Category: javascript

import React,{useState} from "react";
export default function Validate() {
  const [value, setValue] = useState("");
  const [disable, setDisable] = useState(false);
  function handleChange(e) {
    setValue(e.target.value);
    if (e.target.value.length <10)
     {
      setDisable(true);
    }
  }
  return (
    <>
      Phn:<input error={disable} type="number" value={value} onChange={handleChange}/>
      <button disabled={!disable}>click</button> 
    </>
  );
}

in this case initially button is disabled but when i type one number button is enabled but i need untill user give 10 digit phone number button is disabled

var userid 


User.find({ name: "송형준" }).then(result =>{
    result.forEach(result => {
        userid = result._id
    })
});

const create_room = new Room({
    room_name: 'sexy',
    user_list: `${userid}`,
})

create_room.save()

I’ve been trying to run this code.
But it doesn’t work.
I think the ploblem is in the grammar

So new window['my_class']() does not appear to work, at least inside a Electron renderer process. Are there any alternatives?

import useState from "react-usestateref";

const [meta, setMeta, metaRef] = useState({});

Inside component’s JSX:

data.result.map((token) => {
                        const id = token.token_id;
                        const params = { uri: token.token_uri };

                        if (token.metadata) {
                            setMeta(JSON.parse(token.metadata));
                        } else {
                            Moralis.Cloud.run("get_token_uri", params).then(
                                (response) => setMeta(response)
                            );
                        }
                        const { name, description, imageUrl } = metaRef.current;
                        return (
                            <Card
                                key={id}
                                tokenId={id}
                                name={name}
                                description={description}
                                user_address={user_address}
                                imageUrl={fixURL(imageUrl)}
                                calledFrom={calledFrom}
                            />
                        );
                    })

I want to update the meta state variable from inside data.result.map and use the updated meta object to return a Card component. I’m using react-usestateref to get the current value of the meta state variable. Otherwise, meta still remains {} when de-structuring, even after being updated. If token.metadata is not null I want to set the meta state var to token.metadata obj and if it is null, I want to make an asynchronous request to get back the object from Moralis and then set it to the meta state var. This code is producing the following error: Uncaught Error: Too many re-renders. React limits the number of renders to prevent an infinite loop.

How can I make this code work as intended?

In the backend I can use my Token to search after Notes which User creates.
In my Frontend project it doesn´t show me my Posts ..

I store my token in localStorage “userInfo” .. so it can be taken from there if I login to my account.

my NotesSchema :

const forumSchema = ({
    forumName: {
        type: String,
        required: true,
    },
    forumDescription: {
        type: String,
        required: true,
    },
    createdBy: { 
        type: Schema.Types.ObjectId, ref: 'User' 
    },
    published_on: {
        type: String,
        default: moment().format("LLL")
    },
});

My note route :

router.get('/getByOwnerID',verifyToken,ForumService.getByToken);

And the function which I wrote for that :

exports.getByToken = async (req, res, next) => {
  Forum.find({ userID: req.token.userID }) 
  .then(doc => {
      if(!doc) { return res.status(400).end();}
      return res.status(200).json(doc);
  })
  .catch(err => next(err));
}

And the frontend noteAction.js:

export const listNotes = () => async (dispatch, getState) => {
    try{
        dispatch({
            type: NOTES_LIST_REQUEST,
        });
        const {
            userLogin: { userInfo },
        } = getState();

        const config = {
            headers: {
                Authorization: `Bearer ${userInfo.token}`,
            },
        };

        const { data } = await axios.get(`http://localhost:8080/forum/getByOwnerID`, config);
        
        dispatch({
            type: NOTES_LIST_SUCCESS,
            payload: data,

        });
        }catch(error){
            const message = 
                error.response && error.response.data.message
                    ? error.response.data.message
                    : error.message;
            dispatch({
                type: NOTES_LIST_FAIL,
                payload: message,
            });
        }
    }

I hope it´s clear if not I can add Information ..

