ChatGPT解决这个技术问题 Extra ChatGPT

How to get parameter value from query string?

How can I define a route in my routes.jsx file to capture the __firebase_request_key parameter value from a URL generated by Twitter's single sign on process after the redirect from their servers?

http://localhost:8000/#/signin?_k=v9ifuf&__firebase_request_key=blablabla

I tried with the following routes configuration, but the :redirectParam is not catching the mentioned param:

<Router>
  <Route path="/" component={Main}>
    <Route path="signin" component={SignIn}>
      <Route path=":redirectParam" component={TwitterSsoButton} />
    </Route>
  </Route>
</Router>
There's a Github discussion here
unfortunate that the question says "query strings" but is actually asking about "url parameters"
query strings "?var1=val&var2=val2" , url paramters: "/photos/:companyiD/new"
For function in React Route v6 : stackoverflow.com/a/70251443/624533

d
dhilt

React Router v6, using hooks

In react-router-dom v6 there's a new hook named useSearchParams. So with

const [searchParams, setSearchParams] = useSearchParams();
searchParams.get("__firebase_request_key")

you will get "blablabla". Note, that searchParams is an instance of URLSearchParams, which also implements an iterator, e.g. for using Object.fromEntries etc.

React Router v4/v5, without hooks, generic

React Router v4 does not parse the query for you any more, but you can only access it via this.props.location.search (or useLocation, see below). For reasons see nbeuchat's answer.

E.g. with qs library imported as qs you could do

qs.parse(this.props.location.search, { ignoreQueryPrefix: true }).__firebase_request_key

Another library would be query-string. See this answer for some more ideas on parsing the search string. If you do not need IE-compatibility you can also use

new URLSearchParams(this.props.location.search).get("__firebase_request_key")

For functional components you would replace this.props.location with the hook useLocation. Note, you could use window.location.search, but this won't allow to trigger React rendering on changes. If your (non-functional) component is not a direct child of a Switch you need to use withRouter to access any of the router provided props.

React Router v3

React Router already parses the location for you and passes it to your RouteComponent as props. You can access the query (after ? in the url) part via

this.props.location.query.__firebase_request_key

If you are looking for the path parameter values, separated with a colon (:) inside the router, these are accessible via

this.props.match.params.redirectParam

This applies to late React Router v3 versions (not sure which). Older router versions were reported to use this.props.params.redirectParam.

General

nizam.sp's suggestion to do

console.log(this.props)

will be helpful in any case.


It is not required to change the react router for it.
I wouldn't suggest using console.dir() due to warning note ...at least :)
Well, it's just for looking at the contents, once. You can also just put a break point and evaluate this.props in the debugger. Nowadays, even console.log will do the job (at least in Chrome you can expand values printed like that) - and even console.log is nothing to use in production.
@Christian I ended up using just plain javascript. const path = window.location.pathname; gives me the URL. I can then parse it the way I need to. I placed this in componentWillMount life cycle event in my React component.
In react-router-dom I had to use withRouter to make this work!
a
andromeda

React Router v4

Using component

<Route path="/users/:id" component={UserPage}/> 
this.props.match.params.id

The component is automatically rendered with the route props.

Using render

<Route path="/users/:id" render={(props) => <UserPage {...props} />}/> 
this.props.match.params.id

Route props are passed to the render function.


I had a similar issue accessing the query params of my app's current URL in a child component using React Router v4. If you're looking for the query params, this.props.location.query in React Router 4 has been removed (currently using v4.1.1). See this answer: stackoverflow.com/a/43630848/1508105
This does not answer the question unfortunately as you will not necessarily have /users/?q=... but you could have /user?q=.... You should use this.props.location.search in React Router v4 and parse the results yourself as explained in my answer below.
This is the correct answer. this.props.location.search does not exist.
@NickJ: which version of React Router do you use?
@NickJ I use 'window.location.search' and it works great, fyi
C
Community

React Router v3

With React Router v3, you can get query-string from this.props.location.search (?qs1=naisarg&qs2=parmar). For example, with let params = queryString.parse(this.props.location.search), would give { qs1 : 'naisarg', qs2 : 'parmar'}

React Router v4

With React Router v4, the this.props.location.query does not exist anymore. You need to use this.props.location.search instead and parse the query parameters either by yourself or using an existing package such as query-string.

