问题描述
因此，我一直在尝试通过使更新方法直接更改状态并在文本字段中读取状态，来使状态“真相”在我的工作中发挥作用。除了编写更多代码之外，此方法是否没有其他缺点？还是通过将update字段设置为TagTable组件内的单独状态并将onSubmit与上下文状态合并，通常不会带来安全隐患。
这些类型的更新方法的最佳实践或一般规则是什么？
TagContextProvider
请注意update（），handleChange（）和resetTag（），因为它们与问题有关。向下滚动以查看表格组件。public String scanAasha(String aashacomand){
aasha=aashacomand;
mAdapter = BluetoothAdapter.getDefaultAdapter();
if (mAdapter!= null) {
mAdapter.startdiscovery();
aashadiscovery();
}
if (mBluetoothChatServiceaasha.maasha.contains("B_")) {
String a[] = mBluetoothChatServiceaasha.maasha.split("_");
return a[1] + " " + a[2];
}
if (mBluetoothChatServiceaasha.maasha.contains("O_")) {
String a[] = mBluetoothChatServiceaasha.maasha.split("_");
return a[1] + " " + a[2];
}
if (mBluetoothChatServiceaasha.maasha.contains("T_")) {
String a[] = mBluetoothChatServiceaasha.maasha.split("_");
return a[2];
}
return aashacomand;
}
public void aashadiscovery() {
int hasPermission = ActivityCompat.checkSelfPermission(MainActivity.this,Manifest.permission.ACCESS_COARSE_LOCATION);
if (hasPermission == PackageManager.PERMISSION_GRANTED) {
registerReceiver(searchAasha,intentFilteractions());
mAdapter.startdiscovery();
return;
}
else{
ActivityCompat.requestPermissions(MainActivity.this,new String[]{
android.Manifest.permission.ACCESS_COARSE_LOCATION},AASHA_REQUEST_COARSE_LOCATION_PERMISSIONS);
registerReceiver(searchAasha,intentFilteractions());
mAdapter.startdiscovery();
return;
}
}
private broadcastReceiver searchAasha = new broadcastReceiver() {
@Override
public void onReceive(Context context,Intent intent) {
String action = intent.getAction();
Bundle b = intent.getExtras();
Object[] lstName = b.keySet().toArray();
// ??????????????????????
for (int i = 0; i < lstName.length; i++) {
String keyName = lstName[i].toString();
Log.e(keyName,String.valueOf(b.get(keyName)));
}
if(BluetoothDevice.ACTION_FOUND.equals(action)){
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
if (device.getName()==null) {
return;
}
if (device.getName().contains("SPP")) {
mBluetoothChatServiceaasha.start();
mBluetoothChatServiceaasha.connect(device);
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
// Todo Auto-generated catch block
e.printstacktrace();
}
}
}
}
};
TagTable
请注意setEdit（），onEditSubmit（）和onEditClose（）import React,{createContext} from 'react';
import {withAlertContext} from './AlertContext';
import axios from 'axios';
export const NewTagContext = createContext();
class NewTagContextProvider extends React.Component {
constructor(props) {
super(props);
this.state = {
tags: null,processing: false,read: this.read.bind(this),create: this.create.bind(this),delete: this.delete.bind(this),update: this.update.bind(this),resetTag: this.resetTag.bind(this),handleChange: this.handleChange.bind(this),};
};
render() {
return (
<NewTagContext.Provider value={{
...this.state,}}>
{this.props.children}
</NewTagContext.Provider>
);
}
/**
* Takes an array of tags and finds the highest number of the id's,adds +1 to it and returns that
* @param {[]} [array=this.state.tags] - array of tags
* @returns {number} - generated id
*/
findHighestId(array = this.state.tags) {
let max = 0;
for (let i = 0,len = array.length; i < len; i++) {
if (array[i].id > max) max = array[i].id;
}
return max + 1;
}
/**
* EDIT TAG HANDLER
* @param {object} index - index of tag to be updated
* @param {object} e - event
*/
handleChange(index,e) {
// find and replace
const TAGS_copY = this.state.tags.slice();
TAGS_copY[index].name = e.target.value;
this.setState({tags: TAGS_copY});
}
/**
* @param originalTag - the tag before the user starts typing in the text field.
