Develop Reference

ReactJS — Creating Refs and accessing DOM elements to use fullpage.js

I am trying to migrate a code I created in JS/JQuery to ReactJS. The code uses the library fullpage.js. The aim is to change the title according to the section on focus. I am struggling to correctly capture the properties of elements in the DOM using Refs. I tried to follow the ReactJS documentation but the example in the docs made everything more confusing.
My question is, how can I store these properties and then apply it using CSS on the required DOM element? Thank you in advance.
Pseudocode
Store title width
Store title height
Apply these properties to the
parents' frame and mask
Listen to the scroll events of fullpage.js
and translate the title position accordingly
Codepen (JS/JQuery)
$(document).ready(function() {
var titleWidth = $(".title").outerWidth();
var titleHeight = $(".title").outerHeight();
$("#mask").css({ height: titleHeight + "px", width: titleWidth + "px" });
$("#frame").css("top", titleHeight);
new fullpage("#fullpage", {
sectionsColor: ["yellow", "orange", "#C0C0C0", "#ADD8E6"],
afterRender: function() {
$("#frame").transition({ top: "-=" + titleHeight, delay: 1000 });
},
onLeave: function(origin, destination, direction) {
var leavingSection = this;
//after leaving section 2
if (direction == "down") {
$("#frame").transition({ top: "-=" + titleHeight });
} else if (direction == "up") {
$("#frame").transition({ top: "+=" + titleHeight });
}
}
});
});
Codesandbox (ReactJS)
import React from "react";
import ReactDOM from "react-dom";
import "fullpage.js/vendors/scrolloverflow"; // Optional. When using scrollOverflow:true
import ReactFullpage from "#fullpage/react-fullpage";
import "./styles.css";
class MySection extends React.Component {
render() {
return (
<div className="section">
<h3>{this.props.content}</h3>
</div>
);
}
}
const anchors = ["firstPage", "secondPage", "thirdPage"];
const FullpageWrapper = () => (
<ReactFullpage
anchors={anchors}
navigation
navigationTooltips={anchors}
sectionsColor={["#282c34", "#ff5f45", "#0798ec"]}
onLeave={(origin, destination, direction) => {
console.log("onLeave event", { origin, destination, direction });
//after leaving section 2
if (origin.index === 1 && direction === "down") {
alert("Going to section 3!");
} else if (origin.index === 1 && direction === "up") {
alert("Going to section 1!");
}
}}
render={({ state, fullpageApi }) => {
console.log("render prop change", state, fullpageApi); // eslint-disable-line no-console
return (
<div>
<MySection content={"Slide down!"} />
<MySection content={"Keep going!"} />
<MySection content={"Slide up!"} />
</div>
);
}}
/>
);
class Index extends React.Component {
constructor(props) {
super(props);
this.title = React.createRef();
// this.title = null;
// this.titleRef = element => {
// this.title = element;
// };
// this.setTitle = () => {
// Focus the text input using the raw DOM API
// if (this.title) this.title.current.offsetWidth;
// };
}
componentDidMount() {
// console.log(this.setTitle())
const titleWidth = this.title.current.offsetWidth;
const titleHeight = this.title.current.offsetHeight;
console.log(titleWidth, titleHeight);
}
render() {
return (
<div class="wrapper">
<div id="mask">
<div id="frame">
<h1 ref={this.title} class="title">
One
</h1>
<h1 ref={this.title} class="title">
Two
</h1>
<h1 ref={this.title} class="title">
Three
</h1>
<h1 ref={this.title} class="title">
Four
</h1>
</div>
</div>
<div class="content">
<FullpageWrapper />
</div>
</div>
);
}
}
ReactDOM.render(<Index />, document.getElementById("react-root"));

How to identify a single div element among set of elements in react?

