Creating User-Defined Properties

A User-Defined Property (UDP) is an example of a client expanding the erwin DM metadata and involves creating and modifying objects on the metadata level. The structure of the UDP definition is similar to the definition of all native properties. The following diagram shows the metamodel objects involved when you define a UDP:

In this diagram an instance of the Property_Type object defines a UDP class, the Object_Type object defines an object class with which the UDP is associated, and the Association_Type object defines the association between object and property classes.

You are only required to create an instance of the Property_Type object to define a UDP. erwin DM populates the rest of the necessary data. The following table describes the properties and tags of the Property_Type object:

Property or Tag Name	Description	Valid Arguments
Name	Property, UDP name	erwin DM upholds the following convention in naming UDPs to ensure their uniqueness. The convention is a three part name separated with dot (.) symbols: <ObjectClassName>.<Logical/Physical>.<Name> An example of this naming convention is: Model.Logical.My UDP The erwin DM editors display only the last component.
Data_Type	Property, SCVT_BSTR	The property is read-only and set by erwin DM. All UDP values have a string datatype.
tag_Is_Locally_Defined	Property, TRUE	The property is read-only and set to TRUE for all user-defined metadata.
Definition	Property, Optional	Optional � Text that displays the UDP description.
tag_Is_Logical	Tag, TRUE or FALSE	Optional � The tag has a TRUE value for UDPs used in logical modeling.
tag_Is_Physical	Tag, TRUE or FALSE	Optional � The tag has a TRUE value for UDPs used in physical modeling.
tag_Udp_Default_Value	Tag	Optional � A string with the UDP default value.
tag_Udp_Data_Type	Tag	Defines the interpretation for the UDP value in the erwin DM editors. The valid values are: 1 (Integer) 2 (Text) 3 (Date) 4 (Command) 5 (Real) 6 (List) The property value can be: VT_I4 � Uses the numeric values listed above. VT_BSTR � Uses the string values listed above. Assumes the Text type if it is not specified.
tag_Udp_Owner_Type	Tag	Required. Defines an object class to host instances of the UDPs. VT_BSTR � Name of an object class. Indicates the host class by the given class name. VT_BSTR � Class ID of an object class. Indicates the host class by the given identifier.
tag_Udp_Values_List	Tag	String with comma-separated values. Only values from the list are valid values for a UDP. Valid only if the tag_Udp_Data_Type tag is set to List.

//the following example was changed in r9.6, because the

Example 33

The following example illustrates how to use the API to define a UDP using Visual Basic Script:

    Dim oAPI

    Set oAPI = CreateObject("erwin9.SCAPI.9.0")

    Dim oPU

    Set oPU = oAPI.PersistenceUnits.Create(Nothing)

    Dim oSession

    Set oSession = oAPI.Sessions.Add

    SCD_SL_M1 = 1

    call oSession.Open(oPU, SCD_SL_M1)

    Dim TransId

    TransId = oSession.BeginNamedTransaction("Create UDP")

    Dim oUDP

    Set oUDP = oSession.ModelObjects.Add("Property_Type")

    ' Populate properties

	' Add udp with Text type

    Set oUDP = oSession.ModelObjects.Add("Property_Type")

    oUDP.Properties("Name").Value = "Entity.Logical.My UDP1"

    oUDP.Properties("tag_Udp_Owner_Type").Value = "Entity"

    oUDP.Properties("tag_Is_Logical").Value = True

    oUDP.Properties("tag_Udp_Data_Type").Value = 2

    oUDP.Properties("tag_Udp_Default_Value").Value = "Text"

     oUDP.Properties("tag_Order").Value = "1"

	'Add udp with list type

    Set oUDP = oSession.ModelObjects.Add("Property_Type")

    oUDP.Properties("Name").Value = "Entity.Logical.My UDP5"

    oUDP.Properties("tag_Udp_Owner_Type").Value = "Entity"

    oUDP.Properties("tag_Is_Logical").Value = True

    oUDP.Properties("tag_Udp_Data_Type").Value = 6

    oUDP.Properties("tag_Udp_Values_List").Value = "1,2,3"
    oUDP.Properties("tag_Udp_Default_Value").Value = "1"

    oUDP.Properties("tag_Order").Value = "1"

    ' Commit changes

    oSession.CommitTransaction (TransId)

    ' Release the session

    oSession.Close

    Set oSession = Nothing

    oAPI.Sessions.Clear

    ' Save to the file

        Call oPU.Save("C:\Temp1\UDP.erwin", "OVF=Yes")