OOP 和 DOP
TodoApp 使用响应式函数
数据驱动编程
在数据驱动编程中,我们将重点放在数据本身和对数据的操作上,而不是数据所在的对象或数据结构。这种编程范式强调的是数据的变化和流动,以及如何响应这些变化。基于响应式函数的 TodoApp 就是一个很好的例子,它使用了响应式编程的概念,当数据(即待办事项列表)发生变化时,UI 会自动更新以反映这些变化。
tsx
import { render, signal, computed, tag, Component, h } from 'omi'
const todos = signal([
{ text: 'Learn OMI', completed: true },
{ text: 'Learn Web Components', completed: false },
{ text: 'Learn JSX', completed: false },
{ text: 'Learn Signal', completed: false }
])
const completedCount = computed(() => {
return todos.value.filter(todo => todo.completed).length
})
const newItem = signal('')
function addTodo() {
todos.value = [...todos.value, { text: newItem.value, completed: false }]
newItem.value = '' // Reset input value on add
}
function removeTodo(index: number) {
todos.value.splice(index, 1)
todos.value = [...todos.value]
}
@tag('todo-list')
class TodoList extends Component {
onInput = (event: Event) => {
const target = event.target as HTMLInputElement
newItem.value = target.value
}
render() {
return (
<>
<input type="text" value={newItem.value} onInput={this.onInput} />
<button onClick={addTodo}>Add</button>
<ul>
{todos.value.map((todo, index) => {
return (
<li>
<label>
<input
type="checkbox"
checked={todo.completed}
onInput={() => {
todo.completed = !todo.completed
todos.value = [...todos.value]
}}
/>
{todo.completed ? <s>{todo.text}</s> : todo.text}
</label>
{' '}
<button onClick={() => removeTodo(index)}>❌</button>
</li>
)
})}
</ul>
<p>Completed count: {completedCount.value}</p>
</>
)
}
}
render(<todo-list />, document.body)
import { render, signal, computed, tag, Component, h } from 'omi'
const todos = signal([
{ text: 'Learn OMI', completed: true },
{ text: 'Learn Web Components', completed: false },
{ text: 'Learn JSX', completed: false },
{ text: 'Learn Signal', completed: false }
])
const completedCount = computed(() => {
return todos.value.filter(todo => todo.completed).length
})
const newItem = signal('')
function addTodo() {
todos.value = [...todos.value, { text: newItem.value, completed: false }]
newItem.value = '' // Reset input value on add
}
function removeTodo(index: number) {
todos.value.splice(index, 1)
todos.value = [...todos.value]
}
@tag('todo-list')
class TodoList extends Component {
onInput = (event: Event) => {
const target = event.target as HTMLInputElement
newItem.value = target.value
}
render() {
return (
<>
<input type="text" value={newItem.value} onInput={this.onInput} />
<button onClick={addTodo}>Add</button>
<ul>
{todos.value.map((todo, index) => {
return (
<li>
<label>
<input
type="checkbox"
checked={todo.completed}
onInput={() => {
todo.completed = !todo.completed
todos.value = [...todos.value]
}}
/>
{todo.completed ? <s>{todo.text}</s> : todo.text}
</label>
{' '}
<button onClick={() => removeTodo(index)}>❌</button>
</li>
)
})}
</ul>
<p>Completed count: {completedCount.value}</p>
</>
)
}
}
render(<todo-list />, document.body)
TodoApp 使用信号类 Signal
面向对象编程
在面向对象编程中,我们将重点放在对象上,对象包含了数据和操作数据的方法。这种编程范式强调的是对象之间的交互和协作,以及如何通过对象的封装、继承和多态性来组织和管理代码。基于响应式函数的 TodoApp 也可以使用面向对象的方式来实现,例如,我们可以创建一个 TodoList 类,这个类包含了待办事项列表的数据和操作这些数据的方法,以及一个 update
方法来更新 UI。
tsx
import { render, Signal, tag, Component, h, computed } from 'omi'
type Todo = { text: string, completed: boolean }
class TodoApp extends Signal<{ todos: Todo[], filter: string, newItem: string }> {
completedCount: ReturnType<typeof computed>
constructor(todos: Todo[] = []) {
super({ todos, filter: 'all', newItem: '' })