I have a react app with a list of Div elements to create some Cards. Each card has 'read more' button to expand and collapse a paragraph and I toggle it for each mouse click. My problem is, for each click, it expand paragraphs in all cards instead only paragraph in the card I clicked. So I can't identify the clicked (this) card.
Component:
class BidCard extends Component {
constructor(props) {
super(props);
this.state = {
readMoreOpen: false,
}
}
readMore() {
this.setState({ readMoreOpen: !this.state.readMoreOpen })
}
render() {
const { articles } = this.props;
return (
articles.map(article => {
return (
<div className="projectCardRoot" key={article.id}>
<div className="projectCardMainLogin">
<div className="projectCardMiddle">
<p className={this.state.readMoreOpen ? 'openFullParagraph' : 'closeFullParagraph'} id="projectCardDesc">{article.description}</p>
<div className="cardReadMore desktopDiv" onClick={this.readMore.bind(this)}>Read more</div>
</div>
</div>
</div>
)
})
)
}
}
export default BidCard;
How can I solve this?

You can save id of the expanded card to the state and the check it when rendering items:
class BidCard extends Component {
constructor(props) {
super(props);
this.state = {
readMoreOpen: [], // Use array here
}
}
// Add card id to the expanded array if not already there, otherwise remove it
readMore = (id) => {
this.setState(state => {
if (state.readMoreOpen.includes(id)) {
return {readMoreOpen: state.readMoreOpen.filter(readId => readId !== id)}
}
return {readMoreOpen: [...state.readMoreOpen, id]}
})
}
render() {
const { articles } = this.props;
return (
articles.map(article => {
return (
<div className="projectCardRoot" key={article.id}>
<div className="projectCardMainLogin">
<div className="projectCardMiddle">
{/*Check if the item is in expanded items array */}
<p className={this.state.readMoreOpen.includes(article.id) ? 'openFullParagraph' : 'closeFullParagraph'} id="projectCardDesc">{article.description}</p>
<div className="cardReadMore desktopDiv" onClick={() => this.readMore(article.id)}>Read more</div>
</div>
</div>
</div>
)
})
)
}
}

You will need to keep expanded state per every card.
I would recommend to create component for card
articles.map(article => {
return (
<Article key={article.id} {...article} />
)
})
)
class Article extends Component {
state = {
readMoreOpen: false
}
readMore() {
this.setState(state => ({ readMoreOpen: !state.readMoreOpen }))
}
render () {
const {description} = this.props;
return (<div className="projectCardRoot" >
<div className="projectCardMainLogin">
<div className="projectCardMiddle">
<p className={this.state.readMoreOpen ? 'openFullParagraph' : 'closeFullParagraph'} id="projectCardDesc">{description}</p>
<div className="cardReadMore desktopDiv" onClick={this.readMore.bind(this)}>Read more</div>
</div>
</div>
</div>)
}
}
Other approach is to keep array of booleans with information of which article div should be currently expanded in this method you will need to update state with id of expanded article
readMore(id) {
this.setState({ articles: this.props.articles.map(article => article.id === id ? true : false) } )
}
and in render use boolean from state as information if it should be expanded

That's because all your cards currently share the same source of truth. You used a ternary operator to determine what class a Card would have depending on the state-value. Well, all Cards are using the same state-value to compare, so understandably, if one is affected, then all would be too.
There's more than one way to resolve this, but the most appropriate would probably be to create a separate Card Component. This makes it so each Card component has their own state to keep track of.
See working sandbox: https://codesandbox.io/s/quizzical-mahavira-wz8iu
Parent.js
import React from "react";
import ReactDOM from "react-dom";
import Card from "./Card";
import "./styles.css";
class BidCard extends React.Component {
render() {
const { articles } = this.props;
return articles.map(article => {
return <Card article={article} />;
});
}
}
BidCard.defaultProps = {
articles: [{ description: "woof" }, { description: "meow" }]
};
const rootElement = document.getElementById("root");
ReactDOM.render(<BidCard />, rootElement);
Card.js
import React, { useState } from "react";
const Card = ({ article }) => {
const [readOpen, setReadOpen] = useState(false);
return (
<div className="projectCardRoot" key={article.id}>
<div className="projectCardMainLogin">
<div className="projectCardMiddle">
<p
className={readOpen ? "openFullParagraph" : "closeFullParagraph"}
id="projectCardDesc"
>
{article.description}
</p>
<div
className="cardReadMore desktopDiv"
onClick={() => setReadOpen(!readOpen)}
>
Read more
</div>
</div>
</div>
</div>
);
};
export default Card;

