父组件Dashboard
保存着我添加到ListItem
的每个Watchlist
的状态。不幸的是,每次我添加一个Item时,它都会被添加到数据库中,但是只有在刷新浏览器时才会显示。
class UserDashboard extends React.Component {
state = {
data: []
}
componentWillMount() {
authService.checkAuthentication(this.props);
}
isLoggedIn = () => {
return authService.authenticated()
}
getAllCoins = () => {
//fetches from backend API
}
addWishlist = () => {
this.getAllCoins()
.then(things => {
this.setState({
data: things
})
})
console.log("CHILD WAS CLICKED")
}
componentDidMount() {
this.getAllCoins()
.then(things => {
this.setState({
data: things
})
})
}
render() {
return (
<div className="dashboard">
<h1>HI, WELCOME TO USER DASHBOARD</h1>
<SearchBar
addWishlist={this.addWishlist}
/>
<UserWatchlist
data={this.state.data}
/>
</div>
);
}
}
用户关注列表:
class UserWatchlist extends React.Component {
constructor(props) {
super(props)
}
// componentDidUpdate(prevProps) {
// if (this.props.data !== prevProps.data) {
// console.log("CURRENT", this.props.data)
// console.log("PREVs", prevProps.data)
// }
// }
render() {
return (
<div>
<h2>These are tssssyou are watching:</h2>
<ul className="coin-watchlist">
{
this.props.data.map((coin, idx) => {
return <ListItem key={idx}
coin={coin.ticker}
price={coin.price}
/>
})
}
</ul>
</div>
)
}
}
显示可能需要监视的物品的搜索栏:
class SearchBar extends React.Component {
constructor(props) {
super(props)
this.state = {
coins: [],
searchValue: ""
}
}
searchHandler = e => {
e.preventDefault()
const value = e.target.value
this.setState({
searchValue: value
});
if (value === "") {
this.setState({
coins: []
})
} else {
this.getInfo()
}
}
getInfo = () => {
// Searches the API
}
addWishlist = () => {
this.props.addWishlist();
}
render() {
const {coins, searchValue} = this.state
return (
<div className="coin-search">
<form>
<input
type="text"
className="prompt"
placeholder="Search by ticker symbol"
value={searchValue}
onChange={this.searchHandler}
/>
</form>
<ul className="search-suggestions">
{
coins.filter(searchingFor(searchValue)).map( coin =>
<Currency
coin={coin}
addWishlist={this.addWishlist}
/>
)
}
</ul>
</div>
);
}
}
以及要添加的实际货币:
class Currency extends React.Component {
addToWatchlist = () => {
// POST to backend DB to save
};
fetch("/api/add-coin", settings)
.catch(err => {
return err
})
}
clickHandler = () => {
this.addToWatchlist()
this.props.addWishlist()
}
render() {
return(
<div className="search-results">
<li>
<h3> { this.props.coin.currency } </h3>
<button
className="add-to-list"
onClick={this.clickHandler}
>
+ to Watchlist
</button>
</li>
</div>
)
}
}
如您所见,我一直在向孩子们发送道具。当我单击“添加到监视列表”按钮时,我看到console.log消息出现,提示“孩子被选中”。我什至尝试过仅调用该方法再次从后端API获取。
此外,在UserWatchlist中,我尝试了componentDidUpdate,但是prevProps和this.props都显示相同的数据数组。在链的某个地方,我的数据丢失了。
这也是我第一次在这里发布问题,因此,如果可以改进,我很乐意添加更多详细信息并为该社区做出贡献
答案 0 :(得分:0)
您可能忘记了等待addToWatchlist完成:
addToWatchlist = () => {
// POST to backend DB to save
return fetch("/api/add-coin", settings)
.catch(err => {
return err
})
}
clickHandler = () => {
this.addToWatchlist().then(() => {
this.props.addWishlist()
})
}