LazyLoading Grid, ScrollBarValueChanged?

51 posts, 0 answers
  1. Simon
    Simon avatar
    9 posts
    Member since:
    Sep 2010

    Posted 24 Sep 2010 Link to this post

    Hello,

    we want to implement LazyLoading to RadGrid. The SQL view returns now rowNumbers.
    I have looked at a few approaches in google and this forum but they look like work arounds.

    Do you have a mentioned way to implement this functionality with (enabled sorting)?


    Thank you.
  2. Vlad
    Admin
    Vlad avatar
    11100 posts

    Posted 27 Sep 2010 Link to this post

    Hi Simon,

    After two/three weeks we will publish our Q3 2010 Beta and you will able to find our new VirtualQueryableCollectionView. This class is extended version of our QueryableCollectionView and will query items only if needed. Here is small video from our Q3 Beta QSF. 

    All the best,
    Vlad
    the Telerik team
    Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items
  3. Simon
    Simon avatar
    9 posts
    Member since:
    Sep 2010

    Posted 29 Sep 2010 Link to this post

    Thank you for your information, its good to hear. Hopefully you publish some examples which use WCF Service in a well performing way.


    Thanks.
  4. Vlad
    Admin
    Vlad avatar
    11100 posts

    Posted 29 Sep 2010 Link to this post

    Hi,

     Indeed the demo in our examples is using service to populate the data on the fly. You can use actually any kind of service to do that - plain WCF service, Web service, WCF Data Service, WCF RIA Service, OData, etc. since that collection will raise an event (ItemsLoading) where you can call your service with provided data.  

    Greetings,
    Vlad
    the Telerik team
    Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items
  5. Simon
    Simon avatar
    9 posts
    Member since:
    Sep 2010

    Posted 29 Sep 2010 Link to this post

    Great! I really look forward to the release of the Q3!
  6. ss
    ss avatar
    50 posts
    Member since:
    Jun 2010

    Posted 12 Oct 2010 Link to this post

    For example I have 10 000 000 articles. Is it possible to keep in memory only for example 1000 articles? Thank you.

    When Q3 Beta will be released?

  7. Vlad
    Admin
    Vlad avatar
    11100 posts

    Posted 13 Oct 2010 Link to this post

    Hello,

    The collection will be populated with empty items (null in most cases) to total items count and will load real items only when requested from IList indexer. Unfortunately UI controls with virtualization (ListBox, RadGidView, etc.) will unable to work with collection where Count is not equal to real items count.  

    The beta will be released this week. 

    Regards,
    Vlad
    the Telerik team
    Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items
  8. Niclas Pehrsson
    Niclas Pehrsson avatar
    15 posts
    Member since:
    Apr 2010

    Posted 13 Oct 2010 Link to this post

    When can we expect that UI virtualization is supported for this feature? I can't really see the big problem why it shouldn't.
  9. Vlad
    Admin
    Vlad avatar
    11100 posts

    Posted 13 Oct 2010 Link to this post

    Hello ,

     I'm not sure I understand the question. Can you clarify?

    Greetings,
    Vlad
    the Telerik team
    Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items
  10. Niclas Pehrsson
    Niclas Pehrsson avatar
    15 posts
    Member since:
    Apr 2010

    Posted 13 Oct 2010 Link to this post

    I took this meaning ". Unfortunately UI controls with virtualization (ListBox, RadGidView, etc.) will unable to work with collection where Count is not equal to real items count.  "

    As EnableColumnVirtualization="true" EnableRowVirtualization="true" on gridview will not be supported with this feature?
  11. Vlad
    Admin
    Vlad avatar
    11100 posts

    Posted 13 Oct 2010 Link to this post

    Hello Niclas,

     I've tried to explain that UI virtual controls cannot support a collection where count for example will return 100 however you will have only 10 items. Our collection (VirtualQueryableCollectionView) will create 100 nulls in this case and will replace these nulls with real items when requested. 

    Regards,
    Vlad
    the Telerik team
    Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items
  12. Niclas Pehrsson
    Niclas Pehrsson avatar
    15 posts
    Member since:
    Apr 2010

    Posted 14 Oct 2010 Link to this post

    Are there any possibilities to get the beta assemblies right now? We would really need this feature.
  13. Vlad
    Admin
    Vlad avatar
    11100 posts

    Posted 14 Oct 2010 Link to this post

    Hi,

     We will do our best to upload the beta before the end of this week. In the meantime I'm attaching small example application with simple ListBox bound to WCF RIA service on demand. You can get also the grid related binaries from the project. 

    Sincerely yours,
    Vlad
    the Telerik team
    Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items
  14. Niclas Pehrsson
    Niclas Pehrsson avatar
    15 posts
    Member since:
    Apr 2010

    Posted 14 Oct 2010 Link to this post

    Great thanks
  15. Kalai
    Kalai avatar
    4 posts
    Member since:
    Aug 2010

    Posted 15 Oct 2010 Link to this post

    Hi,

           We would like to implement lazy loading in WPF. When I tried to use VirtualQueryableCollectionView class, it expects System.Windows assembly which contradicts with PresentationFramework assembly.

           It would be really great if you can help me on this.

