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Tagged: grid virtualization

This topic contains 5 replies, has 3 voices, and was last updated by ngc2 7 years, 2 months ago.

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Grid in virtual mode calls server-side script twice Posts

July 16, 2013 at 7:56 am Grid in virtual mode calls server-side script twice #25223

Dan Fad

Participant

hello,

i have a grid in virtual mode. i set the grid in a two step process.

first step is setting the grid columns.
second step is loading data on a click of a button.

the problem is that the server-side script is called twice: during setting of the grid source ( source:dataAdapter ) and again when rendergridrows function returns dataAdapter.records.

here is the sample code:

<script type="text/javascript">
$(document).ready(function () {
	var theme=getTheme();
/*first step is setting the grid coulmns*/
	$("#jqxgrid").jqxGrid({
		altrows: true,
		theme:theme,
		autoheight: true,			
		pagesize: 20,	
		pageable: true,	
		columns: [
			{ text: 'Lastname', datafield: 'col1', width: 150},
			{ text: 'Firstname', datafield: 'col2', width: 150 },
			{ text: 'Birthdate', datafield: 'col3', width: 100 }
		]
	});
/*second step is loading data on click of a button*/
	$("#btnLoad").jqxButton({ width: '160', theme: theme});
	$("#btnLoad").on('click', function () {
		var source ={
				datatype: "json",
				datafields: [
					{ name: 'col1'},
					{ name: 'col2'},
					{ name: 'col3'},
				],
				url:'randomdata.php',
				root: 'Rows',
				cache: false,
				async:true,
				beforeprocessing: function(data){	
					if (data) {
						source.totalrecords = data[0].TotalRows;
					}	
				}			
		};
		var dataAdapter = new $.jqx.dataAdapter(source, {
				loadComplete: function (data) { 
					/* here this function is called twice */
				}
			}
		);	
		$("#jqxgrid").jqxGrid({
			virtualmode: true,			
			source: dataAdapter,
			rendergridrows: function(){
				return dataAdapter.records;     
			}
		});
	});	
});	
</script>
</head>
	<body>
		<input type="button" value="Load Data" id='btnLoad'/>
		<div id="jqxgrid"></div>
        <div id="eventsLog" style="margin-top: 10px;"> </div>
	</body>
</html>

here is the server side script – generates random data {randomdata.php}

<?php
/*simulated data as if coming from MySql*/
/*this is just a random text data*/
$rows=10;
for($r=1;$r<=$rows;$r++) {
	$ln = substr(str_shuffle(str_repeat("abcdefghijklmnopqrstuvwxyz", 6)), 0, 5);  /*Lastname*/
	$fn = substr(str_shuffle(str_repeat("abcdefghijklmnopqrstuvwxyz", 8)), 0, 5);  /*Firstname*/
	$int= mt_rand(100000000,1262055681);
	$bdate = date("m-d-Y",$int);
	$rowdata[]=array(
		'col1'=>ucfirst($ln),
		'col2'=>ucfirst($fn),
		'col3'=>$bdate
	);	
}
$data[] = array(
	'TotalRows' => $rows,
	'Rows' => $rowdata
);
writetofile(json_encode($data)); /* writes data to text file -> logs.txt */
echo json_encode($data);	
	
/*
this function will write data to text file
this will check if this script is called twice
*/
function writetofile($content) {
	$filename="logs.txt";
	$file = fopen($filename, 'a');   //w-> write; a->apend 
    fwrite($file, $content."\n");
	fclose($file);
}
?>

am i doing it right?

thanks,
dan fad

July 16, 2013 at 8:31 am Grid in virtual mode calls server-side script twice #25224

Peter Stoev

Keymaster

Hi,

The following code should not be there:

	$("#jqxgrid").jqxGrid({
			virtualmode: true,			
			source: dataAdapter,
			rendergridrows: function(){
				return dataAdapter.records;     
			}
		});

If you want to load a Grid with data, then just set its “source” property. The other 2 properties should be set during the initialization.

Best Regards,
Peter Stoev

jQWidgets Team
http://www.jqwidgets.com

July 16, 2013 at 9:12 am Grid in virtual mode calls server-side script twice #25226

Dan Fad

Participant

Hello Peter,

Thank you for the reply.

I transferred these two properties in the initialization stage (virtualmode and rendergridrows) but when I clicked the Load button, the data were not shown in the grid. Only the loader image is shown.

Am I missing some properties?

Best Regards,
Dan Fad

July 16, 2013 at 9:25 am Grid in virtual mode calls server-side script twice #25228

Peter Stoev

Keymaster

Hi,

Most probably that is due to the fact that you will try to access “return dataAdapter.records;” and dataAdapter will be undefined. I suppose that you will have to either define the dataAdapter before that or use the “rendergridrows” “data” parameter instead.

Best Regards,
Peter Stoev

jQWidgets Team
http://www.jqwidgets.com

July 16, 2013 at 9:46 am Grid in virtual mode calls server-side script twice #25232

Dan Fad

Participant

Hi Peter

I transferred the initialization of the source and dataAdapter on top of the grid. This solves the problem.

Thank you very much,
Dan Fad

February 26, 2018 at 3:13 pm Grid in virtual mode calls server-side script twice #98909

ngc2

Participant

How can you get this to work with server-side pagination?

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