Steps to Reproduce

1. run the zul with client mvvm enabled

Current Result

it takes 5 seconds to render just 30 rows

Expected Result

reduce the total rendering time.
The initial quick appearance of the empty listbox fulfills an expectation of speed, but the subsequent gradual loading of each row can lead to a perception of the application being sluggish. This incremental loading, while technically reducing the initial load time, can frustrate users as they wait for all data to be displayed, especially if they can see the listbox but cannot interact with the complete dataset immediately. Besides, the complete data is 30 rows which is a small amount.

Debug Information

• org.zkoss.zul.listbox.rod="true" doesn't help
• if using model="@init(vm.largeData)", it takes a longer time
• In server mvvm, it takes around 1.5 second, an end user waits and sees the processing message for around 1 second and zk suddenly renders all 30 rows at once.

Workaround

using server mvvm