    Thanks,
    Kalai.
  16. Vlad
    Admin
    Vlad avatar
    11100 posts

    Posted 15 Oct 2010 Link to this post

    Hello,

     The attached binaries in the previous project are for Silverlight. I'm attaching WPF application to illustrate you how to use VirtualQueryableCollectionView with IQueryable.

    Greetings,
    Vlad
    the Telerik team
    Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items
  17. Manuel Felício
    Manuel Felício avatar
    64 posts
    Member since:
    Oct 2009

    Posted 15 Oct 2010 Link to this post

    Hi, I have my own implementation of ICollectionView, which either does in-memory queries using LINQ or does server-side queries using wcf ria services. Will I be able to use this functionallity with my own ICollectionView implementation? I'd really like to be able to do paging through the scrollbar.

    Best regards,
    Manuel Felício.
  18. Vlad
    Admin
    Vlad avatar
    11100 posts

    Posted 15 Oct 2010 Link to this post

    Hi Manuel,

     You can use the ItemsLoading even to call your collection methods and Load() method to load data once you have it. 

    Regards,
    Vlad
    the Telerik team
    Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items
  19. Manuel Felício
    Manuel Felício avatar
    64 posts
    Member since:
    Oct 2009

    Posted 16 Oct 2010 Link to this post

    That sounds promising :)

    I'm looking forward to see it in action!
  20. ss
    ss avatar
    50 posts
    Member since:
    Jun 2010

    Posted 20 Oct 2010 Link to this post

    can you please provide some example how to use  lazy loading with WCF? 


    Thank you.

  21. Vlad
    Admin
    Vlad avatar
    11100 posts

    Posted 20 Oct 2010 Link to this post

    Hello ss,

     In ItemsLoading event you can call your WCF method and load the data when available with Load() method.

    Kind regards,
    Vlad
    the Telerik team
    Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items
  22. ss
    ss avatar
    50 posts
    Member since:
    Jun 2010

    Posted 20 Oct 2010 Link to this post

    Thank you.

    Can you please explain me following VirtualQueryableCollectionView properties?

    1. LoadSize

    2. ItemCount 

    3. TotalItemCount 

    4. VirtualItemCount

    Thank you.

  23. Vlad
    Admin
    Vlad avatar
    11100 posts

    Posted 20 Oct 2010 Link to this post

    Hi,

     ItemCount and TotalItemCount are inherited from QueryableCollectionView. You can use LoadSize to define maximum number of items requested at once and you should set VirtualItemCount to the total number of items available on the server-side for example.

    Best wishes,
    Vlad
    the Telerik team
    Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items
  24. ss
    ss avatar
    50 posts
    Member since:
    Jun 2010

    Posted 21 Oct 2010 Link to this post

    Thank you very much,

     

    Everythings works fine but I have some different problem. How can I change VirtualItemCount after/before load data? Is it possible or no? I need to change VirtualItemCount because number of loded items is not constant. For example user can delete articles or add new articles to database.

    Next question: 

    I would like to set VirtualItemCount = 500 000, For example one item size = 500KB. Do you keep in memory all loaded items or do you kepp in memory only specific number of items? 

    Thank you.

  25. Kalai
    Kalai avatar
    4 posts
    Member since:
    Aug 2010

    Posted 21 Oct 2010 Link to this post

    Hi Vlad,

               Thank you so much for your promising answers. We are early waiting for Q3 release for implementing this feature. Could you please let us know when we will get Q3 RAD Controls Suite?

    Thanks,
    Kalai.
  26. Vlad
    Admin
    Vlad avatar
    11100 posts

    Posted 21 Oct 2010 Link to this post

    @ss If you set VirtualItemCount runtime the collection will refresh itself. When you have 500 000 the collection will create 500 000 nulls and will replace them when the real item is loaded. Once the item is loaded (not null) -  this item will be cached. 

     @Kalai The official release is scheduled for the middle of November. 

    Best wishes,
    Vlad
    the Telerik team
    Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items
  27. ss
    ss avatar
    50 posts
    Member since:
    Jun 2010

    Posted 21 Oct 2010 Link to this post

    Everytime I change VirtualItemCount before or after VirtualQueryableCollectionView.Load method call, i get IndexOutOfRange exception. I have no idea where is problem.

    Thank you.

  28. Vlad
    Admin
    Vlad avatar
    11100 posts

    Posted 21 Oct 2010 Link to this post

    Hi ss,

     I've just tried this however didn't get any exception. Please check the attached application for reference - you can comment also ItemsLoading event handler. 

    Kind regards,
    Vlad
    the Telerik team
    Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items
  29. ss
    ss avatar
    50 posts
    Member since:
    Jun 2010

    Posted 22 Oct 2010 Link to this post

    Thank you. Your example helped me to find my problem. DataLoadMode cannot be se to Asynchronous. Now, everythings works fine.
  30. Vlad
    Admin
    Vlad avatar
    11100 posts

    Posted 22 Oct 2010 Link to this post

    Hi ss,

     Thank you for reporting this! We've fixed this immediately and I've added 1000 Telerik points to your account. 

    Best wishes,
    Vlad
    the Telerik team
    Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items
Back to Top