Develop Reference

Issues rendering the right dashboard UI user based on roles

I am trying to render UI in my project based on selected roles (brands, agency, influencer) on click. However, the logic that I am putting together is not loading the right UI and I don't quiet understand why not.
I have tried moving the role and setRole to the top component and passed the props down to the child components that read role and updated it via setRole so that I can have the state to be available in two places.
I also set a logic that should display components based on if the role equals the value of the buttons.
What happened was the components weren't loading upon clicking the function that handles click. However, logging out to the console if the role equals the value of the clicked button returns true, the right string that the logic was based on.
What I am expecting to happen is to load the component e.g: "Brands" when users click and select "brands" which is the value of the clicked button. Vise versa for the other components.
My code is as follows:
import { useState } from 'react';
import { useSession } from 'next-auth/react';
import Brands from './Brands';
import Agency from './Agency';
import CreatorsDash from './CreatorsDashboard';
export default function FirstPageModal({ role: userRole }) {
const [role, setRole] = useState(userRole);
const { data: session } = useSession();
const handleClick = (e) => {
e.preventDefault();
let buttonValue = e.target.value;
const clickedRole = role?.map((user) => {
let { role } = user;
if (buttonValue) {
userRole = { role: buttonValue };
}
return { userRole };
});
console.log(clickedRole); //Returns an array
clickedRole.map((item) => {
const { role } = item.userRole;
console.log(role); //Returns string ("agency" / "brands" / "Influencer")
if (session && role === 'brands') {
console.log(role); //This logs "brands" as expected but doesn't return the component
// return <Brands session={session} role={role} />;
} else if (session && role === 'agency') {
return <Agency session={session} role={role} />;
} else if (session && role === 'Influencer') {
return <CreatorsDash session={session} role={role} />;
} else {
console.log('Select a role');
}
});
};
return (
<>
<div className="">
<button type="button" className="" onClick={handleClick} value="agency">
As an Agency
</button>
<button type="button" className="" onClick={handleClick} value="brands">
As a Brand
</button>
<button
type="button"
className=""
onClick={handleClick}
value="Influencer"
>
As an Influencer
</button>
</div>
</>
);
}

Returning a component from an onClick handler doesn't automatically render the component. One thing you could do is to keep track of the role in the state and then put the <Brands /> <Agency/> and <CreatorsDash /> components in the render function and dynamically show/hide them like {role === "brands" && <Brands />. This can also be done with css, although the benefits of this are not so clear,.
Side note, it is very helpful to post a codepen with your code, especially as your code gets more complicated

