How to bind Complex Entity type to Gridview using ObjectDataSource

Question

I have an entity

class Person
{
public int Age{get;set;}
public string Name{get;set;}
public Department Dept{get;set;}
}

class Department
{
public int DeptId{get;set;}
public string DeptName{get;set}
}

Now I binds Collection to GridView using ObjectDataSource Control. Under the TemplateField for Dept of Person class looks like

<EditItemTemplate>
      <asp:DropDownList ID="cmbStatus" DataTextField="DeptName" SelectedValue='<%# Bind("Dept.DeptId") %>'
          DataValueField="DeptId" runat="server" CssClass="ddl150px ddlbg" 
          DataSourceID="deptCollection" />
      <asp:ObjectDataSource ID="deptCollection" runat="server" 
                   SelectMethod="GetDeptList" TypeName="LIMS.BusinessObject.Department" >
     </asp:ObjectDataSource>
 </EditItemTemplate>

Now my Grid gets binded using

            <asp:ObjectDataSource ID="PersonCollection" runat="server" 
                SelectMethod="GetPersonList" 
                TypeName="LIMS.BusinessObject.Person" 
                DataObjectTypeName="LIMS.DomainModel.Person" 
                DeleteMethod="Delete" InsertMethod="Create" UpdateMethod="Update" 
                ondeleting="PersonCollection_Deleting" 
                onupdating="PersonCollection_Updating">  
            </asp:ObjectDataSource>

Now when I tries to update this Person entity, it throws error because dropdown displays Value field and text field and Person entity needs a Dept Entity which is actually binded to dropdownlist

onof · Accepted Answer · 2011-09-19 22:07:49Z

3

You shouldn't use complex entities directly in the presentation layer aspx. Because if you domain model change, for example adding some field, you would update every aspx of your application. You should provide a "view model" like this:

class PersonView
{
  public int Age{get;set;}
  public string Name{get;set;}

  public int DeptId{get;set;}
  public string DeptName {get { ... }}
}

It shouldn't be a DTO: you don't need to transfer data to be serialized between hosts, but a model for the view.

A thin layer can convert model entities to view models. It could be a DataObject well supported by ObjectDataSource.

answered Sep 19, 2011 at 22:07

onof

17.4k7 gold badges52 silver badges86 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How to bind Complex Entity type to Gridview using ObjectDataSource

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related