Hi,

I just looked into the IsEmptyParent, but I'm not sure what you're suggesting to do with it. Which method do you suggest for getting just the records I need?  I really like the idea of altering the sql selectcommand in the rowislanddatabinding event.  I need to get my key field from the parent row which I can't seem to get.  I tried using e.RowIsland.ParentRow but it's always nothing in the rowislanddatabinding event.

Thanks, Ed

Hi,

The reason that the parentrow is empty is because I'm doing it on the rowislanddatabinding event which means that the child row is not there yet.  How can I get some parent row info at that stage in the child band binding process?

In the meantime, what do you guys say in general how to not retrieve all records from the database when expanding child rows?

Thanks, Ed

I was just experimenting with this yesterday, so thought I'd chime in...  With a combination of EnableDataViewState="true" and InitialDataBindDepth="-1" (or maybe "1" in your case) you can avoid all trips to the databae on child expand.  However, the trade-off is that it loads more data on initial load and stores it in the page (presumably in ViewState) which makes for a larger page being sent back and forth across the line.  Note that it will still hit the database on a page change if you are using Paging.

Hi,

Yes, and I have used that in other parts of my site. In this case though, I have many thousands of records and the initial load is unacceptable as well as the paging loads. Once, we figure out a good way to do some smart data selecting, I would actually want to load all the data and child data for an entire page at a  time.

Either way, the InitialDataBindDepth is a helpful property to be mentioned in this post.

Thanks, Ed

Hi,

This is an important post.  I think some of the developers should weigh in on this one.  It's extremely limiting of the WHDG to constantly select the entire database.

Thanks, Ed

I am having problems as well with perfomance and editing. I found that when I am using the LoadOnDemand whith no DataSources in markup and creating everything inside RowIslandsPopulating this does solve the multiple "getAll" queries.

My problem comes in when I try and do an update inside a child row, are you doing updates in a child or parent row?

I get an "Object reference not set to an instance of an object" ......

Any thoughts on this?

I've been playing around with this, and had one large problem - something is missing when you create a new containerGrid - when any cells in the new rows are updated there is a "not implemented" error on the client side (the update may or may not go through). Something appears to be not quite linked between the containerGrid bound server side and the requirements of the grid client side to save (despite it working fine when everything was bound using only the default "getAll" queries)

Any ideas?

I also notice that the grid internally still calls the default "getall" query in the hierarchical data markup on the page, sometime MULTIPLE times before it then calls the RowIslandsPopulating event server side. While I commented out the sever side ftn so it didn't return any rows, it is a concern - no wonder it runs slowly.

I found that you can do something like this

        ContainerGrid childGrid = new ContainerGrid();
        childGrid.Band = WebHierarchicalDataGrid1.Bands[0];
        e.Row.RowIslands.Add(childGrid);

if you have an existing band declared in markup, athough it gives me a casting error if I try and expand multiple bands at a time.

hi

i tried above code but no expansion indicator in the webHierarchicalDataGrid, i am also trying same thing  manual load on demand.

if there is any other options...

thanks

Srikanth

The example in the help file for manually populating the island in the RowIslandsPopulating event looks like the following:

// Create Container Grid
ContainerGrid childGrid = new ContainerGrid();
e.Row.RowIslands.Add(childGrid);

// Bind Grid
childGrid.DataSource = products;
childGrid.DataBind();

Instead of creating a new ContainerGrid, can I somehow use an 

existing band and bind to that instead in the 

RowIslandsPopulating event? 

<Bands>
   <ig:Band AutoGenerateColumns="false" Key="TXN" >
     <Columns>
       <ig:BoundDataField DataFieldName="TXN_CD" Key="TXN_CD" 

Header-Text="Transaction Code" />                                            
       <ig:BoundDataField DataFieldName="ISSUED_DT" Key="ISSUED_DT" 

Header-Text="Issue Date"/>
     </Columns>
   </ig:Band>
</Bands>