Example

Here is a minimal example using React Router v4 and the query-string library.

import { withRouter } from 'react-router-dom';
import queryString from 'query-string';
    
class ActivateAccount extends Component{
    someFunction(){
        let params = queryString.parse(this.props.location.search)
        ...
    }
    ...
}
export default withRouter(ActivateAccount);

Rational

The React Router's team rational for removing the query property is:

There are a number of popular packages that do query string parsing/stringifying slightly differently, and each of these differences might be the "correct" way for some users and "incorrect" for others. If React Router picked the "right" one, it would only be right for some people. Then, it would need to add a way for other users to substitute in their preferred query parsing package. There is no internal use of the search string by React Router that requires it to parse the key-value pairs, so it doesn't have a need to pick which one of these should be "right". [...] The approach being taken for 4.0 is to strip out all the "batteries included" kind of features and get back to just basic routing. If you need query string parsing or async loading or Redux integration or something else very specific, then you can add that in with a library specifically for your use case. Less cruft is packed in that you don't need and you can customize things to your specific preferences and needs.

You can find the full discussion on GitHub.


why do you even need a lib when you can use URLSearchParams
@SuperUberDuper because of Edge and iOS Safari - developer.mozilla.org/en-US/docs/Web/API/…
Sure, but then just use the URLSearchParams polyfill
It worked well for me having used .split("=") with difficulty.
M
MING WU

As far as I know there are three methods you can do that.

1.use regular expression to get query string.

2.you can use the browser api. image the current url is like this:

http://www.google.com.au?token=123

we just want to get 123;

First

 const query = new URLSearchParams(this.props.location.search);

Then

const token = query.get('token')
console.log(token)//123

3. use a third library called 'query-string'. First install it

npm i query-string

Then import it to the current javascript file:

 import queryString from 'query-string'

Next step is to get 'token' in the current url, do the following:

const value=queryString.parse(this.props.location.search);
const token=value.token;
console.log('token',token)//123

Hope it helps.

Updated on 25/02/2019

if the current url looks like the following:

http://www.google.com.au?app=home&act=article&aid=160990

we define a function to get the parameters:

function getQueryVariable(variable)
{
        var query = window.location.search.substring(1);
        console.log(query)//"app=article&act=news_content&aid=160990"
        var vars = query.split("&");
        console.log(vars) //[ 'app=article', 'act=news_content', 'aid=160990' ]
        for (var i=0;i<vars.length;i++) {
                    var pair = vars[i].split("=");
                    console.log(pair)//[ 'app', 'article' ][ 'act', 'news_content' ][ 'aid', '160990' ] 
        if(pair[0] == variable){return pair[1];}
         }
         return(false);
}

We can get 'aid' by :

getQueryVariable('aid') //160990

URLSearchParams is not supported by IE (if that's relevant for anyone:)
@Christian Typical IE
J
JTG

React Router v4 no longer has the props.location.query object (see github discussion). So the accepted answer will not work for newer projects.

