Alright, so I wanted to build a dynamically/DB driven role-based menu system utilizing framework 2. I started with this article… http://msdn.microsoft.com/msdnmag/issues/06/02/WickedCode/
And then converted to VB.NET…Not to come across some items that I needed to change…
I came across the following errors:
“'System.Web.Caching.CacheItemRemovedCallback' is a delegate type and requires a single 'addressof' expression as the only argument to the constructor”
Which required this line “New CacheItemRemovedCallback(AOnSiteMapChanged))” in the BuildSiteMap() function to be changed to “New CacheItemRemovedCallback(AddressOf OnSiteMapChanged))” No biggy.
Then there was some funky stuff going on with NULL values (mainly in the “description” and “parentID” columns” Turns out there was a bunch of this going on..
Dim title As String = IIf(reader.IsDBNull(_indexTitle), Nothing, reader.GetString(_indexTitle).Trim())
Which was freaking out because of the NULL values (see http://weblogs.asp.net/psteele/archive/2003/10/09/31250.aspx)
So I added a simple function “CheckNullRefs” to account for that.
Lastly, it looks like the “Roles” property from SqlSiteMapProvider was actually giving me the _number_ of roles assigned to a siteMapNode rather than a collection of the actual roles themselves. So for example roles=”2” instead of
roles{0}=”Users”
roles(1)=”Admin”
I added a public array list, and then added the line below to the “CreateSiteMapNodeFromDataReader” function.
roles = ArrayList.Adapter(rolelist)
I’m sure there is a more elegant way to do all of this…but figured this would be helpful since I found little to no info on it by googling.
Update! I had a, uhm, "feature" in my code..the signature of the ReplaceNullRefs was wrong (was accepting ByVal rdrVal As String instead of Integer. Thanks to Benjamin Howarth for pointing this out!
Update 9/20: I've updated the ReplaceNullRefs function below, thanks Rob!
This allows me to dynamically build my menu by doing the following in the MenuItemDataBound sub
Protected Sub PublicMenu_MenuItemDataBound(ByVal sender As Object, ByVal e As MenuEventArgs)
'Users can be in multiple groups so...if the roles attribute of a siteMapNode contains one of the roles that a user belongs to
'do not remove it. Remove all others.
If (UserRoleName.Length) < 1 Then
UserRoleName = Roles.GetRolesForUser()
End If
Dim blmRemoveRole As Boolean = True
For i As Integer = 0 To UserRoleName.Length - 1
If CType(e.Item.DataItem, System.Web.SiteMapNode).Roles.Contains(UserRoleName(i)) Then
blmRemoveRole = False
Exit For
End If
Next
If blmRemoveRole Then
If e.Item.Parent Is Nothing Then
Me.MainMenu.Items.Remove(e.Item)
Else
e.Item.Parent.ChildItems.Remove(e.Item)
End If
End If
End Sub
Imports System
Imports System.Web
Imports System.Data.SqlClient
Imports System.Collections.Specialized
Imports System.Configuration
Imports System.Web.Configuration
Imports System.Collections.Generic
Imports System.Configuration.Provider
Imports System.Security.Permissions
Imports System.Data.Common
Imports System.Data
Imports System.Web.Caching
''' <summary>
''' Summary description for SqlSiteMapProvider
''' </summary>
<SqlClientPermission(SecurityAction.Demand, Unrestricted:=True)> _
Public Class SqlSiteMapProvider
Inherits StaticSiteMapProvider
Private Const _errmsg1 As String = "Missing node ID"
Private Const _errmsg2 As String = "Duplicate node ID"
Private Const _errmsg3 As String = "Missing parent ID"
Private Const _errmsg4 As String = "Invalid parent ID"
Private Const _errmsg5 As String = "Empty or missing connectionStringName"
Private Const _errmsg6 As String = "Missing connection string"
Private Const _errmsg7 As String = "Empty connection string"
