Category: javascript

I wanted to use @keyframes, so I did this:

div {
  width: 100px;
  height: 100px;
  background: red;
  position: relative;
  animation: action 5s infinite;
}

@keyframes action {
  0%   {top: 0px;}
  25%  {top: 200px;}
  75%  {top: 50px}
  100% {top: 100px;}
}

However, this code runs when the page loads. Is there a way to trigger the @keyframes at a certain time with js? eg.

for (var i = 0; i < 10; i++) {
    //Do something
}
//Activate @keyframes

Thanks!

I can open the Chrome DevTools console for this URL: https://www.google.com/ and enter the following command to print “Hello world!” to the console:

console.log("Hello world!")

However, when I attempt to use the same command for this URL: https://svc.mt.gov/dor/property/prc my message isn’t printed in the console. Why is that?

Is there any way to force the console to work for this MT website?

I’ve tried using python/selenium to open the page and execute_script() to issue the command, but that hasn’t worked either.

I’m making a small online multiplayer game with JavaScript and the native Canvas API (WebGL). I want to find the color of pixels on the screen as a form of collision detection, I figure it’d save resources to not have to process every shape every frame, but rather to simply check if the color of a pixel at a certain position is such that it is contacting a shape. (I hope that makes sense)

I ran some tests and I have an average frame delay of about 4-5 milliseconds without collision detection, and then when I make a single call to my canvas context’s .getImageData() method, suddenly that frame delay shoots up to 19-20 milliseconds…

As far as I can find online getImageData() is the only means of checking the color of a given pixel, but I have to think there’s some other way that doesn’t introduce such a huge amount of lag.

I tried running getImageData() on a small section of the screen vs larger sections, and a 1×1 pixel request introduces 10ms latency, where a 600×600 pixel request is about 15ms… So the issue isn’t the amount/size of the request, but rather just the request itself is extremely slow, so there’s no potential for optimization here, I NEED another way.

Also, caching the image data is also not an option. I need to poll these pixels every single frame, I can’t cache it (because the player and the object it needs to collide with are all constantly moving, and they’re being controlled over the internet so there’s also no way of predicting where they’ll be at any given time… I NEED to poll every frame with no exceptions)

I am using Quasar, vue and vuex. I have created a layout and would like to use jest to unit test.
I have been copying bits of my layout code and running test as I go along.

This is my spec code

    import MainLayout from "../../../src/layouts/test";
    import { mountFactory } from "@quasar/quasar-app-extension-testing-unit-jest";
    import { QLayout, QHeader, QToolbar, QBtn, QToolbarTitle, QImg } from "quasar";
    
    const factory = mountFactory(MainLayout, {
      mount: { type: "full" },
      quasar: {
        components: { QLayout, QHeader, QToolbar, QBtn, QToolbarTitle, QImg },
      },
    });
    
    describe("test", () => {
      it("Show leftdrawer if leftDrawer is true", async () => {
        const wrapper = factory(MainLayout);
        await wrapper.vm.$nextTick();
        expect(wrapper.findComponent("button").isVisible()).toBe(true);
      });
    });

When I add this part in my MainLayout.vue 

<div v-if="!isAuthenticated">
      <q-btn
        @click="goTo('signin')"
        outline
        roundeded
        label="sign in"
        name="signin"
        class="q-mr-sm"
      >

And This part

computed: {
  ...mapState("member", {
  isAuthenticated: (state: MemberState) => state.isAuthenticated,
 })

},

I get this error when testing
TypeError: Cannot read properties of undefined (reading ‘state’)

...mapState("member", {
isAuthenticated: (state: MemberState) => state.isAuthenticated,
})

How do I set up my spec file so that it reads in isAuthenticated from state in store.

I need to set my webPage from beginning to start. So I write code like this.

function BasicDetails() {

    React.useEffect(()=>{
        scrollView();
    }, []);

    function scrollView() {
        document.getElementById('main-root').scrollIntoView({behavior: 'smooth'});
    }
    return (
        <Nav>
            <div id="main-root" style={{scrollBehavior: 'smooth'}}>
                <div>
                    <Header pageTitle={'Shop Settings'}/>
                    <Button
                        onClick={saveBasicDetails}
                        variant="contained"
                        id='save'
                        className={classes.saveButton}>
                        SAVE
                    </Button>
                </div>

                <BasicDetailsData style={{scrollBehavior: 'smooth'}} ref={childRef}/>
            </div>
        </Nav>
    );
}

But When I Tried to run my code, I have an error TypeError: Cannot read properties of null (reading ‘scrollIntoView’)
So I tried many times but can’t find the error.
I am a new student for react, so. I don’t know much about it.
Anyone can help me with this…I really need your help..thank you.

