i have react carousel in the functional component , i am trying to change that component in to class component.. can any one help on this..
this is the link of code sand box....https://codesandbox.io/s/suspicious-cookies-fvm80?file=/src/App.js
functional component
import React, { useState } from 'react';
import ItemsCarousel from 'react-items-carousel';
export default () => {
const [activeItemIndex, setActiveItemIndex] = useState(0);
const chevronWidth = 40;
return (
<div style={{ padding: `0 ${chevronWidth}px` }}>
<ItemsCarousel
requestToChangeActive={setActiveItemIndex}
activeItemIndex={activeItemIndex}
numberOfCards={2}
gutter={20}
leftChevron={<button>{'<'}</button>}
rightChevron={<button>{'>'}</button>}
outsideChevron
chevronWidth={chevronWidth}
>
<div style={{ height: 200, background: '#EEE' }}>First card</div>
<div style={{ height: 200, background: '#EEE' }}>Second card</div>
<div style={{ height: 200, background: '#EEE' }}>Third card</div>
<div style={{ height: 200, background: '#EEE' }}>Fourth card</div>
</ItemsCarousel>
</div>
);
};
Wrap jsx in render() method, change useState hook to destruct from this.state, and create function for setting state.
Example
export default class carousel extends Component {
constructor(props) {
super();
this.state = {
activeItemIndex:0
};
}
setActiveItemIndex = (value) => {
this.setState({ activeItemIndex: value });
}
render() {
const { activeItemIndex } = this.state;
const chevronWidth = 40;
return (
<div style={{ padding: `0 ${chevronWidth}px` }}>
<ItemsCarousel
requestToChangeActive={this.setActiveItemIndex}
activeItemIndex={activeItemIndex}
numberOfCards={2}
gutter={20}
leftChevron={<button>{"<"}</button>}
rightChevron={<button>{">"}</button>}
outsideChevron
chevronWidth={chevronWidth}
>
<div style={{ height: 200, background: "#EEE" }}>First card</div>
<div style={{ height: 200, background: "#EEE" }}>Second card</div>
<div style={{ height: 200, background: "#EEE" }}>Third card</div>
<div style={{ height: 200, background: "#EEE" }}>Fourth card</div>
</ItemsCarousel>
</div>
);
}
}
Related
I am working on a food app that adds items to a cart then calculates the total amount. I am trying to implement a reducer as opposed to having multiple instances of state hooks and I am running into this error when trying to click open my cart modal.
I know the items are being added successfully to the cart because when I add them, then inspect in the console and remove the "display: none " property from my modal and see the added food items there. For some reason its specifically when I click my cart to see the modal is when I receive the error.
The error message is saying the error is located in my app.js file where I assign define the cartFoods prop to my Cartmodal component
App.js Component
import logo from "./logo.svg";
import "./App.css";
import NavHeader from "./NavHeader";
import { useState, useEffect, useReducer } from "react";
import FoodList from "./FoodList";
import CartModal from "./CartModal";
import "animate.css";
function App() {
const [foods, setFoods] = useState([
{
food: "sushi roll",
description: "fresh tuna topped with eel sauce and avocado",
price: "14.99",
quantity: 1,
},
{
food: "pizza",
description: "baked to a crisp with mozarrella, basil and tomato sauce",
price: "9.99",
quantity: 1,
},
{
food: "special fried rice",
description: "cooked with onions , shrimp , chicken",
price: "19.99",
quantity: 1,
},
{
food: "tacos",
description:
"choice of either ,shrimp , chicken, or steak, topped with pico de gallo",
price: "15.99",
quantity: 1,
},
]);
