React Button Click Hiding and Showing Components - reactjs

I have a toggle button that show and hides text. When the button is clicked I want it to hide another component and if clicked again it shows it.
I have created a repl here:
https://repl.it/repls/DapperExtrasmallOpposites
I want to keep the original show / hide text but I also want to hide an additional component when the button is clicked.
How to I pass that state or how do I create an if statement / ternary operator to test if it is in show or hide state.
All makes sense in the repl above!

To accomplish this you should take the state a bit higher. It would be possible to propagate the state changes from the toggle component to the parent and then use it in any way, but this would not be the preferred way to go.
If you put the state in the parent component you can use pass it via props to the needed components.
import React from "react";
export default function App() {
// Keep the state at this level and pass it down as needed.
const [isVisible, setIsVisible] = React.useState(false);
const toggleVisibility = () => setIsVisible(!isVisible);
return (
<div className="App">
<Toggle isVisible={isVisible} toggleVisibility={toggleVisibility} />
{isVisible && <NewComponent />}
</div>
);
}
class Toggle extends React.Component {
render() {
return (
<div>
<button onClick={this.props.toggleVisibility}>
{this.props.isVisible ? "Hide details" : "Show details"}
</button>
{this.props.isVisible && (
<div>
<p>
When the button is click I do want this component or text to be
shown - so my question is how do I hide the component
</p>
</div>
)}
</div>
);
}
}
class NewComponent extends React.Component {
render() {
return (
<div>
<p>When the button below (which is in another component) is clicked, I want this component to be hidden - but how do I pass the state to say - this is clicked so hide</p>
</div>
)
}
}

I just looked at your REPL.
You need to have the visibility state in your App component, and then pass down a function to update it to the Toggle component.
Then it would be easy to conditionally render the NewComponent component, like this:
render() {
return (
<div className="App">
{this.state.visibility && <NewComponent />}
<Toggle setVisibility={this.setVisibility.bind(this)} />
</div>
);
}
where the setVisibility function is a function that updates the visibility state.

Related

NextJS: Replace

I have a div in a Next JS application that displays the currency and price of a product once a user enters a product page.
<div className="flex">
<Image src={EuroCurrency} alt="Euro Sign} />
<h1 className="ml-5>9.800,00</h1>
</div>
Through an onClick event on a button, I want to exchange this div with another, evenly formatted but contextually different, div.
<div>
<Image src={DollarCurrency} alt="Dollar Sign} />
<h1 className="ml-5>9,500.00</h1>
</div>
This div would need to be hidden until the user clicks the aforementioned button.
I'm aware that this would be achieved through a state - but I'm uncertain on how to hide (and exchange) a complete div.
this is how you can use conditional rendering and useState together to switch the component
import React from 'react'
export default function App() {
const [toggle, setToggle] = React.useState(false);
return (
<div className="App">
{toggle ? ( <div >
<h1 >9.800,00</h1>
</div>): (<div><h1>9,500.00</h1></div>)
}
<button onClick={()=>{setToggle(!toggle)}}>Toogle</button>
</div>
);
}
Here you need to change the conditional rendering that suits you like
{toggle ? ( COMPONENT 1 ): ( COMPONENT 2 )}
I'm making a few guesses at what you're asking, but hopefully this example helps.
This is an example of a functional component that uses state to switch between rendering euro and dollars components:
import { useState } from 'react';
function MyAwesomeComponent(){
// expected state values are "dollar" or "euro"
// if you use TypeScript, you can enforce that,
// but I'm just a TypeScript shill :P
// "dollar" is the initial state
const [currency, setCurrency] = useState("dollar");
return(
<div className="flex">
{ currency === "dollar"
? <Image src={DollarCurrency} alt="Dollar Sign" />
: <Image src={EuroCurrency} alt="Euro Sign" />
}
<h1 className="ml-5">9.800,00</h1>
<button onClick={
() => currency === "dollar" ? setCurrency("euro") : setCurrency("dollar")
}
>
Click to Switch Currency
</button>
</div>
)
}
There are plenty of other ways to do it. But notice how, instead of having the whole div rendered conditionally and duplicating code, I just render the specific Image component conditionally. Depending on your use case, you could conditionally render divs instead, any component can go in the two slots of the terney expression.

