Styjun

I want to pass a value as the hash in the url (myapp.com#somevalue) and have the page scroll to that item when the page loads - exactly the behavior of using a hash fragment since the beginning of the internet. I tried using scrollIntoView but that fails on iOS. Then I tried just unsetting/setting window.location.hash but there seems to be a race condition. It only works when the delay is more than 600ms.

I would like a more solid solution and don't want to introduce an unnecessary delay. When the delay is too short, it appears to scroll to the desired item but then scrolls to the top of the page. You won't see the effect on this demo but it happens in my actual app https://codesandbox.io/s/pjok544nrx line 75

 componentDidMount() 
 let self = this;

 let updateSearchControl = hash => 
 let selectedOption = self.state.searchOptions.filter(
 option => option.value === hash
 )[0];
 if (selectedOption) 
 // this doesn't work with Safari on iOS
 // document.getElementById(hash).scrollIntoView(true);

 // this works if delay is 900 but not 500 ms
 setTimeout(() => 
 // unset and set the hash to trigger scrolling to target
 window.location.hash = null;
 window.location.hash = hash;
 // scroll back by the height of the Search box
 window.scrollBy(
 0,
 -document.getElementsByClassName("heading")[0].clientHeight
 );
 , 900);
 else if (hash) 
 this.searchRef.current.select.focus();
 
 ;

 // Get the hash
 // I want this to work as a Google Apps Script too which runs in
 // an iframe and has a special way to get the hash
 if (!!window["google"]) 
 let updateHash = location => 
 updateSearchControl(location.hash);
 ;
 eval("google.script.url.getLocation(updateHash)");
 else 
 let hash = window.location.hash.slice(1);
 updateSearchControl(hash);
 
 

EDIT: I tracked down the line of React that re-renders the page and consequently resets the scroll position after it already scrolled where I told it to go in componentDidMount(). It's this one.
style[styleName] = styleValue; At the time the page is re-rendered it is setting the width style property of the inputbox component of the react-select box component. The stack trace right before it does this looks like

(anonymous) @ VM38319:1
setValueForStyles @ react-dom.development.js:6426
updateDOMProperties @ react-dom.development.js:7587
updateProperties @ react-dom.development.js:7953
commitUpdate @ react-dom.development.js:8797
commitWork @ react-dom.development.js:17915
commitAllHostEffects @ react-dom.development.js:18634
callCallback @ react-dom.development.js:149
invokeGuardedCallbackDev @ react-dom.development.js:199
invokeGuardedCallback @ react-dom.development.js:256
commitRoot @ react-dom.development.js:18867
(anonymous) @ react-dom.development.js:20372
unstable_runWithPriority @ scheduler.development.js:255
completeRoot @ react-dom.development.js:20371
performWorkOnRoot @ react-dom.development.js:20300
performWork @ react-dom.development.js:20208
performSyncWork @ react-dom.development.js:20182
requestWork @ react-dom.development.js:20051
scheduleWork @ react-dom.development.js:19865
scheduleRootUpdate @ react-dom.development.js:20526
updateContainerAtExpirationTime @ react-dom.development.js:20554
updateContainer @ react-dom.development.js:20611
ReactRoot.render @ react-dom.development.js:20907
(anonymous) @ react-dom.development.js:21044
unbatchedUpdates @ react-dom.development.js:20413
legacyRenderSubtreeIntoContainer @ react-dom.development.js:21040
render @ react-dom.development.js:21109
(anonymous) @ questionsPageIndex.jsx:10
./src/client/questionsPageIndex.jsx @ index.html:673
__webpack_require__ @ index.html:32
(anonymous) @ index.html:96
(anonymous) @ index.html:99

I don't know where to move my instruction to scroll the page. It has to happen after these styles are set which is happening after componentDidMount().

EDIT: I need to better clarify exactly what I need this to do. Apologies for not doing that before.

Must haves

This has to work on all common desktop and mobile devices.

When the page loads there could be three situations depending on what query is provided in the url after the #:

• 1) no query was provided - nothing happens


• 2) a valid query was provided - the page scrolls instantly to the desired anchor and the page's title changes to the label of the option


• 3) an invalid query was provided - the query is entered into the search box, the search box is focused and the menu opens with options limited by the provided query as if they had been typed in. The cursor is located in the search box at the end of the query so the user can modify the query.

