使用npm uuid包反应16表数据更新操作不更新行数据
我面临反应表格表格更新挑战。当我更新一行时,会创建一个新条目。我发现我需要制作唯一的键/ id来跟踪行ID。我建议使用uuid package
https://www.npmjs.com/package/uuid。导入此包后,我通过这个uuid()
在handlesubmit
函数中,仍然无法按预期工作。场景后面缺少或发生了什么?这里是现场演示live demo谢谢。使用npm uuid包反应16表数据更新操作不更新行数据
import React, { Component } from "react"; import {
Form,
FormGroup,
//ControlLabel,
FormControl,
Col,
Button,
// PageHeader,
Row,
Grid,
Modal,
ButtonToolbar,
Table
} from "react-bootstrap";
let uuidv4 = require("uuid/v4");
//const Dashboard = ({ email }) => (
class Dashboard extends Component {
constructor(props) {
super(props);
this.state = {
name: "",
description: "",
amount: "",
date: "",
show: false,
formdata: []
};
this.handleSubmit = this.handleSubmit.bind(this);
this.handleInputChange = this.handleInputChange.bind(this);
this.showModal = this.showModal.bind(this);
this.hideModal = this.hideModal.bind(this);
this.showEditModal = this.showEditModal.bind(this);
}
showModal() {
this.setState({ show: true });
}
showEditModal(event, i) {
const recordToEdit = this.state.formdata.filter((item, index) => {
return index === i;
})[0];
this.setState({
show: true,
name: recordToEdit.name,
description: recordToEdit.description,
amount: recordToEdit.amount,
date: recordToEdit.date
});
}
hideModal() {
this.setState({
show: false,
name: "",
description: "",
amount: "",
date: ""
});
}
handleInputChange(event) {
// update the input that changed
this.setState({
[event.target.name]: event.target.value
});
}
handleSubmit(event) {
const formItem = {
id: this.state.id,
name: this.state.name,
description: this.state.description,
amount: this.state.amount,
date: this.state.date
};
if (
this.state.name === "" ||
this.state.amount === "" ||
this.state.date === ""
) {
alert("Please fill mandatory filed");
} else {
if (
this.state.formdata.filter(item => item.id === formItem.id).length > 0
) {
// update item
this.setState(prevState => ({
formdata: prevState.formdata.map(item => {
if (item.name === formItem.name) return formItem;
else return item;
})
}));
} else {
// add new item
this.setState((prevState,id) => ({
formdata: prevState.formdata.concat(formItem)
}));
}
alert("form submited: ");
this.setState({
name: "",
description: "",
amount: "",
date: ""
});
}
event.preventDefault();
}
deleteExpense(i) {
alert("are you sure you want to Delete this item ?");
this.setState({
formdata: this.state.formdata.filter((item, index) => {
return index !== i;
})
});
}
render() {
return (
<Grid>
<p>Welcome</p>
<Row>
<Col>
<ButtonToolbar>
<Button bsStyle="primary" onClick={this.showModal}>
Add Expenses
</Button>
<Table striped bordered condensed hover>
<thead>
<tr>
<th>name</th>
<th>description</th>
<th>amount</th>
<th>date</th>
<th>Action</th>
</tr>
</thead>
<tbody>
{this.state.formdata.map((item, i) => (
<tr key={i}>
<td>{item.name}</td>
<td>{item.description}</td>
<td>{item.amount}</td>
<td>{item.date}</td>
<td>
<Button
bsStyle="warning"
onClick={e => this.showEditModal(e, i)}
>
Update
</Button>
<Button
bsStyle="danger"
onClick={() => this.deleteExpense(i)}
>
Delete
</Button>
</td>
<td />
</tr>
))}
</tbody>
</Table>
<Modal
{...this.props}
show={this.state.show}
onHide={this.hideModal}
dialogClassName="custom-modal"
>
<Modal.Header closeButton>
<Modal.Title
id="contained-modal-title-lg "
className="text-center"
>
Add Expenses
</Modal.Title>
</Modal.Header>
<Modal.Body>
<Form horizontal onSubmit={this.handleSubmit}>
<FormGroup controlId="formHorizontalEmail">
<Col smOffset={4} sm={4}>
<FormControl
type="Text"
placeholder="name"
name="name"
value={this.state.name}
onChange={this.handleInputChange}
/>
</Col>
</FormGroup>
<FormGroup controlId="formHorizontalPassword">
<Col smOffset={4} sm={4}>
<FormControl
type="description"
placeholder="description"
name="description"
value={this.state.description}
onChange={this.handleInputChange}
/>
</Col>
</FormGroup>
<FormGroup controlId="formHorizontalPassword">
<Col smOffset={4} sm={4}>
<FormControl
type="amount"
placeholder="amount"
name="amount"
value={this.state.amount}
onChange={this.handleInputChange}
/>
</Col>
</FormGroup>
<FormGroup controlId="formHorizontalPassword">
<Col smOffset={4} sm={4}>
<FormControl
type="date"
placeholder="date"
name="date"
value={this.state.date}
onChange={this.handleInputChange}
/>
</Col>
</FormGroup>
<FormGroup>
<Col smOffset={5} sm={4}>
<Button type="submit" bsStyle="primary">
Add
</Button>
</Col>
</FormGroup>
</Form>
</Modal.Body>
</Modal>
</ButtonToolbar>
</Col>
</Row>
</Grid>
);
}
}
export default Dashboard;
回答:
let uuidv4 = require("uuid/v4");
此行之后,我没有看到任何你使用uuidv4,使用它,只是简单uuidv4()
,你可以用console.log(uuidv4());
测试它让每一个使用UUID键,只是
<tr key={uuidv4()}>
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