React-router: Passing props to children

Question

I'm trying to learn React by building a very basic "portfolio" site with react-router. My main components are: App, Work, Project and ProjectDetail. On the 'Work' page you should be able to see all of the project thumbnails and titles. Clicking on a specific project should route you to that project's detail page, which will include the rest of the project's details. How can I pass the props of Project to ProjectDetail?

My files:

main.js
/*
  Routes
*/

var routes = (
    <Router history={createHistory()}>
        <Route path="/" component={App}>
            <IndexRoute component={Work} />
            <Route path="work" component={Work} />
            <Route path="work/:id" component={ProjectDetail} />
            <Route path="about" component={About} />
        </Route>
    </Router>
);

ReactDOM.render(routes, document.getElementById('main'));

-

App.js
/*
  App
*/


class App extends React.Component {
    render() {
        return (
            <div>
                <h1>App</h1>
                <ul>
                    <li><Link to="/">Home</Link></li>
                    <li><Link to="/work">Work</Link></li>
                    <li><Link to="/about">About</Link></li>
                </ul>
                {this.props.children}
                <footer>footer</footer>
            </div>
        )
    }
}

export default App;

-

Work.js
class Work extends React.Component {
    render() {
        return (
            <div>
                <p>Work</p>
                <ul>
                    {/* Need to loop of all projects */}
                    {PROJECTS.map(project => (
                        <li key={project.id}>
                            <Project project={project} />
                        </li>
                    ))}
                </ul>
            </div>
        )
    }
}

export default Work;

-

Project.js
class Project extends React.Component {
    render() {
        var project = this.props.project;
        var linkTo = "/work/" + project.id;

        return (
            <Link to={linkTo}>
                {project.title}
                <span> </span>
                {project.type}
             </Link>
        )
    }
}

export default Project;

-

ProjectDetail.js
class ProjectDetail extends React.Component {
    render() {
        return (
            <div>
                {/* THIS IS WHAT INFORMATION I NEED */}
                {this.props.project.title}
                {this.props.project.description}
                {this.props.project.type}
                {this.props.project.technologies}
            </div>
        )
    }
}

export default ProjectDetail;

I can access the data in my Project component, but how can I pass that along to ProjectDetail since I never explicitly use the ProjectDetail component (only used in my routing)?

EDIT: I should add that I suppose I am technically not trying to pass the props to a child since Project is no longer rendered once you are routed to a ProjectDetail. Does that make this impossible?

Answer 1

You need to use the createElement handler for your routes to control the instancing of the route handler. There you can pass props around to the components. React-Router decouples mother-child components, any state propagation needs to be done in the routes.

Update Based on your edit, in your case ProjectDetail must re-query the applicable project using this.props.params.id, something like...

ProjectDetail.js

class ProjectDetail extends React.Component {
    render() {
        let project = PROJECTS.find((item)=>item.id == this.props.params.id);
        return (
            <div>
                {project.title}
                {project.description}
                {project.type}
                {project.technologies}
            </div>
        )
    }
}