I did a few modifications to your code. This way it should work.
I added comments that explain the the changes. The main idea is that you should not simply store the boolean readMoreOpen status (which in your code is treated as a kind of shared between all the cards) but specific card identity.
My changes works if there could be only one "expanded" card at any moment. If your design supposes that there could be a few "expanded" cards at the same time the solution would be more complex though not much.
class BidCard extends Component {
constructor(props) {
super(props);
// the way you've tried to keep status (open/closed) it wasn't tied to any speciifc card
// you should store this specific card instead
this.state = {
//readMoreOpen: false,
expandedCard: null,
}
this.readMore = this.readMore.bind(this);
}
readMore(article) {
//this.setState({ readMoreOpen: !this.state.readMoreOpen })
this.setState({expandedCard: article})
}
render() {
const { articles } = this.props;
const { expandedCard } = this.state;
return (
articles.map(article => {
// the look of each card depends on state.expandedCard only if article == expandedCard it's shown with 'openFullParagraph' class
return (
<div className="projectCardRoot" key={article.id}>
<div className="projectCardMainLogin">
<div className="projectCardMiddle">
<p className={article == expandedCard ? 'openFullParagraph' : 'closeFullParagraph'} id="projectCardDesc">{article.description}</p>
<div className="cardReadMore desktopDiv" onClick={() => this.readMore(article)}>Read more</div>
</div>
</div>
</div>
)
})
)
}
}
export default BidCard;

Not rendering JSX from function in React

The function is getting the value of a button click as props. Data is mapped through to compare that button value to a key in the Data JSON called 'classes'. I am getting all the data correctly. All my console.logs are returning correct values. But for some reason, I cannot render anything.
I've tried to add two return statements. It is not even rendering the p tag with the word 'TEST'. Am I missing something? I have included a Code Sandbox: https://codesandbox.io/s/react-example-8xxih
When I click on the Math button, for example, I want to show the two teachers who teach Math as two bubbles below the buttons.
All the data is loading. Just having an issue with rendering it.
function ShowBubbles(props){
console.log('VALUE', props.target.value)
return (
<div id='bubbles-container'>
<p>TEST</p>
{Data.map((item,index) =>{
if(props.target.value == (Data[index].classes)){
return (
<Bubble key={index} nodeName={Data[index].name}>{Data[index].name}
</Bubble>
)
}
})}
</div>
)
}

