FilterDescriptor Class
Filters are the fundamental way in which the Business Data Catalog captures user (or system) input and plumbs it through to the backend API invocation. FilterDescriptors describe where in a complex series of parameters, a filter value should be inserted. This is accomplished by 'tagging' the TypeDEscriptors representing complex parameters of a Method definition to flag where the insertion should happen. It is important to note that the backend must supply the functionality for filtering; the FilterDescriptors merely form a mechanism to surface this to the end user. FilterDescriptor objects are owned (contained) inside Method objects. They are subsequently referred by TypeDescriptor objects.
Inheritance Hierarchy
System.Object
Microsoft.Office.Server.ApplicationRegistry.MetadataModel.MetadataObject
Microsoft.Office.Server.ApplicationRegistry.MetadataModel.FilterDescriptor
Namespace: Microsoft.Office.Server.ApplicationRegistry.MetadataModel
Assembly: Microsoft.SharePoint.Portal (in Microsoft.SharePoint.Portal.dll)
Syntax
'Declaration
<SharePointPermissionAttribute(SecurityAction.InheritanceDemand, ObjectModel := True)> _
<SharePointPermissionAttribute(SecurityAction.LinkDemand, ObjectModel := True)> _
Public Class FilterDescriptor _
Inherits MetadataObject
'Usage
Dim instance As FilterDescriptor
[SharePointPermissionAttribute(SecurityAction.InheritanceDemand, ObjectModel = true)]
[SharePointPermissionAttribute(SecurityAction.LinkDemand, ObjectModel = true)]
public class FilterDescriptor : MetadataObject
Remarks
Users may want to retrieve the instances of an entity that match some criteria. For example, a user may want to display the customers whose names begin with "A" or the orders made by a certain customer. The API used to retrieve customers requires that this user input be passed in as the third String parameter in the invocation. The metadata author will create a FilterDescriptor of a Wildcard Type, and then tag the third parameter's root TypeDescriptor with this newly created FilterDescriptor. Many such FilterDescriptors may be associated with a single Method (API).Users then choose the filter they want at run time, specify a value for it, and the Business Data Catalog passes that filter's value to the back-end method, inserting it into the exact location where the backend expects it, which causes it to then returns only the rows the user wants to see.
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
See Also
Reference
Microsoft.Office.Server.ApplicationRegistry.MetadataModel Namespace