GetDatatypeProperty

This function gets the value(s) of a certain datatypeTypeProperty in the context of an instance.
The value of card gives the actual card of the values list.
The list values of undefined (void) items is a list of booleans, chars, integers or doubles, this list has a length as givin in the value card. The actual used type is given by the definition of the dataTypeProperty.
The return value always should be 0, if not something is wrong in the way this property is called.

Syntax

//
//   Strong typing definition
//
int64_t         GetDatatypeProperty(
                        OwlInstance             owlInstance,
                        OwlDatatypeProperty     owlDatatypeProperty,
                        const void              ** values,
                        int64_t                 * card
                    );

static  inline  int64_t GetDatatypeProperty(
                                OwlInstance             owlInstance,
                                OwlDatatypeProperty     owlDatatypeProperty,
                                void                    ** values,
                                int64_t                 * card
                            )
{
    return  GetDatatypeProperty(
                    owlInstance,
                    owlDatatypeProperty,
                    (const void**) values,
                    card
                );
}


//
//   Weak typing definition
//
int64_t __declspec(dllexport) __stdcall GetDatatypeProperty(
                                                int64_t                 owlInstance,
                                                int64_t                 owlDatatypeProperty,
                                                const void              ** values,
                                                int64_t                 * card
                                            );

static  inline  int64_t GetDatatypeProperty(
                                int64_t                 owlInstance,
                                int64_t                 owlDatatypeProperty,
                                void                    ** values,
                                int64_t                 * card
                            )
{
    return  GetDatatypeProperty(
                    owlInstance,
                    owlDatatypeProperty,
                    (const void**) values,
                    card
                );
}
    

Property owlInstance

Size: 64 bit / 8 byte (value)
The handle to the specific instance in the design tree. The instance handle is static within one open model but is most probably different when the same instance is opened in another model. The instance is always exactly of one unique class.

Property owlDatatypeProperty

Size: 64 bit / 8 byte (value)
This attribute represents a handle to the datatype property (attribute). 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: 64 bit / 8 byte (reference)
The output array for datatype properties content. The contents memory is allocated by the library

Property card

Size: 64 bit / 8 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 snippits that show how the API call GetDatatypeProperty can be used.

#include    "./include/engine.h"
#include    <stdio.h>
#include    <string.h>

int64_t model = CreateModel();

if (model) {
    //
    //  Classes
    //
    int64_t classAbcd = CreateClass(model, "ABCD");

    //
    //  Datatype Properties (attributes)
    //
    int64_t propertyAb = CreateProperty(model, DATATYPEPROPERTY_TYPE_BOOLEAN, "Ab"),
            propertyCd = CreateProperty(model, DATATYPEPROPERTY_TYPE_CHAR, "Cd"),
            propertyEf = CreateProperty(model, DATATYPEPROPERTY_TYPE_INTEGER, "Ef"),
            propertyGh = CreateProperty(model, DATATYPEPROPERTY_TYPE_DOUBLE, "Gh");

    //
    //  Instances
    //
    int64_t instanceAbcd = CreateInstance(classAbcd, nullptr);

    //
    //  Set Properties
    //
        
    {
        bool    valuesAb[2] = { true, false };
        SetDatatypeProperty(instanceAbcd, propertyAb, valuesAb, 2);

        char    * valuesCd[2] = { "First Line", "Second Line" };
        SetDatatypeProperty(instanceAbcd, propertyCd, valuesCd, 2);

        int64_t valuesEf[2] = { 1234, 5678 };
        SetDatatypeProperty(instanceAbcd, propertyEf, valuesEf, 2);

        double  valuesGh[2] = { 12.34, 56.78 };
        SetDatatypeProperty(instanceAbcd, propertyGh, valuesGh, 2);
    }

    //
    //  Get Properties
    //

    {
        int64_t card = 0;
        bool    * values = nullptr;
        GetDatatypeProperty(instanceAbcd, propertyAb, (void**) &values, &card);

        assert(card == 2 && values[0] == true && values[1] == false);
    }

    {
        int64_t card = 0;
        char    ** values = nullptr;
        GetDatatypeProperty(instanceAbcd, propertyCd, (void**) &values, &card);

        assert(card == 2 && strcmp(values[0], "First Line") == 0 && strcmp(values[1], "Second Line") == 0);
    }

    {
        int64_t card = 0,
                * values = nullptr;
        GetDatatypeProperty(instanceAbcd, propertyEf, (void**) &values, &card);

        assert(card == 2 && values[0] == 1234 && values[1] == 5678);
    }

    {
        int64_t card = 0;
        double  * values = nullptr;
        GetDatatypeProperty(instanceAbcd, propertyGh, (void**) &values, &card);

        assert(card == 2 && values[0] == 12.34 && values[1] == 56.78);
    }

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

    //
    //  Classes
    //
    int64_t classCylinder = GetClassByName(model, "Cylinder");

    //
    //  Datatype Properties (attributes)
    //
    int64_t propertyClosed = GetPropertyByName(model, "closed"),
            propertyLength = GetPropertyByName(model, "length"),
            propertyName = GetPropertyByName(model, "name"),
            propertyRadius = GetPropertyByName(model, "radius"),
            propertySegmentationParts = GetPropertyByName(model, "segmentationParts");

    //
    //  Instances (creating)
    //
    int64_t myInstanceCylinder = CreateInstance(classCylinder, nullptr);

    double  length = 1.8,
            radius = 1.3;
    int64_t segmentationParts = 36;
        
    SetDatatypeProperty(myInstanceCylinder, propertyLength, &length, 1);
    SetDatatypeProperty(myInstanceCylinder, propertyRadius, &radius, 1);
    SetDatatypeProperty(myInstanceCylinder, propertySegmentationParts, &segmentationParts, 1);

    //
    //  non related / restricted properties (user defined and pre defined) can be connected in any quantity
    //
    bool    closed = true;
    char    * name = "Example text added";

    SetDatatypeProperty(myInstanceCylinder, propertyClosed, &closed, 1);
    SetDatatypeProperty(myInstanceCylinder, propertyName, &name, 1);

    assert(GetArea(myInstanceCylinder, nullptr, nullptr) > 0.);

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