Btukfyl

I'm writing a music player. In this player, a server streams music to a client using socket.io and socket.io-stream. When I start the server and play a song streamed from the server, it works—but when I request a new song (using the next or previous function), I get this error:

Uncaught TypeError: Cannot read property '_read' of null

at IOStream._read (socket.io-stream.js:255)

at IOStream.Readable.read (socket.io-stream.js:4647)

at resume_ (socket.io-stream.js:4998)

at afterTickTwo (socket.io-stream.js:3978)

at Item.run (socket.io-stream.js:4150)

at drainQueue (socket.io-stream.js:4120)

Here's the client code:

play() {

    if (this.sound) {

        let controlPanelObj = this.controlPanel;

        let infoBarObj = this.infoBar;

        Array.from(controlPanelObj.classList).find((element) => {

            return controlPanelObj.classList.add('active');

        });

        Array.from(infoBarObj.classList).find((element) => {

            return infoBarObj.classList.add('active');

        });

        this.sound.play();

        console.log('playing');

    }

}



pause() {

    if (this.sound) {

        let controlPanelObj = this.controlPanel,

            infoBarObj = this.infoBar;

        Array.from(controlPanelObj.classList).find((element) => {

            return controlPanelObj.classList.remove('active');

        });

        Array.from(infoBarObj.classList).find((element) => {

            return infoBarObj.classList.remove('active');

        });

        this.sound.pause();

        console.log('stopped')

    }

}



next() {

    if (this.sound) {

        index < song_list.length-1 ? index=0 : index++;

        console.log('next');

        this.pause();

        socket.emit("get_song", this.songs[index]);

        ss(socket).on('audio-stream', (stream, data) => {

            let parts = ;

            stream.on('data', (chunk) =>{

                parts.push(chunk);

            });

            stream.on('end', () =>{

                console.log((window.URL || window.webkitURL).createObjectURL(new Blob(parts)));

                this.sound.changeSrc((window.URL || window.webkitURL).createObjectURL(new Blob(parts)));

                console.log(this.sound);

                this.play();

            });

        });

    }

}



previous() {

    if (this.sound) {

        index === 0 ? index=0 : index--;

        this.pause();

        socket.emit("get_song", this.songs[index]);

        ss(socket).on('audio-stream', (stream, data) => {

            let parts = ;

            stream.on('data', (chunk) =>{

                parts.push(chunk);

            });

            stream.on('end', () =>{

                console.log((window.URL || window.webkitURL).createObjectURL(new Blob(parts)));

                this.sound.changeSrc((window.URL || window.webkitURL).createObjectURL(new Blob(parts)));

                console.log(this.sound);

                this.play();

            });

        });

    }

}



// on startup load function is called

load() {

    console.log('loaded');

    socket.emit("get_song", this.songs[index]);

    ss(socket).on('audio-stream', (stream, data) => {

        let parts = ;

        stream.on('data', (chunk) =>{

            parts.push(chunk);

        });

        stream.on('end', () =>{

            console.log((window.URL || window.webkitURL).createObjectURL(new Blob(parts)));

            this.sound = new Howl({

                src: (window.URL || window.webkitURL).createObjectURL(new Blob(parts)),

                format: ['mp3'],

                onend: this.next()

            });

            console.log(this.sound);

        });

    });

}

and the server code:

socket.on('get_song', (filename) => {

        console.log("filename: " + filename);

        let file_path = path.join(__dirname, '/public/music', filename);

        console.log('path: ' + file_path);

        let stream = ss.createStream();

        ss(socket).emit('audio-stream', stream, { name: file_path });

        fs.createReadStream(file_path).pipe(stream);

    });