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How to target DOM and change style in react with mapped elements

I have a multi page form that renders a list of buttons for each possible answer.
I am currently using getElementByID to change the button style when a button is clicked. I think this is not considered good practice in react.
can I use the useRef hook to target the DOM element and change its style instead of using getElementByID if the buttons are dynamically displayed with map?
{answers.map((answer, count = 0) => {
return (
<Button
key={count}
id=`button${count}`
onClick={(e) => {
document.getElementById(`${e.currentTarget.id}`).style.color = "white";
}}
>
<ButtonTitle>{answer.name}</ButtonTitle>
</Button>
);
})}
(animations on safari are breaking the active style, so I can't use the active pseudo element)

You can do this by adding a new state and toggle active class by that state.
Code something like this.
const [activeindex, setActiveIndex] = useState("");
return(
<>
{answers.map((answer, count = 0) => {
return (
<Button
key={count}
className={count==activeindex?"acvie":""}
onClick={(e) => {
setActiveIndex(count)
}}
>
<ButtonTitle>{answer.name}</ButtonTitle>
</Button>
);
})}
}
</>
And use .active class in css file.

Get getAttribute from button and toggle class name to body react hooks

i want to improve my code, with several buttons that has custom class names (attr), when clicked should add to body tag (toggle), now is adding the first button only because for ("button")[0] but should work for each button
import React, { useState, useEffect } from "react"
function Test() {
const [isClass, setIsClass] = useState(false)
useEffect(() => {
const x = document.getElementsByTagName("button")[0].getAttribute("custom-class")
document.body.classList.toggle(x, isClass)
}, [isClass])
return (
<>
<button custom-class='test1' onClick={() => setIsClass(!isClass)}>
Setting test1 className
</button>
<button custom-class='test2' onClick={() => setIsClass(!isClass)}>
Setting test2 className
</button>
</>
)
}
export default Test
Thanks

Please use this code.
let oldStyle = "";
const handleClick = (index) => {
const x = [...document.getElementsByTagName("button")].map(value => value.getAttribute("custom-class"));
document.body.classList.contains(x[index]) ? document.body.classList.remove(x[index]) : document.body.classList.add(x[index]);
if(document.body.classList.length > 1) document.body.classList.replace(oldStyle, x[index]);
oldStyle = x[index];
}
return (
<>
<button custom-class='test1' onClick={() => handleClick(0)}>
Setting test1 className
</button>
<button custom-class='test2' onClick={() => handleClick(1)}>
Setting test2 className
</button>
</>
)

It is better not to use DOM querying and manipulation directly with elements that are created and controlled by react. In your particular example it is ok to use document.body, but not ok to search for buttons, especially when you try to find them by tag name. To actually toggle a class in classList you don't need second parameter in most cases, so additional state is also not needed.
React way to get reference to element renderend by React would be to use Ref. However, in your particular case side effect can be launched inside event handler, so you don't need useEffect or useRef.
Your onClick handler can accept event object that is Synthetic Event. It holds property target that holds reference to your button.
So, the easiest way would be simply to write like this:
function Test() {
function clickHandler(event) {
let classToToggle = event.target.getAttribute("custom-class");
document.body.classList.toggle(classToToggle);
}
return (
<>
<button key="test1" custom-class="test1" onClick={clickHandler}>
Setting test1 className
</button>
<button key="test2" custom-class="test2" onClick={clickHandler}>
Setting test2 className
</button>
</>
);
}
export default Test;
If you need to have only single className from the list, you can decide which class to enable or disable with a bit of a state. Since anything can add classes on body it might be useful to operate only on some set of classes and not remove everything.
Also, not mentioned before, but consider using data attribute as its purpose is to keep some additional data.
function Test() {
// this can come from props or be hardcoded depending on your requirements
// If you intend to change it in runtime, consider adding side effect to cleanup previous classes on body
let [classesList] = React.useState(["test1", "test2"]);
let [activeClass, setActiveClass] = React.useState("");
// You can switch actual classes in effect, if you want to
function clickHandler(event) {
let classToToggle = event.target.dataset.customClass;
// we remove all classes from body that are in our list
document.body.classList.remove(...classesList);
if (activeClass === classToToggle) {
setActiveClass("");
} else {
// if class not active - set new one
document.body.classList.add(classToToggle);
setActiveClass(classToToggle);
}
}
return (
<>
{classesList.map((cn) => (
<button key="cn" data-custom-class={cn} onClick={clickHandler}>
Setting {cn} className
</button>
))}
</>
);
}

