I am trying to toggle the state of a component in ReactJS but I get an error stating:
Maximum update depth exceeded. This can happen when a component repeatedly calls setState inside componentWillUpdate or componentDidUpdate. React limits the number of nested updates to prevent infinite loops.
I don't see the infinite loop in my code, can anyone help?
ReactJS component code:
import React, { Component } from 'react';
import styled from 'styled-components';
class Item extends React.Component {
constructor(props) {
super(props);
this.toggle= this.toggle.bind(this);
this.state = {
details: false
}
}
toggle(){
const currentState = this.state.details;
this.setState({ details: !currentState });
}
render() {
return (
<tr className="Item">
<td>{this.props.config.server}</td>
<td>{this.props.config.verbose}</td>
<td>{this.props.config.type}</td>
<td className={this.state.details ? "visible" : "hidden"}>PLACEHOLDER MORE INFO</td>
{<td><span onClick={this.toggle()}>Details</span></td>}
</tr>
)}
}
export default Item;
This question is related to
javascript
reactjs
react-native
ReactJS: Maximum update depth exceeded error
inputDigit(digit){
this.setState({
displayValue: String(digit)
})
<button type="button"onClick={this.inputDigit(0)}>
why that?
<button type="button"onClick={() => this.inputDigit(1)}>1</button>
The function onDigit sets the state, which causes a rerender, which causes onDigit to fire because that’s the value you’re setting as onClick which causes the state to be set which causes a rerender, which causes onDigit to fire because that’s the value you’re… Etc
I know this has plenty of answers but since most of them are old (well, older), none is mentioning approach I grow very fond of really quick. In short:
Use functional components and hooks.
In longer:
Try to use as much functional components instead class ones especially for rendering, AND try to keep them as pure as possible (yes, data is dirty by default I know).
Two bluntly obvious benefits of functional components (there are more):
Quick proof for 2nd point - Isn't this absolutely disgusting?
constructor(props) {
super(props);
this.toggle= this.toggle.bind(this);
this.state = {
details: false
}
}
If you are using functional components for more then rendering you are gonna need the second part of great duo - hooks. Why are they better then lifecycle methods, what else can they do and much more would take me a lot of space to cover so I recommend you to listen to the man himself: Dan preaching the hooks
In this case you need only two hooks:
A callback hook conveniently named useCallback
. This way you are preventing the binding the function over and over when you re-render.
A state hook, called useState
, for keeping the state despite entire component being function and executing in its entirety (yes, this is possible due to magic of hooks). Within that hook you will store the value of toggle.
If you read to this part you probably wanna see all I have talked about in action and applied to original problem. Here you go: Demo
For those of you that want only to glance the component and WTF is this about, here you are:
const Item = () => {
// HOOKZ
const [isVisible, setIsVisible] = React.useState('hidden');
const toggle = React.useCallback(() => {
setIsVisible(isVisible === 'visible' ? 'hidden': 'visible');
}, [isVisible, setIsVisible]);
// RENDER
return (
<React.Fragment>
<div style={{visibility: isVisible}}>
PLACEHOLDER MORE INFO
</div>
<button onClick={toggle}>Details</button>
</React.Fragment>
)
};
PS: I wrote this in case many people land here with similar problem. Hopefully, they will like what I have shown here, at least well enough to google it a bit more. This is NOT me saying other answers are wrong, this is me saying that since the time they have been written, there is another way (IMHO, a better one) of dealing with this.
You should pass the event object when calling the function :
{<td><span onClick={(e) => this.toggle(e)}>Details</span></td>}
If you don't need to handle onClick event you can also type :
{<td><span onClick={(e) => this.toggle()}>Details</span></td>}
Now you can also add your parameters within the function.
1.If we want to pass argument in the call then we need to call the method like below
As we are using arrow functions no need to bind the method in cunstructor
.
onClick={() => this.save(id)}
when we bind the method in constructor like this
this.save= this.save.bind(this);
then we need to call the method without passing any argument like below
onClick={this.save}
and we try to pass argument while calling the function as shown below then error comes like maximum depth exceeded.
onClick={this.save(id)}
if you don't need to pass arguments to function, just remove () from function like below:
<td><span onClick={this.toggle}>Details</span></td>
but if you want to pass arguments, you should do like below:
<td><span onClick={(e) => this.toggle(e,arg1,arg2)}>Details</span></td>
onClick you should call function, thats called your function toggle.
onClick={() => this.toggle()}
In this case , this code
{<td><span onClick={this.toggle()}>Details</span></td>}
causes toggle function to call immediately and re render it again and again thus making infinite calls.
so passing only the reference to that toggle method will solve the problem.
so ,
{<td><span onClick={this.toggle}>Details</span></td>}
will be the solution code.
If you want to use the () , you should use an arrow function like this
{<td><span onClick={()=> this.toggle()}>Details</span></td>}
In case you want to pass parameters you should choose the last option and you can pass parameters like this
{<td><span onClick={(arg)=>this.toggle(arg)}>Details</span></td>}
In the last case it doesn't call immediately and don't cause the re render of the function, hence avoiding infinite calls.
Forget about the react first:
This is not related to react and let us understand the basic concepts of Java Script. For Example you have written following function in java script (name is A).
function a() {
};
Q.1) How to call the function that we have defined?
Ans: a();
Q.2) How to pass reference of function so that we can call it latter?
Ans: let fun = a;
Now coming to your question, you have used paranthesis with function name, mean that function will be called when following statement will be render.
<td><span onClick={this.toggle()}>Details</span></td>
_x000D_
Then How to correct it?
Simple!! Just remove parenthesis. By this way you have given the reference of that function to onClick event. It will call back your function only when your component is clicked.
<td><span onClick={this.toggle}>Details</span></td>
_x000D_
One suggestion releated to react:
Avoid using inline function as suggested by someone in answers, it may cause performance issue.
Avoid following code, It will create instance of same function again and again whenever function will be called (lamda statement creates new instance every time).
Note: and no need to pass event (e) explicitly to the function. you can access it with in the function without passing it.
{<td><span onClick={(e) => this.toggle(e)}>Details</span></td>}
_x000D_
https://cdb.reacttraining.com/react-inline-functions-and-performance-bdff784f5578
Source: Stackoverflow.com