A solution for v4 is to use an outside library query-string to parse the props.location.search

const qs = require('query-string');
//or
import * as qs from 'query-string';

console.log(location.search);
//=> '?foo=bar'

const parsed = qs.parse(location.search);
console.log(parsed);
//=> {foo: 'bar'}

For some reason for me qs.parse results in: {'?foo': 'bar'}
@Chris var prefixed = qs.parse('?a=b&c=d', { ignoreQueryPrefix: true }); should fix it. Example found here: github.com/ljharb/qs
@Chris Or simply remove question mark: const parsed = qs.parse(location.search.replace('?', ''));
t
t-reksio

When using React hooks there is no access to access to this.props.location. To capture url parameters use window object.

const search = window.location.search;
const params = new URLSearchParams(search);
const foo = params.get('bar');

You can use "useLocation" from "react-router-dom" instead of window object to achieve same results.
URLSearchParams Is not supported by IE developer.mozilla.org/en-US/docs/Web/API/URLSearchParams/…
Additionally, accessing window.location will not allow to trigger React's re-render on changes.
this answer is useful if you get location.search from react-router dom as is done in dsgriffin's answer
d
dsgriffin

React Router 5.1+

5.1 introduced various hooks like useLocation and useParams that could be of use here.

Example:

<Route path="/test/:slug" component={Dashboard} />

Then if we visited say

http://localhost:3000/test/signin?_k=v9ifuf&__firebase_request_key=blablabla

You could retrieve it like

import { useLocation } from 'react-router';
import queryString from 'query-string';

const Dashboard: React.FC = React.memo((props) => {
    const location = useLocation();

    console.log(queryString.parse(location.search));

    // {__firebase_request_key: "blablabla", _k: "v9ifuf"}

    ...

    return <p>Example</p>;
}

useParams is more relevant to this issue
H
Hunter

With this one-liner, you can use it anywhere in both React Hook and React Class Component with plain JavaScript.

https://www.hunterisgod.com/?city=Leipzig

let city = (new URLSearchParams(window.location.search)).get("city")

M
Mike Frenil L

React Router v4

const urlParams = new URLSearchParams(this.props.location.search)
const key = urlParams.get('__firebase_request_key')

Please note that it is currently experimental.

Check browser compatibility here: https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams/URLSearchParams#Browser_compatibility


Nice solution but unfortunately IE does not support ((
@AndreyPatseiko there's a polyfill for that github.com/WebReflection/url-search-params
H
Hassan Saeed

http://localhost:8000/#/signin?id=12345

import React from "react";
import { useLocation } from "react-router-dom";

const MyComponent = () => {
  const search = useLocation().search;
const id=new URLSearchParams(search).get("id");
console.log(id);//12345
}

For even a simpler solution, I've created a 'useClearParams` hook to be used with function components, github.com/oyalhi/use-clear-params#readme if anyone is interested.
T
TommyLike

you can check the react-router, in simple,you can use the code to get query parameter as long as you defined in your router:

this.props.params.userId

This not the right answer in the case of OP. props.params is for URL params (url segment prefixed with ':' in react router), props.location.query stores query string params (after the '?') and is what OP want.
M
Milan Panigrahi

If your Router is like this

<Route exact path="/category/:id" component={ProductList}/>

You will get that id like this

this.props.match.params.id

Does anyone know how this works in React Router 5.0.1? this.props.match.params is always empty.
@MarkA.Tagliaferro The prop is only avialable to components being rendered by a Route. If that is not the case for your component, you can access them by wrapping your component in the withRouter HOC.
N
Naziks

Not the react way, but I beleive that this one-line function can help you :)

const getQueryParams = (query = null) => (query||window.location.search.replace('?','')).split('&').map(e=>e.split('=').map(decodeURIComponent)).reduce((r,[k,v])=>(r[k]=v,r),{});

Example:
URL:  ...?a=1&b=c&d=test
Code:

getQueryParams()
//=> {a: "1", b: "c", d: "test"}

getQueryParams('type=user&name=Jack&age=22')
//=> {type: "user", name: "Jack", age: "22" }

S
Senthuran

Say there is a url as follows

http://localhost:3000/callback?code=6c3c9b39-de2f-3bf4-a542-3e77a64d3341

If we want to extract the code from that URL, below method will work.

const authResult = new URLSearchParams(window.location.search); 
const code = authResult.get('code')

