Johnson, R.E.: Frameworks = (components + patterns). Communications of the ACM 40 (1997) 39--42  Home/Search   Document Not in Database   Summary   ACM   TOC   Related Articles   Check

....by the developer to support the functionality required from a given application domain. The framework further distinguishes between the notions of compound interactions, coordination of concurrency, and synchronization. Such notions are studied in interactive systems using object oriented [NGT92, MN98, Joh97, Sch95, SFJ96] or agent oriented [SC99] techniques. In this case, our work is intended as a study investigating how to support similar techniques in computational logic setting. Compared with our previous formulation of games using object level programs [SS97, Sta96] this work introduces metaprograms to ....

R. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10):39--42, October 1997.

....simulations, like VR AR or digital entertainment systems, there is currently no widely referenced position available on the shelf. of 11 Currently developers move away from constructing from scratch in favour of composing and integrating applications using frameworks and reusable components [7][8] The natural reaction to this demand is the quickly growing number of powerful middleware solutions constituting very dynamic research and development domain, moving away from the previous trend of scenegraph based 3D applications [18] Thus, depending on the particular project context, ....

R. Johnson, Frameworks = Patterns + Components, Communications of the ACM, Vol. 40, No.10, October 1997.

....data between processing nodes. The sequential objects express ideal SPMD computation kernels, which are independent and do not require global consistency, and thus, communication. An evaluation of the object model. We use our prototype implementation of an object oriented framework( 47] [62]) to illustrate how the object model can support concurrency for the solution of PDEs on irregular meshes (described in Chapter 11) We evaluate the resulting programming model versus other approaches to distributed programming for scientific applications. We use two perspectives for our ....

....is at the core of the physical phenomena simulation (numerical applications) This chapter describes the prototype system used to implement the techniques and the numerical applications presented in this thesis. Thus, it describes the design and the implementation of the component based framework [62] that captures the concurrency infrastructure for dynamic, distributed numerical applications. Furthermore, it discusses the main design choices, and it motivates our approach. The system uses the techniques described throughout this thesis to account for efficiency. The remainder of the chapter ....

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Ralph E. Johnson. Frameworks = (Components + Patterns). Communications of the ACM, 40(10):39--42, October 1997.

....[4] 5] provide an approach to build applications that are more robust, more correct and with shorter development time that those built from scratch. A framework is a reusable design of all or part of a system that is represented by a set of abstract classes and the way their instances interact [8]. The primary benefits of OO application frameworks stem from the modularity, reusability, extensibility, and inversion of control they provide to developers [3] However, the development of a framework and the subsequent instantiation or extension to build custom domain specific applications is ....

R. E. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10), October 1997.

....reusable software; and they act as building blocks from which more complex designs can be built. 11, 4] Design patterns are the micro architectural elements of frameworks. For example, Model View Controller can be decomposed into three major design patterns, and several less important ones. [12] It uses the Observer pattern to ensure the views picture of the model is up to date, the Composite pattern to nest views, and the Strategy pattern to cause views to delegate responsibility for handling user events to their controller. Object oriented patterns [5, 6, 10, 9, 13] are invariably ....

Johnson R. Frameworks = (Components + Patterns). Communications of the ACM, Vol. 40, No. 10, pages 39-42, October 1997.

....the relevant pattern (s) solves most of the structuring problem already. The patterns discussed in the course are: the distributed components patterns (described already very well by Douglas Schmidt in ACE [9] and TAO [10] and the patterns for low level motion control. Frameworks. A framework [5] is a set of computer code files that implement a reusable software solution for a particular problem domain. In that sense a framework is much broader ( programming in the large ) than a software pattern ( programming in the small ) A framework typically contains several patterns, but a pattern ....

R. E. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10):39--42, 1997.

....encounter in practice. Arti cial problems are useful for testing GAs under carefully controlled conditions so that speci c aspects of the algorithm can be analyzed. If that was not done, it wouldn t be possible to get a better understanding of GAs, and it wouldn t be 1 This analogy is taken from (Johnson, 1997) in the context of software design and used here in the context of genetic algorithm usability. 1 possible to improve the state of the art in GA technology. However, it is also important to keep an eye on the applications side and see how the GA performs on problems that are not arti cially ....

Johnson, R. E. (1997). Frameworks = (components + patterns). Communications of the ACM , 40 (10), 39-42.

....of a software system. It is accordingly this software architecture that must be made reusable in order to make the intellectual investment that went into developing it available to multiple projects. In mainstream applications, this form of reuse has led to the construction of software frameworks [1,2,3], namely artifacts that encapsulate an architecture optimized for all applications within a certain domain and that provide a ready made skeleton from which individual applications within that domain can be instantiated. This approach has brought unquestioned benefits to fields as diverse as GUI, ....

Johnson R, 1997, Frameworks = (Components + Patterns), Communications of the ACM, Vol. 40, N. 10, p. 39-42, Oct. 1997

....adapting the hotspots. The identification of hot spots is one of the early tasks in the product line design process. A major hot spot can be the core around which a framelet is built. 5.4. 3 Building framelets around design patterns Design patterns are among the building blocks of product lines [16]. Applicable design patterns are identified at the beginning of the product line design process. Since design patterns typically consist of a handful of cooperating classes addressing a localized design problem without making any assumptions about execution control, they can serve as the basis ....

R. Johnson, Frameworks=(Components+Patterns), Communications of the ACM, Vol. 40, N. 10, p. 39-42, Oct. 1997

....system is described for organizing a pattern catalog at different granularity and abstraction levels. Sample patterns identified on a number of a large scale distributed system are presented in [27] showing the process of reusing communications architectures. Application frameworks described in [20] also represent a kind of pattern. Patterns are viewed as a description of a problem, of a solution, and of the context in which this solution works. In [16] patterns, or more precisely, pattern languages, are related to frameworks in that patterns capture unifying aspects in software development ....