Sandbox Link: https://codesandbox.io/embed/react-example-m1880
import React, {Component} from 'react';
import ReactDOM from 'react-dom';
const circleStyle = {
width: 100,
height: 100,
borderRadius: 50,
fontSize: 30,
color: "blue"
};
const Data = [
{
classes: ["Math"],
name: "Mr.Rockow",
id: "135"
},
{
classes: ["English"],
name: "Mrs.Nicastro",
id: "358"
},
{
classes: ["Chemistry"],
name: "Mr.Bloomberg",
id: "405"
},
{
classes: ["Math"],
name: "Mr.Jennings",
id: "293"
}
];
const Bubble = item => {
let {name} = item.children.singleItem;
return (
<div style={circleStyle} onClick={()=>{console.log(name)}}>
<p>{item.children.singleItem.name}</p>
</div>
);
};
function ShowBubbles(props) {
var final = [];
Data.map((item, index) => {
if (props.target.value == Data[index].classes) {
final.push(Data[index])
}
})
return final;
}
function DisplayBubbles(singleItem) {
return <Bubble>{singleItem}</Bubble>
}
class Sidebar extends Component {
constructor(props) {
super(props);
this.state = {
json: [],
classesArray: [],
displayBubble: true
};
this.showNode = this.showNode.bind(this);
}
componentDidMount() {
const newArray = [];
Data.map((item, index) => {
let classPlaceholder = Data[index].classes.toString();
if (newArray.indexOf(classPlaceholder) == -1) {
newArray.push(classPlaceholder);
}
// console.log('newArray', newArray)
});
this.setState({
json: Data,
classesArray: newArray
});
}
showNode(props) {
this.setState({
displayBubble: true
});
if (this.state.displayBubble === true) {
var output = ShowBubbles(props);
this.setState({output})
}
}
render() {
return (
<div>
{/* {this.state.displayBubble ? <ShowBubbles/> : ''} */}
<div id="sidebar-container">
<h1 className="sidebar-title">Classes At School</h1>
<h3>Classes To Search</h3>
{this.state.classesArray.map((item, index) => {
return (
<button
onClick={this.showNode}
className="btn-sidebar"
key={index}
value={this.state.classesArray[index]}
>
{this.state.classesArray[index]}
</button>
);
})}
</div>
{this.state.output && this.state.output.map(item=><DisplayBubbles singleItem={item}/>)}
</div>
);
}
}
ReactDOM.render(<Sidebar />, document.getElementById("root"));
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.0.0/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.0.0/umd/react-dom.production.min.js"></script>
<div id="root"></div>

The issue here is ShowBubbles is not being rendered into the DOM, instead (according the sandbox), ShowBubbles (a React component) is being directly called in onClick button handlers. While you can technically do this, calling a component from a function will result in JSX, essentially, and you would need to manually insert this into the DOM.
Taking this approach is not very React-y, and there is usually a simpler way to approach this. One such approach would be to call the ShowBubbles directly from another React component, e.g. after your buttons using something like:
<ShowBubbles property1={prop1Value} <etc...> />
There are some other issues with the code (at least from the sandbox) that you will need to work out, but this will at least help get you moving in the right direction.

Custom component not getting rendered properly on this basic ReactJS app

I have a very basic ReactJS app which uses Redux which contains the following components:
PanelMaterialSize > Select
/src/controls/PanelMaterialSize/PanelMaterialSize.js
import React, { Component } from 'react';
import { connect } from 'react-redux';
import './PanelMaterialSize.scss';
import Select from '../Select/Select';
import { setThemeList } from '../../store/AppConfig/actions';
class PanelMaterialSize extends Component {
componentDidMount() {
this.n = 1;
setInterval(() => {
let themeList = [
{ value: this.n, text: 'Option ' + this.n },
{ value: this.n + 1, text: 'Option ' + (this.n + 1) },
{ value: this.n + 2, text: 'Option ' + (this.n + 2) },
];
this.props.setThemeList(themeList);
this.n += 3;
}, 1000);
}
render() {
return (
<div className="partial-designer-panel-material-size">
<div>
<div className="label-input">
<div className="label">MATERIAL</div>
<div className="input">
<Select data={this.props.themeList} style={{ width: '100%' }} />
</div>
</div>
</div>
</div>
);
}
}
const mapStateToProps = (appState) => {
return {
themeList: appState.appConfig.themeList,
}
}
const mapDispatchToProps = (dispatch) => {
return {
setThemeList: (themeList) => dispatch(setThemeList(themeList)),
}
}
export default connect(mapStateToProps, mapDispatchToProps)(PanelMaterialSize);
In my opinion the Redux logic is fine because I have tested by doing couple of things.
My problem is that when the render(...) method of: PanelMaterialSize gets called, the component: Select doesn't get rendered with the new data (which changes every one second).
Here you have a Codesandbox.io you can play with (preferable use Chrome):
https://codesandbox.io/s/03mj405zzv
Any idea on how to get its content changed properly?
If possible, please, provide back a new Codesandbox.io with your solution, forked from the previous one.
Thanks!

