Overview

This chapter covers features that relate to dynamically defining data at run time: dynamic properties, dynamic objects, dynamic dictionary objects, and user classes.

Dynamic properties provide an efficient and easy way to add properties to existing persistent instances without requiring a database reorganization. They are also convenient for situations when ad hoc values need to be attached to existing classes. In addition, changing or deleting dynamic properties does not require a reorganization.

The two types of dynamic property are:

• Runtime dynamic properties, which are added through code when an application is running.

  For details, see "Runtime Dynamic Properties", later in this chapter.

• Design‑time dynamic properties, which are added through the Class Browser when designing classes.

  For details, see "Dynamic Clusters and Properties", in Chapter 4 of the JADE Development Environment User’s Guide.

Dynamic objects are instances of the JadeDynamicObject class. They are self‑describing objects whose attributes are specified and available at run time.

Dynamic dictionaries, which are instances of the DynaDictionary class, enable you to access entries in member key dictionary subclasses but to defer the specification of the membership and keys until run time.

User classes are class definitions that are added at run time by a user application.