Can anyone tell me that how we can download maps and graph in react native
please help it this, i am not able to find any solution for this

I imported a project and when I try todo something that calls the symlink I get this error:
Here is the console

Here is the file with the error:

Here is the file with the error:

I tried reimporting the project multiple times on different IDE’s

I am working on html file. I have two two labels(say L1 and L2). Each label has two radio buttons. I want to hide L2 and it’s radio buttons if a user selects any radio button from L1.

I know this can be done using java script but how to capture the selection of radio buttons on which i can execute my java script.

I got this error when I installed Microsoft’s orchestrator in my node modules using npm install botbuilder-ai-orchestrator and then installed orchestrator-core. Now when I try to run my code of orchestrator, It shows this error. Can anyone tell how to resolve this

i am new to Spring boot application. i have been getting this error every time I try running the codes. i use intellij IDEA as my eidtor.and I have tried the multiple solutions online but I couldn’t fix it. here are the errors

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2021-12-02 12:36:19.105 ERROR 14880 --- [  restartedMain] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not determine type for: Server.accessingdata.Secondhand, at table: reserve, for columns: [org.hibernate.mapping.Column(secondhand)]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1804) ~[spring-beans-5.3.12.jar:5.3.12]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:620) ~[spring-beans-5.3.12.jar:5.3.12]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.12.jar:5.3.12]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.12.jar:5.3.12]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.12.jar:5.3.12]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.12.jar:5.3.12]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.12.jar:5.3.12]
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1154) ~[spring-context-5.3.12.jar:5.3.12]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:908) ~[spring-context-5.3.12.jar:5.3.12]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.12.jar:5.3.12]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.5.6.jar:2.5.6]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) [spring-boot-2.5.6.jar:2.5.6]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434) [spring-boot-2.5.6.jar:2.5.6]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:338) [spring-boot-2.5.6.jar:2.5.6]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) [spring-boot-2.5.6.jar:2.5.6]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1332) [spring-boot-2.5.6.jar:2.5.6]
    at Server.Application.main(Application.java:21) [classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_281]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_281]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_281]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_281]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.5.6.jar:2.5.6]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not determine type for: Server.accessingdata.Secondhand, at table: reserve, for columns: [org.hibernate.mapping.Column(secondhand)]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:421) ~[spring-orm-5.3.12.jar:5.3.12]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396) ~[spring-orm-5.3.12.jar:5.3.12]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.3.12.jar:5.3.12]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1863) ~[spring-beans-5.3.12.jar:5.3.12]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1800) ~[spring-beans-5.3.12.jar:5.3.12]
    ... 21 common frames omitted
Caused by: org.hibernate.MappingException: Could not determine type for: Server.accessingdata.Secondhand, at table: reserve, for columns: [org.hibernate.mapping.Column(secondhand)]
    at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:512) ~[hibernate-core-5.6.1.Final.jar:5.6.1.Final]
    at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:479) ~[hibernate-core-5.6.1.Final.jar:5.6.1.Final]
    at org.hibernate.mapping.Property.isValid(Property.java:231) ~[hibernate-core-5.6.1.Final.jar:5.6.1.Final]
    at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:627) ~[hibernate-core-5.6.1.Final.jar:5.6.1.Final]
    at org.hibernate.mapping.RootClass.validate(RootClass.java:267) ~[hibernate-core-5.6.1.Final.jar:5.6.1.Final]
    at org.hibernate.boot.internal.MetadataImpl.validate(MetadataImpl.java:359) ~[hibernate-core-5.6.1.Final.jar:5.6.1.Final]
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:307) ~[hibernate-core-5.6.1.Final.jar:5.6.1.Final]
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:471) ~[hibernate-core-5.6.1.Final.jar:5.6.1.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1498) ~[hibernate-core-5.6.1.Final.jar:5.6.1.Final]
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) ~[spring-orm-5.3.12.jar:5.3.12]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.3.12.jar:5.3.12]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409) ~[spring-orm-5.3.12.jar:5.3.12]
    ... 25 common frames omitted
Process finished with exit code 0

this is my application.properties

    spring.jpa.hibernate.ddl-auto=update
spring.datasource.url=jdbc:mysql://localhost:3306/4sshop?allowPublicKeyRetrieval=true&useSSL=false
spring.datasource.username=root
spring.datasource.password=12345
spring.datasource.driver-class-name =com.mysql.jdbc.Driver
spring.jpa.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.show-sql: true

this is my application class

package Server;


import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.context.annotation.Bean;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.hibernate5.LocalSessionFactoryBean;
;