const [totalFoodAmount, setTotalFoodAmount] = useState(0);
// const [modalDisplay, setModalDisplay] = useState("none");
const [totalPrice, setTotalPrice] = useState(0);
const [cartFoods, setCartFoods] = useState([]);
const [cartItem, setCartItem] = useState({});
const [modalDisplay, setModalDisplay] = useState("none");
const [amountValue, setAmountValue] = useState(0);
function foodReducer(state, action) {
if (action.type === "ADD_CART_ITEMS") {
return { cartFoodItems: state.cartFoodItems.concat(action.val) };
}
}
const [foodState, dispatch] = useReducer(foodReducer, {
modalDisplay: "none",
totalFoodPrice: 0,
cartFoodItems: [],
});
function setDisplay() {
dispatch({ type: "ADD_MODAL_DISPLAY" });
setModalDisplay("flex");
}
function removeModal() {
dispatch({ type: "REMOVE_MODAL_DISPLAY" });
setModalDisplay("none");
}
function setQuantity(e) {
console.log(e.target.value);
setAmountValue(e.target.value);
}
function addFood(food) {
console.log(food);
let newFoodItem = { ...food, quantity: amountValue };
// setCartFoods((prevState) => cartFoods.concat(newFoodItem));
dispatch({ type: "ADD_CART_ITEMS", val: newFoodItem });
// ask slavo specific question on why state doesnt update right away when you console.log(cartFoods) inside the function
}
useEffect(() => {
let total = foodState.cartFoodItems.reduce(function (a, b) {
return a + Number(b.quantity);
}, 0);
setTotalFoodAmount(total);
foodState.cartFoodItems.map((food) =>
setTotalPrice(totalPrice + food.price * food.quantity)
);
}, [foodState]);
return (
<div className="App">
<NavHeader cartQuantity={totalFoodAmount} setDisplay={setDisplay} />
<FoodList foodList={foods} addFood={addFood} setAmount={setQuantity} />
<CartModal
cartFoods={foodState.cartFoodItems}
display={modalDisplay}
closeModal={removeModal}
totalPrice={totalPrice}
/>
</div>
);
}
export default App;
Cart.js component
import React from "react";
export default function Cart(props) {
return (
<div
style={{
display: "flex",
marginRight: "35px",
border: "1px solid lightgray",
padding: "5px",
borderRadius: "5px",
margin: "10px",
}}
className="cart-section"
onClick={props.setDisplay}
>
<div style={{ marginRight: "20px" }}>
<h4>Your Cart</h4>
</div>
<div style={{ position: "relative", top: "0vh" }}>
<h4>Quantity: {props.cartQuantity}</h4>
</div>
</div>
);
}
CartModal.js
import React from "react";
import "animate.css";
import { CSSTransition } from "react-transition-group";
export default function CartModal(props) {
return (
<div
style={{
background: "#000000a6",
width: "100vw",
height: "100vh",
position: "fixed",
top: "0",
left: "0",
overflow: "scroll",
display: props.display,
justifyContent: "center",
alignItems: "center",
}}
>
<div
style={{
background: "white",
padding: "30px",
minHeight: "60vh",
minWidth: "75vw",
borderRadius: "10px",
}}
className="cart-modal"
>
<div style={{ display: "flex", justifyContent: "flex-end" }}>
<h3 onClick={props.closeModal}>x</h3>
</div>
<h4 style={{ textAlign: "center" }}>Your Cart</h4>
{props.cartFoods.length === 0 ? (
<h1>There are no Items in your cart</h1>
) : (
props.cartFoods.map((food, index) => (
<div
style={{
display: "flex",
justifyContent: "space-between",
borderBottom: "2px solid lightgray",
}}
key={index}
>
<div style={{ width: "10vh" }}>
<h3>{food.food}</h3>
<p>{food.price}</p>
<p>Quantity: {food.quantity}</p>
</div>
<div style={{ display: "flex" }}>
<button style={{ margin: "10px", maxHeight: "20px" }}>-</button>
<button style={{ margin: "10px", maxHeight: "20px" }}>+</button>
</div>
</div>
))
)}
<h2>Price: ${props.totalPrice}</h2>
</div>
</div>
);
}
