Databind to Collection Properties
Environment
| Product | Progress® Telerik® Reporting |
Description
A common scenario is the need to set a data item’s DataSource property to a custom Business object. Depending on the underlying data structure ObjectDataSource, EntityDataSource, etc. components can be used to expose the properties of the Business object to the report. However, if the data schema is not flat and some of the properties represent child data collections, you may need to bind a report to hierarchical data.
In order to be able to use hierarchical data, you can take advantage of the Bindings functionality. Using it, you can bind declaratively the data item's DataSource property to a given collection property from your business object and the data item will display all collection items.
Solution
Consider the following scenario illustrating a custom business object Contact having as a property a collection of Phone objects.
public class Contact
{
public string Name { get; set; }
public List<Phone> Phones { get; set; }
}
public class Phone
{
public string Number { get; set; }
}
Public Class Contact
Private m_Name As String
Public Property Name() As String
Get
Return m_Name
End Get
Set(value As String)
m_Name = value
End Set
End Property
Private m_Phones As List(Of Phone)
Public Property Phones() As List(Of Phone)
Get
Return m_Phones
End Get
Set(value As List(Of Phone))
m_Phones = value
End Set
End Property
End Class
Public Class Phone
Public Property Number() As String
Get
Return m_Number
End Get
Set(value As String)
m_Number = value
End Set
End Property
Private m_Number As String
End Class
The Report.DataSource property is set to a collection of Contact objects and we want to display a list of Phone objects for each Contact object. For this purpose, add a Table item and set its DataSource property to =Fields.Phones via binding as illustrated on the image below.
Notes
The expressions are evaluated only during the report processing. Thus, the data schema for the nested data item (Table) will not be available in the data explorer and in the wizards. You can use additional data source components bound to the nested business objects to help yourself with creating the report layout. Finally, apply the required bindings and remove the helper object data source components.