Generating Smalltalk code from graphical operations and rules

A method for prototyping interactive software systems is described. The method requires three phases. In the first phase, an ER diagram modelling a system is specified and the ER database is created. In the second phase, the semantics of system operators are given in terms of graphical specifications. These graphical specifications include two components: ER operations and ER rules. In the last phase, Smalltalk code is generated and included as a central component of the prototyped system. We discuss the method of rapid prototyping in detail on the example of a graphical query interface. An ER model (meta model) for a query system is described. Next, the meta model is used to specify graphically the operations for graphical query interface in terms of ER operations and ER rules. The characteristics of the generated Smalltalk code are discussed