A valid query is one that matches the value of one of the options. An invalid query is one that doesn't.

The browser back and forward buttons should move the scroll position accordingly.

Any time an option is chosen from the Search box the page should scroll instantly to that anchor, the query should clear returning to the placeholder "Search...", the url should update, and the document's title should change to the option's label.

Optional but would be great

After making a selection the menu closes and the query goes back to "Search...", and either

• the Search box retains the focus so the user can begin typing another query. The next time it is clicked, the menu opens, and the Searchbox query from before the selection, the menu's filter and the menu scroll position are restored (most preferred), or


• the Search box loses focus. The next time it is focused, the menu opens, and the Search box query from before the selection, the menu's filter and the menu scroll position are restored (preferred), or


• the Search box retains the focus so the user can begin typing another query. The prior query and menu scroll position are lost.

Probably easier to do this with the react-scrollable-anchor library:

import React from "react";
import ReactDOM from "react-dom";
import ScrollableAnchor from "react-scrollable-anchor";

class App extends React.Component 
 render() 
 return (
 <React.Fragment>
 <div style= marginBottom: 7000 >nothing to see here</div>
 <div style= marginBottom: 7000 >never mind me</div>
 <ScrollableAnchor id="doge">
 <div>bork</div>
 </ScrollableAnchor>
 </React.Fragment>
 );
 


const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);

You can see it working by going here: https://zwoj0xw503.codesandbox.io/#doge

I put this right after the imports in my component's file:

let initialValidSlug = '';

window.addEventListener('load', () => 
 window.location.hash = '';
 window.location.hash = (initialValidSlug ? initialValidSlug : '');
 window.scrollBy(0, -document.getElementsByClassName("heading")[0].clientHeight);
 console.log('window.addEventListener')
);

and have this for my componentDidMount():

 componentDidMount() 
 const pathname, isValid = this.state;
 if(!isValid && pathname) // if there's a pathname but it's invalid,
 this.searchRef.current.select.focus(); // focus on the search bar
 
 initialValidSlug = pathname; // sets the value to be used in the $.ready() above
 

You can simplify your code by using react-router-dom's HashRouter with React's ref.current.scrollIntoView() or window.scrollTo(ref.currrent.offsetTop).

Currently tested and working on Chrome (desktop/android), Firefox(desktop), Silk Browser(android), Saumsung Internet(android), and Safari(iOS -- with one caveat in that it instantly jumps to the selection). While I was able to test and confirm it's working within the sandbox environment's iframe, you'll have to adapt/test it within a standalone iframe.

I'd also like to point out that your approach is very jQuery like and that you should avoid directly attempting to utilize or manipulate the DOM and/or the window. In addition, you seem to use a lot of let variables throughout your code, but they remain unchanged. Instead, they should be a const variable as React evaluates variables each time it re-renders, so unless you plan on changing that variable during the re-render process, there's no need to use let.

Working example: https://v6y5211n4l.codesandbox.io

components/ScrollBar

import React, Component from "react";
import PropTypes from "prop-types";
import Helmet from "react-helmet";
import Select from "react-select";
import withRouter from "react-router-dom";
import "./styles.css";

const scrollOpts = 
 behavior: "smooth",
 block: "start"
;

class ScrollBar extends Component 
 constructor(props) 
 super(props);

 const titleRefs = props.searchOptions.map(
 ( label ) => (this[label] = React.createRef())
 ); // map over options and use "label" as a ref name; ex: this.orange
 this.topWindow = React.createRef();
 this.searchRef = React.createRef();
 const pathname = props.history.location.pathname.replace(///g, ""); // set current pathname without the "/"

 this.state = 
 titleRefs,
 menuIsOpen: false,
 isValid: props.searchOptions.some(( label ) => label === pathname), // check if the current pathname matches any of the labels
 pathname
 ;
 

 componentDidMount() 
 const pathname, isValid = this.state;
 if (isValid) this.scrollToElement(); // if theres a pathname and it matches a label, scroll to it
 if (!isValid && pathname) this.searchRef.current.select.focus(); // if there's a pathname but it's invalid, focus on the search bar
 

 // allows us to update state based upon prop updates (in this case
 // we're looking for changes in the history.location.pathname)
 static getDerivedStateFromProps(props, state) 
 const nextPath = props.history.location.pathname.replace(///g, "");
 const isValid = props.searchOptions.some(( label ) => label === nextPath);
 return state.pathname !== nextPath ? pathname: nextPath, isValid : null; // if the path has changed, update the pathname and whether or not it is valid
 

