Close connection outside the function

[Nikotecnology]

Hi, i was tryng to install this repo but i can't start the application because of this error: "TypeError: undefined is not an object (evaluating '_reactNativeTcpSocket.default.createConnection')". Now i reinstalled the library and now it says this error: "Native module cannot be null" Someone knows how to resolve this?

[Rapsssito]

@Nikotecnology, take a look at #27, it might be the same issue.

[Nikotecnology]

No, I see that but it didn't resolve the problem

[Rapsssito]

@Nikotecnology, what RN version are you using? Are you on iOS or Android? How are you importing the library?

[Nikotecnology]

The latest version, I downloaded with "npm i react-native-tcp-socket" I'm using expo cli with app on iOS

[Rapsssito]

@Nikotecnology, I am sorry I cannot help you with Expo. However, you might need to eject your project first in order to get custom modules to work.

[Nikotecnology]

Ok, ill'try but I see more people that having this problem ,not with expo

[Rapsssito]

@Nikotecnology it is a common issue among custom modules. React Native automatic linking sometimes fails, the XCode cache is not correctly cleared, the module download is corrupt, metro cache is not correctly cleared, etc.

[Nikotecnology]

Ok for that it's ok I will eject it and try

[Nikotecnology]

I removed expo and it seems working, but i cant close the connection externaly the function for connecting, how i can do?

[Rapsssito]

@Nikotecnology, I don't understand your problem, could you elaborate?

[Nikotecnology]

I created a function(_connect) and when the user clicks the button the connection stabilish, i want to do the disconect button and the reconnect button how i can do?

[Rapsssito]

@Nikotecnology, take a look at the docs. You might want to use the destroy() method.

[Nikotecnology]

no, i didn't explain that this is my code:

import React from 'react';
import {
  SafeAreaView,
  TouchableOpacity,
  Text,
  StyleSheet,
  Alert,
} from 'react-native';
import Clipboard from '@react-native-community/clipboard';
import TcpSocket from 'react-native-tcp-socket';
let that;
let connected = true;

function sleep(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

const client = TcpSocket.createConnection(
  {
    host: '192.168.1.202',
    port: 49155,
  },
  () => {},
);

export default class App extends React.Component {
  constructor(props) {
    super(props);
    that = this;
    this._connect = this._connect.bind(this);
    this.state = {
      textValue: 'Change me',
    };
  }

  _connect = () => {
    if (!connected) {
      client.connect();
    }
    client.on('data', function (data) {
      console.log(String.fromCharCode.apply(null, data));
      that.setState({
        textValue: String.fromCharCode.apply(null, data),
      });
      setInterval(() => {
        Clipboard.setString(String.fromCharCode.apply(null, data));
      }, 1500);
    });

    client.on('error', function (error) {
      console.log(error);
    });

    client.on('close', function () {
      console.log('Connection closed!');
      that.setState({
        textValue: ' ',
      });
    });
  };

  _destroy = () => {
    client.destroy();
    connected = false;
  };

  render() {
    return (
      <>
        <SafeAreaView style={styles.container}>
          <TouchableOpacity
            style={{
              alignItems: 'center',
              color: 'black',
              fontFamily: 'SemiBold',
              marginTop: 40,
            }}
            onPress={this._connect}>
            <Text>Connect</Text>
          </TouchableOpacity>
          <Text style={styles.text}>{this.state.textValue}</Text>
          <TouchableOpacity
            style={{
              alignItems: 'center',
              color: 'black',
              fontFamily: 'SemiBold',
              marginTop: 80,
            }}
            onPress={this._destroy}>
            <Text>Disconect</Text>
          </TouchableOpacity>
        </SafeAreaView>
      </>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#61dafb',
  },
  text: {
    justifyContent: 'center',
    alignItems: 'center',
  },
});

It closes the connection but i can't reopen it

[Rapsssito]

@Nikotecnology, if you destroy the socket you must create a new socket to reopen the connection.

[Nikotecnology]

there isn't a way to close and reopen it without destroyng it

[Rapsssito]

@Nikotecnology, that is not how TCP connections work, it is a connection-oriented protocol. Take a look at the wikipedia article about TCP for more info.

[Nikotecnology]

ok thanks i will close the issue