fnReloadAjax issue

rage10940

Hello Allan, I came across a problem with fnReloadAjax.

The problem :

>> When two different computers are on the same page using fnReloadAjax on the same table when some one alters the data for example say when column = 3 instead of 2 the data in the first client that initiated the change is gone (which should work) but in the second client / computer the old data where is still there.

When I say still there, I mean that since the value of column is not 2 any more (it is 3) the data should not be showing in that table, but the second client still has the data shown on the table.

Possible issue (that I can think of?) :

One minute the fnReloadAjax is in fact retrieving the JSON data, but when the JSON data is not present any more (when the column value now equals 3 rather then 2) the data on the second client still shows up on that table (when it shouldn’t').

When I go home tonight I will turn my server on and hopefully you can have a look at it. I will also upload a video and put it on this thread to show you in more detail the issue.

For the mean time my code is :

[code]
function ajaxcall() {
$this->load->model('queue_model');

$data['waiting'] = $this->queue_model->waiting();
$data['beingseen'] = $this->queue_model->beingseen();

$this->output->set_header('Content-Type: application/json; charset=utf-8');
echo json_encode($data);
}
[/code]

[code]

$(document).ready(function()
{
var table1 = $('#waiting').dataTable(
{
"sPaginationType": "full_numbers",
"bJQueryUI": true,
"iDisplayLength": 10,
"aLengthMenu": [5, 10],
"sAjaxDataProp": "waiting",
"sAjaxSource": '<?php echo base_url();?>studentqueue_controller/ajaxcall',
"bDeferRender": true,
"bAutoWidth": false,
"aoColumns":
[
{"mdata": "id",
"sWidth": "7%",
"mRender": function(data, full)
{
var div = '';
var url = '' + '' + '' + '' + data + '';
}
},
{"mdata": "first"},
{"mdata": "last"},
{"mdata": "SECOND",
"sWidth": "1%"
},
{"mdata": "reason"},
{"mdata": "studentcomments"},
{"mdata": "aidyear",
"sWidth": "1%"
},
{"mdata": "counselorcomments"}
]
});
setInterval(function() {
table1.fnReloadAjax(null, null, true);
}, 1000);
});


$(document).ready(function()
{
var table2 = $('#beingseen').dataTable(
{
"sPaginationType": "full_numbers",
"bJQueryUI": true,
"iDisplayLength": 10,
"aLengthMenu": [5, 10],
"sAjaxDataProp": "beingseen",
"sAjaxSource": '<?php echo base_url();?>studentqueue_controller/ajaxcall',
"bDeferRender": true,
"bAutoWidth": false,
"aoColumns":
[
{"mdata": "id",
"sWidth": "1%",
"mRender": function(data, full)
{
var div = '';
var url = '' + '' + '

rage10940

Hey Allan here is the video :

http://www.youtube.com/watch?v=Dod5Rznj6BQ

I will also keep my server up tonight, and the login is the same as before, if my IP changed I will send you notification!

Thanks Allan,

Hopefully this is a small issue.

allan

Students waiting is being reloaded very 1 second yes? What does the data for the Ajax request when it in the 'wrong' state look like?

If you have a look at the fnReloadAjax plug-in, you will see that it calls fnClearTable followed by fnAddData - so my guess is that the Ajax request is getting incorrect data back (i.e. it is reporting a row when it shouldn't be).

Allan

rage10940

Yes the students waiting is being reloaded on a second by second basis. I am in the chrome developer tools and it is showing two errors called :

Uncaught TypeError: Cannot read property 'length' of null

and

Uncaught TypeError: Cannot read property 'length' of null

http://www.freeimagehosting.net/wh71n

allan

I'm not sure what is causing that I'm afraid. I'd need a test case to be able to debug it.

Allan

rage10940

I sent you an email with my server IP and your credentials. Is that what yo mean by a test case?

rage10940

To test it like I explained in the email, you would sign a student in on computer and then on another computer you would see the ajax refresh the table. Then on the same computer you signed in a student, accept the student (with the green check box) and then notice on another computer how the table "freezes"

rage10940

Any word Allan?

allan

I'm getting no response from the IP address you previously sent me.

Allan

rage10940

Sent you a message on DataTables conversation thing (PM?)

rage10940

No bug here, (unless Allan can fix my brain? oO....)

I was sending a NULL value to the datatables so it was always looking for data saying Loading Data.... when there was none.

So in my query :

[code]

function waiting() {
$sql = "SELECT DISTINCT
session.session_id as id,
session.anum,
student.first,
student.last,
SEC_TO_TIME(TIMESTAMPDIFF(SECOND, signintime, NOW())) as SECOND,
reasons.reason,
session.studentcomments,
session.aidyear,
support.counselorcomments
FROM session
INNER JOIN student
ON student.anum = session.anum
LEFT JOIN support
ON session.session_id = support.session_id
INNER JOIN reasons
ON reasons.reason_id = session.why
LEFT JOIN support support2
ON support.session_id = support2.session_id
AND support.starttime < support2.starttime
WHERE session.status IN (0,2) AND support2.session_id IS NULL
ORDER BY id asc;";
$q = $this->db->conn_id->prepare($sql);
$q->execute();

if ($q) {
if ($q->rowCount() > 0) {
return $q->fetchall();
} else {
return $q = array(); // All I had to add was an empty array
}
}
}

[/code]

Literally two lines of code fixed this... One line for this query and another line for the other query. Thanks Allan!