Thanks!! Perfect Answer.
No need additional libraries means less complexity to maintain when the app grow up... Thanks.
j
jerryurenaa

do it all in one line without 3rd party libraries or complicated solutions. Here is how

let myVariable = new URLSearchParams(history.location.search).get('business');

the only thing you need to change is the word 'business' with your own param name.

example url.com?business=hello

the result of myVariable will be hello


history.location.search not work in my case, Instead of I use window.location.search and its work perfectly. new URLSearchParams(window.location.search).get('bussiness')
Y
Yash Pokar

React Router Dom V6 https://reactrouter.com/docs/en/v6/hooks/use-search-params

import * as React from "react";
import { useSearchParams } from "react-router-dom";

function App() {
  let [searchParams, setSearchParams] = useSearchParams();

  function handleSubmit(event) {
    event.preventDefault();
    // The serialize function here would be responsible for
    // creating an object of { key: value } pairs from the
    // fields in the form that make up the query.
    let params = serializeFormQuery(event.target);
    setSearchParams(params);
  }

  return (
    <div>
      <form onSubmit={handleSubmit}>{/* ... */}</form>
    </div>
  );
}

Till React Router Dom V5

function useQueryParams() {
    const params = new URLSearchParams(
      window ? window.location.search : {}
    );

    return new Proxy(params, {
        get(target, prop) {
            return target.get(prop)
        },
    });
}

React hooks are amazing

If your url looks like /users?page=2&count=10&fields=name,email,phone

// app.domain.com/users?page=2&count=10&fields=name,email,phone

const { page, fields, count, ...unknown } = useQueryParams();

console.log({ page, fields, count })
console.log({ unknown })

In case of your query parameter contains hyphone ("-") or space (" ") then you can not unpack like { page, fields, count, ...unknown }

You'll need to go with treditional assignment like

// app.domain.com/users?utm-source=stackOverFlow

const params = useQueryParams();

console.log(params['utm-source']);

This response has a few problems, see my answer for these improvements. I am sorry to see my edit did not get accepted.
j
jtlindsey

If you aren't getting the this.props... you were expecting based on the other answers, you may need to use withRouter (docs v4):

import React from 'react'
import PropTypes from 'prop-types'
import { withRouter } from 'react-router'

// A simple component that shows the pathname of the current location
class ShowTheLocation extends React.Component {
  static propTypes = {
    match: PropTypes.object.isRequired,
    location: PropTypes.object.isRequired,
    history: PropTypes.object.isRequired
  }

  render() {
    const { match, location, history } = this.props

    return (
      <div>You are now at {location.pathname}</div>
    )
  }
}

// Create a new component that is "connected" (to borrow redux terminology) to the router.  
const TwitterSsoButton = withRouter(ShowTheLocation)  

// This gets around shouldComponentUpdate
withRouter(connect(...)(MyComponent))

// This does not
connect(...)(withRouter(MyComponent))

N
NarDd

I had a hard time solving this issue. If none of the above work you can try this instead. I am using the create-react-app

Requirements

react-router-dom": "^4.3.1"

Solution

At the location where router is specified

<Route path="some/path" ..../>

Add the parameter name that you would want to pass in like this

<Route path="some/path/:id" .../>

At the page where you are rendering some/path you can specify this to view the parameter name call id like this

componentDidMount(){
  console.log(this.props);
  console.log(this.props.match.params.id);
}

At the end where you export default

export default withRouter(Component);

Remember to include import

import { withRouter } from 'react-router-dom'

When console.log(this.props) you would be able what has been passed down. Have fun!


And if using TypeScript don't forget to add RouteComponentProps<{id: number}>
where do you add RouteComponentProps<{id: number}> ??
type Props = RouteComponentProps<{id: number}>;
class MyClass extends React.PureComponent {
Then in componentDidMount (for example), const myId = this.props.match.params.id;
B
Bear

React Router v5.1 introduced hooks:

For

<Route path="/posts/:id">
  <BlogPost />
</Route>

You can access params / id with hook:

const { id } = useParams();

More here.