I am new to native script with angular. I was searching for checkbox and radio button but i can’t find anything for native script. I found some npm packages for checkbox and radio button but it doesn’t support for ios devices. It only supports for android device. Please help me for right solutions

i would like to create a battle system for an rpg game ,where an opening animation plays showing the battling characters move from the side of the screen to a location on the screen. Current code, assets and current running view provided below;

<!doctype html> 
<html lang="en"> 
<head> 
    <meta charset="UTF-8" />
    <title>battle</title>
    <script src="phaser.js"></script>
    <style type="text/css">
        body {
            margin: 0;
        }
    </style>
</head>
<body>


<script type="text/javascript">
var config = {
    type: Phaser.AUTO,
    width: 1900,
    height: 900,
    physics: {
        default: 'arcade',
        arcade: {
            gravity: { y: 0},
            debug: false
        }
    },
    scene: {
        preload: preload,
        create: create,
        update: update,
        
        }
    };
var game = new Phaser.Game(config);

function preload(){ 
    this.load.image("background","assets/battle background.png");
    this.load.image("hydroBot","assets/water hydrant.png");
    
};
function create(){
    const battle = this.add.image(0,0,"background").setOrigin(0,0);
    const bot= this.add.image(1000,200,"hydroBot");
    bot.setScale(5);
   
    
};
function update(){

};

</script>
</body> 

water_hydrant/hydrobot

the battle background

the current view when running the code

much appreciated thanks 🙂

With the code below, I am trying to open a new window, look for certain span-elements, and click each of them. However, I cannot access the code of the new window through XPath.

• Inserting the code (copy & paste) of the clickElem function directly in the new tab works fine
• CORS shouldn’t be a problem since it’s the same domain
• I’ve been also following this answer.

JavaScript:

const w = window.open('https://example.com', 'Example', 'width=500, height=500');
w.clickElem = () => {
    const xpath = '//span[text()="Click here"]';
    const selectedNodeElements = w.document.evaluate(xpath, document, null, XPathResult.ANY_TYPE, null);
    let currentNode = selectedNodeElements.iterateNext();
    while (currentNode) {
        currentNode.click();
        currentNode = selectedNodeElements.iterateNext();
    }
}
setTimeout(w.clickElem, 8000);

When I try to access the text via currentNode.textContent I receive following error:

"Error in protected function: Cannot read properties of null (reading 'textContent')"

Grateful for every hint!

HOW CAN I SET DATA INTO THE STATE?

** And how can i solve createContext error? **

export const LastChanceContext = createContext() //in there return error: Expected 1 arguments, but got 0.

export const GET_LASTCHANCE = “GET_LASTCHANCE”

const LastChanceWrapper = ({children} : {children:any}) => {

const initialState = {
    lastChances: [],
    lastChance: {}
};
console.log('asd',initialState);

const [state, dispatch] = useReducer(lastChanceReducer, initialState);

useEffect(() => {
    const getLastChance = async () => {
        const result = await axiosFetch('http://65.21.148.176:2803/api/Home/Get');
        const action = {
            type:GET_LASTCHANCE,
            payload:result.data.data.lastChanceList
        };
        if(Object.keys(result).length !== 0) {
             dispatch(
                 {state,
                action}
             )

            console.log(result.data.data.lastChanceList);
        }

    };

    getLastChance();
}, [])


return (
    <LastChanceContext.Provider value={{
        lastChances: state.lastChances,
        lastChance: state.lastChance
    }}>
        {children}
    </LastChanceContext.Provider>
)

}

export default LastChanceWrapper

I have a small loop of code which is throwing Uncaught RangeError: Invalid Array Length

I was able to reproduce it with just this in the Google Chrome console

const COUNT = 100_000_000;
const xValues = new Array(COUNT);
const yValues = new Array(COUNT);
for (let i = 0; i < COUNT; i++) {
    xValues[i] = i;
    yValues[i] = Math.sin(i * 0.000001);
}
console.log(`count: ${yValues.length}`);

Here’s the output in developer console

As far as I know the maximum array size in Javascript is 2^32-1? There should be enough memory to allocate here and the index i is never negative or outside the bounds of the array as far as I can see.

Curiously enough, if I use this code, there is no crash

const COUNT = 100_000_000;
const xValues = new Array(COUNT);
const yValues = new Array(COUNT);
for (let i = 0; i < COUNT; i++) {
    xValues[i] = i;
    yValues[i] = i;
}
console.log(`count: ${yValues.length}`);

The value assigned to yValues[i] never goes outiside of the range -1, +1 so I can’t see this as a number out of range problem either.

Anyone shed any light on this?

