我正在尝试使照片博客/ phlog管理器组件正常运行。但是控制台通过props表示存在一个未定义的对象。
import React, { Component } from 'react';
import axios from 'axios';
import DropzoneComponent from 'react-dropzone-component';
import "../../../node_modules/react-dropzone-component/styles/filepicker.css";
import "../../../node_modules/dropzone/dist/min/dropzone.min.css";
class PhlogEditor extends Component {
constructor(props) {
super(props);
this.state = {
id: '',
phlog_status: '',
phlog_image: '',
editMode: false,
position: '',
apiUrl: 'http://127.0.0.1:8000/phlogapi/phlog/',
apiAction: 'post'
};
this.handleChange = this.handleChange.bind(this);
this.handleSubmit = this.handleSubmit.bind(this);
this.componentConfig = this.componentConfig.bind(this);
this.djsConfig = this.djsConfig.bind(this);
this.handlePhlogImageDrop = this.handlePhlogImageDrop.bind(this);
this.deleteImage = this.deleteImage.bind(this);
this.phlogImageRef = React.createRef();
}
deleteImage(event) {
event.preventDefault();
axios
.delete(
`http://127.0.0.1:8000/phlogapi/phlog/${this.props.id}/delete`,
{ withCredentials: true }
)
.then(response => {
this.props.handlePhlogImageDelete();
})
.catch(error => {
console.log('deleteImage failed', error)
});
}
错误发生在Object.keys（this.props.phlogToEdit）.length> 0
componentDidUpdate() {
if (Object.keys(this.props.phlogToEdit).length > 0) {
// debugger;
const {
id,
phlog_image,
phlog_status,
position
} = this.props.phlogToEdit;
this.props.clearPhlogsToEdit();
this.setState({
id: id,
phlog_image: phlog_image || '',
phlog_status: phlog_status || '',
position: position || '',
editMode: true,
apiUrl: `http://127.0.0.1:8000/phlogapi/phlog/${this.props.id}/update`,
apiAction: 'patch'
});
}
}
handlePhlogImageDrop() {
return {
addedfile: file => this.setState({ phlog_image_url: file })
};
}
componentConfig() {
return {
iconFiletypes: [".jpg", ".png"],
showFiletypeIcon: true,
postUrl: "https://httpbin.org/post"
};
}
djsConfig() {
return {
addRemoveLinks: true,
maxFiles: 3
};
}
buildForm() {
let formData = new FormData();
formData.append('phlog[phlog_status]', this.state.phlog_status);
if (this.state.phlog_image) {
formData.append(
'phlog[phlog_image]',
this.state.phlog_image
);
}
return formData;
}
handleChange(event) {
this.setState({
[event.target.name]: event.target.value
});
}
handleSubmit(event) {
axios({
method: this.state.apiAction,
url: this.state.apiUrl,
data: this.buildForm(),
withCredentials: true
})
.then(response => {
if (this.state.phlog_image) {
this.phlogImageRef.current.dropzone.removeAllFiles();
}
this.setState({
phlog_status: '',
phlog_image: ''
});
if (this.props.editMode) {
this.props.handleFormSubmission(response.data);
} else {
this.props.handleSuccessfulFormSubmission(response.data);
}
})
.catch(error => {
console.log('handleSubmit for phlog error', error);
});
event.preventDefault();
}
render() {
return (
<form onSubmit={this.handleSubmit} className='phlog-editor-wrapper'>
<div className='one-column'>
<div className='image-uploaders'>
{this.props.editMode && this.props.phlog_image_url ? (
<div className='phlog-manager'>
<img src={this.props.phlog.phlog_image_url} />
<div className='remove-image-link'>
<a onClick={() => this.deleteImage('phlog_image')}>
Remove Photos
</a>
</div>
</div>
) : (
<DropzoneComponent
ref={this.phlogImageRef}
config={this.componentConfig()}
djsConfig={this.djsConfig()}
eventHandlers={this.handlePhlogImageDrop()}
>
<div className='phlog-msg'>Phlog Photo</div>
</DropzoneComponent>
)}
</div>
<button className='btn' type='submit'>Save</button>
</div>
</form>
);
}
}
export default PhlogEditor;
我不明白当道具来自父组件时对象是如何空的
phlog-manager.js：
import React, { Component } from "react";
import axios from "axios";
import PhlogEditor from '../phlog/phlog-editor';
export default class PhlogManager extends Component {
constructor() {
super();
在这里，我将phlogToEdit定义为作为道具传递给phlogEditor子组件的对象
this.state = {
phlogItems: [],
phlogToEdit: {}
};
this.handleNewPhlogSubmission = this.handleNewPhlogSubmission.bind(this);
this.handleEditPhlogSubmission = this.handleEditPhlogSubmission.bind(this);
this.handlePhlogSubmissionError = this.handlePhlogSubmissionError.bind(this);
this.handleDeleteClick = this.handleDeleteClick.bind(this);
this.handleEditClick = this.handleEditClick.bind(this);
this.clearPhlogToEdit = this.clearPhlogToEdit.bind(this);
}
clearPhlogToEdit() {
this.setState({
phlogToEdit: {}
});
}
handleEditClick(phlogItem) {
this.setState({
phlogToEdit: phlogItem
});
}
handleDeleteClick(id) {
axios
.delete(
`http://127.0.0.1:8000/phlogapi/phlog/${id}`,
{ withCredentials: true }
)
.then(response => {
this.setState({
phlogItems: this.state.phlogItems.filter(item => {
return item.id !== id;
})
});
return response.data;
})
.catch(error => {
console.log('handleDeleteClick error', error);
});
}
handleEditPhlogSubmission() {
this.getPhlogItems();
}
handleNewPhlogSubmission(phlogItem) {
this.setState({
phlogItems: [phlogItem].concat(this.state.phlogItems)
});
}
handlePhlogSubmissionError(error) {
console.log('handlePhlogSubmissionError', error);
}
getPhlogItems() {
axios
.get('http://127.0.0.1:8000/phlogapi/phlog',
{
withCredentials: true
}
)
.then(response => {
this.setState({
phlogItems: [...response.data]
});
})
.catch(error => {
console.log('getPhlogItems error', error);
});
}
componentDidMount() {
this.getPhlogItems();
}
render() {
return (
<div className='phlog-manager'>
<div className='centered-column'>
这是将phlogToEdit对象作为道具传递给提到的子组件的地方
<PhlogEditor
handleNewPhlogSubmission={this.handleNewPhlogSubmission}
handleEditPhlogSubmission={this.handleEditPhlogSubmission}
handlePhlogSubmissionError={this.handleEditPhlogSubmission}
clearPhlogToEdit={this.clearPhlogToEdit}
phlogToEdit={this.phlogToEdit}
/>
</div>
</div>
);
}
}
最佳答案
@ Jaycee444解决了它是父组件的问题！
phlogToEdit = {this.state.phlogToEdit}