Virtual mode and JSON webservice

I'm trying to realize a grid in virtual mode that updates it's content when the grid scrolls, just like the virtual mode. But instead of loading the data from one big array or CSV file, I want the data to be updated from a JSON webservice that returns the celldata array. Is there a way to intercept an AW method that loads the next set of data to call this webservice?

Maybe this could help -

http://www.activewidgets.com/javascript.forum.13524.9/when-will-ajax-paging-be.html

Alex,

Thanks for the reply. But I don't quite get the sample provided. I'm using ASP.NET AJAX for my webservices. So I don't need AW to fetch any data, I can take care of that myself. What I want is a method I can override so when my grid is scrolled, this function is called and I can fetch fresh data. Something like:

<warning: pseudo-code>

var obj = new AW.UI.Grid;
obj.setId("myGrid");

//set other properties here...

obj.onScrollSoFetchNewData = function(startRow, endRow)
{
//call my webservice here with startRow and endRow parameters...
};

</warning: pseudo-code>

The startRow and endRow parameters should of course be based on the position of the scrollbar at that moment. Can you provide a sample of how something like this can be accomplished?

You can use onScrollTopChanged(pixelOffset) event, but you have to calculate startRow and endRow using rowHeight property.

Alternatively you can assign a function as a data source, like

grid.setCellText(function(col, row){
...
});

- if row is not loaded yet, return empty string and refresh later when data arrives.