Javascript. POST request. It is not an API request (axios or fetch), but the old classical request.

I need a payload like ...&_selected_action=5&_selected_action=10.
So I think I cannot use a form submitting technique here.
With a single occurence ...&_selected_action=5 I am able to do it, everything works well.
For the repeated value I can create the string by hand or by URLSearchParams().toString() but I am not able to send it.

Any idea?

More details. I need create this request in Django+Vue application which partially replaces the old school Django Admin. The ListView is replaced using Vue and now I want to reuse the actions where Django Admin uses Post request formatted as above. So with single selected row in list I am able to do it, but with 2+ selected rows I cannot find a good way how to do it.

I have a script that I’m using to calculate the price of a selected field

When i run the function ‘calculateTotal()’ i get this error “Cannot access ‘usagePrice’ before initialization”.

Here is my code:

// Returns total for step 1
const usagePrice = () => {
    const field = document.querySelector('input[name="usage"]:checked');
    const subField = document.querySelector('input[name="varifocal-lenses"]:checked');

    let price = field.dataset.price;
       

    if (field.value == 'varifocal') {
        
        price = subField.dataset.price;
    }

    console.log('Usage price: ' + price);
    return price;
}

// Adds all totals together
const calculateTotal = () => {
    const usagePrice = usagePrice();
    const prescriptionPrice = prescriptionPrice();
    const lensPackagePrice = lensPackagePrice();
    const lensTypePrice = lensTypePrice();

    const total = usagePrice + prescriptionPrice + lensPackagePrice + lensTypePrice;

    return total;
}


console.log(calculateTotal());

Can anyone explain whats going wrong? Thank you in advance.

Here is my code:

useEffect(() => {
    playerRef.current.seekTo(convertedflat[currentTimeIndex], 'seconds');
  });
  return (
    <>
      <main>
        <div className={style.main_container}>
          <NavBar />

          <div className={style.heronext}>
            <div className={style.hero_container}>
              <ReactPlayer
                ref={playerRef}
                playing
                controls={true}
                url={`videos/${episList[currentEpisodeIndex]}.mkv`}
                width="90%"
                height="55rem"
                />
               </div>

              <button
              className={style.next}
              onClick={() => {
                setCurrentTimeIndex((prevTimeIndex) => prevTimeIndex + 1) %
                  convertedflat.length;

                setcurrentEpisodeIndex((prevTimeIndex) => prevTimeIndex + 1) %
                  convertedflat.length;

                console.log(currentTimeIndex);
                console.log(currentEpisodeIndex);
              }}
            >
              Next
            </button>

basically when you click on the next button it moves to the next timestamp until the array finishes. but I want to it starts again when the array list is finished.Currently when the array navigation is finished it shows error.

I used % length but it doesnt work.
Here is the error message when the list is finished:

TypeError: Failed to set the ‘currentTime’ property on ‘HTMLMediaElement’: The provided double value is non-finite.

I’m trying to create an interface to be able to monitor the outputs of a relay board.
When the page is loaded, the status of the output is set by changing the image of the component. I want read the status of the outputs every 1 second and update the relative component.
If I open another tab where I go to change the status of the output automatically I have to change the status of the first tab as well.
I don’t know how to make react render only the component that has changed

import React, { useState, useEffect } from 'react'
import EventBus from "../common/EventBus";
import api from "../services/api";
import Device from "../components/Device"
const serverLink = "http://localhost:8080";

const Devices = () => {
    const [loading, setLoading] = useState(true);
    const [error, setError] = useState(false);
    const [errorCode, setErrorCode] = useState("")
    const [state, setState] = useState()
    const [refreshInterval, setRefreshInterval] = useState(4000)
    async function setDevice(_id, outId, value) {
        try {
            const response = await api({ url: `${serverLink}/api/device/setdevice`, method: "POST", data: { _id: _id, outId: outId, value: value } })
            if (response.data.status === "error") {
                setError(true)
                setErrorCode(response.data.description)
                setLoading(false)
            }
        } catch (error) {
            const _content =
                (error.response &&
                    error.response.data &&
                    error.response.data.message) ||
                error.message ||
                error.toString();
            setErrorCode(_content);
            if (error.response && error.response.status === 403) {
                EventBus.dispatch("logout");
            }
        }
    }
    async function getStatus() {
        try {
            const response = await api.get(`${serverLink}/api/device/getstatus`)
            if (response.data.status === "error") {
                setError(true)
                setErrorCode(response.data.description)
                setLoading(false)
            } else {
                setState(response.data.data)
                setLoading(false)
            }
        } catch (error) {
            const _content =
                (error.response &&
                    error.response.data &&
                    error.response.data.message) ||
                error.message ||
                error.toString();
            setErrorCode(_content);
            if (error.response && error.response.status === 403) {
                EventBus.dispatch("logout");
            }
        }
    }