Okay then how to use in class?
@SudhakarKrishnan You can't use it in class component, it is a hook. For class component try wrapping your Class Component into withRouter HOC, for example in export line: export default withRouter(Component); It allows you to access property called match, location and history. For more information look here: v5.reactrouter.com/web/api/withRouter
M
Md. Khairullah Nayan

Actually there is no need to use 3rd party library. We can make with pure JavaScript.

consider the following URL:

https://example.com?yourParamName=yourParamValue

Now we get:

const url = new URL(window.location.href);
const yourParamName = url.searchParams.get('yourParamName');

In short

const yourParamName = new URL(window.location.href).searchParams.get('yourParamName')

Another Smart Solution (Recommended)

const params = new URLSearchParams(window.location.search);
const yourParamName = params.get('yourParamName');

In short

const yourParamName = new URLSearchParams(window.location.search).get('yourParamName')

NOTE:

use "getAll" instead of "get" for Params having multiple value

https://example.com?yourParamName[]=yourParamValue1&yourParamName[]=yourParamValue2

const yourParamName = new URLSearchParams(window.location.search).getAll('yourParamName[]')

Result will be like:

["yourParamValue1", "yourParamValue2"]

G
GMKHussain

Try This

http://localhost:4000/#/amoos?id=101

// ReactJS
import React from "react";
import { useLocation } from "react-router-dom";

const MyComponent = () => {
    const search = useLocation().search;
    const id = new URLSearchParams(search).get("id");
    console.log(id); //101
}



// VanillaJS
const id = window.location.search.split("=")[1];
console.log(id); //101

S
Shubham Khatri

React router from v4 onwards no longer gives you the query params directly in its location object. The reason being

There are a number of popular packages that do query string parsing/stringifying slightly differently, and each of these differences might be the "correct" way for some users and "incorrect" for others. If React Router picked the "right" one, it would only be right for some people. Then, it would need to add a way for other users to substitute in their preferred query parsing package. There is no internal use of the search string by React Router that requires it to parse the key-value pairs, so it doesn't have a need to pick which one of these should be "right".

Having included that, It would just make more sense to just parse location.search in your view components that are expecting a query object.

You can do this generically by overriding the withRouter from react-router like

customWithRouter.js

import { compose, withPropsOnChange } from 'recompose';
import { withRouter } from 'react-router';
import queryString from 'query-string';

const propsWithQuery = withPropsOnChange(
    ['location', 'match'],
    ({ location, match }) => {
        return {
            location: {
                ...location,
                query: queryString.parse(location.search)
            },
            match
        };
    }
);

export default compose(withRouter, propsWithQuery)

n
nizam.sp

this.props.params.your_param_name will work.

This is the way to get the params from your query string.
Please do console.log(this.props); to explore all the possibilities.


M
Mo.
componentDidMount(){
    //http://localhost:3000/service/anas
    //<Route path="/service/:serviceName" component={Service} />
    const {params} =this.props.match;
    this.setState({ 
        title: params.serviceName ,
        content: data.Content
    })
}

Welcome to Stack Overflow! Please don't answer just with source code. Try to provide a nice description about how your solution works. See: How do I write a good answer?. Thanks
Probably going to get a 'data' is not defined no-undef
R
Rudy Huynh

Maybe a bit late but this react hook can help you get/set values in URL query: https://github.com/rudyhuynh/use-url-search-params (written by me).

