Abstract:
Computer method and apparatus provides lightweight stereotypes in a programming model. An alternative to applied profiles is disclosed. A keyword list or list of strings is recorded as an annotation to a model element. The keywords are indicative of applied stereotypes of the model element, where the stereotypes are empty or are used as labels. The list of strings effectively augments the collection of applied stereotypes of the model element.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation of U.S. application Ser. No. 11/001,649, filed Dec. 1, 2004. The entire teachings of the above application(s) are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    With the proliferation of software products and services, attempts have been made to codify and/or standardize the designing of software and software architecture. Examples include:
       The Booch Method and Modeling Language (see “Object Oriented Analysis and Design” by Grady Booch);   James Rumbaugh and Associates&#39; Object Modeling Technique (OMT);   the Object Oriented Software Engineering (OOSE) method by Ivar Jacobson; and   the Unified Modeling Language (UML) which combines the foregoing and industry best practices.       
 
         [0007]    The UML is a visual modeling language (with formal syntax and semantics) for communicating a model or conceptionalization. Thus the modeling language specification specifies modeling elements, notation and usage guidelines and not order of activities, specification of artifacts, repository interface, storage, run-time behavior and so forth. In general, at the modeling level a “problem” is posed in terms of a customer&#39;s needs and requirements and may be referred to as the business problem system. The software designer develops a “solution” software product and or service that addresses the problem. The UML syntax enables software designers to express (specify and document) the subject problems and solutions in a standardized manner, while the UML semantics enable knowledge about the subject system to be captured and leveraged during the problem solving phase. See “UML in a Nutshell” by Simon Si Alhir, published by O&#39;Reilly &amp; Associates, September 1998. As such, the UML enables the sharing of information (including prior solution portions) and extension (without reimplementation) of core object oriented concepts (analysis and design) during the iterative problem-solving process for designing software products. 
         [0008]    The UML2 specification defines stereotypes contained within a profile and applied to a model as a method of providing lightweight metaclass extensions. This enables the use of domain-specific terminology and notation for a given extended metaclass. As defined in the specification, a stereotype must be owned by a profile which is applied to a model through a ProfileApplication instance added to the model&#39;s appliedProfiles collection. 
         [0009]    Though applied stereotypes are intended to be lightweight extensions when compared to alternative methods in UML, they actually impose substantial overhead in both memory and run-time processing. In cases where the stereotype is used as a simple domain-specific label (i.e. it contains no owned properties), the overhead of stereotypes stands out. 
       BRIEF SUMMARY 
       [0010]    The present invention addresses and/or overcomes the above problems of the prior art. In particular, the present invention provides an alternative to applied profiles and a given modeling tool&#39;s mechanism for determining which stereotypes are applied to a given element. 
         [0011]    In a preferred embodiment, a computer method and apparatus provides lightweight stereotypes (i.e., stereotypes that are used as labels or are empty) in a programming model. The invention method includes the steps of:
       given a model element having a collection of applied stereotypes, storing keywords indicative of the applied stereotypes; and   interpreting the stored keywords and generating therefrom a model that implements the applied stereotypes.       
 
         [0014]    The step of storing keywords preferably stores a keyword list or list of strings as an annotation to the model element. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0015]    The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. 
           [0016]      FIG. 1  is a schematic illustration of stereotypes applied to an element within a model in the prior art. 
           [0017]      FIGS. 2 and 3  are block diagrams of a preferred embodiment of the present invention. 
           [0018]      FIG. 4  is a schematic view of a computer environment in which the principles of the present invention may be implemented. 
           [0019]      FIG. 5  is a block diagram of the internal structure of a computer from the  FIG. 4  computer environment. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    A description of preferred embodiments of the invention follows. 
