Custom implementation of smart rendering on grid

Suite and Optimus Suite 5
#1

I want to be able to implement smart rendering on the grid, but without the conventional way of getting xml responses , with new data,from the server.
I have a separate service API which can give me new to-be-loaded data. I want to know, if i can achieve smart rendering , by using this API and the event handlers of the dhtmlxGrid.

I understand the grid , provides “onXLS” and “onDynXLS” events. I can place my service API call in the handlers of these events, to get new data, and return false, to achieve smart rendering with my custom web service.

However, i find that the “onDynXLS” event is not thrown at all.
grid.enableSmartRendering(true, 50)
This call throws the event, “onXLS”. But even if I scroll the grid, i dont see the “onDynXLS” event being thrown. Isnt the onDynXLS event handler called with params (start, count) , as per the doc ?

Also,
does grid.parse(data, “jsarray”) load data incrementally into the grid. Because, i will be creating “jsarray” data, which then has to be loaded into the grid incrementally, after every scroll (call to onDynXLS handler). If not, how can i bulk-load data incrementally. I would prefer not to use addRow , for every jsarray row.

Please help.

#2

The problem is , that you have not load command at all, and grid will not initiate dyn. loading because it don’t know uri for data requests.

You can add the next line

grid.xmlFileUrl = “dummy”;

as result grid will generate correct onDynXLS events ( dummy value will not be used for any other operations, if you will return false from onDynXLS )

does grid.parse(data, “jsarray”) load data incrementally into the grid
Nope, it will not works. But you can use

json_data.pos = 100; //position at which new data need to be added
grid.parse(json_data, “json”)

docs.dhtmlx.com/doku.php?id=dhtm … at_details

#3

Thanks for the information !
Can i not use grid.loadXML(“dummy”) ;
and then return false, in onXLS and onDynXLS event handlers ?

Actually, i have tried this, but i get an alert saying
"Error type: loadXML
Description: Incorrect XML " ,
inspite of my onXLS eventHandler returning false.

#4

Can i not use grid.loadXML("dummy") ; and then return false, in onXLS and onDynXLS event handlers ?
Unfortunately it will not work. onDynXLS will not be executed for load command - so your blocking handler will not be used.

onXLS can be used for information only, it is not blockable.

#5

So how do I get the initial load? For the initial load "onDynXLS " event is not triggered.

#6

Why not use

grid.xmlFileUrl = "dummy"; grid.parse(my_initial_data, "json");

#7

But even after the initial load ,“onDynXLS” is not being called for subsequent fetches of data.
Should the event be thrown after every scroll of the grid ?

How does the grid know the size of the scroller ? Is the total_count to be set somewhere ?

#8

Sample is attached

Be sure to include dhtmlxgrid_json.js
1290087624.zip (103 KB)

#9

Thank you for the file !
Surely clears a lot of things.

Is there a way to use grid.parse(data, “jsarray”);

If yes, how to set total_count and pos ?

Thanks.
Really appreciate your prompt help.

#10

jsarray can’t store extra attributes , so it can’t be used to organize dynamic loading.

#11

The JSON parsing is not working completely for me

I tried this :

[code]var jsonObj = new Object();
jsonObj.total_count = 100;
jsonObj.pos = 0;

jsonObj.rows = [];
var r = new Object(); r.data = ["a", "b"]; jsonObj.rows.push(r);
         mygrid.parse(jsonObj,"json");

[/code]

And the grid shows me the first row.However , if try to add another row, it still shows me only the first row, meaning only the first row gets parsed.

[code]var jsonObj = new Object();
jsonObj.total_count = 100;
jsonObj.pos = 0;

jsonObj.rows = [];
var r = new Object(); r.data = ["a", "b"]; jsonObj.rows.push(r);
r = new Object(); r.data = ["c", "d"]; jsonObj.rows.push(r);
         mygrid.parse(jsonObj,"json");

[/code]

I am not able to upload the file . So here is the code in sample.html

 

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>
<head>
	<title>For demo purpose only :: &1</title>
	<link rel='STYLESHEET' type='text/css' href='codebase/dhtmlxgrid.css'>
	<link rel='STYLESHEET' type='text/css' href='codebase/skin/dhtmlxgrid_dhx_skyblue.css'>
	<script src='codebase/dhtmlxcommon.js'></script>
	<script src='codebase/dhtmlxgrid.js'></script>
	<script src='codebase/dhtmlxgrid_json.js'></script>
	<script src='codebase/dhtmlxgridcell.js'></script>	
</head>

<body>
	<h1>Configuration from XML</h1>
    <p>Configuration of grid can be loaded from XML file. You need only 2-3 script commands to get the grid up and running.</p>
	
	<div id="gridbox" style="width:600px; height:270px; background-color:white;"></div>
	
	<a href='#alfa' onClick="if(mygrid.setSerializationLevel){ser();} else {alert('Available in Pro Edition only')}">Serialize grid</a>

<script>
    mygrid = new dhtmlXGridObject('gridbox');
	mygrid.setImagePath('codebase/imgs/');
	mygrid.setSkin("dhx_skyblue")
	mygrid.setHeader("A,B")
	mygrid.setInitWidths("100,100");
	mygrid.init();
	
	mygrid.attachEvent("onDynXLS", function(pos, count){
		alert("Extra data request");
		return false;
	});

	mygrid.xmlFileUrl = "dummy";

	var jsonObj = new Object();
	jsonObj.total_count = 100;
	jsonObj.pos = 0;

	jsonObj.rows = [];
	var r = new Object(); r.data = ["a", "b"]; jsonObj.rows.push(r);
	r = new Object(); r.data = ["c", "d"]; jsonObj.rows.push(r);
	//alert("Set the rows JSON");
	
	/*
	[{
	    data: ["a", "b"]
	}, {data:["c", "d"]}
	];
	*/
	/*
	mygrid.parse({
		total_count:100,
		pos:0,
		rows:[["a","b"],[["c","d"]]]
	},"json");
	*/
	mygrid.parse(jsonObj,"json");

</script>

<a name="alfa">
<div id="alfa1"></div>
</a>

</body>
</html>

Also, there is no call to
grid.enableSmartRendering()

How does the grid know to fetch rows from the server and also the count of new rows to be fetched ?

#12

Check the updated sample

The problem with second row adding in your sample was caused by missed row id ( it must be any unique value )
json_updated.zip (105 KB)

#13

Hello, I tried your example because I’m developing an application with similar requerimets of smartRendering and custom parse. I need to capture “pos” and “count” to call my custom xml parse but the event onDynXLS is not firing when scrolling the grid. What can I do to fire the onDynXLS event every time the user scrolls the grid?

#14

Any idea about why is the onDynXLS event not firing when scrolling?

#15

Grid must know about possibility of dyn. loading for that

a) grid must be loaded with grid.load ( not grid.parse )
b) first loaded dataset must have total_count attribute with expected total count of row ( which must be greater than already loaded data to generate onDynXLS )

In case of json data, be sure to include ext/dhtmlxgrid_json.js on the page