GetObjectProperty

This function gets the value(s) of a certain property of an instance, class or model.
The value of card gives the actual card of the values list.
The list values of integers is a list of handles to instance, classe or property, this list
has a length as given in the value card.
Caller should not dispose the list
The return value always should be 0, if not something is wrong in the way this property is called.

Syntax

C++ 32 bit

C++ 64 bit

C# 32 bit

C# 64 bit

public const string enginedll = @"engine.dll";

[DllImport(enginedll, EntryPoint = "GetObjectProperty")]
public static extern Int64 GetObjectProperty(Int64 rdfsResource, Int64 owlObjectProperty, out IntPtr values, out Int64 card);

Property rdfsResource

Size: 64 bit / 8 byte (value)
???.

Property owlObjectProperty

Size: 64 bit / 8 byte (value)
This attribute represents a handle to the object property (relation). The handle will be static during the life-time of the model, when the model (or part of it) is saved and opened again, the handle will most probably be different.

Property values

Size: 32 bit / 4 byte (reference)
The output array for object properties content. The contents memory is allocated by the library

Property card

Size: 32 bit / 4 byte (reference)
The cardinality (i.e. number of elements) of the array as given or returned.

Example (based on pure API calls)

Here you can find code snippets that show how the API call GetObjectProperty can be used.

using RDF;      //  include at least engine.cs within your solution

static void Main(string[] args)
{
    Int64 model = RDF.engine.CreateModel();

    if (model != 0)
    {
        //
        //  Classes
        //
        Int64   classAbcd = RDF.engine.CreateClass(model, "ABCD");

        //
        //  Object Properties (relations)
        //
        Int64   propertyAb = RDF.engine.CreateProperty(model, RDF.engine.OBJECTPROPERTY_TYPE, "Ab");

        //
        //  Instances
        //
        Int64   instanceAbcdI = RDF.engine.CreateInstance(classAbcd, (string) null),
                instanceAbcdII = RDF.engine.CreateInstance(classAbcd, (string) null);

        //
        //  Set Properties
        //
        
        {
            RDF.engine.SetObjectProperty(instanceAbcdI, propertyAb, ref instanceAbcdII, 1);

            Int64[] valuesAb = { instanceAbcdI, instanceAbcdII, instanceAbcdI };
            RDF.engine.SetObjectProperty(instanceAbcdII, propertyAb, ref valuesAb[0], 3);
        }

        //
        //  Get Properties
        //

        {
            Int64   card = 0;
            IntPtr  valuesPtr = IntPtr.Zero;
            RDF.engine.GetObjectProperty(instanceAbcdI, propertyAb, out valuesPtr, out card);

            System.Diagnostics.Debug.Assert(card == 1);

            if (card > 0)
            {
                Int64[] valuesAb = new Int64[card];
                System.Runtime.InteropServices.Marshal.Copy(valuesPtr, valuesAb, 0, (int) card);

                System.Diagnostics.Debug.Assert(valuesAb[0] == instanceAbcdII);
            }
        }

        {
            Int64   card = 0;
            IntPtr  valuesPtr = IntPtr.Zero;
            RDF.engine.GetObjectProperty(instanceAbcdII, propertyAb, out valuesPtr, out card);

            System.Diagnostics.Debug.Assert(card == 3);

            if (card > 0)
            {
                Int64[] valuesAb = new Int64[card];
                System.Runtime.InteropServices.Marshal.Copy(valuesPtr, valuesAb, 0, (int) card);

                System.Diagnostics.Debug.Assert(valuesAb[0] == instanceAbcdI && valuesAb[1] == instanceAbcdII && valuesAb[2] == instanceAbcdI);
            }
        }

        //
        //  The same can be applied to existing classes and properties
        //

        //
        //  Classes
        //
        Int64   classCollection = RDF.engine.GetClassByName(model, "Collection"),
                classCube = RDF.engine.GetClassByName(model, "Cube");

        //
        //  Object Properties (relations)
        //
        Int64   propertyObjects = RDF.engine.GetPropertyByName(model, "objects");

        //
        //  Datatype Properties (attributes)
        //
        Int64   propertyLength = RDF.engine.GetPropertyByName(model, "length");

        //
        //  Instances (creating)
        //
        Int64   instanceCollectionI = RDF.engine.CreateInstance(classCollection, (string) null),
                instanceCollectionII = RDF.engine.CreateInstance(classCollection, (string) null),
                instanceCube = RDF.engine.CreateInstance(classCube, (string) null);

        double  length = 1.0;
        
        RDF.engine.SetDatatypeProperty(instanceCube, propertyLength, ref length, 1);

        Int64[] values = { instanceCollectionII, instanceCube, instanceCube };
        RDF.engine.SetObjectProperty(instanceCollectionI, propertyObjects, ref values[0], 3);
        RDF.engine.SetObjectProperty(instanceCollectionII, propertyObjects, ref instanceCube, 1);

        //
        //  CollectionI contains 3 cubes and CollectionII contains 1 cube
        //
        System.Diagnostics.Debug.Assert(RDF.engine.GetVolume(instanceCollectionI, (IntPtr) 0, (IntPtr) 0) == 3);
        System.Diagnostics.Debug.Assert(RDF.engine.GetVolume(instanceCollectionII, (IntPtr) 0, (IntPtr) 0) == 1);

        //
        //  The resulting model can be viewed in 3D-Editor.exe
        //
        RDF.engine.SaveModel(model, "c:\\created\\myFile.bin");
        RDF.engine.CloseModel(model);
    }
}