How to scroll beyond the focused element in React

I am working on a React App, and using antd as the UI-library. What I intend to do is whenever a button named Open Modal is clicked, a Modal will open up, and when user clicks on the Ok button in the modal, an input field will be displayed and page should automatically be scrolled to the top. However, since the input field contains focus, the scroll happens only until the input field becomes visible. Is there any way to make the page scroll to top, ignoring focused elements using JS only. This is the minimal code to reproduce the example:
const App = () => {
const [isModalVisible, setIsModalVisible] = useState(false);
const [isInputVisible, setIsInputVisible] = useState(false);
const showModal = () => {
setIsModalVisible(true);
};
const handleOk = () => {
setIsInputVisible(true);
window.scroll(0, 0);
};
const handleCancel = () => {
setIsInputVisible(false);
setIsModalVisible(false);
};
return (
<>
<Button type="primary" onClick={showModal}>
Open Modal
</Button>
<Modal
title="Basic Modal"
visible={isModalVisible}
onOk={handleOk}
onCancel={handleCancel}
>
/*Some contents...*/
{isInputVisible && <input autoFocus />}
/*Some contents...*/
</Modal>
</>
);
};
This is the sandbox link to reproduce the use-case.
Code Sandbox

You can always use scrollIntoView method.
scrollIntoView
I tried with ref and useRef but it didnt work, so the other solution was to find the modal through it's class name and use the above method.
Check this
sandbox

I am not sure if it will work but I think you can work your way through with the useRef hook where you can focus after the click event. Refer this

Not able to display "Modal" for respective "viewmore" button

In app.js while displaying Modal clicking "view more" button for respective person, can see data in modal only for the last person.
link:-https://codesandbox.io/s/lucid-tree-kjoim?file=/src/App.js

There is a single instance of the modal in the DOM (typically managed through a react portal), so when you map each person and create a modal, the last one set wins out. You can refactor the code to render just a single Modal and set the person you want displayed in it.
/**
* Manage modal instance
*/
const [selectedPerson, setSelectedPerson] = useState({});
const openModal = person => {
setSelectedPerson(person);
toggleModal(true);
};
const closeModal = () => {
setSelectedPerson({});
toggleModal(false);
};
In the mapping on the button's onClick handler you want to call openModal to set the person and open state.
.map(person => {
return (
<Col sm="4">
<EmployeeCard key={person.id} person={person} />
<button onClick={() => openModal(person)}>VIEW MORE</button>
</Col>
);
});
Move the Modal to end of the render function and use the selectedPerson object and closeModal callback.
<Modal isOpen={isModalOpen} toggle={toggleModal}>
<h1>
NAME: {selectedPerson.firstName} {selectedPerson.lastName}
</h1>
<h3>AGE: {selectedPerson.age}</h3>
<p>{selectedPerson.bio}</p>
<button onClick={closeModal}>CLOSE</button>
</Modal>

What's the correct pattern to change parent state inside a child state in React?

Imagine I have a page "Parent" which conditionally renders a div "Child".
On the click of a button, "Child" opens. To close "Child" one has to click in a X button inside it.
This is how I would do it and in my opinion it looks clean.
const Parent = (props) => {
const [childVisible, setChildVisible] = useState(false);
return (
<>
{childVisible && <Child close={setChildVisible.bind(false)} />}
<button onClick={setChildVisible.bind(true)}>
Open Child
</button>
</>
)
}
const Child = (props) => {
return (
<div>
<p>Im Child</p>
<button onClick={props.close()}> X </button>
</div>
)
}
Since react v16.13.0 react has introduced a warning Warning: Cannot update a component from inside the function body of a different component. and it seems I can't do this anymore.
What's the correct pattern now? I would rather not have a state in both components stating the same thing.

Call back was not properly added .You could do like this onClick={props.close}
While use onClick={props.close()} like this. close() function run on child mount instead of click event
const Child = (props) => {
return (
<div>
<p>Im Child</p>
<button onClick={props.close}> X </button>
</div>
)
}