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I am having an issue getting the result set back to the client using Node.js. I am new to it and using it for a project but I am stuck and not sure why. Here's the situation: I have a webpage, a server, a request handler and a database interface. I am able to send data back and forth the client and server without any issue. The only time it doesn't work is when I try to send the result from my query back to the client.

function doSomething(response)
{
    var data = {
        'name': 'doSomething'
    };

    response.writeHead(200, {'Content-Type': 'text/html', 'Access-Control-Allow-Origin': '*'});     
    response.end(JSON.stringify(data));
}

This works fine as I can read the name from the object on the client side, but

function fetchAllIDs(response)
{
    dbInterface.fetchAllIDs(function(data) {
        // console.log(data) prints the correct information here        
        response.writeHead(200, {'Content-Type': 'text/html', 'Access-Control-Allow-Origin': '*'});     
        response.end(data);
        // console.log(data) from the client side is just blank
    });
}

I believe the issue is the way I handle my callback and response because without trying to use mysql the rest of my code works fine. Thanks!

EDIT: I removed a piece code that seems to confuse people. It was just to show that if I have the response code outside the callback then I am able to get any data back to the server. In my actual code, I do not have the two response statements together. I just can't get the rows from the fetchAllIDs function back to the client.

srbdev
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  • Did you tried doing response.write(data); response.end(); instead? Edit: Do you have 2 ends on the same function?? – Riwels Jan 27 '13 at 09:01
  • Yes I tried that as well but it didn't make a difference. I only added the second end outside the callback to show that when I put it there I am able to get data from the response. In my code I have it one way or the other, not both. – srbdev Jan 27 '13 at 15:31

1 Answers1

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The way you have it written means the 

reponse.end('This string is received by the client');

line is always called before the callback function meaning the reponse has ended.

Under JS all the code will finish before the next event (your callback function) is taken off the queue. Comment out the above line // and test it

Simon Tomlin
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  • Hey thanks for the input. You can look at my edit since the way I had it shown keep confusing people. In my code, I have it without that line but it still doesn't work. – srbdev Jan 27 '13 at 17:20
  • OK, It works for me if I put your first part in JSON.stringify(data) into the second function. Other than that I am stumped – Simon Tomlin Jan 27 '13 at 18:34