Reusable Modal Component React Typescript

I have a component which has a button within it, like so -
<Button variant="primary" disabled={checkAccepted} onClick={openModal}>Send</Button>
I would like this button to, when it is active, to open up a modal when clicked. I am unsure how to do this and have been messing around with props but can't seem to figure it out. I also want the modal to be reusable so that any content can be passed in the modal body.I am thinking how do I open up the modal from within my openModal function?
I tried returning it like so -
const openModal = () => {
return (
<Modal>
<ModalBody>*Pass in swappable content here*</ModalBody>
</Modal>
)
}
But that doesn't seem to work. I am sure I am missing something.
You can't return components from an event handler. The way to handle events in react is almost always to alter the state of your application which triggers a re-render. In your case you need to keep track of the open state of your modal.
This can be done either in a controlled way (you keep track of the open state yourself and pass it to your <Modal> component as a prop) or in an uncontrolled way (the <Modal> component manages the open state itself). The second approach requires that you provide e.g. an element to render to your Modal component that acts as a trigger:
const MyModal = ({ children, trigger }) => {
const [modal, setModal] = useState(false);
const toggle = () => setModal(!modal);
return (
<div>
{React.cloneElement(trigger, { onClick: toggle })}
<Modal isOpen={modal} toggle={toggle}>
<ModalBody>{children}</ModalBody>
</Modal>
</div>
);
};
Then you can use it like that:
<MyModal trigger={<Button variant="primary">Send</Button>}>
<p>This is the content.</p>
</MyModal>
Or you can implement it in a controlled way. This is more flexible as it allows you to render the triggering element anywhere:
const MyModal = ({ children, isOpen, toggle }) => (
<div>
<Modal isOpen={isOpen} toggle={toggle}>
<ModalBody>{children}</ModalBody>
</Modal>
</div>
);
Usage Example:
function App() {
const [isOpen, setIsOpen] = useState(false);
const toggle = () => setIsOpen(!isOpen);
return (
<div className="App">
<Button variant="primary" onClick={toggle}>
Send
</Button>
<MyModal isOpen={isOpen} toggle={toggle}>
<p>This is the content.</p>
</MyModal>
</div>
);
}
You should pass the function which triggers the modal to your <Button /> component as prop. Then, in your component, you want to add the onClick event. You can't set an onClick event to the <Button />. It will think of onClick as a prop being passed to <Button />. Within <Button /> you can set the onClick event to an actual <button> element, and use the function which was passed in as a prop on that event.
You can use state to keep track of when the modal button is clicked. Your function can look like: (I am using class based components here, but you can do the same thing with functional components)
buttonClickedHandler = () => {
this.setState({isModalButtonClicked: !this.state.isModalButtonClicked});
}
Then, you can set the Modal component,
<Modal isShow={this.state.isModalButtonClicked} modalButton={this.buttonClickedHandler}>
<div> ...set contents of modal</div>
</Modal>
<button onClick={this.buttonClickedHandler}>Show Modal</button>
So, within the Modal component, you can have something like this:
<React.Fragment>
<Backdrop showModal={this.props.isShow} clicked={this.props.modalButton}/>
{this.props.children}
</React.Fragment>
Backdrop is basically the greyed out background. You can also set an onClick event to listen to when the backdrop is clicked.

