MVVM / AutoSync unwanted losing user typing

[Chris]

Hi,

We have a scenario that shows a form (e.g. with field A and field B) with multiple text fields being edited using MVVM tied to a data source that’s is set to AutoSync. This datasource is tied to a remote connection, so there can be a momentary lag e.g. 1-2 secs.

What we can observe is that :-
- The user types in field A
- The user then clicks on field B, and starts typing… 
- As the field A lost focus, AutoSync has kicked in (so network request starts)
- User starts to type in field B, but then previous network request finishes and fieldB resets to the value in the datasource, effectively undoing what the user has just typed

Is this ‘expected’ behaviour? Do you know any methods (or workarounds) to prevent this?  Or do we need to disable AutoSync?

Is there any documentation about what events on html input fields that MVVM / AutoSync use, and when ?

Thanks

Chris

[Chris]

...in addition it seems that focus can get lost from field B when the save completes

Thanks

Chris

[Tsvetina]

Hi Chris,

Indeed, this is expected. The MVVM bindings are updated on focus out of an edited input. When an item in the DataSource is updated (via the MVVM binding), the auto sync feature automatically triggers a synchronization. So, it is safe to say that in a form like yours, DataSource synchronization will be triggered each time a field is edited and blurred. 

In my opinion, unless such type of synchronization is really needed, it would be better to disable it both in terms of user experience and performance. You can let the user submit the form when ready, when you can manually call the DataSource sync method to send changes to the server.

If you prefer to stay with the current set up, you can consider showing a loader on DataSource change event if e.action=="itemchange" and then hide it in the requestEnd event. You could consider using the kendo.ui.progress method for this purpose.This will prevent the user from typing in new data while the DataSource is syncing.

Regards,
Tsvetina
Telerik by Progress

[Milehigh JT]

I have the same issue as the original poster. My users prefer to type values in and have them saved automatically in the background, not in batch as suggested. I can save the values as they are typed using my own save code, but I need to prevent the grid from refreshing. When the grid refreshes it erases the user's next edit. How can I prevent grid refresh? 

[Plamen]

Hello,

The scenario seems quite custom and the thread is quite old - would you please try to elaborate little bit your scenario by providing some runnable sample or dojo so we could replicate it locally and be more helpful with a possible solution.

Regards,
Plamen
Progress Telerik