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How to call a Component which name is passed as props in React?

i'm new at React. Basically i want to call different components based on the string passed as props. I've component named Device that have as prop the name of a particular device and in Device i want to call another components which has as name the props. Something like this: <DeviceName/>
This is my code:
App.js
<Device name = {devName} />
Device.js
import DeviceMark from ./devices/DeviceMark
function DeviceName({devName}) {
const DevName = devName;
return (
<Router>
<Switch>
<Route path = "/" exact><DevName /></Route>
</Switch>
</Router>
)
}
Imagine that in this case DevName will replace DeviceMark

When you really need to convert string component names to actual components while rendering, I can suggest following way
import DeviceMark from ./devices/DeviceMark
function DeviceName({devName}) {
const mappingComponents = {
foo: FooComponent,
bar: BarComponent,
deviceMark: DeviceMark
};
const ComponentToRender = mappingComponents[devName || 'foo'];
return (
<Router>
<Switch>
<Route path = "/" exact><ComponentToRender></ComponentToRender></Route>
</Switch>
</Router>
)
}
More details in official doc - https://reactjs.org/docs/jsx-in-depth.html

I guess you need to use React.createElement. It allows to create React element from string (if it's a basic html tag) or from function (if it's a React component).
import React from 'react'
import ReactDOM from 'react-dom'
const DeviceName = () => {
return 'sub component'
}
const Device = ({subDev}) => {
return (
<div>
{ React.createElement(subDev) }
</div>
)
}
function App() {
return <Device subDev={DeviceName} />
}
ReactDOM.render(<App />, document.getElementById('root'))
It's a little example. I have a main component Device. It accepts a sub-component via a prop and I pass sub-component to createElement. It does not matter if sub-component whether basic html tag or React component.
It's codesandbox example.

React: Unable to navigate views with router after changing the state of Context (useContext)

I have a simple setup to test the use of the useContext hook, when you want to change the context value in child components.
A simple Context is defined in its own file like such:
import React from 'react'
const DataContext = React.createContext({})
export const DataProvider = DataContext.Provider
export default DataContext
Then I wrap my router in a provider in a component that exposes its state to use as a reference for the ContextProvider, as such:
import { DataProvider } from './dataContext.js'
export default function App(props) {
const [data, setData] = useState("Hello!")
const value = { data, setData }
const hist = createBrowserHistory();
return (
<DataProvider value={value}>
<Router history={hist}>
<Switch>
<Route path="/admin" component={Admin} />
<Redirect from="/" to="/admin/services" />
</Switch>
</Router>
</DataProvider>
)
}
Finally I have two Views that I am able to navigate between initially, one of them showcasing the context value, as well as containing a button to change it:
export default function EndpointView(props) {
const { data, setData } = useContext(DataContext)
return (
<div>
<h1>{data}!</h1>
<Button onClick={() => setData(Math.random())}>Update context state</Button>
</div>
)
}
The functionality seems to work, as the showcases text is updated.
The problem is, when I have clicked the button, I can no longer navigate in my navbar, even though the url is changing. Any ideas as to why?
This is showcased in this picture, where the url is corresponding to the top-most item in the side bar, even though we are stuck in the "endpoint view"-component.
Edit:
So the routing works by including a switch in the Admin layout:
const switchRoutes = (
<Switch>
{routes.map((prop, key) => {
if (prop.layout === "/admin") {
return (
<Route
path={prop.layout + prop.path}
component={prop.component}
key={key}
/>
);
}
return null;
})}
<Redirect from="/admin" to="/admin/services" />
</Switch>
);
Where the routes (which we .map) are fetched from another file that looks like this:
const dashboardRoutes = [
{
path: "/services",
name: "Services view",
icon: AccountBalance,
component: ServicesView,
layout: "/admin"
},
{
path: "/endpoint",
name: "Endpoint view",
icon: FlashOn,
component: EndpointView,
layout: "/admin"
}
];
export default dashboardRoutes;

I was able to solve this issue.
I suspect the problem was that updating the state reloaded the root router component which caused some issues.
Instead I moved the DataProvider tag one step down the tree, to wrap the switch in the Admin component.

