VirtualQueryableCollectionView + Grouping + Paging

4 posts, 0 answers
  1. Roy
    Roy avatar
    9 posts
    Member since:
    Dec 2014

    Posted 12 Apr Link to this post

    I'm currently evaluating my options for using RadGridView ( And maybe RadPivotGrid in the future ) in combination with large serverside datasets. For performance reasons we don't want to send the complete dataset to the client.

    Therefore I'm now implementing a custom IQueryable provider that delegates grouping/paging/filtering to te serverside. For simple paging this works fine, I get simple Skip/Take requests on my IQueryable.

    However when i start to use grouping I get a grouping request on my datasource, without any paging Skip/Take requests. This means that I should get all data from te server which is not acceptable for our solution.

    What solution do you propose for this problem?

  2. Stefan X1
    Admin
    Stefan X1 avatar
    514 posts

    Posted 14 Apr Link to this post

    Hi Roy,

    Can you please take a look at the Paging Before Grouping online example, or its WPF equivalent? Basically, the approach demonstrated in it consists of extending the default QueryableCollectionView by swapping the order in which the paging and grouping operations are processed.

    Let me know whether this corresponds to your needs.

    Regards,
    Stefan X1
    Telerik
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  4. Roy
    Roy avatar
    9 posts
    Member since:
    Dec 2014

    Posted 14 Apr in reply to Stefan X1 Link to this post

    Hi Stefan,

    Thanks for your reply, unfortunately this doesn't realy solve my problem. My setup needs virtualization instead of real paging. It is important for the user to be able to scroll through all groups, and when requested expand a group an scroll throug al entries within a group.

    With the data we have it is possible that we have a lot of groups, but also possible that we have lots of entries within a group.

    To be able to manage the number of rows ( Wich can be in the millions ), we only want to get the rows visible on the screen. So when grouping i'd first like to do a request to the server for (e.g.) groups 0 to 20, that contain the key and the child count. When the group is expanded I want to get a paged result of the containing elements, and when scrolling getting the needed elements.

    I hope you understand what it is that I'm trying to achieve.

     

    Regards,

    Roy

  5. Dilyan Traykov
    Admin
    Dilyan Traykov avatar
    368 posts

    Posted 19 Apr Link to this post

    Hello Roy,

    I'm afraid, there's no straightforward way to achieve the desired effect, as the VirtualQueryableCollectionView needs to first get all the items, in order to correctly group them.

    We're sorry for any inconvenience caused.

    Regards,
    Dilyan Traykov
    Telerik
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