         [0021]      FIG. 1  illustrates how stereotypes  15  are applied to an element  13  within a model  11  according to the UML  2  specification. The model “TestModel”  11  has an element “TestClass”  13 . A metaclass extension  23  for TestClass element  13  is provided by stereotype “Article”  15 . A profile “Library Profile”  17  owns the stereotype “Article”  15  and is applied to TestModel  11  through ProfileApplication instance  19 . ProfileApplication instance  19  is added to model&#39;s  11  appliedProfiles collection as indicated at  21 . 
         [0022]    In many cases, a stereotype  15  is used as a domain-specific label and it is in these situations that the amount of memory and processing load can be significantly reduced using techniques which require neither the creation of a profile  17  nor the overhead of references to ProfileApplication instances  19  in the model  11 . 
         [0023]    For situations where the stereotype is used for simple labeling, the present invention introduces a concept of a collection of keyword strings to be used instead of the traditional stereotypes  15 . The keyword list can be implemented using any standard container class provided by the host language. For example in Java an ArrayList object may be used. This list is attached to a selected element  13  within the model  11  to provide a set of keywords. There is no requirement to create a relatively “heavy” construct like a stereotype  15  and no need to reference UML profiles  17  through a ProfileApplication instance  19 . The memory savings for even small models is notable. 
         [0024]      FIG. 2  is illustrative in part. A model  11  has element TestClass  13 . A keyword list  25  is attached to element  13  as an eAnnotation  27  and provides a set of keywords (corresponding to desired stereotype labels). 
         [0025]    Keywords must mimic some of the basic concepts of stereotypes  15 —for example they may be applied or removed from a given model element  13 . When using a programming language such as Java, one choice for implementing the invention keyword concept is a standard list containing strings representing the domain-specific labels. 
         [0026]    Most meta-modeling languages provide a mechanism to attach arbitrary data to a model element  13 . Eclipse Modeling Framework (EMF) is one such language, which provides an EAnnotation class that can hold arbitrary data on behalf of its owning class. In one implementation using EMF, an EAnnotation has been successfully used to implement a prototype for the present invention UML keywords. 
         [0027]      FIGS. 2 and 3  further show, in accordance with the present invention, a mechanism for creating very light stereotype-like keywords using EMF. A collection of applied stereotypes  57  is represented and/or provided by a keyword list  25 . The collection of applied stereotypes  57  is effectively augmented by the addition of a list of strings  29  attached to model element  13  using an established metamodel reference (e.g., an EAnnotation in EMF). Unlike applied stereotypes  57 , the keyword list  25  has an added advantage in that keywords can be modified at runtime without requiring a separate profile  17 /stereotype construction phase. 
         [0028]    In a preferred embodiment with reference to  FIG. 3 , model  11  is a Rose model that represents the code generation (model) of interest, i.e., the software product model being designed. Other UML or data models are suitable. The present invention records the keywords and augmenting list of strings  25 ,  29  in the form of annotations in respective parts of the code generation model  11 . Next the preferred embodiment employs EMF  63  (or similar model interpreter) to generate Java templates or the like code  65  from the annotated Rose model  11 ,  25 ,  29 . The generated Java template or the like code  65  simulates lightweight stereotypes, i.e., empty stereotypes or stereotypes used as domain-specific labels. The resulting EMF (model interpreter)  63  output is an API  65  (e.g., in an object oriented or other programming language) that correctly implements applied stereotypes  57  and in particular lightweight (or empty) stereotypes  57 . 
         [0029]    Keywords (at  25 ) may be used in parallel with applied stereotypes  57  and may easily be tied into the diagramming engine of a UML tool built using the UML2 API such that keywords added to the element  13  have similar notation to stereotypes (e.g. surrounded by “&lt;&lt; &gt;&gt;”). 
         [0030]    The result is a very light mechanism that simulates applying empty stereotypes to a UML element  13 . Restated, the present invention effectively provides an alternative to applied profiles  19 ,  21  and a given modeling tool&#39;s mechanism for determining which stereotypes  15  are applied to a given element  13 . 