It works with or without react-router. Below is code sample in your case:

import React from "react";
import { useUrlSearchParams } from "use-url-search-params";

const MyComponent = () => {
  const [params, setParams] = useUrlSearchParams()
  return (
    <div>
      __firebase_request_key: {params.__firebase_request_key}
    </div>
  )
}

Thank you so much for providing such a simple but a great hook!
a
andras

You can use the following react hook:

Hook state updates if the url changes SSR: typeof window === "undefined", just checking window causes errors (try it out) Proxy object hides implementation, so undefined is returned instead of null

So this is the function to get the search param as object:

const getSearchParams = <T extends object>(): Partial<T> => {
    // server side rendering
    if (typeof window === "undefined") {
        return {}
    }

    const params = new URLSearchParams(window.location.search) 

    return new Proxy(params, {
        get(target, prop, receiver) {
            return target.get(prop as string) || undefined
        },
    }) as T
}

And then use it as hook like that:

const useSearchParams = <T extends object = any>(): Partial<T> => {
    const [searchParams, setSearchParams] = useState(getSearchParams())

    useEffect(() => {
        setSearchParams(getSearchParams())
    }, [typeof window === "undefined" ? "once" : window.location.search])

    return searchParams
}

If your url looks like this:

/app?page=2&count=10

You can just read it like this:

const { page, count } = useQueryParams();

console.log(page, count)

In your last example, did you mean to destructure count instead of fields? or where did fields come from?
@micnil it seems there is indeed something wrong with this answer, useQueryParams does not even exist. I proposed another solution for this answer that wasn't accepted and this answer was written after that. The edit history of that answer and this one should give you the full picture. Sorry I don't have time for this issue rn. Hope it helps.
C
Chilaxathor

React Router v6

Source: Getting Query Strings (Search Params) in React Router

Use the new useSearchParams hook and the .get() method:

const Users = () => {
  const [searchParams] = useSearchParams();
  console.log(searchParams.get('sort')); // 'name'

  return <div>Users</div>;
};

With this approach, you can read one or a few params.

BONUS Get params as an object:

If you need to get all query string params at once, then we can use Object.fromEntries like this:

const Users = () => {
  const [searchParams] = useSearchParams();
  console.log(Object.fromEntries([...searchParams])); // ▶ { sort: 'name', order: 'asecnding' }
  return <div>Users</div>;
};

Read more and live demo: Getting Query Strings (Search Params) in React Router


Everyone should upvote this solution! :)
Spent hours trying to get this to work, such a great solution. Thank you!
k
kajkal

You could create simple hook for extracting search params from current location:

import React from 'react';
import { useLocation } from 'react-router-dom';

export function useSearchParams<ParamNames extends string[]>(...parameterNames: ParamNames): Record<ParamNames[number], string | null> {
    const { search } = useLocation();
    return React.useMemo(() => { // recalculate only when 'search' or arguments changed
        const searchParams = new URLSearchParams(search);
        return parameterNames.reduce((accumulator, parameterName: ParamNames[number]) => {
            accumulator[ parameterName ] = searchParams.get(parameterName);
            return accumulator;
        }, {} as Record<ParamNames[number], string | null>);
    }, [ search, parameterNames.join(',') ]); // join for sake of reducing array of strings to simple, comparable string
}

then you could use it inside your functional component like this:

// current url: http://localhost:8000/#/signin?_k=v9ifuf&__firebase_request_key=blablabla
const { __firebase_request_key } = useSearchParams('__firebase_request_key');
// current url: http://localhost:3000/home?b=value
const searchParams = useSearchParameters('a', 'b'); // {a: null, b: 'value'}

s
sigmapi13

Maybe someone can help clarify why but if you're attempting to hit props to find location from a fresh install of Create React App on the App.js page you get:

TypeError: Cannot read property 'search' of undefined

Even though I have App.js as the home route:

<Route exact path='/' render={props => (

On App.js only, using window.location worked for me:

import queryString from 'query-string';
...
const queryStringParams = queryString.parse(window.location.search);

this worked for me. any clarification on the downvote would be much appreciated
Worked for me too
Worked for me too.
R
Rocco Ghielmini

In the component where you need to access the parameters you can use

this.props.location.state.from.search

which will reveal the whole query string (everything after the ? sign)


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