I'm trying to use setState to access my css const mystyle object to change the background color on the squares from blue to red but everytime the button is pressed. It seems everytime I press the button the Setstate does not render on screen any advice or help? Would be greatly appreciated
class MyHeader extends React.Component {
constructor(props){
super(props)
this.state = {backgroundColor: 'blue'};
}
render() {
const mystyle = {
borderRadius: "10px",
background: this.state.backgroundColor,
padding: "10px",
width: "100px",
height: "100px",
marginTop: "10px",
lineHeight: "80px",
color: "dimGrey",
fontWeight: "bold",
fontSize: "3em",
textAlign: "center"
};
function State() {
this.setState({backgroundColor: 'red'})
}
return (
<div>
<h1 style={mystyle}></h1>
<h1>{this.state.backgroundColor}</h1>
</div>
);
}
}
function Test() {
function Test2() {
setchange(change + Math.floor(Math.random() * 10));
if(change > 20) {
setchange(change + Math.floor(Math.random() - 10))
}
}
const [change, setchange] = React.useState(1)
return (
<div>
<h1>click the button to randomize colors</h1>
<button onClick={this.State}>Randomize colors!</button>
<div className='.flex-item'></div>
<h1>{change}</h1>
<div className="flex-item"></div>
<MyHeader />
<MyHeader />
</div>
);
}
ReactDOM.render(<Test />, document.getElementById("root"));
my codepen link to the code
The main issue is trying to do something where the child component, MyHeader, has the function to change state, but trying to invoke it from the parent component, Test. It's just simpler to pass the color as a prop from Test to MyHeader.
Alternatively, you can do the useContext thing, but I think this is easier. I've stripped out all superfluous code that wasn't getting used. You can of course, add them back as you need to.
const MyHeader = ({backgroundColor}) => {
const mystyle = {
borderRadius: "10px",
background: backgroundColor,
padding: "10px",
width: "100px",
height: "100px",
marginTop: "10px",
lineHeight: "80px",
color: "dimGrey",
fontWeight: "bold",
fontSize: "3em",
textAlign: "center"
};
return (
<div>
<h1 style={mystyle}></h1>
<h1>{backgroundColor}</h1>
</div>
);
}
}
const Test = (props) => {
const [backgroundColor, setBackgroundColor] = useState("blue");
const onButtonClick = () => {
setBackgroundColor("red");
}
return (
<div>
<h1>click the button to randomize colors</h1>
<button onClick={onButtonClick}>Randomize colors!</button>
<div className='.flex-item'></div>
<h1>{change}</h1>
<div className="flex-item"></div>
<MyHeader backgroundColor={backgroundColor} />
</div>
);
};
I have an instagram widget thas uses iframe, but when I switch between routes, the widget loads too slow and does'nt have time to render properly.
Can You tell me, how to set delay rendering of the component, jr another solution to this problem?
Here is the component:
import React, { Component } from 'react';
const divStyle = [
{
border: 'none',
overflow: 'hidden',
width: '100%'
},
{
font: "10px/14px 'Roboto','Helvetica Neue',Arial,Helvetica,sans-serif",
fontWeight: '400',
width: '100%',
textAlign: 'right'
},
{
color: '#777',
textDecoration: 'none'
}
];
class Instagram extends Component {
render() {
return (
<div id="instagram">
<iframe src="https://snapwidget.com/embed/711808" className="snapwidget-widget" allowtransparency="true" frameborder="0" scrolling="no" style={divStyle[0]}></iframe>
</div>
);
}
}
export default Instagram;
Also the code is located in the CodeSandbox.
Thanks for any help!
This can be possible solution from your code sandbox.
NOTE: Please Replace your loader with loading div.
