eggheadio-projects/getting-started-with-redux: null

<!DOCTYPE html>
<html>
<head>
 <meta charset="utf-8">
 <title>Plunker</title>
 <script src="https://unpkg.com/react@16.3.2/umd/react.production.min.js"></script>
 <script src="https://unpkg.com/react-dom@16.3.2/umd/react-dom.production.min.js"></script>
 <script src="https://unpkg.com/babel-standalone@6.26.0/babel.min.js"></script>

 <script src="https://unpkg.com/redux@4.0.0/dist/redux.js"></script>
 <script src="https://unpkg.com/react-redux@5.0.7/dist/react-redux.js"></script>
</head>
<body>
 <div id='root'></div>
 <script type="text/jsx" src="script.jsx"></script>
</body>
</html>

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;
  }
};

const { combineReducers } = Redux;
const todoApp = combineReducers({
  todos,
  visibilityFilter
});

const { createStore } = Redux;
const store = createStore(todoApp);

const { Component } = React;

const Link = ({
  active,
  children,
  onClick
}) => {
  if (active) {
    return <span>{children}</span>;
  }

  return (
    <a href='#'
       onClick={e => {
         e.preventDefault();
         onClick();
       }}
    >
      {children}
    </a>
  );
};

class FilterLink extends Component {
  componentDidMount() {
    this.unsubscribe = store.subscribe(() =>
      this.forceUpdate()
    );
  }
  
  componentWillUnmount() {
    this.unsubscribe();
  }
  
  render() {
    const props = this.props;
    const state = store.getState();
    
    return (
      <Link
        active={
          props.filter ===
          state.visibilityFilter
        }
        onClick={() =>
          store.dispatch({
            type: 'SET_VISIBILITY_FILTER',
            filter: props.filter
          })
        }
      >
        {props.children}
      </Link>
    );
  }
}

const Footer = () => (
  <p>
    Show:
    {' '}
    <FilterLink filter='SHOW_ALL'>
      All
    </FilterLink>
    {', '}
    <FilterLink filter='SHOW_ACTIVE'>
      Active
    </FilterLink>
    {', '}
    <FilterLink filter='SHOW_COMPLETED'>
      Completed
    </FilterLink>
  </p>
);

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>
);

let nextTodoId = 0;
const AddTodo = () => {
  let input;

  return (
    <div>
      <input ref={node => {
        input = node;
      }} />
      <button onClick={() => {
        store.dispatch({
          type: 'ADD_TODO',
          id: nextTodoId++,
          text: input.value
        })
        input.value = '';
      }}>
        Add Todo
      </button>
    </div>
  );
};

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
      );
  }
}

class VisibleTodoList extends Component {
  componentDidMount() {
    this.unsubscribe = store.subscribe(() =>
      this.forceUpdate()
    );
  }
  
  componentWillUnmount() {
    this.unsubscribe();
  }
  
  render() {
    const props = this.props;
    const state = store.getState();
    
    return (
      <TodoList
        todos={
          getVisibleTodos(
            state.todos,
            state.visibilityFilter
          )
        }
        onTodoClick={id =>
          store.dispatch({
            type: 'TOGGLE_TODO',
            id
          })            
        }
      />
    );
  }
}

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

ReactDOM.render(
  <TodoApp />,
  document.getElementById('root')
);