React render previous values during conditional fade out animation

I am using react-transition-group to fade out various components. I'm converting simple conditional renders such as:
{valueToDisplay && <MyComponent {...valueToDisplay} />}
To transitions such as:
<CSSTransition
in={!!valueToDisplay}
unmountOnExit
classNames="fade"
addEndListener={(node, done) => node.addEventListener("transitionend", done, false)}
>
<MyComponent {...valueToDisplay} />
</CSSTransition>
The issue I'm running into is when the "in" property of the transition becomes false, and the exit transition is running, the child component will now have null prop values. This can cause exceptions or cause the child content to flash and change during the exit. What I would like to see instead is that during the exit transition, the content will remain unchanged.
The first solution I came up with was to make child components to cache previous values of their props, and then use those previous values when their props become null. However I don't like this solution because it forces all components which will be transitioned to introduce new and confusing internal logic.
The second attempt I made was to create a wrapper component which cached the previous value of props.children, and whenever "in" becomes false, renders the cached children instead. This essentially "freezes" the children as they were the last time in was true, and they don't change during the exit transition. (If this solution is the general practice, is there a better way of doing this, perhaps with the useMemo hook?)
For such a common use case of fading content out, this solution doesn't seem very intuitive. I can't help but feeling I'm going about this the wrong way. I can't really find any examples of having to cache/memoize content to keep it displaying during fade outs. It seems like something somewhere has to remember the values to display when performing the exit transition. What am I missing?
Here is a minimal example and working example:
import { useRef, useEffect, useState } from 'react';
import { createRoot } from 'react-dom/client';
import { CSSTransition } from 'react-transition-group';
const Pet = ({ type, age }) => {
return (
<div>
Your pet {type || 'null'} is age {age || 'null'}
</div>
);
};
const Fade = ({ show, children }) => {
const nodeRef = useRef(null);
return (
<CSSTransition
nodeRef={nodeRef}
in={show}
unmountOnExit
classNames="fade"
addEndListener={(done) => nodeRef.current.addEventListener("transitionend", done, false)}
>
<span ref={nodeRef}>
{children}
</span>
</CSSTransition>
);
};
const FadeWithMemo = ({ show, children }) => {
const previousChildren = useRef();
useEffect(() => {
previousChildren.current = show ? children : null;
}, [show, children]);
return (
<Fade show={show}>
{show ? children : previousChildren.current}
</Fade>
);
};
const Example = () => {
const [currentPet, setCurrentPet] = useState(null);
const getPet = () => {
return {
type: (Math.random() > .5) ? 'Cat' : 'Dog',
age: Math.floor(Math.random() * 15) + 1
};
};
return (
<>
<button onClick={() => setCurrentPet(getPet())}>Set</button>
<button onClick={() => setCurrentPet(null)}>Clear</button>
<div>
The Problem:
<Fade show={!!currentPet}>
<Pet {...currentPet} />
</Fade>
</div>
<div>
Potential Fix:
<FadeWithMemo show={!!currentPet}>
<Pet {...currentPet} />
</FadeWithMemo>
</div>
</>
);
};
const root = createRoot(document.getElementById('root'));
root.render(<Example />);

You can detach the visible condition from the pet state so that you have more granular control over whether something is visible and what is actually being displayed.
const Example = () => {
const [currentPet, setCurrentPet] = useState(null);
const [showPet, setShowPet] = useState(false);
const getPet = () => {
return {
type: (Math.random() > .5) ? 'Cat' : 'Dog',
age: Math.floor(Math.random() * 15) + 1
};
};
return (
<>
<button onClick={() => {
setCurrentPet(getPet());
setShowPet(true);
}}>Set</button>
<button onClick={() => setShowPet(false)}>Clear</button>
<div>
<Fade show={showPet}>
<Pet {...currentPet} />
</Fade>
</div>
</>
);
};
or you can have the visible be part of the pet state and only set that part to false.

how to keep the last component styles?

i'm building a to-do app using React Js . inside the task component i used a state to apply a certain styles for the completed task and it works fine . but , after i cliked any delete button the style of the completed task deleted . how can i prevent that ?
import Task from "../Task/Task";
import style from "./TasksList.module.css";
const TasksList = ({ tasks, deleteTaskHandler }) => {
return (
<div className={style.tasks}>
<div className="container">
{tasks.map((task, idx) => {
return (
<Task
task={task}
id={idx}
key={Math.random()}
deleteTaskHandler={deleteTaskHandler}
/>
);
})}
</div>
</div>
);
};
export default TasksList;
import { useState } from "react";
import style from "./Task.module.css";
const Task = ({ task, id, deleteTaskHandler }) => {
const [isComplete, setIsComplete] = useState(false);
const markComplete = () => {
setIsComplete(!isComplete);
};
return (
<div
className={
isComplete ? `${style.task} ${style.completed}` : `${style.task}`
}
onClick={markComplete}
>
<label>{task.desc}</label>
<button onClick={() => deleteTaskHandler(id)}> Delete </button>
</div>
);
};
export default Task;