         [0031]      FIG. 4  illustrates a computer network or similar digital processing environment in which the present invention may be implemented. 
         [0032]    Client computer(s)/devices  50  and server computer(s)  60  provide processing, storage, and input/output devices executing application programs and the like. Client computer(s)/devices  50  can also be linked through communications network  70  to other computing devices, including other client devices/processes  50  and server computer(s)  60 . Communications network  70  can be part of a remote access network, a global network (e.g., the Internet), a worldwide collection of computers, Local area or Wide area networks, and gateways that currently use respective protocols (TCP/IP, Bluetooth, etc.) to communicate with one another. Other electronic device/computer network architectures are suitable. 
         [0033]      FIG. 5  is a diagram of the internal structure of a computer (e.g., client processor/device  50  or server computers  60 ) in the computer system of  FIG. 4 . Each computer  50 ,  60  contains system bus  79 , where a bus is a set of hardware lines used for data transfer among the components of a computer or processing system. Bus  79  is essentially a shared conduit that connects different elements of a computer system (e.g., processor, disk storage, memory, input/output ports, network ports, etc.) that enables the transfer of information between the elements. Attached to system bus  79  is I/O device interface  82  for connecting various input and output devices (e.g., keyboard, mouse, displays, printers, speakers, etc.) to the computer  50 ,  60 . Network interface  86  allows the computer to connect to various other devices attached to a network (e.g., network  70  of  FIG. 4 ). Memory  90  provides volatile storage for computer software instructions  92  and data  94  used to implement an embodiment of the present invention (e.g., annotated Rose model  11 ,  25 ,  29  and model interpreter EMF code  63  detailed above). Disk storage  95  provides non-volatile storage for computer software instructions  92  and data  94  used to implement an embodiment of the present invention. Central processor unit  84  is also attached to system bus  79  and provides for the execution of computer instructions. 
         [0034]    In one embodiment, the processor routines  92  and data  94  are a computer program product (generally referenced  92 ), including a computer readable medium (e.g., a removable storage medium such as one or more DVD-ROM&#39;s, CD-ROM&#39;s, diskettes, tapes, etc.) that provides at least a portion of the software instructions for the invention system. Computer program product  92  can be installed by any suitable software installation procedure, as is well known in the art. In another embodiment, at least a portion of the software instructions may also be downloaded over a cable, communication and/or wireless connection. In other embodiments, the invention programs are a computer program propagated signal product  107  embodied on a propagated signal on a propagation medium (e.g., a radio wave, an infrared wave, a laser wave, a sound wave, or an electrical wave propagated over a global network such as the Internet, or other network(s)). Such carrier medium or signals provide at least a portion of the software instructions for the present invention routines/program  92 . 
         [0035]    In alternate embodiments, the propagated signal is an analog carrier wave or digital signal carried on the propagated medium. For example, the propagated signal may be a digitized signal propagated over a global network (e.g., the Internet), a telecommunications network, or other network. In one embodiment, the propagated signal is a signal that is transmitted over the propagation medium over a period of time, such as the instructions for a software application sent in packets over a network over a period of milliseconds, seconds, minutes, or longer. In another embodiment, the computer readable medium of computer program product  92  is a propagation medium that the computer system  50  may receive and read, such as by receiving the propagation medium and identifying a propagated signal embodied in the propagation medium, as described above for computer program propagated signal product. 
         [0036]    Generally speaking, the term “carrier medium” or transient carrier encompasses the foregoing transient signals, propagated signals, propagated medium, storage medium and the like. 
         [0037]    While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims. 
         [0038]    For example, the present invention may be implemented in a variety of computer architectures. The computer network of  FIGS. 4 and 5  are for purposes of illustration and not limitation of the present invention. 
         [0039]    Further the model interpreter  63  may be implemented in UML, EMF and other modeling languages. The produced API or target code  65  may be in Java, UML, EMF, XML and the like.