javascript - Pass props in Link react-router

Question

I am using react with react-router. I am trying to pass property’s in a "Link" of react-router

var React  = require('react');
var Router = require('react-router');
var CreateIdeaView = require('./components/createIdeaView.jsx');

var Link = Router.Link;
var Route = Router.Route;
var DefaultRoute = Router.DefaultRoute;
var RouteHandler = Router.RouteHandler;
var App = React.createClass({
  render : function(){
    return(
      <div>
        <Link to="ideas" params={{ testvalue: "hello" }}>Create Idea</Link>
        <RouteHandler/>
      </div>
    );
  }
});

var routes = (
  <Route name="app" path="/" handler={App}>
    <Route name="ideas" handler={CreateIdeaView} />
    <DefaultRoute handler={Home} />
  </Route>
);

Router.run(routes, function(Handler) {

  React.render(<Handler />, document.getElementById('main'))
});

The "Link" renders the page but does not pass the property to the new view. Below is the view code

var React = require('react');
var Router = require('react-router');

var CreateIdeaView = React.createClass({
  render : function(){
    console.log('props form link',this.props,this)//props not recived
  return(
      <div>
        <h1>Create Post: </h1>
        <input type='text' ref='newIdeaTitle' placeholder='title'></input>
        <input type='text' ref='newIdeaBody' placeholder='body'></input>
      </div>
    );
  }
});

module.exports = CreateIdeaView;

How can I pass data using "Link"?

Answer 1

This line is missing path:

<Route name="ideas" handler={CreateIdeaView} />

Should be:

<Route name="ideas" path="/:testvalue" handler={CreateIdeaView} />

Given the following Link (outdated v1):

<Link to="ideas" params={{ testvalue: "hello" }}>Create Idea</Link>

Up to date as of v4/v5:

const backUrl = '/some/other/value'
// this.props.testvalue === "hello"

// Using query
<Link to={{pathname: `/${this.props.testvalue}`, query: {backUrl}}} />

// Using search
<Link to={{pathname: `/${this.props.testvalue}`, search: `?backUrl=${backUrl}`} />
<Link to={`/${this.props.testvalue}?backUrl=${backUrl}`} />

and in the withRouter(CreateIdeaView) components render(), out dated usage of withRouter higher order component:

console.log(this.props.match.params.testvalue, this.props.location.query.backurl)
// output
hello /some/other/value

And in a functional components using the useParams and useLocation hooks:

const CreatedIdeaView = () => {
    const { testvalue } = useParams();
    const { query, search } = useLocation(); 
    console.log(testvalue, query.backUrl, new URLSearchParams(search).get('backUrl'))
    return <span>{testvalue} {backurl}</span>    
}

From the link that you posted on the docs, towards the bottom of the page:

Given a route like <Route name="user" path="/users/:userId"/>

---

Updated code example with some stubbed query examples:

// import React, {Component, Props, ReactDOM} from 'react';
// import {Route, Switch} from 'react-router'; etc etc
// this snippet has it all attached to window since its in browser
const {
  BrowserRouter,
  Switch,
  Route,
  Link,
  NavLink
} = ReactRouterDOM;

class World extends React.Component {
  constructor(props) {
    super(props);
    console.dir(props);      
    this.state = {
      fromIdeas: props.match.params.WORLD || 'unknown'
    }
  }
  render() {
    const { match, location} = this.props;
    return (
      <React.Fragment>
        <h2>{this.state.fromIdeas}</h2>
        <span>thing: 
          {location.query 
            && location.query.thing}
        </span><br/>
        <span>another1: 
        {location.query 
          && location.query.another1 
          || 'none for 2 or 3'}
        </span>
      </React.Fragment>
    );
  }
}

class Ideas extends React.Component {
  constructor(props) {
    super(props);
    console.dir(props);
    this.state = {
      fromAppItem: props.location.item,
      fromAppId: props.location.id,
      nextPage: 'world1',
      showWorld2: false
    }
  }
  render() {
    return (
      <React.Fragment>
          <li>item: {this.state.fromAppItem.okay}</li>
          <li>id: {this.state.fromAppId}</li>
          <li>
            <Link 
              to={{
                pathname: `/hello/${this.state.nextPage}`, 
                query:{thing: 'asdf', another1: 'stuff'}
              }}>
              Home 1
            </Link>
          </li>
          <li>
            <button 
              onClick={() => this.setState({
              nextPage: 'world2',
              showWorld2: true})}>
              switch  2
            </button>
          </li>
          {this.state.showWorld2 
           && 
           <li>
              <Link 
                to={{
                  pathname: `/hello/${this.state.nextPage}`, 
                  query:{thing: 'fdsa'}}} >
                Home 2
              </Link>
            </li> 
          }
        <NavLink to="/hello">Home 3</NavLink>
      </React.Fragment>
    );
  }
}


class App extends React.Component {
  render() {
    return (
      <React.Fragment>
        <Link to={{
          pathname:'/ideas/:id', 
          id: 222, 
          item: {
              okay: 123
          }}}>Ideas</Link>
        <Switch>
          <Route exact path='/ideas/:id/' component={Ideas}/>
          <Route path='/hello/:WORLD?/:thing?' component={World}/>
        </Switch>
      </React.Fragment>
    );
  }
}

ReactDOM.render((
  <BrowserRouter>
    <App />
  </BrowserRouter>
), document.getElementById('ideas'));

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-router-dom/4.3.1/react-router-dom.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-router/4.3.1/react-router.min.js"></script>

<div id="ideas"></div>