Object is the most obvious of the GOPPRR metatypes, as objects are usually the main elements of a diagram in your modeling language. In our case, our domain concept of Person falls into this category. To add a new object type, move the cursor into the Objects list in Graph Tool’s Types page, click the right mouse button and select Add New... from the popup menu. This will open a new Object Tool (as in Figure 3-5).

Start creating the Person type by typing its name (i.e. ‘Person’) into the text field at the top of the Object Tool. Person needs some properties, too, so move the cursor down to the Properties list, open the popup menu and select Add Property.... You will now see a dialog prompting you to either select the existing Family name property type or to create a new one (Figure 3-6). Select ‘New Property Type’ from the list and press OK to open the Property Tool for a new property type.

In the Property Tool enter ‘First name’ as the name and press Save and Close – we don’t need to change anything else as the default values for other fields suit our purposes in this case.

After adding First name, the Object Tool should look like Figure 3-7. What we want to have next is the Family name property for our Person. This time we do not want to create a completely new property type, instead we shall reuse the existing ‘Family name’ property that we created for the Family Tree graph type. With no selection in Object Tool’s Properties list, click the right mouse button in the empty space below the last element, select Add Property... and choose ‘Family name’ from the list of possible property types. A property slot for Family name is added at the end of the list. If a property slot had been selected in the list, the new slot would have been added above the selection – you can change the order by selecting a property and choosing Move Property... in its pop-up menu. Your Object Tool should now look similar to Figure 3-8.

Press Save and Close on the toolbar to accept the changes and close the Object Tool. The new Person object is added to the Objects list on the Graph Tool’s Types page (as in Figure 3-9). Press Save in the Graph Tool. You have now completed the definition of the Person concept.