the problem is here in your select component.
you are passing initially empty array and checking your component with this.state.data props, next time reducer change your this.state.data will not update the data. because you initialize in constructor. constructor only invoke once when component mount.
SOLVED DEMO LINK
The Problem is in your select render method:
render() {
let data = this.state[this.name];
return (
<div className="control-select" {...this.controlProps}>
<div className="custom-dropdown custom-dropdown--grey">
<select className="custom-dropdown__select custom-dropdown__select--grey">
//change data with this.props.data
{this.props.data.length > 0 &&
this.props.data.map((elem, index) => {
return (
<option value={elem.value} key={index}>
{elem.text}
</option>
);
})}
</select>
</div>
</div>
);
}

react.js antd modal wrong behaviour

So I have this big messy component, I will try to slim it down, however keep most of it since I am unsure at this point what could be cause.
The issue is, that the game works as expected. When it is time for the modal to render, it appears at the bottom left of the page, with no styling floating left. The functionality however works as expected, the buttons work and it displays the raw content.
import { Modal } from 'antd';
//rest of imports
const initialState = {
visible: false,
streak: 0,
score: 0,
turn: 0,
previousPicks: [],
result: { result: "", player: "", computer: "" }
};
class Game extends React.Component {
constructor(props) {
super(props);
this.turnLimit = 10;
this.state = initialState;
}
componentWillUnmount() {
this.setState(initialState)
}
updateScore = () => {
//handles score
}
updatePreviousPicks = () => {
//update game data
}
onClickHandler = async (choice) => {
//fetching data from backend
self.showModal();
}
getAIResult = () => {
//
}
showModal = () => {
if (this.state.turn === 10) {
this.setState({
visible: true,
});
}
}
handleOk = () => {
this.setState(initialState)
}
handleCancel = () => {
this.setState(initialState)
}
render() {
return (
<div>
<div>
<Modal
title="Basic Modal"
centered={true}
visible={this.state.visible}
onOk={this.handleOk}
onCancel={this.handleCancel}></Modal>
</div>
<div className="container">
<div id="rockDiv" className={`choice`} onClick={() => this.onClickHandler("rock")}>
<Choices choice="rock"></Choices>
</div>
<div id="paperDiv" className={`choice`} onClick={() => this.onClickHandler("paper")}>
<Choices choice="paper"></Choices>
</div>
<div id="scissorsDiv" className={`choice`} onClick={() => this.onClickHandler("scissors")}>
<Choices choice="scissors"></Choices>
</div>
<Score score={this.state.score} bonus={this.state.streak} turn={this.state.turn} />
<div id="PlayerResult" className={this.state.result.result} >
{this.state.turn >= 1 ? <p>You</p> : <p></p>}
<Answer choice={`${this.state.result.player}`} />
</div>
<div id="AIResult" className={this.getAIResult()} >
{this.state.turn >= 1 ? <p>AI</p> : <p></p>}
<Answer choice={`${this.state.result.computer}`} />
</div>
</div>
</div>
)
}
}
export default Game
I have tried removing all CSS from the component, and still the modal does not show with the default antd design?

As I understand that current style you have doesn't like example of Antd.
Missing is you didn't import styles of Antd like this.
import { Modal, Button } from "antd";
import "antd/dist/antd.css";
Just need import style you will have what you need.
You can check my example here https://codesandbox.io/embed/8lr93mw8yj

<Modal
title="Basic Modal"
centered="true"
visible={this.state.visible}
onOk={this.handleOk}
onCancel={this.handleCancel}></Modal>
You do not need to wrap the "true" in brackets here as you are not calling a variable.