redux practice

redux demo js

//https://egghead.io/lessons/javascript-redux-the-single-immutable-state-tree
//redux
const createStore = (reducer, initialState) => {
  let state = initialState;
  let listeners = [];
  
  const getState = () => state;
  
  const dispatch = (action) => {
    state = reducer(state, action);
    listeners.forEach(listener => listener());
  };
  
  const subscribe = (listener) => {
    listeners.push(listener);
    return () => {
      listeners = listeners.filter(l => l !== listener);
    };
  };
  return { getState, dispatch, subscribe }
};

/*const todoApp = (state = {}, action) => {
  return {
    todos: todos(state.todos, action),
    visibilityFilter: visibilityFilter(state.visibilityFilter, action)
  }
};*/

//const { combineReducers } = Redux;
const combineReducers = (reducers) => {
  return (state = {}, action) => {
    return Object.keys(reducers).reduce(
      (nextState, key) => {
        nextState[key] = reducers[key](
          state[key],
          action
        );
        return nextState;
      },
      {}
    );
  };
}



//------reducer
const todo = (state, action) => {
  switch (action.type) {
    case 'ADD_TODO':
      return {
        id: action.id,
        text: action.text,
        completed: false
      };
    case 'TOGGLE_TODO':
      if (state.id !== action.id) {
        return state;
      }
      return {
        ...state,
        completed: !state.completed
      };
    default:
      return state;
  }
};

const todos = (state = [], action) => {
  switch (action.type) {
    case 'ADD_TODO':
      return [
        ...state,
        todo(undefined, action)
      ];
    case 'TOGGLE_TODO':
      return state.map(t => todo(t, action));
    default:
      return state;
  }
};

const visibilityFilter = (state = 'SHOW_ALL', action) => {
  switch (action.type) {
    case 'SET_VISIBILITY_FILTER':
      return action.filter;
    default:
      return state;
  }
}
//---------action
let nextTodoId = 0;
const addTodo = (text)=> {
  return {
    type: 'ADD_TODO',
    id: nextTodoId++,
    text
  };
};

const setVisibilityFilter = (filter) => {
  return {
    type: 'SET_VISIBILITY_FILTER',
    filter
  };
};

const toggleTodo = (id) => {
  return {
     type: 'TOGGLE_TODO',
     id
  };
};

const { Component } = React;
const { connect } = ReactRedux;

//---------AddTodo
let AddTodo = ({ dispatch }) => {
  let input;

  return (
    <div>
        <input ref={node => {
          input = node;
        }} />
        <button 
          onClick={() => {
            dispatch(addTodo(input.value));
            input.value = '';
          }}>
          Add Todo
        </button>
    </div>
  );
};
AddTodo = connect()(AddTodo);

//--------------VisibleTodoList
const getVisibleTodos = (todos, filter) => {
  switch (filter) {
    case 'SHOW_ALL':
      return todos;
    case 'SHOW_COMPLETED':
      return todos.filter(t => t.completed);
    case 'SHOW_ACTIVE':
      return todos.filter(t => !t.completed);
  }
};
const Todo = ({onClick, completed, text}) => (
  <li 
    onClick={onClick}
    style={{
       textDecoration:
       completed ? 'line-through' : 'none'
    }}>
    {text}
  </li>
);

const TodoList = ({todos, onTodoClick}) => (
  <ul>
    {todos.map(todo =>
      <Todo 
         key ={todo.id}
         {...todo}
         onClick={() => onTodoClick(todo.id)}/> 
    )}
  </ul>
);
const mapStateToTodoListProps = (state) => {
  return {
    todos: getVisibleTodos(
      state.todos,
      state.visibilityFilter
    )
  };
}
const mapDispatchToTodoListProps = (dispatch) => {
  return {
    onTodoClick: (id) => {
      dispatch(toggleTodo(id));  
    }
  };
};

const VisibleTodoList = connect(
  mapStateToTodoListProps,
  mapDispatchToTodoListProps
)(TodoList);

//---------footer
const Link = ({active, children, onClick}) => {
  if (active) {
    return <span>{children}</span>;
  }
  return (
    <a href='#' 
      onClick={(e) => {
        e.preventDefault();
        onClick();
      }} >
      {children}
    </a>
  );
};
const Footer = () => (
    <p>
      Show:
      {''}
      <FilterLink 
        filter='SHOW_ALL'>
        All
      </FilterLink>
      {','}
      <FilterLink 
        filter='SHOW_ACTIVE'>
        Active
      </FilterLink>
      {','}
      <FilterLink 
        filter='SHOW_COMPLETED'>
        completed
      </FilterLink>
  </p>
);

const mapStateToLinkProps = (state, ownProps) => {
  return {
      active: ownProps.filter === state.visibilityFilter
  };
};
const mapDispatchToLinkProps = (dispatch, ownProps) => {
  return {
    onClick: () => {
      dispatch(setVisibilityFilter(ownProps.filter));
    }
  };
}
const FilterLink = connect(
  mapStateToLinkProps,
  mapDispatchToLinkProps
)(Link);

//------Provider
class Provider extends Component {
  getChildContext() {
    return {
      store: this.props.store
    };
  }
  render() {
    return (
      <TodoApp/>
    );
  }
}
Provider.childContextTypes = {
  store: React.PropTypes.object
};
//---------Todo APP
const initialState = {
  todos : [],
  visibilityFilter: 'SHOW_ALL'
}

const rootReducers = combineReducers({
  todos,
  visibilityFilter
});

const appStore = createStore(rootReducers, initialState);

const TodoApp = () => (
  <div>
    <AddTodo />
    <VisibleTodoList />
    <Footer />
  </div>
);

ReactDOM.render(
  <Provider store={appStore} />,
  document.getElementById('root')
);

redux demo html

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <script  src="//cdnjs.cloudflare.com/ajax/libs/redux/3.0.5/redux.min.js"></script>
    <script  src="//fb.me/react-0.14.3.min.js"></script>
    <script  src="//fb.me/react-dom-0.14.3.min.js"></script>
    <script  src="//cdnjs.cloudflare.com/ajax/libs/react-redux/4.0.1/react-redux.min.js"></script>
  <title>JS Bin</title>
</head>
<body>
  <div id="root"></div>
</body>
</html>