 // allows us to compare new state to old state (in this case
 // we're looking for changes in the pathname)
 componentDidUpdate(prevProps, prevState) 
 if (this.state.pathname !== prevState.pathname) 
 this.scrollToElement();
 
 

 scrollToElement = () => 
 const isValid, pathname = this.state;
 const elem = isValid ? pathname : "topWindow";
 setTimeout(() => 
 window.scrollTo(
 behavior: "smooth",
 top: this[elem].current.offsetTop - 45
 );
 , 100);
 ;

 onInputChange = (options, action ) => 
 if (action === "menu-close") 
 this.setState( menuIsOpen: false , () =>
 this.searchRef.current.select.blur()
 );
 else 
 this.setState( menuIsOpen: true );
 
 ;

 onChange = ( value ) => 
 const history = this.props;
 if (history.location.pathname.replace(///g, "") !== value) // if the select value is different than the previous selected value, update the url -- required, otherwise, react-router will complain about pushing the same pathname/value that is current in the url
 history.push(value);
 
 this.searchRef.current.select.blur();
 ;

 onFocus = () => this.setState( menuIsOpen: true );

 render() 
 const pathname, menuIsOpen, titleRefs = this.state;
 const searchOptions, styles = this.props;

 return (
 <div className="container">
 <Helmet title= "Select an option" />
 <div className="heading">
 <Select
 placeholder="Search..."
 isClearable=true
 isSearchable=true
 options=searchOptions
 defaultInputValue=pathname
 onFocus=this.onFocus
 onInputChange=this.onInputChange
 onChange=this.onChange
 menuIsOpen=menuIsOpen
 ref=this.searchRef
 value=null
 styles=
 />
 </div>
 <div className="fruits-list">
 <div ref=this.topWindow />
 searchOptions.map(( label, value , key) => (
 <div key=value id=value>
 <p ref=titleRefs[key]>label</p>
 [1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 14].map(num => (
 <p key=num>num</p>
 ))
 </div>
 ))
 </div>
 </div>
 );
 


ScrollBar.propTypes = 
 searchOptions: PropTypes.arrayOf(
 PropTypes.shape(
 label: PropTypes.string.isRequired,
 value: PropTypes.string.isRequired
 ).isRequired
 ).isRequired,
 styles: PropTypes.objectOf(PropTypes.func)
;

export default withRouter(ScrollBar);

index.js

import React from "react";
import render from "react-dom";
import HashRouter from "react-router-dom";
import Helmet from "react-helmet";
import ScrollBar from "../src/components/ScrollBar";

const config = 
 htmlAttributes: lang: "en" ,
 title: "My App",
 titleTemplate: "Scroll Search - %s",
 meta: [
 
 name: "description",
 content: "The best app in the world."
 
 ]
;

const searchOptions = [
 
 label: "apple",
 value: "apple"
 ,
 
 label: "orange",
 value: "orange"
 ,
 
 label: "banana",
 value: "banana"
 ,
 
 label: "strawberry",
 value: "strawberry"
 
];

const styles = 
 menu: base => ( ...base, width: "100%", height: "75vh" ),
 menuList: base => ( ...base, minHeight: "75vh" ),
 option: base => ( ...base, color: "blue" )
;

const App = () => (
 <HashRouter>
 <Helmet ...config />
 <ScrollBar searchOptions=searchOptions styles=styles />
 </HashRouter>
);

render(<App />, document.getElementById("root"));

You can use https://www.npmjs.com/package/element.scrollintoviewifneeded-polyfill.

As soon as possibile in your application import the library

import 'element.scrollintoviewifneeded-polyfill';

Than you can use the method scrollIntoViewIfNeeded(); on all the dom nodes.
The library will polyfill the method so you could use this on all browsers.

I recommend you to use this with a react ref so you don't have to call getElementById or other document method in order to retrieve the dom node.

const ref = React.createRef();
<div id="somevalue" ref=ref />

Than in your componentDidMount you can use the same method you describe for retrieving the id of the div you want to scroll in, get the associated ref and call

 ref.current.scrollIntoViewIfNeeded();

Where the ref is the right div reference, you can obviously store all the ref in a map and than retrieve in your components methods.