Reducer running twice when using useReducer and React Context API

Question

I am kind of running my head into a wall on a weird circumstance using the React Context API along with the useReducer and useContext hooks.

Here is my main store.

import React, { createContext, useReducer } from 'react';
import { Reducers } from './Reducers';
import { surveys } from '../../testData.json';

export const context = createContext();
const { Provider } = context;

export const Store = ({ children }) => {
  const [store, dispatch] = useReducer(Reducers, {
    editSurvey: { display: false },
    surveys,
  });
  return <Provider value={{ store, dispatch }}>{children}</Provider>;
};

Here is my Reducers function and my Action types:

import { Actions } from './Actions';
const { DISPLAY_NEW_SURVEY, HIDE_SURVEY } = Actions;
export const Reducers = (state, action) => {
  const { type, payload } = action;
  console.log(state, action);
  switch (type) {
    case DISPLAY_NEW_SURVEY:
      return { ...state, editSurvey: { display: true } };
    case HIDE_SURVEY:
      return { ...state, editSurvey: { display: false } };
    default:
      return state;
  }
};

export const Actions = {
  DISPLAY_NEW_SURVEY: 'DISPLAY_NEW_SURVEY',
  HIDE_SURVEY: 'HIDE_SURVEY',
};

I have a display property inside my edit property which is used to conditionally render a react portal, see below:

import React, { useContext } from 'react';
import { EditSurveyPortal } from '../EditSurvey/EditSurveyPortal';
import { context } from '../../store/Store';

export const NavItem = ({ name, NavImage }) => {
  const { dispatch } = useContext(context);
  return (
    <div
      id={name}
      style={{ cursor: 'pointer' }}
      onClick={() => {
        dispatch({ type: 'DISPLAY_NEW_SURVEY' });
      }}
    >
      <NavImage alt={name} width={10} height={10} />
      <EditSurveyPortal />
    </div>
  );
};

import React, { useContext } from 'react';
import { createPortal } from 'react-dom';
import { context } from '../../store/Store';
import { EditSurvey } from './EditSurvey';

export const EditSurveyPortal = () => {
  const {
    store: {
      editSurvey: { display },
    },
    dispatch,
  } = useContext(context);
  return display
    ? createPortal(
        <div className="absolute top-0 left-0 w-screen h-screen z-10 flex justify-center items-center bg-gray-400 bg-opacity-50">
          <EditSurvey />
        </div>,
        document.getElementById('root'),
      )
    : null;
};

And here is the actual edit survey component:

import React from 'react';
import { Card, CardHeader } from '../Utility/Card';
import { Close } from '../Images/Close';

export const EditSurvey = ({ dispatch }) => {
  return (
    <Card>
      <CardHeader className="flex justify-between align-center">
        <div className="inline-block relative rounded">
          <span className="absolute top-0 l-0 bg-gray-200 text-gray-800 rounded-l px-2 py-1">
            Title
          </span>
          <input type="text" className="rounded p-1" />
        </div>
        <div
          className="text-gray-800"
          style={{ cursor: 'pointer' }}
          onClick={() => {
            dispatch({ type: 'HIDE_SURVEY' });
          }}
        >
          <Close width={8} height={8} />
        </div>
      </CardHeader>
    </Card>
  );
};

My issue is that when I click the close button on the portal, it dispatches HIDE_SURVEY then immediately dispatches DISPLAY_NEW_SURVEY:

I cannot for the life of me figure this out. Any help would be greatly appreciated.

Thanks!

@PrateekThapa I edited the post and added the component which calls the `DISPLAY_NEW_SURVEY` — Graham Vasquez, Sep 03 '20 at 15:50

score 1 · Accepted Answer · answered Sep 03 '20 at 16:46

Event Bubbling, mate.

The problem here is that your EditSurvey is below the clickable area of NavItem. What is happening here is that when you clicked on that div in your EditSurvey, it registers the click on that div first and then bubbles up to your NavItem clickable div. This is basically what is called as event-bubbling

You could learn about event bubbling and capturing here

Also, you could check the event bubbling issue here as well

In order to stop the event from bubbling up, you could simply stop the propagation of the event.

<div
    className="text-gray-800"
    style={{ cursor: 'pointer' }}
    onClick={(event) => {
      event.stopPropagation();
      dispatch({ type: 'HIDE_SURVEY' });
    }}
  >
    <Close width={8} height={8} />
  </div>

Dude, thank you so much! I've gotta do some research on event bubbling, thanks for the links! — Graham Vasquez, Sep 03 '20 at 16:55

Reducer running twice when using useReducer and React Context API

1 Answers1