I'm trying to play an animation on dismounting of my component with exit attribute, but it doesn't work despite the presence of !
The input animation works fine but not the output one !
I guess I'm mismanaging the dismounting of my description which is displayed if the props data.show is true, boolean that I change at the click on the project, in short if someone can point me...
codesandbox
Thanks in advance
There are quite a few issues to cover in your code and suggest you first understand what triggers re-rendering in React.
By creating a new uuid key every time you change prop data, you are breaking the ability for React to know which components need to be rendered again so it re-renders them all - so it's always a new instance on AnimatePresence and no way for AnimatePresence to know there has been a change to the key or a change in mounting. Also make use of useCallback hooks when passing in functions to child components to avoid re-renders.
Move the state up to the parent, update the card key to a consistent value between renders, and don't update the entire props data just to expand/collapse.
See the updated sandbox
I suggest that you don’t animate multiple items inline within the same space like this as you will always have the remaining boxes jump a little, but that is another topic.
Related
I am trying to use a parent component to control animations in a child Canvas element. Specifically I want an animation to happen when a user inputs a correct answer.
It works until the user changes the state in the parent component, and then it no longer works.
I've made a stripped-back, minimal version of my code here to show my issue: https://codesandbox.io/s/epic-leaf-08jqvy?file=/src/App.js
My desired behaviour is that the red box bounces when a user clicks submit. That happens if they don't type anything in the input box, but as soon as you enter anything into there - changing state and re-rendering the component - the button no longer triggers the animation in the Canvas child component.
As far as I can tell, the issue is to do with changing the state when inputing text. If I make a version where the input is just assigned to a variable, it works fine, but I need to be able to use state and re-render other parts of it.
I have put a console.log in the jump() function, so I can see that it is being called, but no animation is taking place in the canvas.
I assume that what's happening is that everything is being re-rendered when the state changes, and so the useRef is no longer tracking to the right thing.
Things I've tried:
putting the canvas in a memoized component to prevent it from re-rendering
using eventlisteners to see if I can trigger the animations in other ways - keydown ones work, but I need the user to be able to type, so I tried other ones (like hashchange or audio.play) but neither of those worked.
You can see the thing I'm actually trying to build here: https://papaya-platypus-86565f.netlify.app/play Basically users answer questions and an animation plays depending on whether they're right or wrong, to give it a game-y feel.
Thanks!
I like your red box as well as your reasoning. Yes, the input state changing on keystroke is causing the entire App component to re-render. Note that your App.js component has a lot going on (all good stuff), such as your Box class instantiation, your canvas instantiation, etc.
The key is to break your components into smaller parts, particularly separating stateful components from non-stateful components. We don't want your canvas re-mounting on every input change, so we make them sibling components!
Here's a working example of your code, just in smaller components:
https://codesandbox.io/s/strange-julien-d3n4zm
I hope this helps.
I want to build a simple app like in picture attached with react js, I just cannot find the right idea of:
How to "select" photos(or item) in an application and have the "cart"-like component appear at the bottom when at least one photo/item is selected(and close and deselect all already selected photo/items) and expand the cart-like component at the bottom when clicked to show what's been already selected.
What is the best approach to this?
P.S I'm new to react with a big idea in mind xD
app's view
This question definitely needs more information, but I will try to point you in the right direction. There are hundred of ways to create the UI/functionality you are describing but here is a very generic overview;
The "items" (Img1-6) looks like a grid of ShopItem components, possibly in a CSS Grid / flexbox. Each ShopItem would probably make use of an onClick method to "do something" when it is clicked - this may involve updating a state (using the useState react hook) somewhere which tells you if a ShopItem is checked or not. It could also potentially use a callback method to do something in the parent when the items are checked.
I imagine that each ShopItem may own its own "checked" state or may update a global state (Such as Zustand or Redux) or a Context (React) when it is toggled on and off. The checked state of a ShopItem would also inform the UI of the component.
The "cart-like" component could be looking at the global state/context/callback from the item component, and could change based on its value and how many checked items there are. (Eg/ checkedItems !== 0 ? show : don't show)
This is just one way in which this UI can be built, if you would like a more specific solution, please edit your question to include code snippets and what you've already tried.
I create 2 Text Boxes one with hook and the another one with the old style, now in Hook mode when the user input change the textbox value the whole page rendered, but with old style there only the text-box rendered not the whole page, if you have the complex page with many objects like (Data Table, form, buttons, inputs, etc..) the single change on one of these components forced to re-render everything and it decease performance, for example typing in the text-box take time to effect on page and the delay time is more than user typing speed.
the one workaround solution is using the callbacks and useMem but if the page is complex(lots of objects as described, and all of these objects has many properties the callback and useMem is very very complicated to handle single object property.
SandBox Example
This is exactly how react hooks should work. what will cause a rerender in react? two things:
change in props
change in hooks or say in a better way hooks state
in the second case, the useInput state is changing so that causes a rerender and it's absolutely normal behavior. I think using custom hook in that way is not a good practice.
I recommend reading this article for more information on react rendering: https://www.codebeast.dev/usestate-vs-useref-re-render-or-not/
I'm an embedded developer who is new to React and am struggling a bit with the behaviour of child components and nested child components.
I understand that for any component to be re-rendered, the state must change. I am using an example of a menu component that has an item component within. When some global level event happens, I want to change the text displayed by the item components.
Here is a fiddle that shows some code that I would expect to work:
https://codesandbox.io/s/dark-rain-8mfsp?file=/src/App.tsx
On clicking the div, the menu's setText function gets called, which calls into the item component, setting the state. This state is used in the render function of the item component, so I would expect both item and menu to be re-rendered.
Instead I get an error saying that I can't set the state of an object that hasn't yet been mounted. I would have thought it had been mounted..
Perhaps the way I have linked the declared components with those in the render functions by calling this.componentname.render() is the issue - but how else could that be done?
Thanks in advance!
Here is a working version of your sandbox.
https://codesandbox.io/s/lucid-bird-qecj0?file=/src/App.tsx:0-899
I see that you are new to react. I would suggest you use hooks instead of class components.
I'm using react-hooks. So there is a modal that pops up with a bunch of inputs (components) like text fields, drop-downs, date pickers and etc...
The problem is when some field is being edited, all my form components are being re-rendered and that makes my form very slow. I totally understand why it happens. However, I would like to find a way when I edit some input within my form, all other input fields (components) should stay "frozen" and not re-rendered. Otherwise, working with my form which has at least 20 input fields, would make the work very slow...
Your assistance is appreciated!
You can use Uncontrolled components. It doesn't use setState, so it won't be re-rendered when you type some input value. Then you can send everything when you submit your form.
Try using React.memo which is in some way an equivalent to shouldComponentUpdate
Check React.memo documentation