javascript - 如何从外部文件访问React组件

Question

首先，对我的语法错误表示歉意。我的英语水平不好。

我创建了一个项目，您可以在其中创建自己的图层 map ，好吗？

我将 map 导出到 iframe 内，这样我就可以在 index.html 文件中加载一个或多个 map 。

我在项目中创建了一个 API，我想从我的 index.html 访问此 API。

如何访问它？

我已经了解到我可以通过以下方式访问:

• global variable
• with react context
• with .env variable

哪个是更好的选择？

如何在我的index.html中声明它？

这是我的代码:

class APIService extends Component {

    constructor(props) {
        super(props);
        this.logged = (this.props.userLogged && this.props.userLogged.logged) ? true : false;
        this.interval = undefined;
    }

    componentWillUnmount() {
        clearInterval(this.interval);
        this.interval = undefined;
    };

    getUserLayers = () => {
        if (!this.logged) return null; 
        const userlayers = this.props.layers.filter(l => l.name).map(l => {
            return { id: l.id, name: l.name, order: l.order };
        });
        return userlayers;
    };

    getVisibilityLayerById = (id) => {
        if (!this.logged) return null; 
        let index = this.props.layers.findIndex(l => l.id === id);
        if (index === -1) return null;
        return (this.props.layers[index] && this.props.layers[index].layout && this.props.layers[index].layout.visibility) ? this.props.layers[index].layout.visibility : null;
    };

    getVisibilityLayerByOrder = (order) => {
        if (!this.logged) return null; 
        let index = this.props.layers.findIndex(l => l.order === order);
        if (index === -1) return null;
        return (this.props.layers[index] && this.props.layers[index].layout && this.props.layers[index].layout.visibility) ? this.props.layers[index].layout.visibility : null;
    };

    changeVisibilityLayerById = (id) => {
        if (!this.logged) return null; 
        let index = this.props.layers.findIndex(l => l.id === id);
        if (index === -1) return null;
        let layer = this.props.layers[index];
        this.props.changeLayerVisibility(layer);
    };

    changeVisibilityLayerByOrder = (order) => {
        if (!this.logged) return null; 
        let index = this.props.layers.findIndex(l => l.order === order);
        if (index === -1) return null;
        let layer = this.props.layers[index];
        this.props.changeLayerVisibility(layer);
    };

    changeLayerVisibilityWithIntervalById = (id, interval) => {
        if (!this.logged) return null;
        setInterval( () => {
            this.changeVisibilityLayerById(id);
        }, interval);
    };

    changeLayerVisibilityWithIntervalByOrder = (order, interval) => {
        if (!this.logged) return null;
        setInterval( () => {
            this.changeVisibilityLayerByOrder(order);
        }, interval);
    };

    getCenter = () => {
        if (!this.logged) return null;
        let properties = (this.props.properties !== null) ? Object.assign({}, this.props.properties) : null;
        let hasCenter = (properties !== null && Object.keys(properties).filter(p => p === "center")) ? true : false;
        let hasLatAndLong = (hasCenter) ? Object.keys(properties.center).filter(c => c === 'latitude' || c === 'longitude') : null;
        let center = (hasLatAndLong !== null && hasLatAndLong.length === 2) ? true : false;
        return (center) ? properties.center : null;
    };

    setCenter = (latitude, longitude) => {
        if (!this.logged) return null;
        if ( isNaN(latitude) || isNaN(longitude) ) return null;
        this.props.setCenter({ latitude: latitude, longitude: longitude });
    };

    getZoom = () => {
        if (!this.logged) return null;
        let properties = (this.props.properties !== null) ? Object.assign({}, this.props.properties) : null;
        let hasZoom = (properties !== null && Object.keys(properties).filter(p => p === "zoom")) ? true : false;
        return (hasZoom !== null) ? properties.zoom : null;
    };

    setZoom = (zoom) => {
        if (!this.logged) return null;
        let checkedZoom;
        if (Array.isArray(zoom)) checkedZoom = zoom;
        else checkedZoom = [zoom];
        this.props.setZoom(checkedZoom);
    };

    render() { return null };
}

function selectStateApp(state) {
    return {
        userLogged: state.auth.userLogged,
        layers: state.maplayers.mapGLlayers,
        properties: state.map.properties,
    };
}

export default compose(withTranslation('maps'), connect(
    selectStateApp,
    dispatch => ({
        changeLayerVisibility: (layer) => LayerActions.changeLayerVisibility(layer)(dispatch),
        setCenter: (center) => MapActions.setCenter(center)(dispatch),
        setZoom: (zoom) => MapActions.setZoom(zoom)(dispatch),
        setProperties: (properties) => MapActions.setProperties(properties)(dispatch),
    })
))(APIService);

Answer 1

如果我理解正确的话，你基本上是想将你的 React 组件渲染到 DOM 中，对吗？如果是这样，这里有官方的 React 文档:Rendering Elements .

或者，如果您想像使用任何其他可在任何地方使用的 HTML 元素一样使用 React 组件，您可以考虑将 React 组件包装在 Web Component 中。 。 React 官方文档也有这样的内容:Using React in your Web Components 。对于您的组件来说，它看起来像这样:

class APIServiceElement extends HTMLElement {
  connectedCallback() {
    const mountPoint = document.createElement('div');
    this.attachShadow({ mode: 'open' }).appendChild(mountPoint);

    ReactDOM.render(<APIService />, mountPoint);
  }
}
customElements.define('api-service', APIServiceElement);

之后您可以使用<api-service></api-service>在你的index.html文件。