@SpringBootApplication(scanBasePackages={"Server.repository"})
@EnableJpaRepositories(basePackages = "Server.repository")


public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

}

this is my entity class

package Server.accessingdata;


import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="user")
public class User{
    @Id

    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="userID")
    private String userID;
    @Column(name="userName")
    private String userName;
    @Column(name="password")
    private String password;
    @Column(name="Level")
    private Integer Level;

    public User() {}
    public User(String userID, String userName, String password, Integer Level) {
        this.userID=userID;
        this.userName=userName;
        this.password=password;
        this.Level=Level;

    }

    public String getuserid() {
        return userID;
    }
    public void setuserID(String userID) {
        this.userID = userID;
    }

    public String getusername() {
        return userName;
    }
    public void setusername(String userName) {
        this.userName = userName;
    }

    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public Integer getlevel() {
        return Level;
    }
    public void setlevel(Integer Level) {
        this.Level = Level;
    }
    @Override
    public String toString() {
        return "User[userID="+ userID +", userName="+ userName +", password="+ password +", Level="+ Level +"]";
    }
}

this is my repository class

package Server.repository;
import java.util.List;
import java.util.Optional;

import org.springframework.data.jpa.repository.JpaRepository;
import Server.accessingdata.User;

public interface UserRepo extends JpaRepository<User,Long>  {
    Optional<User>  findByUsername(String userName);
    List<User>  findByuserID(String userID);
    List<User>  findByPassword(String password);
    List<User>  findBylevel(Integer Level);
}

and this is my controller class

package Server.controller;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import Server.accessingdata.User;
import Server.repository.UserRepo;

@CrossOrigin(origins="http://localhost:8081")
@RestController
@RequestMapping("/api")

public class UserControl {
    @Autowired

    UserRepo userRepo;

    @GetMapping("/users")
    public ResponseEntity<List<User>>getAllUsers(@RequestParam(required=false) String userID){
        try {
            List<User> users= new ArrayList<User>();
            if(userID==null)
                userRepo.findAll().forEach(users::add);
            else
                userRepo.findByuserID(userID).forEach(users::add);
            if(users.isEmpty()) {
                return new ResponseEntity<>(HttpStatus.NO_CONTENT);
            }
            return new ResponseEntity<>(users, HttpStatus.OK);
        }catch (Exception e) {
            return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }
    @GetMapping("/users/{userName}")
    public ResponseEntity<User>getUserByUsername(@PathVariable("userName")String userName){
        Optional<User> UserData= userRepo.findByUsername(userName);
        if(UserData.isPresent()) {
            return new ResponseEntity<>(UserData.get(), HttpStatus.OK);
        }else {
            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
        }
    }
    @PostMapping("/users")
    public ResponseEntity<User> createUser(@RequestBody User user){
        try {
            User _user= userRepo.save(new User(user.getuserid(), user.getusername(), user.getPassword(), user.getlevel()));
            return new ResponseEntity<>(_user, HttpStatus.CREATED);
        }catch(Exception e) {
            return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }
    @PutMapping("/users{userName}")
    public ResponseEntity<User> updateUser(@PathVariable("userName") String userName, @RequestBody User user){
        Optional<User> UserData= userRepo.findByUsername(userName);
        if(UserData.isPresent()) {
            User _user= UserData.get();
            _user.setusername(user.getusername());
            _user.setuserID(user.getuserid());
            _user.setPassword(user.getPassword());
            _user.setlevel(user.getlevel());
            return new ResponseEntity<>(userRepo.save(_user), HttpStatus.OK);
        }else {
            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
        }
    }
    @DeleteMapping("/users")
    public ResponseEntity<HttpStatus> deleteAllUsers(){
        try {
            userRepo.deleteAll();
            return new ResponseEntity<>(HttpStatus.NO_CONTENT);
        }catch(Exception e) {
            return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }
    @GetMapping("/users/Level")
    public ResponseEntity<List<User>> findByLevel(){
        try{
            List<User> users= userRepo.findBylevel(null);
            if(users.isEmpty()) {
                return new ResponseEntity<>(HttpStatus.NO_CONTENT);
            }return new ResponseEntity<>(users, HttpStatus.OK);
        }catch(Exception e) {
            return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }

