Can't ClientSide Sort with Fields mapped on related fields if null key?
Joined: 22-Dec-2006
Joined: 22-Dec-2006
Joined: 22-Dec-2006
Okay, sorry... I forgot you could do that. 
The "Server Application Unavailable" Error webpage was something I thought was different. The exception was:
System.StackOverflowException was unhandled - {Cannot evaluate expression because the current thread is in a stack overflow state.}
It bombs on some generated code:
/// <summary>Returns a new IEntityRelation object, between GeneralAgentContactEntity and DepartmentEntity over the m:1 relation they have, using the relation between the fields:
/// GeneralAgentContact.DepartmentId - Department.DepartmentId
/// </summary>
public virtual IEntityRelation DepartmentEntityUsingDepartmentId
{
get
{
IEntityRelation relation = new EntityRelation(SD.LLBLGen.Pro.ORMSupportClasses.RelationType.ManyToOne);
relation.StartEntityIsPkSide = false;
(BOMBS HERE) relation.AddEntityFieldPair(EntityFieldFactory.Create(DepartmentFieldIndex.DepartmentId), EntityFieldFactory.Create(GeneralAgentContactFieldIndex.DepartmentId));
relation.InheritanceInfoPkSideEntity = InheritanceInfoProviderSingleton.GetInstance().GetInheritanceInfo("DepartmentEntity", false);
relation.InheritanceInfoFkSideEntity = InheritanceInfoProviderSingleton.GetInstance().GetInheritanceInfo("GeneralAgentContactEntity", true);
return relation;
}
}
DepartmentId can be null (in the DB). If it isn't null, it doesn't bomb. I mapped Department.Name as "DepartmentName" so that I could display GeneralAgentContact.DepartmentName in the GridView & sort on that field. This "field mapped on related field" was set up in the LLBLGen Pro designer.
<asp:TemplateField HeaderText="Department" SortExpression="DepartmentName">
<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Bind("DepartmentName") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
Same kind of crash happens if I try to sort on any other FieldMappedOnRelatedField that is Null. Thanks for assistance!
EDIT: wait, maybe I need to update my Designer! I only updated my runtime .dlls... 
I will need to wait 'till tomorrow to try that...
Darrell Bircsak
Joined: 22-Dec-2006
Joined: 22-Dec-2006
I can reproduce both: the stack overflow and the sort failure.
The stack overflow happens when you sort on another column and then the field mapped onto related field.
The field mapped onto related field should be sortable with SortingMode="ClientSide", set on the datasourcecontrol, however that has no effect.
Looking into it. (note: it does work on adapter, so it's a bit strange why this doesn't work on selfservicing)
(edit). I know why it does work on adapter, and it also works on selfservicing: use a prefetch path.
In our example, we have a simple grid and two entities; Dep and Emp. Emp has a field mapped onto related fields, DepName, which is the name of the related Dep. The grid loads all Emp's.
To efficiently load such a grid, it's highly recommended you use a prefetch path, because every row will otherwise trigger lazy loading and will load the entity manually.
First, set the llblgenprodatasource control's SortMode to ClientSide, as you're going to sort on a field which is in another entity (or a custom property you added yourself).
then, set the prefetch path, as in the example below.
Page:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="WebApplication1._Default" %>
<%@ Register Assembly="SD.LLBLGen.Pro.ORMSupportClasses" Namespace="SD.LLBLGen.Pro.ORMSupportClasses"
TagPrefix="llblgenpro" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<llblgenpro:LLBLGenProDataSource ID="LLBLGenProDataSource1" runat="server" DataContainerType="EntityCollection"
EntityCollectionTypeName="NS.CollectionClasses.EmpCollection, NS" SortingMode="clientSide" >
</llblgenpro:LLBLGenProDataSource>
</div>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="Id"
DataSourceID="LLBLGenProDataSource1" AllowSorting="True">
<Columns>
<asp:BoundField DataField="Id" HeaderText="Id" InsertVisible="False" ReadOnly="True"
SortExpression="Id" />
<asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" />
<asp:BoundField DataField="DepId" HeaderText="DepId" SortExpression="DepId" />
<asp:BoundField DataField="DepName" HeaderText="DepName" SortExpression="DepName" />
</Columns>
</asp:GridView>
</form>
</body>
</html>
code behind:
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using SD.LLBLGen.Pro.ORMSupportClasses;
using NS;
using NS.EntityClasses;
namespace WebApplication1
{
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if(!Page.IsPostBack)
{
PrefetchPath path = new PrefetchPath((int)EntityType.EmpEntity);
path.Add(EmpEntity.PrefetchPathDep);
LLBLGenProDataSource1.PrefetchPathToUse = path;
}
}
}
}
The datasourcecontrol will cache the set path, so you just have to set it once.
I still would like to know why it's dying in the infinite loop, though this will get you up and running: you have a more efficient grid and it now also works 
Joined: 22-Dec-2006
Cool... I feel like I helped someone else make the world a better place.
I'm really impressed by how your team jumped into this. Thank you for the support & patience!
Yes, I've been putting off prefetching.... 
Darrell Bircsak
Thanks Darrell!
The fix is now available.