Private Const _errmsg8 As String = "Invalid sqlCacheDependency"
Private Const _cacheDependencyName As String = "__SiteMapCacheDependency"
Private _connect As String
' Database connection string
Private _database As String, _table As String
' Database info for SQL Server 7/2000 cache dependency
Private _2005dependency As Boolean = False
' Database info for SQL Server 2005 cache dependency
Private _indexID As Integer, _indexTitle As Integer, _indexUrl As Integer, _indexDesc As Integer, _indexRoles As Integer, _indexParent As Integer
Private _nodes As New Dictionary(Of Integer, SiteMapNode)(16)
Private ReadOnly _lock As New Object()
Private _root As SiteMapNode
'Added...Declare an arraylist to hold all the roles this menu item applies to
Public roles As New ArrayList
Public Overloads Overrides Sub Initialize(ByVal name As String, ByVal config As NameValueCollection)
' Verify that config isn't null
If config Is Nothing Then
Throw New ArgumentNullException("config")
End If
' Assign the provider a default name if it doesn't have one
If [String].IsNullOrEmpty(Name) Then
Name = "SqlSiteMapProvider"
End If
' Add a default "description" attribute to config if the
' attribute doesnt exist or is empty
If String.IsNullOrEmpty(config("description")) Then
config.Remove("description")
config.Add("description", "SQL site map provider")
End If
' Call the base class's Initialize method
MyBase.Initialize(Name, config)
' Initialize _connect
Dim connect As String = config("connectionStringName")
If [String].IsNullOrEmpty(connect) Then
Throw New ProviderException(_errmsg5)
End If
config.Remove("connectionStringName")
If WebConfigurationManager.ConnectionStrings(connect) Is Nothing Then
Throw New ProviderException(_errmsg6)
End If
_connect = WebConfigurationManager.ConnectionStrings(connect).ConnectionString
If [String].IsNullOrEmpty(_connect) Then
Throw New ProviderException(_errmsg7)
End If
' Initialize SQL cache dependency info
Dim dependency As String = config("sqlCacheDependency")
If Not [String].IsNullOrEmpty(dependency) Then
If [String].Equals(dependency, "CommandNotification", StringComparison.InvariantCultureIgnoreCase) Then
SqlDependency.Start(_connect)
_2005dependency = True
Else
' If not "CommandNotification", then extract database and table names
Dim info As String() = dependency.Split(New Char() {":"c})
If info.Length <> 2 Then
Throw New ProviderException(_errmsg8)
End If
_database = info(0)
_table = info(1)
End If
config.Remove("sqlCacheDependency")
End If
' SiteMapProvider processes the securityTrimmingEnabled
' attribute but fails to remove it. Remove it now so we can
' check for unrecognized configuration attributes.
If config("securityTrimmingEnabled") IsNot Nothing Then
config.Remove("securityTrimmingEnabled")
End If
' Throw an exception if unrecognized attributes remain
If config.Count > 0 Then
Dim attr As String = config.GetKey(0)
If Not [String].IsNullOrEmpty(attr) Then
Throw New ProviderException("Unrecognized attribute: " + attr)
End If
End If
End Sub
Public Overloads Overrides Function BuildSiteMap() As SiteMapNode
SyncLock _lock
' Return immediately if this method has been called before
If _root IsNot Nothing Then
Return _root
End If
' Query the database for site map nodes
Dim connection As New SqlConnection(_connect)
Try
Dim command As New SqlCommand("proc_GetSiteMap", connection)
command.CommandType = CommandType.StoredProcedure
' Create a SQL cache dependency if requested
Dim dependency As SqlCacheDependency = Nothing
If _2005dependency Then
dependency = New SqlCacheDependency(command)
ElseIf Not [String].IsNullOrEmpty(_database) AndAlso Not String.IsNullOrEmpty(_table) Then
dependency = New SqlCacheDependency(_database, _table)
End If
connection.Open()