CodeSandbox: https://codesandbox.io/s/damp-platform-950yw
import React, { Component } from "react";
const divStyle = [
{
border: "none",
overflow: "hidden",
width: "100%"
},
{
font: "10px/14px 'Roboto','Helvetica Neue',Arial,Helvetica,sans-serif",
fontWeight: "400",
width: "100%",
textAlign: "right"
},
{
color: "#777",
textDecoration: "none"
}
];
class Instagram extends Component {
state = {
loading: true
}
handelOnLoad = () => {
this.setState({
loading: false
})
}
render() {
return (
<>
{this.state.loading && <div style={{
position: "fixed",
background: "rgba(0,0,0,0.7)",
top: 0,
bottom: 0,
right: 0,
left: 0,
color: "#fff"
}}>Loading</div>}
<div id="instagram">
<iframe
src="https://snapwidget.com/embed/711808"
className="snapwidget-widget"
allowtransparency="true"
frameborder="0"
scrolling="no"
style={divStyle[0]}
onLoad={this.handelOnLoad}
/>
</div>
</>
);
}
}
export default Instagram;
You can make use of state to render,
class Instagram extends Component {
state={
show: false
}
componentDidMount(){
setTimeout(()=>{
this.setState({show: true})
},5000) //runs after 5sec
}
render() {
return (
<div id="instagram">
{ this.state.show && <iframe src="https://snapwidget.com/embed/711808" className="snapwidget-widget" allowtransparency="true" frameborder="0" scrolling="no" style={divStyle[0]}></iframe> }
</div>
);
}
}
I'm creating a React widget and using the react-jss HOC for styling. The widget is just a small part of a larger page, and I want to be able to signal it to open or close with a button on another part of the page outside of the React render. Originally I was doing it like this:
var modal = ReactDOM.render(<Modal />, document.getElementById('widget'))
// Inside an onClick function
modal.toggleModal()
That was before JSS, but now widget doesn't return the component, it returns the JSS HOC. I've tried passing <Widget /> a prop and updating that and then using widget.forceUpdate() but that did nothing. Not really sure what else to try at this point. I'm currently just toggling everything outside of React, but I want the component to be able to close itself as well.
import React, { Component } from 'react'
import injectSheet from 'react-jss'
const styles = {
show: {
display: 'block',
},
modal: {
display: 'none',
background: 'rgba(0, 0, 0, 0.3)',
position: 'fixed',
top: 0,
left: 0,
bottom: 0,
right: 0,
width: '100%',
height: '100%',
},
form: {
maxWidth: '440px',
margin: '15px',
padding: '30px',
background: '#fff',
position: 'fixed',
top: '50%',
left: '50%',
transform: 'translate(-50%, -50%)'
},
input: {
width: '100%',
marginBottom: '15px'
},
button: {
width: '100%'
}
}
class Modal extends Component {
constructor(props) {
super(props)
this.state = {
show: false
}
this.toggleModal = this.toggleModal.bind(this)
}
toggleModal() {
this.setState({show: !this.state.show})
}
render() {
const { classes } = this.props
return (
<div className={`${classes.modal} ${this.state.show ? classes.show : ''}`}>
<form className={classes.form}>
<label htmlFor="aatitle-field">Title</label>
<input className={classes.input} type="text" id="aatitle-field" name="title" value="" />
<button className={`btn ${classes.button}`}>Save</button>
</form>
</div>
)
}
}
export default injectSheet(styles)(Modal)
First of all, please use the classnames library to generate classNames, it's so more elegant.
Secondly, classes are applied in order they are parsed by the brower. So what you're doing is tricky. How can we know if the modal class is parsed before show? (This is a requirement in your current code). You can simply move the modal declaration before the show declaration in styles and surely this will work, but this is a fragile solution. Better is to use a show and hide class and apply them according the state. This removes the dependency of which style class is loaded first. So remove display:none from modal and introduce hide:
Something like:
import React, { Component } from 'react'
import injectSheet from 'react-jss'
const styles = {
show: {
display: 'block',
},
hide: {
display: 'none',
},
modal: {
background: 'rgba(0, 0, 0, 0.3)',
position: 'fixed',
top: 0,
left: 0,
bottom: 0,
right: 0,
width: '100%',
height: '100%',
},
form: {
maxWidth: '440px',
margin: '15px',
padding: '30px',