*/
resetTag(originalTag) {
//copy state
const TAGS_copY = this.state.tags.slice();
//find tag in copy
let TAG_copY = TAGS_copY.find(tag => tag.id === originalTag.id);
//replace new name to the old name
TAG_copY.name = originalTag.name;
//overwrite the state
this.setState({
tags: TAGS_copY,});
}
/**
* @param {object} createdTag - a new tag created by the user
* @param {string} createdTag.name - name of the created tag
*/
async create(createdTag) {
// INITIATE
if (this.state.processing) return;
else this.setState({processing: true});
// PREParaTION START
const INITIAL_TAGS = this.state.tags.slice();
const RESET = () => this.setState({tags: INITIAL_TAGS,processing: false});
const {alertContext} = this.props;
// PREParaTION END
if (INITIAL_TAGS)
try {
// CLIENT OPTIMIZATION START
const NEW_TAG_FROM_CLIENT_WITH_ID = {...createdTag,id: this.findHighestId()};
this.setState({tags: this.state.tags.concat(NEW_TAG_FROM_CLIENT_WITH_ID)});
// CLIENT OPTIMIZATION END
// REQUEST START
const r = await axios.post('/api/tag/create',NEW_TAG_FROM_CLIENT_WITH_ID);
const {alert: ALERT,tag: NEW_TAG_FROM_SERVER} = r.data;
// REQUEST END
// PROCESS ALERT
alertContext.setAlert(ALERT);
// SERVER SIDE ERROR CATCHER START
if (ALERT.level !== 'success') {
RESET();
return;
}
// SERVER SIDE ERROR CATCHER END
// IF SERVER SIDE IS SUCCESSFUL
// CHECK IF SERVER DATA MATCHES CLIENT DATA START
if (NEW_TAG_FROM_SERVER.id !== NEW_TAG_FROM_CLIENT_WITH_ID.id) {
// CORRECT THE DATA
this.setState((state) => {
const TAGS = state.tags.slice();
const TAG = TAGS.find(tag => tag.id === NEW_TAG_FROM_CLIENT_WITH_ID.id);
TAG.id = NEW_TAG_FROM_SERVER.id;
return {tags: TAGS,processing: false};
});
}
// CHECK IF SERVER DATA MATCHES CLIENT DATA END
else {
this.setState({processing: false});
}
} catch (e) {
alertContext.setAlert({
text: [
e,'Something went wrong while trying to create a tag.','Check your internet connection to make sure you didn\'t lose it or perhaps our servers may be down for maintenance.',],level: 'error',});
RESET();
}
}
/**
* Gets all tags from the database
* @returns {Promise<void>}
*/
async read() {
// INITIATE
if (this.state.processing) return;
else this.setState({processing: true});
// PREParaTION START
const {alertContext} = this.props;
// PREParaTION END
try {
//REQUEST
const r = await axios.get('/api/tag/read');
//HANDLE REQUEST
this.setState({tags: r.data,processing: false});
} catch (e) {
//CLIENT SIDE ERROR START
alertContext.setAlert({
text: [
e,});
this.setState({tags: [],processing: false});
//CLIENT SIDE ERROR END
}
}
/**
* Updates a tag by replacing the name key of the tag object
* @param {object} originalTag
* @param {number} originalTag.id
* @param {string} originalTag.name
* @returns {Promise<void>}
*/
async update(originalTag) {
// PREParaTION START
const INITIAL_TAGS = this.state.tags.slice();
const RESET = () => {this.setState({tags: INITIAL_TAGS,processing: false});};
const {alertContext} = this.props;
// PREParaTION END
try {
// UPDATE CLIENT START
const TAG_copY = INITIAL_TAGS.slice().find(tag => tag.id === originalTag.id);
if (TAG_copY.name === originalTag.name) {
alertContext.setAlert({text: 'There was no change to the tag.',level: 'info'});
this.setState({processing: false});
return;
}
// UPDATE CLIENT END
// REQUEST START
const r = await axios.put('/api/tag/update/' + originalTag.id,TAG_copY);
const {alert: ALERT} = r.data;
alertContext.setAlert(ALERT);
// REQUEST END
// SERVER SIDE ERROR START
if (ALERT.level !== 'success')
RESET();
else
this.setState({processing: false});
// SERVER SIDE ERROR END
} catch (e) {
// CLIENT SIDE ERROR START
alertContext.setAlert({
text: [
e,'Something went wrong while trying to update the tag.',});
RESET();
// CLIENT SIDE ERROR END
}
}
/**
* Removes a tag from the state,in case it Could not be removed from the database: undo
* @param {object} tag
* @param {number} tag.id
* @param {string} tag.name
*/
async delete(tag) {
// INITIATE
if (this.state.processing) return;
else this.setState({processing: true});
//PREParaTION START
const INITIAL_TAGS = this.state.tags.slice();
const RESET = () => {this.setState({tags: INITIAL_TAGS,processing: false});};
const {alertContext} = this.props;
//PREParaTION END
try {
// DELETE ON CLIENT SIDE START
const FILTERED_TAGS = INITIAL_TAGS.slice().filter(initialTag => initialTag.id !== tag.id);
this.setState({tags: FILTERED_TAGS});
// DELETE ON CLIENT SIDE END
// REQUEST START
const r = await axios.delete('/api/tag/delete/' + tag.id);
const {alert: ALERT} = r.data;
// REQUEST END
// PROCESS ALERT
alertContext.setAlert(ALERT);
// SERVER SIDE ERROR START
if (ALERT.level !== 'success')
RESET();
else
this.setState({processing: false});
// SERVER SIDE ERROR END
} catch (e) {
alertContext.setAlert({
text: [
e,'Something went wrong while trying to delete the tag.',});
RESET();
}
}
}
export default withAlertContext(NewTagContextProvider);
解决方法
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