Limitations of CriteriaOperator.Parse

• Aug 05, 2022
• 2 minutes to read

The common way to query objects is to use the static CriteriaOperator.Parse method. However, there are two limitations you must know when using this method:

• The Parse method does not accept arrays as arguments. Instead, you should use InOperator.

  C#

  DateTime[] dates = new DateTime[] { new DateTime(2010, 10, 10), DateTime.Today };
  // Wrong. An exception is raised.
  XPCollection<Order> col1 = new XPCollection<Order>(session1,
      CriteriaOperator.Parse("[OrderDate] in (?)", dates));
  // Right
  XPCollection<Order> col2 = new XPCollection<Order>(session1,
      new InOperator("OrderDate", dates));
  

  VB.NET

  Dim dates() As DateTime = {New DateTime(2007, 10, 10), DateTime.Today}
  ' Wrong. An exception is raised.
  Dim col1 As New XPCollection(Of Order)(session1, CriteriaOperator.Parse("[OrderDate] in (?)", dates))
  ' Right
  Dim col2 As New XPCollection(Of Order)(session1, New InOperator("OrderDate", dates)) 
  

• The Parse method does not work with a string returned by the CriteriaOperator.ToString method, if criteria contain object references.

  C#

  // Gets any order
  Order o = session1.FindObject<Order>(null); 
  CriteriaOperator filter = new BinaryOperator("Customer", o.Customer);
  string filterString = filter.ToString();
  // Wrong
  XPCollection<Order> col1 = new XPCollection<Order>(session1,
      CriteriaOperator.Parse(filterString)); 
  // Right
  XPCollection<Order> col2 = new XPCollection<Order>(session1,
      filter); 
  

  VB.NET

  ' Gets any order.
  Dim o As Order = session1.FindObject(Of Order)(Nothing) 
  Dim filter As CriteriaOperator = New BinaryOperator("Customer", o.Customer)
  Dim filterString As String = filter.ToString()
  ' Wrong
  Dim col1 As New XPCollection(Of Order)(session1, CriteriaOperator.Parse(filterString))
  ' Right
  Dim col2 As New XPCollection(Of Order)(session1, filter)
  

To avoid the problems mentioned above, we suggest that you use Simplified Criteria Syntax:

C#

XPCollection<Order> col3 = new XPCollection<Order>(session1, Order.Fields.Customer == o.Customer);

VB.NET

Dim col3 As New XPCollection(Of Order)(session1, Order.Fields.Customer = o.Customer)

Note

You can register custom enumerations using static methods of the EnumProcessingHelper class and then refer to enumeration values as follows:

Status = ##Enum#MyNamespace.Status,InProgress#