【发布时间】：2019-06-14 11:17:54
【问题描述】：
当我使用 React 和 Flux 完成了一个 crud 应用程序时，我对 react 不熟悉，我收到了这个错误，我的代码如下，
用户列表
import React, { Component } from "react";
import $ from "jquery";
import UserStore from "../../stores/UserStore";
import * as UserActions from "../../actions/UserActions";
import AddUser from "./AddUser";
$.DataTable = require("datatables.net");
class UserList extends Component {
constructor() {
super();
this.getUsers = this.getUsers.bind(this);
this.state = {
users: UserStore.getAll()
};
this.loadUsers();
}
componentDidMount() {
$(document).ready(function() {
$("#example").DataTable({
ordering: true
});
});
}
componentWillMount() {
UserStore.on("change", this.getUsers);
}
componentWillUnmount() {
UserStore.removeListener("change", this.getUsers);
}
getUsers() {
console.log(" get users called");
this.setState({
users: UserStore.getAll()
});
}
loadUsers() {
UserActions.getUsersList();
}
render() {
const userlistitem = this.state.users.map((user, index) => (
<tr key={index}>
<th scope="row">{index}</th>
<td>{user.name}</td>
<td>{user.username}</td>
<td>{user.email}</td>
<td>{user.dob}</td>
<td>{user.address}</td>
<td>{user.mobile}</td>
<td>{user.branch}</td>
</tr>
));
return (
<div
style={{
marginTop: 80,
marginLeft: 150,
marginRight: 150
}}
>
<div className="card text-white bg-info mb-3">
<div className="card-body">
<div className="d-flex justify-content-between">
<h5>User List</h5>
<div>
<button
style={{
marginTop: 10
}}
type="button"
className="btn btn-light "
data-toggle="modal"
data-target="#exampleModalCenter"
>
Add New User
</button>
</div>
</div>
</div>
</div>
<table id="example" className="table table-bordered table-striped ">
<thead className="thead-dark">
<tr>
<th scope="col">#</th>
<th scope="col">Name</th>
<th scope="col">User Name</th>
<th scope="col">Email</th>
<th scope="col">DOB</th>
<th scope="col">Address</th>
<th scope="col">Mobile</th>
<th scope="col">Branch</th>
</tr>
</thead>
<tbody>{userlistitem}</tbody>
</table>
<AddUser />
</div>
);
}
}
export default UserList;
添加用户
import React, { Component } from "react";
import DatePicker from "react-datepicker";
import "react-datepicker/dist/react-datepicker.css";
import "../../css/datepicker.css";
import * as UserActions from "../../actions/UserActions";
class AddUser extends Component {
constructor(props) {
super(props);
this.state = {
branch: "",
name: "",
username: "",
mobile: "",
email: "",
address: "",
dob: new Date()
};
this.handleInputChange = this.handleInputChange.bind(this);
this.handledatepickerchange = this.handledatepickerchange.bind(this);
}
handleInputChange(event) {
const target = event.target;
const value = target.value;
const name = target.name;
this.setState({ [name]: value });
}
handledatepickerchange(event) {
this.setState({ dob: event });
}
createUser = () => {
console.log("this is:", this);
const user = {
branch: this.state.branch,
name: this.state.name,
username: this.state.username,
mobile: this.state.mobile,
email: this.state.email,
address: this.state.address,
dob: this.state.dob
};
UserActions.createNewUser(user);
this.setState({
branch: "",
name: "",
username: "",
mobile: "",
email: "",
address: "",
dob: new Date()
});
};
render() {
return (
<div
className="modal fade"
id="exampleModalCenter"
tabIndex="-1"
role="dialog"
aria-labelledby="exampleModalCenterTitle"
aria-hidden="true"
>
<div className="modal-dialog modal-dialog-centered" role="document">
<div className="modal-content">
<div className="modal-header">
<h5 className="modal-title" id="exampleModalCenterTitle">
Add New User
</h5>
<button
type="button"
className="close"
data-dismiss="modal"
aria-label="Close"
>
<span aria-hidden="true">×</span>
</button>
</div>
<div className="modal-body">
<div className="input-group mb-3">
<input
name="name"
type="text"
className="form-control"
placeholder="Name"
aria-label="Name"
aria-describedby="button-addon2"
value={this.state.name}
onChange={this.handleInputChange}
/>
</div>
<div className="input-group mb-3">
<input
name="username"