     useEffect(() => {
         getStatus()
         const interval = setInterval(getStatus, refreshInterval)
         return () => clearInterval(interval);
     }, []);
    return (
        <div className='conteiner-rw'>
            {loading ? "caricamento..." : error ? <p>{errorCode}</p> :(
                state.map((dev) => {
                    return dev.out.map((el, index) => {
                        return <Device key={index} {...el} _id={dev._id} setDevice={setDevice} />
                    })
                }))
            }
        </div>
    )
}

export default Devices

The device component

import React, { useState, useEffect } from 'react';
import image from "../assets/image/image"

const Device = ({ id, _id, name, type, value, setDevice }) => {
    const [state, setState] = useState(value)
    const changeState = () => {
        if (state == 1) {
            setState(0)
            setDevice(_id, id, 0)
        } else if (state == 0) {
            setState(1)
            setDevice(_id, id, 1)
        }

    }

    return (
        <div className='device conteiner-cl' onClick={() => changeState()}>
            <img src={state == 1 ? image.lamp_on : image.lamp_off} alt={name} className='icon' />
            {
                name
            }
        </div>

    )
}

export default Device

The api response

{
    "status": "ok",
    "data": [
        {
            "_id": "619e17af1479f1846c8afaee",
            "name": "dev1",
            "ip": "192.168.0.50",
            "descr": "denkovi",
            "channel": "",
            "type": "denkovi",
             "out": [
                {"id": 1,"name": "output1","value": "0"},
                {"id": 2,"name": "output2","value": "0"},
                {"id": 3,"name": "output3","value": "0"},
                {"id": 4,"name": "output4","value": "0"},
                {"id": 5,"name": "output5","value": "0"},
                {"id": 6,"name": "output6","value": "0"},
                {"id": 7,"name": "output7","value": "0"},
                {"id": 8,"name": "output8","value": "0"},
                {"id": 9,"name": "output9","value": "0"},
                {"id": 10,"name": "output10","value": "0"},
                {"id": 11,"name": "output11","value": "0"},
                {"id": 12,"name": "output12","value": "0"},
                {"id": 13,"name": "output13","value": "0"},
                {"id": 14,"name": "output14","value": "0"},
                {"id": 15,"name": "output15","value": "0"},
                {"id": 16,"name": "output16","value": "0"}
                        ]
        },
        {
            "_id": "619e17af1479f1846c8afaef",
            "name": "dev2",
            "ip": "192.168.0.50",
            "descr": "denkovi",
            "channel": "",
            "type": "denkovi",
            "out": [
                {"id": 1,"name": "output1","value": "0"},
                {"id": 2,"name": "output2","value": "0"},
                {"id": 3,"name": "output3","value": "0"},
                {"id": 4,"name": "output4","value": "0"},
                {"id": 5,"name": "output5","value": "0"},
                {"id": 6,"name": "output6","value": "0"},
                {"id": 7,"name": "output7","value": "0"},
                {"id": 8,"name": "output8","value": "0"},
                {"id": 9,"name": "output9","value": "0"},
                {"id": 10,"name": "output10","value": "0"},
                {"id": 11,"name": "output11","value": "0"},
                {"id": 12,"name": "output12","value": "0"},
                {"id": 13,"name": "output13","value": "0"},
                {"id": 14,"name": "output14","value": "0"},
                {"id": 15,"name": "output15","value": "0"},
                {"id": 16,"name": "output16","value": "0"}
            ]
        }
    ]
}

I use

JSON.parse($(‘#globalmodel’).val()); and get the following in quick watch

JsonDetail “{“ConnectionId”:”1234″,”Pin”:null,”Id”:”8765″,”Street”:null,”Sender”:”Bob”}”

How can i extract each field value , connectionid , Pin , Id Street and Sender ?