How are you maintaining the complete status of task in higher components?
Currently you are not initializing the complete state of Task.
If the task object contains the isComplete property, then you can use as shown below
const [isComplete, setIsComplete] = useState(task.isComplete);
however, you also need to update value of completed in task. So, I would suggest to have all lower components as stateless. and maintain the state at Higher component i.e. TaskList
import style from "./Task.module.css";
const Task = ({ task, id, deleteTaskHandler, setTaskCompleteHandler }) => {
const markComplete = () => {
setTaskCompleteHandler(!task.isComplete);
};
return (
<div
className={
task.isComplete ? `${style.task} ${style.completed}` : `${style.task}`
}
onClick={markComplete}
>
<label>{task.desc}</label>
<button onClick={() => deleteTaskHandler(id)}> Delete </button>
</div>
);
};
export default Task;
Implement setTaskCompleteHandler in TaskList and pass is as prop as part of Task component reandering.

Your problem is in position of your delete button, that wrapped by div with makrComplete handler, so then you click on your delete button, markComplete fired too, so your isComplete changed and styles deleted.
To prevent this behavor, you can do a little trick with prevent default. So, try to wrap your deleteTaskHandler in another function like that:
const deleteButtonClickHandler = (e) => {
e.preventDefault();
e.stopPropagation();
deleteTaskHandler(id)
}
and your delete button makrdown should be look like this:
<button onClick={deleteButtonClickHandler}> Delete </button>

How to save a component state after re-rendering? React js

There are some movie cards that clients can click on them and their color changes to gray with a blur effect, meaning that the movie is selected.
At the same time, the movie id is transferred to an array list. In the search bar, you can search for your favorite movie but the thing is after you type something in the input area the movie cards that were gray loses their style (I suppose because they are deleted and rendered again based on my code) but the array part works well and they are still in the array list.
How can I preserve their style?
Search Page:
export default function Index(data) {
const info = data.data.body.result;
const [selectedList, setSelectedList] = useState([]);
const [searchTerm, setSearchTerm] = useState('');
return (
<>
<main className={parentstyle.main_container}>
<NavBar />
<div className={style.searchbar_container}>
<CustomSearch
onChange={(e) => {
setSearchTerm(e.target.value);
}}
/>
</div>
<div className={style.card_container}>
{info
.filter((value) => {
if (searchTerm === '') {
return value;
} else if (
value.name
.toLocaleLowerCase()
.includes(searchTerm.toLocaleLowerCase())
) {
return value;
}
})
.map((value, key) => {
return (
<MovieCard
movieName={value.name}
key={key}
movieId={value._id}
selected={selectedList}
setSelected={setSelectedList}
isSelected={false}
/>
);
})}
</div>
<div>
<h3 className={style.test}>{selectedList}</h3>
</div>
</main>
Movie Cards Component:
export default function Index({ selected, movieName, movieId, setSelected }) {
const [isActive, setActive] = useState(false);
const toggleClass = () => {
setActive(!isActive);
};
useEffect(()=>{
})
const pushToSelected = (e) => {
if (selected.includes(e.target.id)) {
selected.splice(selected.indexOf(e.target.id), 1);
console.log(selected);
} else {
selected.push(e.target.id);
console.log(selected);
console.log(e.target);
}
setSelected([...selected]);
toggleClass();
};
return (
<div>
<img
className={isActive ? style.movie_selected : style.movie}
id={movieId}
name={movieName}
src={`images/movies/${movieName}.jpg`}
alt={movieName}
onClick={pushToSelected}
/>
<h3 className={style.title}>{movieName}</h3>
</div>
);
}

I can't directly test your code so I will assume that this is the issue:
Don't directly transform a state (splice/push) - always create a clone or something.
Make the setActive based on the list and not dependent. (this is the real issue why the style gets removed)
try this:
const pushToSelected = (e) => {
if (selected.includes(e.target.id)) {
// filter out the id
setSelected(selected.filter(s => s !== e.target.id));
return;
}
// add the id
setSelected([...selected, e.target.id]);
};
// you may use useMemo here. up to you.
const isActive = selected.includes(movieId);
return (
<div>
<img
className={isActive ? style.movie_selected : style.movie}
id={movieId}
name={movieName}
src={`images/movies/${movieName}.jpg`}
alt={movieName}
onClick={pushToSelected}
/>
<h3 className={style.title}>{movieName}</h3>
</div>
);

