JSON parsing issues and sEcho prolbem

mschloz

I am having some major issues. I have enabled server side process and have properly formatted JSON data to give back to the table. I am get a JSON parsing error and I think it is due to sEcho being 0. When examining with Firebug nothing seems to being passed to my server side script from the data table. (no sEcho=balh), but bServerSide is set to true... Also, it will display the Test info received, and then complain about parse error... and it says sEcho is undefined index on the server side php script.

Here is the JSON data returned:
[code]
{
"sEcho":0,
"iTotalRecords":1,
"iTotalDisplayRecords":1,
"aaData":[
{"id":"1","appname":"Test","site":"","status":"00H:00M:00S","state":"0","enabled":"0","recStartDate":"","cmdRecording":"0"}
]
}
[/code]


Javascript code:
[code]
currentTable = $("#camDataTable").dataTable({
"bJQueryUI": true,
"bProcessing": true,
"bServerSide": true,
"iDisplayLength": 25,
"sAjaxSource": '/inc/cameraData.php',
"aoColumns": [
{ "bVisible":false, "mDataProp": "id" },
{ "sWidth": "40%", "sTitle": "Name", "mDataProp": "appname" },
{ "sClass": "my_class", "bSortable": false, "sWidth": "35%", "fnRender": function(oObj){
//alert(oObj.aData.enabled);
$("#startbtn").attr('name', oObj.aData.id);
$("#stopbtn").attr('name', oObj.aData.id);
var name = document.getElementsByName(oObj.aData.id);
var start = name[0];
start.type = "button";
if(oObj.aData.enabled == 0){
start.value = "Start";
start.removeAttribute('readonly');
start.removeAttribute('size', '10px');
start.style.color = 'grey';
start.setAttribute('disabled', 'disabled');
name[1].value = "Stop";
name[1].removeAttribute('readonly');
name[1].removeAttribute('size', '10px');
name[1].style.color = 'grey';
name[1].setAttribute('disabled', 'disabled');
}
else{
if(oObj.aData.cmdRecording == oObj.aData.state){
if(oObj.aData.state == 1){
start.value = "Recording...";
start.type = "text";
start.setAttribute('readonly', 'readonly');
start.setAttribute('size', '10px');
start.style.color = 'orange';
start.setAttribute('disabled', 'disabled');
name[1].removeAttribute('disabled');
name[1].style.color = 'green';
}
else{
start.value = "Start";
start.removeAttribute('readonly');
start.removeAttribute('size', '10px');
start.style.color = 'green';
start.removeAttribute('disabled');
name[1].style.color = "grey";
name[1].disabled = true;
}

}
else{
start.value = "Start";
start.removeAttribute('readonly');
start.removeAttribute('size', '10px');
start.style.color = 'green';
start.removeAttribute('disabled');
name[1].type = "button";
name[1].value = "Stop";
name[1].style.color = "green";
name[1].disabled = false;
}
}
return $("#serviceButtons").html();
}
},
{ "sClass": "my_class", "bSortable": false, "sTitle": "Record Time", "sWidth": "25%", "fnRender": function(oObj){
var status = document.getElementById("status");
status.type = "button";

if(oObj.aData.status == 0){
status.value = "Error...";
status.type = "text";
status.style.color = 'red';
}
else{
status.value = oObj.aData.status;
status.style.color = 'green';
}
return $("#record").html();
}
},
{ "mDataProp": "site" }
],
"fnRowCallback": function( nRow, aData, iDisplayIndex ) {
var status = document.getElementById("status");
status.type = "button";
var id = aData.id;
$(nRow).attr('id', id );
var site = aData.site;
$(nRow).attr('value', site );
return nRow;
}
});
[/code]

allan

Can you give us a link to the page so we can see what is going wrong please?

Allan

mschloz

It is in a sandbox dev environment right now. I can see about getting a temp web page up. If I suppress the the errors to a javascript warning. It stops displaying the data to the table. But if I let the parsing errors through, it will display the data in the table after dismissing the error alter boxes.

allan

Okay

I would say that sEcho can never be 0 - it simply won't work. It is a counter for the number of draws and changes on every draw of the data: http://datatables.net/usage/server-side . So if you are getting 0 back from the server, then there is something going wrong with the server-side script.

Allan

mschloz

It turns out that someone tweaked fnReloadAjax function and it was not able to correctly request an update from the server side processing. Thank you for your help :) I will update when I have figure out the root cause.

allan

fnReloadAjax and server-side processing are mutually exclusive. As the documentation for fnReloadAjax says:

> Note: To reload data when using server-side processing, just use the built-in API function fnDraw rather than this plug-in.

Possibly that is part of the issue?

Allan

mschloz

You beat me to it. Exactly the issue. My table is updating and beautiful :-) Thank you for all the help.