CODEWITHSUNDEEP
javascriptreactjsreduxreact-redux
Santosh
Santosh

Reputation: 126

how to dispatch an action to return default state

In a reducer function we usually return default state if it doesn't go to switch block.

function reducer(state = initialState, action: any): any {
  switch (action.type) {
    case SOME_TYPE:
      return Object.assign({}, state, {
        someBoolean: false
      });
  }

  return state;
}

I tried dispatch(undefined, {type: undefined}) but I got error action may not have undefined type.

Is there a way that we could dispatch action which will return defalut state.

PS: Just trying a different way. Of-course we can have some action type and return default state.

Upvotes: 0

Views: 1848

Answers (3)

Taki
Taki

Reputation: 17664

You should use the action's paylaod to update the state, and you can check if you have any payload, use it, otherwise go back to initial state

function reducer(state = initialState, action: any): any {
  switch (action.type) {
    case SOME_TYPE:
      return Object.assign({}, state, {
        someBoolean: action.payload.someBoolean || initialState.someBoolean
      });
  }

  return state;
}

And dispatch an undefined : 

dispatch({
  type: SOME_TYPE,
  payload: {
    someBoolean: undefined
  }
});

But a better way would be to have a type to revert back to initialState 

function reducer(state = initialState, action: any): any {
  switch (action.type) {
    case SOME_TYPE:
      return Object.assign({}, state, {
        someBoolean: false
      });
    case REVERT:
      return initialState;
  }

  return state;
}

Upvotes: 0

kind user
kind user

Reputation: 41913

If I have understood you correctly, you want to reset your state to the initial value. 

switch (action.type) {
  case SOME_TYPE:
    return Object.assign({}, state, {
      someBoolean: false
    });
  case 'DEFAULT':
    return initialState;
  default:
     return state;
}

Then simply dispatch it:

dispatch({ type: 'DEFAULT' });

Note: remember to add a default case inside your reducer.

Upvotes: 1

Alexander
Alexander

Reputation: 538

Not sure if I'm getting this correctly, but to return your state simply do:

function reducer(state = initialState, action: any): any {
  switch (action.type) {
    case SOME_TYPE:
      return state;
  }

  return state;
}

Or to reset your initial state, do:

function reducer(state = initialState, action: any): any {
  switch (action.type) {
    case SOME_TYPE:
      return initialState;
  }

  return state;
}

Upvotes: 0

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