How to show a block of collapsible text on click of button

I am trying to implement a collapsible component. I have designed it such as, on click of a button, a block of dynamic text will appear. I made a functional component and using the tags in a class. The name of the component is, CustomAccordion.jsx and using this component in Container.jsx
I have tried to create a button and a function for onClick event.
Part of the CustonAccordion.jsx
const handleToggle = () : string =>{
let content = this.nextElementSibling;
if (content.style.maxHeight){
content.style.maxHeight = null;
}else{
content.style.maxHeight = content.scrollHeight +'px';
}
}
export default function CustomAccordion(props: PropType): React.Component<*> {
const { title, children } = props
return(
<div>
<AccordionButton onClick={() => this.handleToggle()}>{title}</AccordionButton>
<AccordionContent>
<p>{children}
</p>
</AccordionContent>
</div>
)
}
Part of calling Container.jsx
<CustomAccordion title = {this.props.name}>
<p>This is the text passed to component.</p>
</CustomAccordion>
<br />
This does not show the expanded text and it seems that the click event does not work properly. I am very new in react, guessing the syntax might be incorrect.
In react you should generally try to avoid touching DOM directly unless you really have to.
Also you are accessing the handleToggle function wrongly. It should be onClick={() => handleToggle()} because this in your case is window/null and so it has no handleToggle method.
Instead you can use a stateful class component to achieve the same thing.
export default class CustomAccordion extends React.Component {
state = {show: false};
toggle = () => this.setState({show: !this.state.show});
render() {
const {title, children} = this.props;
const {show} = this.state;
return (
<div>
<AccordionButton onClick={this.toggle}>{title}</AccordionButton>
{show && (
<AccordionContent>
<p>{children}</p>
</AccordionContent>
)}
</div>
)
}
}
If you want to have some kind of animation, you can set different className based on the show state instead of adding/removing the elements.

Can't get button component value onClick

I'm sure this is something trivial but I can't seem to figure out how to access the value of my button when the user clicks the button. When the page loads my list of buttons renders correctly with the unique values. When I click one of the buttons the function fires, however, the value returns undefined. Can someone show me what I'm doing wrong here?
Path: TestPage.jsx
import MyList from '../../components/MyList';
export default class TestPage extends React.Component {
constructor(props) {
super(props);
this.state = {};
this.handleButtonClick = this.handleButtonClick.bind(this);
}
handleButtonClick(event) {
event.preventDefault();
console.log("button click", event.target.value);
}
render() {
return (
<div>
{this.props.lists.map((list) => (
<div key={list._id}>
<MyList
listCollection={list}
handleButtonClick={this.handleButtonClick}
/>
</div>
))}
</div>
);
}
}
Path: MyListComponent
const MyList = (props) => (
<div>
<Button onClick={props.handleButtonClick} value={props.listCollection._id}>{props.listCollection.title}</Button>
</div>
);
event.target.value is for getting values of HTML elements (like the content of an input box), not getting a React component's props. If would be easier if you just passed that value straight in:
handleButtonClick(value) {
console.log(value);
}
<Button onClick={() => props.handleButtonClick(props.listCollection._id)}>
{props.listCollection.title}
</Button>
It seems that you are not using the default button but instead some sort of customized component from another libray named Button.. if its a customezied component it wont work the same as the internatls might contain a button to render but when you are referencing the event you are doing it throug the Button component

How to access ref of an element within custom react component

I'm building a Modal component. This component takes modal content as children and the button to trigger the modal as a button prop.
This Modal component should render the button. When clicked it has to position a fixed element exactly on top of that button that then animates to a modal dialog. For this the Modal component needs a ref to the button DOM element to measure it's size and position with getBoundingClientRect.
I want the Modal component to be able to receive through button prop both
button DOM element or a custom React element that renders button.
The api of the component looks like this then
const ModalUser = () => (
<div>
<Modal button={<button>Button</button>}/>
<Modal button={<CustomButton>Button</CustomButton>}/>
</div>
)
The render method of Modal looks like this then
class Modal extends React.PureComponent {
render() {
return (
<div>
{React.cloneElement(this.props.button, {
ref: (el) => { this.button = el && el.button ? el.button : el },
onClick: this.onClick,
})}
<span>top: {this.state.top}</span>
<span>left: {this.state.left}</span>
</div>
);
}
}
And thus requires any CustomElement button to expose this.button as a ref to it's containing button.
class CustomButton extends React.PureComponent {
render() {
return (
<button
ref={(el) => { this.button = el }}
onClick={this.props.onClick}
>
<span>Custom</span>
<span>{this.props.children}</span>
</button>
)
}
}
For me this feels not optimal, but it works. I feel like there should be a more elegant solution to this. Does anyone have a suggestion how to do this better.
Here is a working demo
Codepen

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