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[英]React: Redirect based on flag: 'redirect' flag should be set to true, yet flag appears false at all times
[英]My isLoading flag never set true in the constructor()
我正在使用一個代表性組件(ProjectFormUpdate)和他的容器(ProjectFormUpdateContainer)。 從容器中,我發送一個文檔對象Project和一個標志isLoading。 但是在ProjectFormUpdate的Constructor()中,該標志為false ...永遠不會設置狀態。
代表性的組成部分
import React, { Component} from 'react';
import ReactDOM from 'react-dom';
import { Projects } from '/imports/api/projects.js';
import PropTypes from 'prop-types'; // ES6
import { withTracker } from 'meteor/react-meteor-data';
export default class ProjectFormUpdate extends Component {
handleUpdate(event) {
event.preventDefault();
console.log("se modificó el estadoooo")
this.setState({
codigo: ReactDOM.findDOMNode(this.refs.codigoInput).value.trim(),
nombre: ReactDOM.findDOMNode(this.refs.nombreInput).value.trim()
});
}
handleSubmit(event){
this.setState({
codigo: ReactDOM.findDOMNode(this.refs.codigoInput).value.trim(),
nombre: ReactDOM.findDOMNode(this.refs.nombreInput).value.trim()
});
}
constructor(props) {
super(props);
if (!props.isLoading){
this.state = {
codigo: props.oneProject.codigo,
nombre: props.oneProject.nombre}
}
else{
this.state = {
codigo: 'dd',
nombre: 'ff'}
}
}
render() {
const { oneProject, isLoading } = this.props;
if (!isLoading){
this.setState = {
codigo: this.props.oneProject.codigo,
nombre: this.props.oneProject.nombre}
return (
<div className="col-xs-11">
<div className="box box-solid">
<form className="form" onSubmit={this.handleSubmit.bind(this)} >
<div className="box-body">
<div className="row">
<div className="col-xs-2">
<input
className = "form-control input-sm"
type="text"
ref="codigoInput"
placeholder="Código del Proyecto"
value = {this.state.codigo}//this.state.codigo}
onChange = {this.handleUpdate.bind(this)}
/>
</div>
<div className="col-xs-6">
<input
className = "form-control input-sm"
type="text"
ref="nombreInput"
placeholder="Título"
value = {this.state.nombre }
onChange = {this.handleUpdate.bind(this)}
/>
</div>
</div>
</div>
<div className="box-footer">
<button type="submit" className="btn btn-sm btn-primary btn-flat">Guardar</button>
</div>
</form>
</div>
</div>
);
}
else {return (<div></div>);}
}}
ProjectFormUpdate.propTypes = {
// This component gets the task to display through a React prop.
// We can use propTypes to indicate it is required
oneProject: React.PropTypes.object,
isLoading: React.PropTypes.bool,
};
容器
import { Meteor } from 'meteor/meteor';
import { withTracker } from 'meteor/react-meteor-data';
import { Projects } from '/imports/api/projects.js';
import ProjectFormUpdate from './ProjectFormUpdate.jsx';
export default ProjectFormUpdateContainer = withTracker(({ key1 }) => {
const sub = Meteor.subscribe('projects');
var oneProject = Projects.findOne(key1);
var isLoading = !sub.ready();
return {
oneProject,
isLoading,
};
})(ProjectFormUpdate);
所以...如果我無法設置狀態,則無法以受控方式設置表單的值。 有什么建議嗎?
為了在constructor()
函數之外設置組件狀態:您必須調用this.setState()
。 this.setState()
會將其第一個參數設置為新狀態,並隨后調用組件的render函數。
您的if (!isLoading)
語句非常危險。 假設!isLoading == true
:您的渲染函數將無限觸發this.setState()
,從而鎖定您的瀏覽器。
您的構造函數按原樣顯示正確。 我將允許它設置初始應用程序狀態,並從render()
函數中處理其余部分。 或者,您可以在此處找到的componentWillMount()
或componentDidMount()
函數中設置初始狀態。
在您的render()
函數中,我將省略if (!isLoading)
部分,而是嘗試返回一個加載組件if (isLoading == true)
。
您還可以將以下邏輯直接應用於<input/>
元素,以巧妙地設置組件的狀態:
<input value={this.state.key} onChange={(event) => this.setState({key: event.target.value})}/>
我已經對您的ProjectFormUpdate
組件進行了如下修改:
import React, { Component} from 'react';
import ReactDOM from 'react-dom';
import { Projects } from '/imports/api/projects.js';
import PropTypes from 'prop-types'; // ES6
import { withTracker } from 'meteor/react-meteor-data';
export default class ProjectFormUpdate extends Component {
handleSubmit(event){
event.preventDefault()
console.log()
}
constructor(props) {
super(props);
if (!props.isLoading) {
this.state = {
codigo: props.oneProject.codigo,
nombre: props.oneProject.nombre
}
}
else {
this.state = {
codigo: '',
nombre: ''
}
}
}
render() {
const { oneProject, isLoading } = this.props;
if (isLoading) {
return (
<div>isLoading == true</div>
)
}
return (
<div className="col-xs-11">
<div className="box box-solid">
<form className="form" onSubmit={this.handleSubmit.bind(this)} >
<div className="box-body">
<div className="row">
{/* Codigo. */}
<div className="col-xs-2">
<input className = "form-control input-sm" type="text" ref="codigoInput" placeholder="Código del Proyecto" value={this.state.codigo} onChange={(event) => this.setState({codigo: event.target.value})} />
</div>
{/* Nombre. */}
<div className="col-xs-6">
<input className = "form-control input-sm" type="text" ref="nombreInput" placeholder="Título" value={this.state.nombre} onChange={(event) => this.setState({nombre: event.target.value}))} />
</div>
</div>
</div>
<div className="box-footer">
<button type="submit" className="btn btn-sm btn-primary btn-flat">Guardar</button>
</div>
</form>
</div>
</div>
)
}
ProjectFormUpdate.propTypes = {
oneProject: React.PropTypes.object,
isLoading: React.PropTypes.bool,
};
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