React-router-dom v.4 BrowseRouter将功能传递给子级

Question

I have just upgraded to React-Router v.4 (and redux-saga). But I am having problems with passing functions from parent container to child inside a route...

Parent:

import React, { Component } from 'react';
import { bindActionCreators } from 'redux';
import { connect } from 'react-redux';
import { BrowserRouter as Router, Route, NavLink } from 'react-router-dom';

import { fetchGalleryImages } from './business_logic/modules/gallery'

import logo from './assets/images/saga-logo.png';
import Gallery from './components/Gallery';

function mapStateToProps(state) {
    return { galleryImages: state.galleryImages };
}
function mapDispatchToProps(dispatch) {
    return { actions: bindActionCreators({ fetchGalleryImages }, dispatch) };
}

class App extends Component {
    constructor(props) {
        super(props);
        this.loadGallery = props.actions.fetchGalleryImages.bind(this);
    }

    loadGalleryHandler() {
        this.loadGallery();
    }

    render() {
        return (
            <div className="App">
                <img src={logo} className="logo" alt="logo" />
                <h1>Welcome to Redux-Saga</h1>
                <section className="content">
                    <p>This is an exersize in using react together with Redux-saga.</p>

                    <Router>
                        <div>
                            <nav className="main">
                                <NavLink activeClassName="selected" exact to="/" >Home</NavLink>
                                <NavLink activeClassName="selected" to="/gallery">Gallery</NavLink>
                            </nav>

                            <Route path="/gallery" onLoadEvent={this.loadGalleryHandler} component={Gallery} />
                        </div>
                    </Router>
                </section>
            </div>
        );
    }
}

export default connect(mapStateToProps, mapDispatchToProps)(App);

My child component looks like this:

import React, { Component } from 'react';

class Gallery extends Component {

    componentDidMount() {
        this.props.onLoadEvent();
    }

    render() {
        return (
            <div className="Gallery">
                <h2>Gallery</h2>
            </div>
        );
    }
}

export default Gallery;

As you can see I am trying to pass the function loadGallery to the Gallery component, however, in the dom the Gallery component gets wrapped in a Route component which does not send the loadGallery function on to its child.

This is what it looks like in React's dom:

<Route path="/gallery" onLoadEvent=loadGalleryHandler() component=Gallery()>
    <Gallery match={...somestuff...} location={...somestuff...} history={...somestuff...}>...</Gallery>
</Route>

Clearly the onLoadEvent=loadGalleryHandler() is not passed to Gallery.

How do I make it work?

Answer 1

As you noticed, that props you pass to <Route> won't be passed down to your component. This is the exact use case for a Route's render prop.

Instead of this,

<Route path="/gallery" onLoadEvent={this.loadGalleryHandler} component={Gallery} />

You can do this and then pass any props to your component that you'd like,

<Route path="/gallery" render={() => (
  <Gallery {...props} onLoadEvent={this.loadGalleryHandler} />
)} />