faster redux

//Action - typ unia, zawierają się w nim wszystkie akcje
//StateTodolist - stan modułu todolisty
//StateApp - stan aplikacji


//todolist.js

export const getOfAction(actionName: string) => ((action: Action, state: StateTodolist): StateTodolist | null) => {
    
            //na te akcje ten reducer cokolwiek robi

    if (actionName === 'TODO_ADD' || actionName === 'TODO_REMOVE') {
        
        return (action: Action, state: StateTodolist): StateTodolist => {
            
            switch (action.kind) {
                'TODO_ADD' : {
                    // nowy stan
                }
                'TODO_REMOVE' : {
                    // nowy stan
                }
                default : {
                    throw Error('W to miejsce nigdy nie powinno trafić żadne wywołanie');
                }
            }
        };
    }
    
    return null;
};


//kombinacja dwóch reducerów

import todolist from './todolist';
import playlista from './playlista';

export const getOfActions = (actionName: string): ((action: Action, state: StateApp): StateApp | null) => {
    
    const reducerTodolist = todolist.getOfActions(actionName);
    const reducerPlaylista = playlista.getOfActions(actionName);
    
    if (reducerTodolist === null || reducerPlaylista === null) {
        return null;
    }
    
    return (action: Action, state: StateApp): StateApp {
        return {
            todolist: reducerTodolist ? reducerTodolist(action, state.todolist) : state.todolist,
            playlista: reducerPlaylista ? reducerPlaylista(action, state.playlista) : state.playlista
        };
    };
};



//główny reducer

export createMainReducer = (): (action: Action, state: StateApp) => StateApp {
    
    const map = {};
    
    return (action: Action, state: StateApp) => StateApp {
        
        const actionName = action.kind;
        
        if (typeof(map[actionName]) === 'undefined') {
            map[actionName] = tenDrugiModul.getOfActions(actionName);
        }
        
        return map[actionName](action, state);
    };
};