Pass dynamic url to React Router

I use react-router-dom version ^5.1.2 and try to pass dynamic property. My root component looks like this:
export const RegisterRoutes: React.FunctionComponent<RouteComponentProps> = ({
match,
}: RouteComponentProps) => {
const root = match.url;
return (
<Switch>
<Route exact path={`${root}/success`} component={RegisterSuccess} />
<Route exact path={`${root}/success/email`} component={RegisterEmail} />
<Route exact path={`${root}/confirmation/email/:code`} component={RegisterEmailConfirmation} />
<Redirect to={root} />
</Switch>
);
};
Here is a child RegisterEmailConfirmation component:
export const RegisterEmailConfirmation: React.FunctionComponent<RouteComponentProps> = ({ match }) => {
console.log(match.params.code) // expected 'code' property from the url
return (
<SomeContent />
/>
);
I have an url from the BE with dynamic 'code' parameter, it looks like this: register/confirmation/email?code=fjds#dfF. How can I render RegisterEmailConfirmation component and read 'code' property inside? What's wrong with my code?

As you are using function component you could use useParams hook in your component. See from useParams documentation:
useParams returns an object of key/value pairs of URL parameters. Use it to access match.params of the current <Route>.
Try as:
export const RegisterEmailConfirmation: React.FunctionComponent<RouteComponentProps> = () => {
let { code } = useParams();
console.log(code);
return <>
{ /* your implementation */ }
</>
}
Also you can import as:
import { useParams } from "react-router-dom";
I hope this helps!

React Query String showing 404 when provided with query parameter

I am new to React and trying to render a page based on the name query like
http://localhost:3000/show?name=james
So I initially added the Route as :
<BrowserRouter>
<Switch>
<Route path='*' component={ErrorComponent} />} />
<Route path="show(/:name)" name="name" component={Show}></Route>
</Switch>
</BrowserRouter>
And then I tried to render the component Show like below:
import React, { Component } from 'react';
import queryString from 'query-string';
class Show extends Component {
componentDidMount(){
console.log(this.props.location.search);
const values = queryString.parse(this.props.location.search);
console.log(values.name);
}
render() {
const { params } = this.props.match;
return <div>
<h4>About</h4>
<p>This is About page.</p>
{params.id ? <b>ID: {params.id}</b> : <i>ID is optional.</i>}
</div>
}
}
export default Show;
then when I try to show the page
http://localhost:3000/show?name=james
It always show 404. Not sure which part I am doing it wrong. Any help is appreciated.
Also I am using react-router-dom 5.1.2 .
Thanks.

path="show(/:name)"
This isn't a valid URL path to match on.
Redefine the path to ["/show/:id", "/show"]
<Route path={["/show/:id", "/show"]} name="name" component={Show} />
And since the Route is directly rendering the component, it can pull the query parameters and match parameters straight from props (this.props.match.params & this.props.location.search). Specifying two matching paths is equivalent to defining two separate Routes that render the same component. The same rules apply to path specificity, so define more complex matches first within the array.
class Show extends Component {
componentDidMount(){
console.log(this.props.location.search);
const values = queryString.parse(this.props.location.search);
console.log(values.name);
}
render() {
const { params } = this.props.match;
return <div>
<h4>About</h4>
<p>This is About page.</p>
{params.id ? <b>ID: {params.id}</b> : <i>ID is optional.</i>}
</div>
}
}

