Virtual scrolling provides an alternative to paging.
While the user is scrolling the table, the Grid requests and displays only the visible pages.
To set up the Grid for virtual scrolling:
- Set its height either through its
- Set the regular or detail row height and the number of records.
- Provide the data for each page through the
onPageChangeevent handler. You can also pass all the data.
To work properly, virtual scrolling requires you to set the following configuration options:
scrollable—Set it to
pageSize—To avoid unexpected behavior during scrolling, set
pageSizeto at least twice the number of the visible Grid elements. The number of the visible Grid elements is determined by the
rowHeightsettings of the Grid.
You can use virtual scrolling in combination with grouped data.
- Set the
groupoptions of the Grid.
- Set the
- Handle the emitted
onDataStateChangeevent fires upon user interaction with the scrolling or changing the groups, and then processes the data and returns the data to the Grid.
To programmatically implement the processing of the data, either:
- Send a request to the server to execute the grouping on the server side, or
- Use the
processmethod of the
DataQuerylibrary which automatically processes the data.
The Grid expects the grouped data to be a collection of
When configured for virtualization, the Grid fires the
onPageChange event as often as possible. This behavior allows for a smoother scrolling experience when the data is available in memory.
If the data is requested from a remote service, it is advisable to debounce or otherwise limit the page changes.