}

And also I have added my pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.6</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>Server</groupId>
    <artifactId>carServer</artifactId>  <version>0.0.1-SNAPSHOT</version>
    <name>4sserver</name>
    <description>server for 4sshop</description>
    <properties>
            
            <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.6.1.Final</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

In web serial api, I am able to open ports on button click. Is there any way to open port once the port is connected ? onconnect event does not open port, asking for user gesture…I need automatic open for mass production…

I am running a nodejs server file, code below. Currently the code you see does not have the HTML or CSS referenced because I don’t know how to do it.

const http = require('http');

// Create an instance of the http server to handle HTTP requests
let app = http.createServer((req, res) => {
    // Set a response type of plain text for the response
    res.writeHead(200, {'Content-Type': 'text/plain'});

    // Send back a response and end the connection
    res.end('Hello World!n');
});

// Start the server on port 3000
app.listen(3000, '127.0.0.1');
console.log('Node server running on port 3000');

In a folder that looks like this

I have already searched online for hours, looked at previous stackoverflow posts, and I still haven’t found the answer. I got the HTML file to load at one point, but I was not able to get the CSS file to load.

I’m trying conect my website with PagSeguro API. In Insomnia the request works, but in my website, the cors is the problem.

Problem:
x

Access to XMLHttpRequest at 'https://sandbox.api.pagseguro.com/charges' from origin 'https://mobile-andre-luis.web.app' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

buyCartela.js:107 POST https://sandbox.api.pagseguro.com/charges net::ERR_FAILED

Code Section:

const request = new XMLHttpRequest();
const body = {
        "reference_id": ``,
        "description": ``,
        "amount": {
            "value": 200,
            "currency": "BRL"
        },
        "payment_method": {
            "type": "CREDIT_CARD",
            "installments": 1,
            "capture": true,
            "soft_descriptor": "Cartela do Bode da Sorte",
            "card": {
                "number": ``,
                "exp_month": ``,
                "exp_year": ``,
                "security_code": ``,
                "holder": {
                    "name": ``
                }
            }
        },
        "notification_urls": [
            "http://127.0.0.1:5500/form/buyVerify.html"
        ],
        "metadata": {
            "idVendedor": "Papai Noel",
            "idCartela": ``,
            "nameComprador": ``,
            "phoneComprador": ``,

        }
    };


    const url = `https://sandbox.api.pagseguro.com/charges`;
    request.open("POST", url, true);
    request.setRequestHeader("Access-Control-Allow-Origin","*");
    request.setRequestHeader("Content-type","application/json");
    request.setRequestHeader("Authorization","x");
    request.setRequestHeader("x-api-version","4.0");
    request.send(body);

    console.log(request.response)

I have the following javascript that works happily the 1st time but fails the second time..

    xhttp = new XMLHttpRequest();               
    xhttp.open("POST","FINDMOVES",false);
    xhttp.send(text);       

This send is actually being received by the server and a respone is written by the server. The server is my own and written in assembler.
The java console reports:-

POST http://localhost:1024/FINDMOVES net::ERR_EMPTY_RESPONSE
Uncaught DOMException: Failed to execute ‘send’ on ‘XMLHttpRequest’: Failed to load ‘http://localhost:1024/FINDMOVES’.

This code works happily where it is used in other programs.

I am aware that:- “[Deprecation] Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user’s experience” but it is not java’s decision as to what my end user experience is like. It is mine.

Anyone got any clues ??

In JavaScript, I can create Symbol -primitives like this:

const ex1 = Symbol('example1');
const ex2 = Symbol.for('example2');

And I can get the original string that was used to create the Symbol by accessing the Symbol.prototype.description, or by calling the Symbol.keyFor() -method like so:

ex1.description; // 'example1'
ex2.description; // 'example2'
// OR
Symbol.keyFor(ex1); // undefined
Symbol.keyFor(ex2); // 'example2'

My questions are;

• Is there any difference between the two methods, other than Symbol.keyFor not working for Symbols that are not in the global registry (i.e. created from Symbol.for())? It seems to me they are otherwise used to achieve the exact same thing.
• Is there a reason to ever prefer using Symbol.keyFor() instead of Symbol.prototype.description? Since the description works for all Symbols, while keyFor works only for ones in the global registry.