react-router 渲染不工作； 路由不工作

Question

I'm making wizard form in react and have got a problem with routing page routing is like this

home -> wizard form(step1) -> step2 ->step3..

<Route
 path="/startAProgram/step1"
 exact
 render={() => <StartAProgram />}
/>

//app.js
//There are many routes in app.js and one of routes is StartAProgram(wizard form)

function StartAProgram() {
  return (
    <WrapperDiv>
      <Stepper />
      <ProgramName /> {/* this is step 1 */}
      <Router>
        {/* <Route path="startAProgram/step1" render={() => <ProgramName />} /> */}
        <Switch>
          <Route
            path="startAProgram/step2"
            exact
            render={() => <SetTargets />}
          />
          <Route
            path="startAProgram/step3"
            render={() => <ParticipationGuidelines />}
          />
        </Switch>
      </Router>
    </WrapperDiv>
  );
}

• react-router-dom version:^5.2.0

function ProgramName() {
  const programName = useSelector((state) => state.programName);

  const {
    register,
    handleSubmit,
    formState: { errors },
  } = useForm({
    defaultValues: programName,
  });

  const dispatch = useDispatch();
  const history = useHistory();

  const handleOnSubmit = (data) => {
    sessionStorage.setItem('programName', Object.values(data));
    dispatch(submitStep1(data));
    history.push('./step2');
    console.log('next~');
  };

  return (
    <form onSubmit={handleSubmit(handleOnSubmit)}>
      <Text size={30} weight={800} mb={10}>
        Step 1. Program name
      </Text>
      <label htmlFor="programName">
        Program Name
        <input
          name="programName"
          {...register('programName', { required: 'fill out!' })}
        />
        <ErrorMessage errors={errors} name="programName" as="p" />
      </label>
      <Button type="submit">next</Button>
    </form>
  );
}

It would be Step2 if the form validation is successful but Step2 component rendering is not working currently. Page Step 1 is rendering well, but it is not letting me render step 2 and more. Anyone can solve this problem?

Answer 1

Issue

StartAProgram is rendering these other routes, so when you navigate to one of those routes, the route rendering StartAProgram is no longer matched and those other routes you are linking to are no longer mounted.

Solution

Make the root stepper route path more generic so it can match rendering any of the steps.

<Route path="/startAProgram" component={StartAProgram} />

Then refactor StartAProgram to render ProgramName back on a ".../step1" path. Remove the extra Router component, you only need one router per app.

function StartAProgram() {
  return (
    <WrapperDiv>
      <Stepper />
      <Switch>
        <Route path="/startAProgram/step1" component={ProgramName} />
        <Route path="/startAProgram/step2" component={SetTargets} />
        <Route
          path="/startAProgram/step3"
          component={ParticipationGuidelines}
        />
      </Switch>
    </WrapperDiv>
  );
}

When nesting descendent routes it is a common pattern to use the useRouteMatch hook to dynamically build relative paths.

import { Switch, Route, useRouteMatch } from 'react-router-dom';

function StartAProgram() {
  const { path } = useRouteMatch();
  return (
    <WrapperDiv>
      <Stepper />
      <Switch>
        <Route path={`${path}/step1`} component={ProgramName} />
        <Route path={`${path}/step2`} component={SetTargets} />
        <Route path={`${path}/step3`} component={ParticipationGuidelines} />
      </Switch>
    </WrapperDiv>
  );
}

This is helpful/useful if you need to move the StartAProgram component around onto a different path, the links and routes from here work relative to the current location.