EDIT: Can't believe I didn't notice this originally...
You need to put your path="*" route at the bottom of the Switch otherwise it'll match everything and anything below it won't even have a chance to match since Switches match only a single route. The description of making sure you have your route path set up correctly (below) is applicable as well, of course.
<Switch>
<Route path="/show/:name?" component={ShowRouteParam} />
<Route path="*">ERROR 404</Route>
</Switch>
https://codesandbox.io/s/elated-browser-d0sew?file=/src/App.js
The routes don't match query parameters.
"Please note: The RegExp returned by path-to-regexp is intended for
use with pathnames or hostnames. It can not handle the query strings
or fragments of a URL."
Depending on how you want to do it, you can either make the id an optional part of the route, or let it be a normal query parameters
Option 1:
<Route path="/show/:name?" component={Show}></Route>
component:
import React, { Component } from 'react';
import queryString from 'query-string';
class Show extends Component {
componentDidMount(){
console.log(this.props.location.search);
const values = queryString.parse(this.props.location.search);
console.log(values.name);
}
render() {
const { params } = this.props.match;
return <div>
<h4>About</h4>
<p>This is About page.</p>
{params.name ? <b>ID: {params.name}</b> : <i>Name is optional.</i>}
</div>
}
}
export default Show;
Option 2:
<Route path="/show" component={Show}></Route>
component:
import React, { Component } from 'react';
import queryString from 'query-string';
class Show extends Component {
componentDidMount(){
console.log(this.props.location.search);
const values = queryString.parse(this.props.location.search);
console.log(values.name);
}
render() {
const values = queryString.parse(this.props.location.search);
return <div>
<h4>About</h4>
<p>This is About page.</p>
{values.name ? <b>ID: {values.name}</b> : <i>Name is optional.</i>}
</div>
}
}
export default Show;
Working example: https://codesandbox.io/s/silent-rain-n61zs

React router v4 breadcrumbs

I am trying to implement React Router Breadcrumbs for v4
Following are my routes:
const routes = {
'/': 'Home',
'/page1': 'Page 1',
'/page2': 'Page 2'
};
I could put the breadcrumbs using this library in my application, however I am having following questions:
Que. #1:
When I click on Home in my breadcrumbs, I can see the URL changes to http://localhost:8080 However, browser still shows the same page I am on.
Que. #2:
When I navigate to Page2 from Page1, url changes from http://localhost:8080/page1 to http://localhost:8080/page2.
So the breadcrumbs shown changes to Home / Page 2 instead of changing like Home / Page 1 / Page 2
I know this may be because the url just has /page2 after hostname. But, can I achieve the display like: Home / Page 1 / Page 2?
Below is the code in my main App.jsx:
<Router>
<div>
<Link to="/"><div className="routerStyle"><Glyphicon glyph="home" /></div></Link>
<Route exact path="/" component={LandingPage}/>
<Route path="/page1" component={Page1}/>
<Route path="/page2" component={Page2}/>
</div>
</Router>
and if I use like belowto cater for breadcrumbs, then my page2 gets rendered below page1 stuff:
<Router>
<div>
<Link to="/"><div className="routerStyle"><Glyphicon glyph="home" /></div></Link>
<Route exact path="/" component={LandingPage}/>
<Route path="/page1" component={Page1}/>
<Route path="/page1/page2" component={Page2}/>
</div>
</Router>
Answer:
Que. #1: No need to wrap <Breadcrumbs ..../> element inside <Router> element inside each Component of application. This may be because, inclusion of <Router> element inside each Component leads to "nesting" of Router elements (note we have Router tag in landing page as well); which does not work with react router v4.
Que. #2: Refer to answer formally marked here (answered by palsrealm below)

Your breadcrumbs are based on links and they work as designed. To display the pages, you need to set up a Switch with Routes in it which would load the appropriate components when the path changes. Something like
<Switch>
<Route path='/' component={Home}/>
<Route path='/page1' component={Page1}/>
<Route path='/page2' component={Page2}/>
</Switch>
If you want the breadcrumb to show Home/Page1/Page2 your routes should be '/page1/page2' : 'Page 2'. The Route should also change accordingly.
Edit: Your Router should be
<Router>
<div>
<Link to="/"><div className="routerStyle"><Glyphicon glyph="home" /></div></Link>
<Switch>
<Route exact path="/" component={LandingPage}/>
<Route exact path="/page1" component={Page1}/>
<Route path="/page1/page2" component={Page2}/>
</Switch>
</div>
</Router>

