[SOLVED] Can't get Ajax working - help

devadittya · 2012-01-22 17:58:09

I am trying to set Ajax up for a media server (hosting professor lectures).
I am trying to update my mysql, if someone likes a particular lecture.

However, I am not able to get any response what so ever. I am using an onclick - however, nothing happens. Check the code below - I have set up an if-else, with onreadyState, and for both the conditions (exhaustive), no change happens. Please suggest what I am doing wrong.

function show_jw()
{
var filepath=jwplayer('container').getPlaylistItem().file;
var xmlhttp;

xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("like").innerHTML="file found";
}
else
{
document.getElementById("like").innerHTML="file not found";
}
}
xmlhttp.open("GET","ajaxphp.php?f="+filepath,true);
xmlhttp.send();
}
</script>

<input type="button" onclick=show_jw() value="like" />

on clicking the button, I should either see "file found" or "file not found". I see nothing (on chrome or firefox).

Last edited by devadittya (2012-01-22 18:33:24)

Raynman · 2012-01-22 18:18:10

Try initializing the xmlhttp variable

And some indentation might be nice.

devadittya · 2012-01-22 18:32:59

Raynman wrote:

Try initializing the xmlhttp variable
And some indentation might be nice.

Ouch. My bad. That surely helped
I was just testing Ajax, so didn't bother much with indentation. Thanks a lot nonetheless

iTwenty · 2012-01-23 17:16:57

Also note that the else statement gets executed even if readyState != 4 which is probably not what you want. Better to implement it as:

xmlhttp.onreadystatechange=function()
{
    if (xmlhttp.readyState==4)
    {
        if (xmlhttp.status==200)
        {
            document.getElementById("like").innerHTML="file found";
        }
        else
        {
            document.getElementById("like").innerHTML="file not found";
        }
    }
}

More info here: http://www.w3.org/TR/2012/WD-XMLHttpReq … readystate. The entire page is a good read actually.

Last edited by iTwenty (2012-01-23 17:17:24)

Arch Linux

#1 2012-01-22 17:58:09

[SOLVED] Can't get Ajax working - help

#2 2012-01-22 18:18:10

Re: [SOLVED] Can't get Ajax working - help

#3 2012-01-22 18:32:59

Re: [SOLVED] Can't get Ajax working - help

#4 2012-01-23 17:16:57

Re: [SOLVED] Can't get Ajax working - help

Board footer