Intersoft Community - WebGrid Enterprise - Self-Ref Load On Demand with ISDatasource

Self-Ref Load On Demand with ISDatasource

qafrank1 — Tue, 21 Feb 2012 17:39:53 GMT

Juliet,

I realize this post is over 2 years old, but I am attempting this same process - I have custom datasets built out of oracle that are my sources. Did you ever figure this out? Did Intersoft ever offer a solution for binding to a custom object?

Thanks.

Self-Ref Load On Demand with ISDatasource

Juliet.Obsteins@us.army.mil — Tue, 15 Sep 2009 14:45:04 GMT

Hierarchical="true"

and

HierarchicalMode="LoadOnDemand"

Self-Ref Load On Demand with ISDatasource

technical@intersoftpt.com — Tue, 15 Sep 2009 13:04:30 GMT

Juliet, is it possible for you to paste the WebGrid's markup declaration? Basically checking whether the Hierarchical property (in LayoutSettings) has been set to true.

Self-Ref Load On Demand with ISDatasource

Juliet.Obsteins@us.army.mil — Tue, 15 Sep 2009 11:17:23 GMT

Yes, I realized a while ago that I could get this working using classic binding. But, I can not get child tables to work under this scenario. When I define WebGrid.IObjectRelations the same way as DataSource.IObjectRelations in my business class the grid binds and loads the root table without error but does not give me the '+' to expand child rows. Only if I RetrieveHierchicalStructure at runtime does it provide them. This is not practical for my solution as I have too many column changes and format conditions to then apply at runtime. I want to define my columns at design time. Can you provide me an example of Self-Referencing Load-On-Demand using Custom Business Objects that also has child tables and does not RetrieveHierarchicalStructure at runtime.

Self-Ref Load On Demand with ISDatasource

technical@intersoftpt.com — Mon, 14 Sep 2009 12:07:39 GMT

Hi Juliet,

When the self referencing is bound to datasource control, it's true that it requires the parent row to be existed in order to create the appropriate data structure for the child. That is not required though using previous approach (InitializeSelfReferencingDataSource) since the data cache is automatically enabled using that previous approach.

We will consider an enhancement in the WebGrid by adding a scenario where developer returns a final shaped data through SelectSelfReferenceRowMethod, thus WebGrid doesn't need to reconstruct the structure again to achieve the shape required to project the children.

The work item# is 410 for your tracking reference. Please subscribe to this thread so you can get the notification when this enhancement is implemented.

Thank you for your post, and let me know if you have any other questions or feedback.

Self-Ref Load On Demand with ISDatasource

Juliet.Obsteins@us.army.mil — Mon, 14 Sep 2009 10:29:57 GMT

After waiting 24hours to find that I can no longer post to TDN - instead of being notified in the automated reply to my posting - I then waited another 24 hours for your response to my post in the new forum - only to find you didn't read my post closely enough.

Once again

If you modify the GetEmployees method - not the GetEmployeesBy method - to SELECT * FROM EMPLOYEES WHERE ReportsTo IS NULL the sample no longer works.

How can you fix this?

Self-Ref Load On Demand with ISDatasource

handy@intersoftpt.com — Mon, 14 Sep 2009 04:17:49 GMT

I made minor changes to your sample by modifying the select method you were using but found no issue. It works fine under two levels. Please see my video recording. I also attached back the modified sample as detail information.

Regards,
Handy

Self-Ref Load On Demand with ISDatasource

Juliet.Obsteins@us.army.mil — Fri, 11 Sep 2009 14:44:22 GMT

Previously you had given me the sample attached. This is a sample of self ref load on demand with custom business objects. I see that the GetEmployees method is executing "SELECT * FROM EMPLOYEES". This is not practical in my situation - that is why I want load on demand. If I change this method to "SELECT * FROM EMPLOYEES WHERE ReportsTo IS NULL" the sample no longer works beyond the first level of self ref. I see the data source is not caching the data that has been loaded on demand, so when additional levels are queried there is no parent for them. How can this be fixed?