Check for empty JSON result

tristanvanbokkem

Hi Allan,

I am using DT with a JSON array as source. However I noticed DT is throwing me an "Cannot read property 'length' of null " if the returning JSON array is empty. When this happens the "Processing..." state keeps loading instead of stating "No data found" or something similar. How can I fix this?

tristanvanbokkem

I guess, this will help me. http://datatables.net/forums/discussion/1605/empty-json-result/p1
I'll check if it works for me.

allan

Two options currently:

1. Use fnServerData to override the Ajax call DataTables makes and catch the return, altering it to be an empty array if null.

2. Listen for the `xhr` event and pre-process the data that way.

[code]
$('#table').dataTable().on('xhr', function (settings, json) {
if ( json.aaData === null ) {
json.aaData = [];
}
} );
[/code]

Allan

tristanvanbokkem

Thanks Allan,

I'm almost there.

[code]
"fnServerData" : function(sSource, aoData, fnCallback){
aoData.push( { "name": "action", "value": "someAction" } );
$.ajax({
"url": sSource,
"data": aoData,
"success": function(result){
// DEBUG
//console.log(result)
if (result.aaData === null) {
result.aaData = [];
}
// DEBUG
console.log(result);
fnCallback // draw the table
}
});
[/code]

I can see that the result contains:

[code]
Object {aaData: Array[0]}
[/code]

But the processing state keeps loading.

allan

You need to actually call the callback function :-). `fnCallback( result );`

Allan

tristanvanbokkem

Perfect! Topic can be closed.