This is a very broad topic. The best thing you can do is look up "React state management".
As with everything in the react ecosystem it can be handled by various different libraries.
But as of the latest versions of React, you can first start by checking out the built-in tools:
Check out the state lifecycle: https://reactjs.org/docs/state-and-lifecycle.html
(I see in your example you are using useState hooks, but I am adding these for more structured explanation for whoever needs it)
Then you might want to look at state-related hooks such as useState: https://reactjs.org/docs/hooks-state.html
useEffect (to go with useState):
https://reactjs.org/docs/hooks-effect.html
And useContext:
https://reactjs.org/docs/hooks-reference.html#usecontext
And for things outside of the built-in toolset, there are many popular state management libraries that also work with React with the most popular being: Redux, React-query, Mobx, Recoil, Flux, Hook-state. Please keep in mind that what you should use is dependant on your use case and needs. These can also help you out to persist your state not only between re-renders but also between refreshes of your app. More and more libraries pop up every day.
This is an ok article with a bit more info:
https://dev.to/workshub/state-management-battle-in-react-2021-hooks-redux-and-recoil-2am0#:~:text=State%20management%20is%20simply%20a,you%20can%20read%20and%20write.&text=When%20a%20user%20performs%20an,occur%20in%20the%20component's%20state.

React returns older state value onClick

I am adding a component onclick and keeping track of the components using useState Array. However when I go to remove one of the added components, it doesn't recognize the full component Array size, only the state that was there when that component was initially added.
Is there a way to have the current state recognized within that delete function?
https://codesandbox.io/s/twilight-water-jxnup
import React, { useState } from "react";
export default function App() {
const Span = props => {
return (
<div>
<span>{props.index}</span>
<button onClick={() => deleteSpan(props.index)}>DELETE</button>
Length: {spans.length}
</div>
);
};
//set initial span w/ useState
const [spans, setSpans] = useState([<Span key={0} index={Math.random()} />]);
//add new span
const addSpan = () => {
let key = Math.random();
setSpans([...spans, <Span key={key} index={key} />]);
};
//delete span
const deleteSpan = index => {
console.log(spans);
console.log(spans.length);
};
//clear all spans
const clearInputs = () => {
setSpans([]);
};
return (
<>
{spans}
<button onClick={() => addSpan()}>add</button>
<button onClick={() => clearInputs()}>clear</button>
</>
);
}

UPDATE - Explaining why you are facing the issue descibed on your question
When you are adding your new span on your state, it's like it captures an image of the current values around it, including the value of spans. That is why logging spans on click returns you a different value. It's the value spans had when you added your <Span /> into your state.
This is one of the benefits of Closures. Every <Span /> you added, created a different closure, referencing a different version of the spans variable.
Is there a reason why you are pushing a Component into your state? I would suggest you to keep your state plain and clean. In that way, it's also reusable.
You can, for instance, use useState to create an empty array, where you will push data related to your spans. For the sake of the example, I will just push a timestamp, but for you might be something else.
export default function App() {
const Span = props => {
return (
<div>
<span>{props.index}</span>
<button onClick={() => setSpans(spans.filter(span => span !== props.span))}>DELETE</button>
Length: {spans.length}
</div>
);
};
const [spans, setSpans] = React.useState([]);
return (
<>
{spans.length
? spans.map((span, index) => (
<Span key={span} index={index} span={span} />
))
: null}
<button onClick={() => setSpans([
...spans,
new Date().getTime(),
])}>add</button>
<button onClick={() => setSpans([])}>clear</button>
</>
);
}
I hope this helps you find your way.