Dim reader As SqlDataReader = command.ExecuteReader()
_indexID = reader.GetOrdinal("ID")
_indexUrl = reader.GetOrdinal("Url")
_indexTitle = reader.GetOrdinal("Title")
_indexDesc = reader.GetOrdinal("Description")
_indexRoles = reader.GetOrdinal("Roles")
_indexParent = reader.GetOrdinal("Parent")
If reader.Read() Then
' Create the root SiteMapNode and add it to the site map
_root = CreateSiteMapNodeFromDataReader(reader)
AddNode(_root, Nothing)
' Build a tree of SiteMapNodes underneath the root node
While reader.Read()
' Create another site map node and add it to the site map
Dim node As SiteMapNode = CreateSiteMapNodeFromDataReader(reader)
AddNode(node, GetParentNodeFromDataReader(reader))
End While
' Use the SQL cache dependency
If dependency IsNot Nothing Then
HttpRuntime.Cache.Insert(_cacheDependencyName, New Object(), dependency, Cache.NoAbsoluteExpiration, Cache.NoSlidingExpiration, CacheItemPriority.NotRemovable, _
New CacheItemRemovedCallback(AddressOf OnSiteMapChanged))
End If
End If
Finally
connection.Close()
End Try
' Return the root SiteMapNode
Return _root
End SyncLock
End Function
Protected Overloads Overrides Function GetRootNodeCore() As SiteMapNode
SyncLock _lock
BuildSiteMap()
Return _root
End SyncLock
End Function
' Helper methods
Private Function CreateSiteMapNodeFromDataReader(ByVal reader As DbDataReader) As SiteMapNode
' Make sure the node ID is present
If reader.IsDBNull(_indexID) Then
Throw New ProviderException(_errmsg1)
End If
' Get the node ID from the DataReader
Dim id As Integer = reader.GetInt32(_indexID)
' Make sure the node ID is unique
If _nodes.ContainsKey(id) Then
Throw New ProviderException(_errmsg2)
End If
' Get title, URL, description, and roles from the DataReader
Dim title As String = ReplaceNullRefs(reader, _indexTitle)
Dim url As String = ReplaceNullRefs(reader, _indexUrl)
'Eliminated...see http://weblogs.asp.net/psteele/archive/2003/10/09/31250.aspx
Dim description As String = ReplaceNullRefs(reader, _indexDesc)
'Changed variable name from 'roles' to 'rolesN' and added line 230 to dump all roles into an arrayList
Dim rolesN As String = IIf(reader.IsDBNull(_indexRoles), Nothing, reader.GetString(_indexRoles).Trim())
Dim rolelist As String() = Nothing
If Not [String].IsNullOrEmpty(rolesN) Then
rolelist = rolesN.Split(New Char() {","c, ";"c}, 512)
End If
roles = ArrayList.Adapter(rolelist)
' Create a SiteMapNode
Dim node As New SiteMapNode(Me, id.ToString(), url, title, description, rolelist, _
Nothing, Nothing, Nothing)
' Record the node in the _nodes dictionary
_nodes.Add(id, node)
' Return the node
Return node
End Function
Private Function ReplaceNullRefs(ByVal rdr As DbDataReader, ByVal rdrVal As Integer) As String
If Not (rdr.IsDBNull(rdrVal)) Then
' Thanks Rob Johnston
Return rdr.GetString(rdrVal)
Else
Return String.Empty
End If
End Function
Private Function GetParentNodeFromDataReader(ByVal reader As DbDataReader) As SiteMapNode
' Make sure the parent ID is present
If reader.IsDBNull(_indexParent) Then
'**** Commented out throw, added exit function ****
Throw New ProviderException(_errmsg3)
'Exit Function
End If
' Get the parent ID from the DataReader
Dim pid As Integer = reader.GetInt32(_indexParent)
' Make sure the parent ID is valid
If Not _nodes.ContainsKey(pid) Then
Throw New ProviderException(_errmsg4)
End If
' Return the parent SiteMapNode
Return _nodes(pid)
End Function
Private Sub OnSiteMapChanged(ByVal key As String, ByVal item As Object, ByVal reason As CacheItemRemovedReason)
SyncLock _lock
If key = _cacheDependencyName AndAlso reason = CacheItemRemovedReason.DependencyChanged Then
' Refresh the site map
Clear()
_nodes.Clear()
_root = Nothing
End If
End SyncLock
End Sub
End Class