Code to be refacted:
const TodoList = ({
todos,
onTodoClick
}) => (
<ul>
{todos.map(todo =>
<Todo
key={todo.id}
{...todo}
onClick={() => onTodoClick(todo.id)}
/>
)}
</ul>
);
let nextTodoId = 0;
const TodoApp = ({
todos,
visibilityFilter
}) => (
<div>
...
...
<TodoList
todos={
getVisibleTodos(
todos,
visibilityFilter
)
}
onTodoClick={id =>
store.dispatch({
type: 'TOGGLE_TODO',
id
})
}
/>
....
</div>
);
Currently we pass the 'todos' and 'onTodoClick' from top container component 'TodoApp', all the way down to the 'Todo' component.
So we want simplfy 'TodoList' Component in TodoApp, create a new container component 'VisibleTodoList'.
In TodoApp:
const TodoApp = ({
todos,
visibilityFilter
}) => (
<div>
<AddTodo
onAddClick={text =>
store.dispatch({
type: 'ADD_TODO',
id: nextTodoId++,
text
})
}
/>
<VisibleTodoList />
<Footer />
</div>
);
VisibleTodoList:
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
})
}
/>
);
}
}
----------------
Code:
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>
);
const AddTodo = ({
onAddClick
}) => {
let input;
return (
<div>
<input ref={node => {
input = node;
}} />
<button onClick={() => {
onAddClick(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
})
}
/>
);
}
}
let nextTodoId = 0;
const TodoApp = ({
todos,
visibilityFilter
}) => (
<div>
<AddTodo
onAddClick={text =>
store.dispatch({
type: 'ADD_TODO',
id: nextTodoId++,
text
})
}
/>
<VisibleTodoList />
<Footer />
</div>
);
const render = () => {
ReactDOM.render(
<TodoApp
{...store.getState()}
/>,
document.getElementById('root')
);
};
store.subscribe(render);
render();