我正在我的反应应用程序上执行排序,过滤和分页,它显示来自包含电影数据的json文件的数据。我能够从输入框中获取数据但无法设置setState以及控制台日志searchKey和电影。
下面是App.js和Hello.js的代码。应用程序组件具有排序和搜索功能。
App.js
import data from './data.json';
class App extends Component {
constructor() {
super();
this.state = {
movies: data.movies, sort_term: '', searchKey: '', filterList: '',
};
this.onSorting = this.onSorting.bind(this);
this.onSearchMovie = this.onSearchMovie.bind(this);
}
onSorting = (e) => {
let term = 'Title';
let option = e.target.value;
let sortedList = [...this.state.movies].sort((a, b) => {
return (option == 'asc' ? (a[term] <= b[term] ? -1 : 1) :
(a[term] >= b[term] ? -1 : 1))
});
this.setState({ sort_term: term });
this.setState({ movies: sortedList });
}
onSearchMovie(e) {
let key = e;
console.log(key);
this.setState({searchKey : key });
console.log(searchKey);
let list = movies.filter(m =>{
return m.Title.toLowerCase().includes(searchKey.toLowerCase());
});
this.setState({movies:list});
}
render() {
const { movies } = this.state;
if (!movies.length) {
return (
<div className="container">
<h2>loading...</h2>
</div>
);
}
else {
return (
<div>
<Hello sort_term={this.state.sort_term}
onSorting={this.onSorting}
onSearch={this.onSearchMovie} />
<br />
<Table movies={this.state.movies} />
</div>
);
}
}
}
Hello.js
class Hello extends Component {
constructor(props) {
super(props);
this.state = { inputField: '', }
this.onSubmitTitle = this.onSubmitTitle.bind(this);
this.getTitle = this.getTitle.bind(this);
}
onSubmitTitle(e){
e.preventDefault();
this.props.onSearch(this.state.inputField);
this.setState({ inputField: '' });
}
getTitle(e){
this.setState({ inputField: e.target.value });
// console.log('---');
// console.log(this.state.inputField);
}
render() {
const { sort_term, onSorting } = this.props;
return (
<div className="header">
Database
<ul className="navLeft">
<li>
<form onSubmit={this.onSubmitTitle}>
<input type="search" onChange={this.getTitle} value={this.state.inputField}
className="search-bar"
placeholder="Type for search..." />
</form>
</li>
<li >
<form >
<select
onChange={onSorting}
className="searchBar">
<option value="desc" >Sort Title(Z - A)</option>
<option value="asc">Sort Title(A - Z)</option>
<option value="descDirector">Sort Director(Z - A)</option>
<option value="ascDirector">Sort Director(A - Z)</option>
</select>
</form>
</li>
</ul>
</div>
);
}
}
你有几个问题:
onSearchMovie(e) {
let key = e;
console.log(key);
this.setState({ searchKey: key });
console.log(searchKey);
let list = movies.filter(m => {
return m.Title.toLowerCase().includes(searchKey.toLowerCase());
});
this.setState({ movies: list });
}
like `searchKey` and `movies`.
setState
是异步的,所以这样做:
this.setState({ sort_term: term });
this.setState({ movies: sortedList });
Is the same as doing this:
this.setState({
sort_term: term,
movies: sortedList
});
onSearchMovie(e) {
let key = e;
console.log(key);
this.setState({ searchKey: key });
console.log(searchKey);
let list = movies.filter(m => {
return m.Title.toLowerCase().includes(searchKey.toLowerCase());
});
this.setState({ movies: list });
}
因为如上所述,setState
是异步的。所以this.state.searchKey
可能不是你在下一行访问时的想法。
要么使用key
变量,要么使用在setState
完成后触发的setState
回调。
this.setState({someKey: someValue}, () => {console.log(this.state.someKey)})
您可以在文档Why is setState giving me the
wrong value?中阅读更多相关信息。onSubmit
时
form
你实际上需要触发提交。由于您没有任何提交按钮,您可以使用enter
密钥进行操作。所以当你
专注于input
按enter
键和form
将提交。filteredMovis
列表而不是movies
列表,因为一旦你过滤掉了物品,你就无法将它们取回。所以当你做过滤你在movies
上做,但更新filteredMovis
列表而不从原来的movies
列表中删除项目。这是一个正在运行的例子:
const data = {
movies: [
{
id: 1,
Title: "wonder woman"
},
{
id: 2,
Title: "kill bill"
},
{
id: 3,
Title: "world war z"
},
{
id: 4,
Title: "pixels"
}
]
};
class Hello extends React.Component {
constructor(props) {
super(props);
this.state = { inputField: "" };
this.onSubmitTitle = this.onSubmitTitle.bind(this);
this.getTitle = this.getTitle.bind(this);
}
onSubmitTitle(e) {
e.preventDefault();
this.props.onSearch(this.state.inputField);
this.setState({ inputField: "" });
}
getTitle(e) {
this.setState({ inputField: e.target.value });
// console.log('---');
// console.log(this.state.inputField);
}
render() {
const { onSorting } = this.props;
return (
<div className="header">
Database
<ul className="navLeft">
<li>
<form onSubmit={this.onSubmitTitle}>
<input
type="text"
onChange={this.getTitle}
value={this.state.inputField}
className="search-bar"
placeholder="Type for search..."
/>
</form>
</li>
<li>
<form>
<select onChange={onSorting} className="searchBar">
<option value="desc">Sort Title(Z - A)</option>
<option value="asc">Sort Title(A - Z)</option>
<option value="descDirector">Sort Director(Z - A)</option>
<option value="ascDirector">Sort Director(A - Z)</option>
</select>
</form>
</li>
</ul>
</div>
);
}
}
class App extends React.Component {
constructor() {
super();
this.state = {
movies: data.movies,
filteredMovis: data.movies,
sort_term: "",
searchKey: "",
filterList: ""
};
this.onSorting = this.onSorting.bind(this);
this.onSearchMovie = this.onSearchMovie.bind(this);
}
onSorting = e => {
let term = "Title";
let option = e.target.value;
let sortedList = [...this.state.movies].sort((a, b) => {
return option == "asc"
? a[term] <= b[term]
? -1
: 1
: a[term] >= b[term]
? -1
: 1;
});
this.setState({
sort_term: term,
filteredMovis: sortedList
});
};
onSearchMovie(key) {
const { movies } = this.state;
let list = movies.filter(m => {
return m.Title.toLowerCase().includes(key.toLowerCase());
});
this.setState({ filteredMovis: list, searchKey: key });
}
render() {
const { filteredMovis, movies } = this.state;
if (!movies.length) {
return (
<div className="container">
<h2>loading...</h2>
</div>
);
} else {
return (
<div>
<Hello
sort_term={this.state.sort_term}
onSorting={this.onSorting}
onSearch={this.onSearchMovie}
/>
<br />
{filteredMovis.map(movie => <div key={movie.id}>{movie.Title}</div>)}
</div>
);
}
}
}
const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="root"></div>