type="text"
className="form-control"
placeholder="User Name"
aria-label="User Name"
aria-describedby="button-addon2"
value={this.state.username}
onChange={this.handleInputChange}
/>
</div>
<div className="input-group mb-3">
<input
name="email"
type="email"
className="form-control"
placeholder="Email"
aria-label="Email"
aria-describedby="button-addon2"
value={this.state.email}
onChange={this.handleInputChange}
/>
</div>
<div className="input-group mb-3">
<input
name="address"
type="text"
className="form-control"
placeholder="Address"
aria-label="Address"
aria-describedby="button-addon2"
value={this.state.address}
onChange={this.handleInputChange}
/>
</div>
<div className="input-group mb-3">
<input
name="branch"
type="text"
className="form-control"
placeholder="Branch"
aria-label="Branch"
aria-describedby="button-addon2"
value={this.state.branch}
onChange={this.handleInputChange}
/>
</div>
<div className="input-group mb-3">
<DatePicker
name="dob"
type="text"
className="form-control"
placeholder="DOB"
aria-label="DOB"
aria-describedby="button-addon2"
selected={this.state.dob}
onChange={this.handledatepickerchange}
/>
<p
style={{
marginTop: "5px",
fontWeight: "200",
marginLeft: "10px"
}}
>
Date of Birth(dd/mm/yyyy)
</p>
</div>
<div className="input-group mb-3">
<input
name="mobile"
type="number"
className="form-control"
placeholder="Mobile No."
aria-label="Mobile No."
aria-describedby="button-addon2"
value={this.state.mobile}
onChange={this.handleInputChange}
/>
</div>
</div>
<div className="modal-footer">
<br />
<br />
<button
type="button"
className="btn btn-secondary"
data-dismiss="modal"
>
Close
</button>
<button
type="button"
className="btn btn-primary"
data-dismiss="modal"
onClick={this.createUser}
>
Save
</button>
</div>
</div>
</div>
</div>
);
}
}
export default AddUser;
动作
import dispatcher from "../dispatcher/dispatcher";
import { BASE_URL } from "../utils/AppConstants";
export function getUsersList() {
console.log("getting the data! ");
fetch(BASE_URL + "/users")
.then(res => res.json())
.then(
result => {
console.log("res " + result);
dispatcher.dispatch({ type: "RECEIVE_USERS", users: result });
},
// Note: it's important to handle errors here instead of a catch() block so that
// we don't swallow exceptions from actual bugs in components.
error => {
// here manage error and close loading;
console.log("getting error " + error);
}
);
}
export function createNewUser(user) {
console.log("post the data!");
fetch(BASE_URL + "/saveuser", {
method: "POST",
headers: {
Accept: "application/json",
"Content-Type": "application/json"
},
body: JSON.stringify(user)
})
.then(res => res.json())
.then(
result => {
dispatcher.dispatch({ type: "CREATE_USER", newUser: user });
},
// Note: it's important to handle errors here instead of a catch() block so that
// we don't swallow exceptions from actual bugs in components.
error => {
// here manage error and close loading;
console.log("getting error " + error);
}
);
}
商店
import { EventEmitter } from "events";
import dispatcher from "../dispatcher/dispatcher";
class UserStore extends EventEmitter {
constructor() {
super();
dispatcher.register(this.handleActions.bind(this));
this.users = [
{
branch: "19",
name: "Javcbvcsim11",
username: "zxcv",
mobile: "5645654",
email: "demo@gmail.com111",
address: "Demo vcbvcbAddress1",
dob: "2020-11-06T00:00:00.000+0000"
}
];
}
createUser(newUser) {
this.users.push(newUser);
console.log("new users lenght " + this.users.lenght);
this.emit("change");
}
getAll() {
return this.users;
}
handleActions(action) {
switch (action.type) {
case "RECEIVE_USERS": {
this.users = action.users;
this.emit("change");
break;
}
case "CREATE_USER": {
this.createUser(action.newUser);
break;
}
}
}
}
export default new UserStore();
我不知道这里发生了什么问题。当检查堆栈溢出时，我知道这是迭代数据的问题。但我已经这样做了。即使错误仍然存在。如果有人可以提供帮助，那将是非常可观的。 setState 方法中抛出的错误。我在这里使用通量作为架构。当我尝试将新用户添加到我的数据时会出现问题。实际上，当我将它添加到数据库时没有任何问题。问题是当我单击 AddUser 组件中的保存按钮时，它会保存到我的数据库中，但是在它需要再次显示为表格列表但抛出错误之后。
【问题讨论】：
标签： javascript html reactjs