The Graph Tool menu bar contains a number of commands, many of which are also available in the toolbar. Most commands are also found in the other metamodeling tools; the name of the first menu, Graph, will change appropriately in other tools.

To create a new object type, press the New toolbar button or select Graph | New... from the menu bar.

By default, new Graph types are subtypes of the generic Graph type. It is also possible, however, to organize Graph types into an inheritance hierarchy. You can build such hierarchies below all of the metatypes. Inheritance is mainly data inheritance, based on the property types in non-property tools (i.e. in Graph Tool, Object Tool, Relationship Tool, Role Tool and Port Tool) and according to the data type in Property Tool. The new object, relationship, role or port type inherits all of the properties of its supertype.

There is also some inheritance of behavior, e.g. an object can take part in a binding which includes an supertype of that object’s type (see Section 2.1.6). Similarly a property whose data type is a given non-property type may also contain non-properties whose types are subtypes of the given type.

To create a new object type as a subtype of another object type, select Graph | New Subtype... (or hold Shift down and press New in the toolbar) and select the desired supertype from the list of available object types. The name of the supertype for the current object type will be shown in the read-only Supertype field.

Graph | Open... will bring up a list of object types in currently open projects. Selecting an object type from the list will load the object type definition in the Graph Tool.

Graph | Save and the Save and Save and Close toolbar buttons save the changes to the object type; the latter also closes the Graph Tool. The buttons are disabled until the user has changed some field in the Graph Tool. Changes to dialogs and symbols are accepted in their respective tools, and thus do not affect the state of these buttons. In a non-Workbench version of MetaEdit+, these buttons are always disabled.

When saving, one of the following messages may appear:

This means that the current user is not one of the metamodelers set by the system administrator. Contact your system administrator.

This only appears in the multi-user version, and means that someone else is modeling or metamodeling at the same time. If the metamodeling security level is exclusive, then you will have to wait until all other users have logged out, and you have committed or abandoned your transaction, before you can make type changes. If the metamodeling security level is single, then you will have to wait until the other metamodeler has logged out, and you have committed or abandoned your transaction, before you can make changes.

Select Graph | Exit or close the window to quit the Graph Tool.

Tools | Generator Editor or the corresponding toolbar button opens a Generator Editor, described in Section 5.3, on the generator definitions of this Graph type. Generators are defined in Graph types and inherited from supertypes, including the Graph metatype.

As an alternative to having an identifying property, Tools | Set Identifier Generator defines a generator for the object type identifier. A separate editor to define the generator will be launched when this menu item is selected.

As such generators are normally short and do not have a name, they have no GeneratorName() header (nor the older Report 'GeneratorName' and EndReport). An identifier generator can call subgenerators, but only those defined in Graph, not its subtypes. Note that you must avoid using the generator id command on this object during its identifier generator: id will try to output the identifier for this object, which will of course call this same generator, leading to an infinite recursion. You can however safely use id for other objects of this type or others.

When the identifier is generated, no asterisk (*) will be shown before any local name in the Properties list. If the object type has no identifier at all, the name of the type is returned.

To remove an Identifier Generator and revert to displaying one of the properties as the identifier, select that property in the property list and choose Set as Identifier from the pop-up menu (see Figure 2–2 in Section 2.1.4).

Tools | Generate Default Dialog automatically defines a dialog for this object type, overriding any custom dialog. This default dialog contains a label and entry field for each property, arranged vertically in the order in which they appear in the property list. At the bottom of the default dialog are OK, Cancel and Info... buttons.

Tools | Edit Dialog opens a Dialog Editor for the properties of this object type. The default dialog can thus be modified for your needs and taste with this operation. See Chapter 4 for details.

Tools | Icon Editor opens an Icon Editor where you can draw the graphical icon to show in browsers etc. for the graph type and its instances. Icons can only be edited for types that already exist, thus this button is not available until the type has been saved. See Section 3.4 for details of using the Icon Editor.

Tools | Info Tool displays an Info Tool for the type, showing which types this type uses, and which other types use this type.

Refactor | Choose New Supertype allows the type to be moved to a different place in the hierarchy. Its metatype cannot change and nor can its project (a type must be in the same project as its supertype). The operation checks that the new supertype does not include a property slot with the same internal id as one already in this type or its subtypes. Existing instances have any new property slots filled with default values.

Refactor | Push Up Property allows to push a property slot up to a supertype, keeping its values in existing instances of this type and its subtypes. The property slot to move must be selected in the property list. There must not be any other unsaved changes in the tool. The default value of the property is added to any already loaded instances of the supertype and its subtypes (except for instances of the current type and below, which already have the property). The operation offers to replace custom dialogs with default dialogs in the supertype and below (except in the current type and below, which will still have the same properties; you may want to edit any custom dialogs to move the property widget to be in the new order).

Sometimes when you want to use Push Up Property, there may already be multiple similar properties below the new supertype. Similar here means they have the same internal slot id and property type. If such matching types exist, you will be prompted, and can choose to merge all into the new property slot in the supertype. If their local name or uniqueness is different, a warning will be shown and you can open the types to inspect them.

Help | Object Tool displays help about the Object Tool.