onAppend

onAppend - Effect

This effect allow us to append an element to an array in the state.

Example:

const initialState = {
  fibonacciArray: [1, 2, 3, 5, 8]
};

const reducerDescription = {
  [actions.APPEND]: onAppend()
};

export default createReducer(initialState, reducerDescription);

If we now do:
dispatch({ type: actions.APPEND, target: 'fibonacciArray', payload: 13 });

Then the state will be:

state = {
  fibonacciArray: [1, 2, 3, 5, 8, 13]
};

Custom selectors

onAppend effect receives an optional parameter:

• selector: This function describes how we read the value from the action.
  (action, state) => any
  By default, is:
  action => action.payload