this.completedCount = computed(() => this.value.todos.filter(todo => todo.completed).length)
}
addTodo = () => {
// api a
this.value.todos.push({ text: this.value.newItem, completed: false })
this.value.newItem = ''
this.update()
// api b, same as api a
// this.update((value) => {
// value.todos.push({ text: value.newItem, completed: false })
// value.newItem = ''
// })
}
toggleTodo = (index: number) => {
const todo = this.value.todos[index]
todo.completed = !todo.completed
this.update()
}
removeTodo = (index: number) => {
this.value.todos.splice(index, 1)
this.update()
}
}
const todoApp = new TodoApp([
{ text: 'Learn OMI', completed: true },
{ text: 'Learn Web Components', completed: false },
{ text: 'Learn JSX', completed: false },
{ text: 'Learn Signal', completed: false }
])
@tag('todo-list')
class TodoList extends Component {
onInput = (event: Event) => {
const target = event.target as HTMLInputElement
todoApp.value.newItem = target.value
}
render() {
const { todos } = todoApp.value
const { completedCount, toggleTodo, addTodo, removeTodo } = todoApp
return (
<>
<input type="text" value={todoApp.value.newItem} onInput={this.onInput} />
<button onClick={addTodo}>Add</button>
<ul>
{todos.map((todo, index) => {
return (
<li>
<label>
<input
type="checkbox"
checked={todo.completed}
onInput={() => toggleTodo(index)}
/>
{todo.completed ? <s>{todo.text}</s> : todo.text}
</label>
{' '}
<button onClick={() => removeTodo(index)}>❌</button>
</li>
)
})}
</ul>
<p>Completed count: {completedCount.value}</p>
</>
)
}
}
render(<todo-list />, document.body)
import { render, Signal, tag, Component, h, computed } from 'omi'
type Todo = { text: string, completed: boolean }
class TodoApp extends Signal<{ todos: Todo[], filter: string, newItem: string }> {
completedCount: ReturnType<typeof computed>
constructor(todos: Todo[] = []) {
super({ todos, filter: 'all', newItem: '' })
this.completedCount = computed(() => this.value.todos.filter(todo => todo.completed).length)
}
addTodo = () => {
// api a
this.value.todos.push({ text: this.value.newItem, completed: false })
this.value.newItem = ''
this.update()
// api b, same as api a
// this.update((value) => {
// value.todos.push({ text: value.newItem, completed: false })
// value.newItem = ''
// })
}
toggleTodo = (index: number) => {
const todo = this.value.todos[index]
todo.completed = !todo.completed
this.update()
}
removeTodo = (index: number) => {
this.value.todos.splice(index, 1)
this.update()
}
}
const todoApp = new TodoApp([
{ text: 'Learn OMI', completed: true },
{ text: 'Learn Web Components', completed: false },
{ text: 'Learn JSX', completed: false },
{ text: 'Learn Signal', completed: false }
])
@tag('todo-list')
class TodoList extends Component {
onInput = (event: Event) => {
const target = event.target as HTMLInputElement
todoApp.value.newItem = target.value
}
render() {
const { todos } = todoApp.value
const { completedCount, toggleTodo, addTodo, removeTodo } = todoApp
return (
<>
<input type="text" value={todoApp.value.newItem} onInput={this.onInput} />
<button onClick={addTodo}>Add</button>
<ul>
{todos.map((todo, index) => {
return (
<li>
<label>
<input
type="checkbox"
checked={todo.completed}
onInput={() => toggleTodo(index)}
/>
{todo.completed ? <s>{todo.text}</s> : todo.text}
</label>
{' '}
<button onClick={() => removeTodo(index)}>❌</button>
</li>
)
})}
</ul>
<p>Completed count: {completedCount.value}</p>
</>
)
}
}
render(<todo-list />, document.body)
这里不讨论哪种方式(DOP,OOP)的好坏,使用 omi 两种方式都可以任意选择。