
                                return (
                                    <li
                                        key={location.id}
                                        onClick={e =>
                                            openInfoHandler(e, location.id)
                                        }
                                    >
                                        {location.name}
                                    </li>
                                );
                            })}
                        </ul>
                    </nav>
                    <p>Information provided by Foursquare</p>
                </aside>
                <a
                    onClick={toggleListHandler}
                    id="nav-toggle"
                    className="position"
                >
                    <span />
                </a>

            </div>
        );
    }
}

export default ListPlaces;

地图

const Map = withScriptjs(withGoogleMap((props) =>

    <GoogleMap
        defaultZoom={14}
        defaultCenter={{ lat: 48.2854790, lng: -143.1407394 }}
        >
        {props.markers.map(restaurant => {
            let marker = (
                <Marker
                    id={restaurant.id}
                    key={restaurant.id}
                    name={restaurant.name}
                    position={{lat: restaurant.location.lat, lng: restaurant.location.lng}}
                    address={restaurant.location.address}
                    defaultAnimation={window.google.maps.Animation.DROP} // Should be 1 or 2 according to Stackoverflow
                    onClick={e => {props.openInfoHandler(e, restaurant.id)}}
                    animation = {props.markerID === restaurant.id && window.google.maps.Animation.BOUNCE}
                    >
                    {props.markerID === restaurant.id && (
                    <InfoWindow onCloseClick={e => {props.closeInfoHandler()}}>
                      <div className="info-window">
                        <p className="restaurant-name">{restaurant.name}</p>
                        <p className="restaurant-address">{restaurant.location.address}</p>
                      </div>
                      </InfoWindow>
                        )}

                    </Marker>
                );
            return marker;
        })}

        </GoogleMap>
    ))

export default Map;

Answer 1

您处在正确的轨道上-您需要将过滤器值/过滤器操作提升到公共父级

App.js

class App extends React.Component {
  onChangeFilter = (newFilter) => {
    this.setState({ filter: newFilter })
  }

  render () {
    const { filter, places } = this.state
    const mPlaces = places.filter(/* filter places here */)

    return (
      <div className="App">
        <ListPlaces 
          places={ mPlaces }
          onChangeFilter={ this.onChangeFilter }
          ...
        />

        <Map 
          locations={ mPlaces }
          ...
        />
      </div>
    )
  }
}

ListPlaces.js

class ListPlaces extends React.Component {
  updateQuery = (query) => {
    this.props.onChangeFilter(query)
  }

  ...
}

这是React中的常见模式-如此普遍it has its own page in the React docs。