background: '#fff',
position: 'fixed',
top: '50%',
left: '50%',
transform: 'translate(-50%, -50%)'
},
input: {
width: '100%',
marginBottom: '15px'
},
button: {
width: '100%'
}
}
class Modal extends Component {
constructor(props) {
super(props)
this.state = {
show: false
}
this.toggleModal = this.toggleModal.bind(this)
}
toggleModal() {
this.setState({show: !this.state.show})
}
render() {
const { classes } = this.props
return (
<div className={`${classes.modal} ${this.state.show ? classes.show : classes.hide}`}>
<form className={classes.form}>
<label htmlFor="aatitle-field">Title</label>
<input className={classes.input} type="text" id="aatitle-field" name="title" value="" />
<button className={`btn ${classes.button}`}>Save</button>
</form>
</div>
)
}
}
export default injectSheet(styles)(Modal)
```
I am trying React MobX on hover over a list item. Here is my code
export default observer(
class SidebarContent extends React.Component {
constructor(props) {
super(props);
}
componentWillMount() {
this.props.store.fetchSources()
}
toggleHover(){
this.props.store.hover = !this.props.store.hover;
}
getArticles(src) {
this.props.store.fetchArticles(src);
}
render() {
const style1 = this.props.style ? {...styles.sidebar, ...this.props.style} : styles.sidebar;
const { sources, hover } = this.props.store
var linkStyle;
if (this.props.store.hover) {
linkStyle = {backgroundColor: 'black'}
} else {
linkStyle = {backgroundColor: 'white'}
}
const links = sources.map( (src,index) => (
<a key={index} href='javascript:;' style={styles.sidebarLink} onClick={this.getArticles.bind(this, src.id)} >
<span style={linkStyle} onMouseEnter={this.toggleHover.bind(this)} onMouseLeave={this.toggleHover.bind(this)} >
<img className="ui-avaatar image" src='{ src.urlsToLogos.small }' />
<span className="side-news-item"> {src.name} </span>
</span>
</a>
))
return (
<MaterialTitlePanel title="Menu" style={style1}>
<div style={styles.content}>
<div style={styles.divider} />
{links}
</div>
</MaterialTitlePanel>
);
}
}
);
const styles = {
sidebar: {
width: 256,
height: '100%',
},
sidebarLink: {
display: 'block',
padding: '16px 0px',
color: '#757575',
textDecoration: 'none',
},
divider: {
margin: '8px 0',
height: 1,
backgroundColor: '#757575',
},
content: {
padding: '16px',
height: '100%',
backgroundColor: 'white',
},
};
this.props.store.hover is a observable.
The problem is that when mouse over one item, all of the items get the hover effect. What did I do wrong?
Do not set Component's props directly, set it on upper Component.
or you could use state feature, and always use setState() to change state.
write an subcomponent to control the Button State
code below maybe help
class SidebarContent extends React.Component {
constructor(props) {
super(props);
}
componentWillMount() {
this.props.store.fetchSources()
}
getArticles(src) {
this.props.store.fetchArticles(src);
}
render() {
const links = sources.map( (src,index) => <Button />);
return (
<MaterialTitlePanel title="Menu" style={style1}>
<div style={styles.content}>
<div style={styles.divider} />
{links}
</div>
</MaterialTitlePanel>
);
}
}
class Button extends React.Component {
toggleHover(){
this.setState({
hover: !this.state.hover,
});
}
render() {
const style1 = this.props.style ? {...styles.sidebar, ...this.props.style} : styles.sidebar;
const { sources } = this.props.store
const { hover } = this.state;
var linkStyle;
if (hover) {
linkStyle = {backgroundColor: 'black'}
} else {
linkStyle = {backgroundColor: 'white'}
}
return (
<a key={index} href='javascript:;' style={styles.sidebarLink} onClick={this.getArticles.bind(this, src.id)} >
<span style={linkStyle} onMouseEnter={this.toggleHover.bind(this)} onMouseLeave={this.toggleHover.bind(this)} >
<img className="ui-avaatar image" src='{ src.urlsToLogos.small }' />
<span className="side-news-item"> {src.name} </span>
</span>
</a>
);
}
}
const styles = {
sidebar: {
width: 256,
height: '100%',
},
sidebarLink: {
display: 'block',
padding: '16px 0px',
color: '#757575',
textDecoration: 'none',
},
divider: {
margin: '8px 0',
height: 1,
backgroundColor: '#757575',
},
content: {
padding: '16px',
height: '100%',
backgroundColor: 'white',
},
};
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>