URL access to SSRS reports and the problem with URL encoded characters like %20

SSRS reports can be executed using URL access, where the settings and parameters are passed to the reporting services report server in the URL.
However this can cause problems when a parameter is displayed on the report that contains spaces encoded as %20 or other characters that are encoded when passed within the URL.

To solve this a custom function is required.

'------------------------------------------------------------------------------
' Function : UrlPathDecode
' Purpose  : Decode a URL-encoded string so that any encoded
'            characters (e.g., %20 for space) are restored.
'
' Parameters:
'   encodedUrl (String) - The URL text that may contain encoded characters
'
' Returns:
'   A decoded string with special characters restored.
'------------------------------------------------------------------------------
Public Function UrlPathDecode(ByVal encodedUrl As String) As String
    ' Validate input to avoid null reference issues
    If String.IsNullOrEmpty(encodedUrl) Then
        Return String.Empty
    End If

    ' Perform a single decoding pass
    Dim decodedUrl As String = System.Net.WebUtility.UrlDecode(encodedUrl)

    Return decodedUrl
End Function

This function should be pasted into the "code" window within the general report properties, that makes it then available to the expression windows within the report.

To do this right click on empty space within the background of the report in the Microsoft Report Builder.

Paste the VB.NET funtion into the code window.
This uses the .NET function to convert the percent encoded characters to the string characters.

Now reference this function with the expression of the report field you wish to display the text in. In this case the "title" parameter is decoded to a string for display within the expression for that field.

The report fields will now appear as they should.