CODEWITHSUNDEEP
javascriptjsonnode.jssocket.io
Joseph Roberts
Joseph Roberts

Reputation: 569

Why can’t I access data sent via socket.io by key in node.js?

I'm sending some data from my web page using socket.io and then handling it in the node.js back end.

The code I use to send my data is:

var joystick1 = new VirtualJoystick({
        container   : document.body,
        strokeStyle : 'cyan'
    });
    setInterval(function(){
                var outputEl    = document.getElementById('resulty');
                outputEl.innerHTML  = joystick1.deltaY();

                //THE DATA IS SENT HERE
                socket.emit('key', {Speed: joystick1.deltaY()});

            }, 1/30 * 1000);
    joystick1.addEventListener('touchStartValidation', function(event){
        var touch   = event.changedTouches[0];
        if( touch.pageX >= window.innerWidth/2 )    return false;
        return true
    });

I handle it in node.js using this code:

socket.on('key', KeyReceived);  //Key received from client

function KeyReceived(data)
{
    //DATA IS PRINTED HERE
    console.log(data);

    switch(data.Key)
    {
    case "Steering":
        _direction = 90 + data.value;
    console.log(_direction);
        break;
    case "Speed":
        _speed = 90 + data.value;
    console.log(_speed);
        break;
    case "Adjustment":
        _adjustment = data.value;
        break;
    }
}

In the console this prints out my data, but for some reason it won’t go into my case statements because my keys don't match?

What do I need to change to make this work?

Upvotes: 1

Views: 140

Answers (2)

mquandalle
mquandalle

Reputation: 2598

The data parameter is a javascript Object or javascript hash. This object doesn't have a Key or a Value property.

To test if this your object has a key use data.hasOwnproperty('Speed'). If you want to get the value of this property use data['Speed'] or the equivalent dot-notation data.Speed.

Upvotes: 2

moka
moka

Reputation: 23045

Log the object you are sending to see its content, it does not have Key.
So what you really want to do is to send this object:

socket.emit('key', { Key: 'Speed', value: joystick1.deltaY() });

Upvotes: 2

Related Questions