Defining an Implicit Reference

The Define Reference dialog enables you to define a new reference property for the selected class.

To define a reference property

  1. If you want the reference property to be exclusive to the current class only, check the Exclusive check box. Exclusive reference properties can be specified when the type of the property is a collection subclass.

    An exclusive reference property is not embedded in the class structure. The collection is created and destroyed automatically when the parent object is created and destroyed.

  2. In the Name text box, specify the name of the property that you want to define. The name cannot be the same as the name of any existing property or non-mapping method in the class, its superclasses, or subclasses.

  3. In the Type combo box, perform one of the following actions.

    • Select the required type in the Type list.

    • Specify the first character or the first few characters of the type in the text box, and then select the required type from the Type list. The selected type is then displayed in the Type combo box.

    The type can be any class in the current schema or its superschemas. The Define Inverse button is disabled if the selected type is defined in a superschema, as inverses cannot be defined between classes in different schemas (the superschema class does not have visibility to the subschema class).

    The type can be any primitive array class defined in the schema.

  4. In the Access group box, select the appropriate type of access if you do not want access to the property to be protected. The Protected option button is selected by default, so that the property can be accessed only by methods defined in the selected class and its subclasses. (A protected property is displayed in the Properties List of the Class Browser with a padlock icon to the left of the property.)

    Select the Public option button if you want the property to be read and modified by any other method in the schema. (A property that has public access is displayed in the Properties List of the Class Browser with the public icon to the left of the property.)

    Select the Read Only option button if you want the property to be read by other methods in the schema but not updated. (A read‑only property is displayed in the Properties List of the Class Browser with the read‑only icon to the left of the property.)

    If the property is of type StringArray, IntegerArray, or one of the other primitive array types, the access mode setting applies to the array object rather than to the elements within the array; that is, a setting of read‑only does not prevent array elements being added, deleted, or updated.

  5. Check the Virtual check box if you want the value of the implicit reference property to be derived at run time and never stored in the database.

    A virtual reference property must have a defined mapping method that is activated when the value of the property is set or retrieved.

    If you check the Virtual check box, the Define Inverse button is disabled.

  6. Check the Subschema Hidden check box if you want to specify that the reference property is available only in the local schema; that is, it is not available for use in any subschemas. For details, see "subschemaHidden Option" under "Controlling the Use of Elements in Other Schemas", in Chapter 1.

  7. Click the Enter Text button if you want to specify or maintain descriptive text for the reference property as part of the definition or maintenance of the reference. For details, see "Specifying Text for a Schema Element", in Chapter 3.

    You can also specify descriptive text for the reference at any time, by selecting the Text command from the Properties menu. For details, see "Using the Free-Standing Editor Window to Define Text", in Chapter 3.

  8. Click the OK button. (Alternatively, click the Define Inverse button if you want to define an inverse for this property. Inverse reference properties are optional.)

If a property template has been defined for all new properties in your JADE development database or for your own JADE properties, the property template is displayed below the reference property details in the editor pane when you click the OK button on the Define Reference dialog. For details, see "Maintaining Text Templates", in Chapter 2.