This can also be accomplished with a HOC which would allow you to use a route config object to set breadcrumbs instead. I've open-sourced it here, but the source code is below as well:
Breadcrumbs.jsx
import React from 'react';
import { NavLink } from 'react-router-dom';
import { withBreadcrumbs } from 'withBreadcrumbs';
const UserBreadcrumb = ({ match }) =>
<span>{match.params.userId}</span>; // use match param userId to fetch/display user name
const routes = [
{ path: 'users', breadcrumb: 'Users' },
{ path: 'users/:userId', breadcrumb: UserBreadcrumb},
{ path: 'something-else', breadcrumb: ':)' },
];
const Breadcrumbs = ({ breadcrumbs }) => (
<div>
{breadcrumbs.map(({ breadcrumb, path, match }) => (
<span key={path}>
<NavLink to={match.url}>
{breadcrumb}
</NavLink>
<span>/</span>
</span>
))}
</div>
);
export default withBreadcrumbs(routes)(Breadcrumbs);
withBreadcrumbs.js
import React from 'react';
import { matchPath, withRouter } from 'react-router';
const renderer = ({ breadcrumb, match }) => {
if (typeof breadcrumb === 'function') { return breadcrumb({ match }); }
return breadcrumb;
};
export const getBreadcrumbs = ({ routes, pathname }) => {
const matches = [];
pathname
.replace(/\/$/, '')
.split('/')
.reduce((previous, current) => {
const pathSection = `${previous}/${current}`;
let breadcrumbMatch;
routes.some(({ breadcrumb, path }) => {
const match = matchPath(pathSection, { exact: true, path });
if (match) {
breadcrumbMatch = {
breadcrumb: renderer({ breadcrumb, match }),
path,
match,
};
return true;
}
return false;
});
if (breadcrumbMatch) {
matches.push(breadcrumbMatch);
}
return pathSection;
});
return matches;
};
export const withBreadcrumbs = routes => Component => withRouter(props => (
<Component
{...props}
breadcrumbs={
getBreadcrumbs({
pathname: props.location.pathname,
routes,
})
}
/>
));

The following component should return a breadcrumb at any depth, except on the home page (for obvious reasons). You won't need React Router Breadcrumb. My first public contribution, so if I'm missing an essential part, it would be great if somebody could point it out. I added » for crumbs splits, but you can obviously update that to match what you need.
import React from 'react'
import ReactDOM from 'react-dom'
import { Route, Link } from 'react-router-dom'
// styles
require('./styles/_breadcrumbs.scss')
// replace underscores with spaces in path names
const formatLeafName = leaf => leaf.replace('_', ' ')
// create a path based on the leaf position in the branch
const formatPath = (branch, index) => branch.slice(0, index + 1).join('/')
// output the individual breadcrumb links
const BreadCrumb = props => {
const { leaf, index, branch } = props,
leafPath = formatPath(branch, index),
leafName = index == 0 ? 'home' : formatLeafName(leaf),
leafItem =
index + 1 < branch.length
? <li className="breadcrumbs__crumb">
<Link to={leafPath}>{leafName}</Link>
<span className="separator">»</span>
</li>
: <li className="breadcrumbs__crumb">{leafName}</li>
// the slug doesn't need a link or a separator, so we output just the leaf name
return leafItem
}
const BreadCrumbList = props => {
const path = props.match.url,
listItems =
// make sure we're not home (home return '/' on url)
path.length > 1
&& path
// create an array of leaf names
.split('/')
// send our new array to BreadCrumb for formating
.map((leaf, index, branch) =>
<BreadCrumb leaf={leaf} index={index} branch={branch} key={index} />
)
// listItem will exist anywhere but home
return listItems && <ul className="breadcrumbs">{listItems}</ul>
}
const BreadCrumbs = props =>
<Route path="/*" render={({ match }) => <BreadCrumbList match={match} />} />
export default BreadCrumbs