ReactJS Warning setState Cannot update during an existing state transition

Question

I am trying to refactor the following code from my render view    lt Button href     active   this state singleJourney  onClick  this handleButtonChange bind this false    gt Retour lt  Button gt    to a version where the bind is within the constructor  The reason for that is that bind in the render view will give me performance issues  especially on low end mobile phones    I have created the following code  but I am constantly getting the following errors  lots of them   It looks like the app gets in a loop   Warning  setState       Cannot update during an existing state transition  such as within  render  or another component s constructor   Render methods should be a pure function of props and state  constructor side-effects are an anti-pattern  but can be moved to  componentWillMount     Below is the code I use   var React   require  react    var ButtonGroup   require  react-bootstrap lib ButtonGroup    var Button   require  react-bootstrap lib Button    var Form   require  react-bootstrap lib Form    var FormGroup   require  react-bootstrap lib FormGroup    var Well   require  react-bootstrap lib Well     export default class Search extends React Component        constructor             super             this state                 singleJourney  false                     this handleButtonChange   this handleButtonChange bind this              handleButtonChange value            this setState               singleJourney  value                        render              return                lt Form gt                    lt Well style  wellStyle  gt                        lt FormGroup className  text-center  gt                            lt ButtonGroup gt                               lt Button href     active   this state singleJourney  onClick  this handleButtonChange false    gt Retour lt  Button gt                               lt Button href     active  this state singleJourney  onClick  this handleButtonChange true    gt Single Journey lt  Button gt                           lt  ButtonGroup gt                       lt  FormGroup gt                    lt  Well gt                lt  Form gt                      module exports   Search

User · Answer

The problem is certainly the this binding while rending the button with onClick handler  The solution is to use arrow function while calling action handler while rendering  Like this       onClick        gt  this handleButtonChange false

User · Answer

If you are trying to add arguments to a handler in recompose  make sure that you re defining your arguments correctly in the handler  It is essentially a curried function  so you want to be sure to require the correct number of arguments  This page has a good example of using arguments with handlers   Example  from the link    withHandlers     handleClick  props   gt   value1  value2    gt  event   gt        console log event      alert value1     was clicked        props doSomething value2            for your child HOC and in the parent  class MyComponent extends Component     static propTypes         handleClick  PropTypes func         render          const  handleClick    this props     return          lt div onClick  handleClick value1  value2     gt                this avoids writing an anonymous function out of your handler to patch fix the problem with not supplying enough parameter names on your handler

User · Answer

The solution that I use to open Popover for components is reactstrap  React Bootstrap 4 components        class Settings extends Component           constructor props                super props                this state                   popoversOpen        array open popovers                                     toggle my popovers         togglePopoverHelp    selected    gt   e    gt                const index   this state popoversOpen indexOf selected               if  index  lt  0                  this state popoversOpen push selected                 else                 this state popoversOpen splice index  1                             this setState   popoversOpen      this state popoversOpen                         render                  lt div id  settings  gt                   lt button id  PopoverTimer  onClick  this togglePopoverHelp 1   className  btn btn-outline-danger  type  button  gt   lt  button gt                   lt Popover placement  left  isOpen  this state popoversOpen includes 1   target  PopoverTimer  toggle  this togglePopoverHelp 1   gt                     lt PopoverHeader gt Header popover lt  PopoverHeader gt                     lt PopoverBody gt Description popover lt  PopoverBody gt                   lt  Popover gt                    lt button id  popoverRefresh  onClick  this togglePopoverHelp 2   className  btn btn-outline-danger  type  button  gt   lt  button gt                   lt Popover placement  left  isOpen  this state popoversOpen includes 2   target  popoverRefresh  toggle  this togglePopoverHelp 2   gt                     lt PopoverHeader gt Header popover 2 lt  PopoverHeader gt                     lt PopoverBody gt Description popover2 lt  PopoverBody gt                   lt  Popover gt               lt  div gt

User · Answer

That usually happens when you call  onClick  this handleButton    - notice the    instead of   onClick  this handleButton  - notice here we are not calling the function when we initialize it

User · Answer

I got the same error when I was calling   this handleClick   this handleClick bind this     in my constructor when handleClick didn t exist     I had erased it and had accidentally left the  this  binding statement in my constructor    Solution   remove the  this  binding statement

User · Answer

From react docs Passing arguments to event handlers   lt button onClick   e    gt  this deleteRow id  e   gt Delete Row lt  button gt   lt button onClick  this deleteRow bind this  id   gt Delete Row lt  button gt

User · Answer

THE PROBLEM is here  onClick  this handleButtonChange false    When you pass this handleButtonChange false  to onClick  you are actually calling the function with value   false and setting onClick to the function s return value  which is undefined  Also  calling this handleButtonChange false  then calls  this setState   which triggers a re-render  resulting in an infinite render loop   THE SOLUTION is to pass the function in a lambda  onClick       gt  this handleButtonChange false    Here you are setting onClick to equal a function that will call handleButtonChange false  when the button is clicked   The below example may help   function handleButtonChange value     console log  State updated       console log handleButtonChange false     output  State updated    output  undefined  console log      gt  handleButtonChange false     output      gt  handleButtonChange false

User · Answer

Looks like you re accidentally calling the handleButtonChange method in your render method  you probably want to do onClick       gt  this handleButtonChange false   instead   If you don t want to create a lambda in the onClick handler  I think you ll need to have two bound methods  one for each parameter   In the constructor   this handleButtonChangeRetour   this handleButtonChange bind this  true   this handleButtonChangeSingle   this handleButtonChange bind this  false     And in the render method    lt Button href     active   this state singleJourney  onClick  this handleButtonChangeSingle   gt Retour lt  Button gt   lt Button href     active  this state singleJourney  onClick  this handleButtonChangeRetour  gt Single Journey lt  Button gt

User · Answer

I am giving a generic example for better understanding  In the following code  render        return         lt div gt            lt h3 gt Simple Counter lt  h3 gt           lt Counter           value  this props counter            onIncrement  this props increment     lt ------ calling the function           onDecrement  this props decrement     lt -----------           onIncrementAsync  this props incrementAsync      gt         lt  div gt                When supplying props I am calling the function directly  this wold have a infinite loop execution and would give you that error  Remove the function call everything works normally    render        return         lt div gt            lt h3 gt Simple Counter lt  h3 gt           lt Counter           value  this props counter            onIncrement  this props increment   lt ------ function call removed           onDecrement  this props decrement   lt -----------           onIncrementAsync  this props incrementAsync    gt         lt  div gt

User · Answer

This same warning will be emitted on any state changes done in a render   call   An example of a tricky to find case  When rendering a multi-select GUI component based on state data  if state has nothing to display  a call to resetOptions   is considered state change for that component   The obvious fix is to do resetOptions   in componentDidUpdate   instead of render

[reactjs] ReactJS: Warning: setState(...): Cannot update during an existing state transition

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