R.E. Johnson. Frameworks = Components + Patterns. Communications of the ACM, 40(10):39-42 (1997).

....by a framework based layered software architecture to Development of Decision Support Systems, used as a case study. 1. Introduction Object oriented (OO) frameworks have been considered an important element to achieve reuse in software development. An object oriented framework [FAY97] GAM94][JOH97] can be described as a reusable design of all or part of a system that is represented by a set of abstract classes and the way their instances interact [JOH97] It is believed that the use of frameworks brings several benefits to software development, such as reusability and extensibility. ....

....frameworks have been considered an important element to achieve reuse in software development. An object oriented framework [FAY97] GAM94] JOH97] can be described as a reusable design of all or part of a system that is represented by a set of abstract classes and the way their instances interact [JOH97]. It is believed that the use of frameworks brings several benefits to software development, such as reusability and extensibility. However, there are still many open problems in framework based development [MAT99] FAY97] MAT98] In this paper, we focus on two of them, namely the integration of ....

JOHNSON, Ralph. Frameworks = (Components + Patterns). Communications of the ACM, New York, v. 40, n. 10, pp. 39-43, Oct. 1997.

....infrastructure for developers [Taligent, 1993] Johnson s definition [1997] contains the idea of frameworks in simple but sophisticated form: A framework is a reusable design of all or part of a system that is represented by a set of abstract classes and the way their instances interact. [Johnson, 1997] Pree [1995] takes a little more concrete approach by stating: A framework is a collection of abstract and concrete classes and the interface between them, and is the design for a subsystem. Pree, 1995] These definitions do not set frameworks into a specific domain in the real world or ....

....advancement. In such cases support framework isolates the writing a new device driver behind its own interface and there is a minimum effect to the rest of the system. As this thesis will cover the design of a concrete framework, both of the presented definitions are valid. Another definition by Johnson [1997] is very close to Pree s definition, by referring to frameworks as customisable application skeletons. In the scope this work, I prefer Pree s definition as we are later going to handle the design and implementation of a framework, that is a generic subsystem for presenting and modifying domain ....

Ralph E. Johnson, Frameworks = Components + Patterns, Communications of the ACM, Vol. 40, No 10, October 1997.

....different levels, such as statements, methods and classes; iii) 43 explicit propagation; and (iv) termination. However, exceptions are not represent as data or full objects, and clean up actions are not supported. Exception Handling, Frameworks and Design Patterns. An object oriented framework [Johnson, 1997] is a reusable software system that can be extended to produce customized applications. Framework designers specify variations within its design by means of extension points, which are those aspects of a domain that have to remain flexible; developers extend and customize the framework design ....

....could have two extension points associated with it: automatic or explicit. It is worth noting that computational reflection can be used to customize the exception handling framework for a particular application in a transparent and non intrusive way for the framework users. According to [Johnson, 1997] the use of design patterns is extremely useful as a guide during the framework development and also for providing a better understanding of its design to potential users [Buschmann et al. 1996] Thus, a system of patterns for exception handling could be developed to assist the building of an ....

Johnson, R., Frameworks = Components + Patterns, Communications of the ACM 40, 39-42 (1997).

....with the application post customisation. Additionally, it is widely accepted that they are more complex to design than applications, require significant investment of effort and remain art as opposed to science (Bumer et al. 1997; Fayed and Schmidt 1997; Gamma et al. 1995; Garlan et al. 1995; Johnson 1997; Schmid 1997) Though the latter remains an outstanding research problem, component based variations of reuse concepts seek to retain a separation between the framework and any given instantiation, one where each has it s own responsibilities. To this extent, the use of design patterns and ....

Johnson, R. E. (1997). Frameworks = (Components + Patterns). Communications of the ACM, 40 (10), pp. 39-42.

....is exacerbated because it is difficult to recognize which portions of the old code are application dependent and which are parts of the pattern. Fortunately, we can learn a valuable lesson about efficient code re use from frameworks, a recent development in sequential object oriented programming [14,10]. Frameworks are a set of classes that implement the basic structure of a specific kind of application. This structural code defines the classes in the application and the way these classes collaborate with each other (the flow of control between operations on the objects from these classes) ....

....utility routines. Frameworks let programmers reuse the overall design of an application because the re usable application independent framework code and the application dependent code are clearly separated. The use of frameworks can reduce the effort required to build applications [14]. If we translate the framework concept to the parallel domain, the programmer could write a single applicationindependent framework to supply the parallel structure (with all of the complicated synchronization and communication code) and then write one set of simple sequential utility routines ....

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R. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10):39-42, October 1997.

....because it is difficult to recognize which portions of the old code are application dependent and which are parts of the pattern. Fortunately, we can learn a valuable lesson about efficient code re use from recent developments in sequential object oriented programming called frameworks [14,10]. Frameworks are a set of classes that implement the basic structure of a specific kind of application. This structural code defines the classes in the application and the way these classes collaborate with each other (the flow of control between operations on the objects from these classes) ....

....utility routines. Frameworks let programmers reuse the overall design of an application because the re usable application independent framework code and the application dependent code are clearly separated. The use of frameworks can reduce the effort required to build applications [14]. If we translate the framework concept to the parallel domain, the programmer could write a single applicationindependent framework to supply the parallel structure (with all of the complicated synchronization and communication code) and then write one set of simple sequential utility routines ....

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R. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10):39-42, October 1997.

....of patterns has become very popular in recent years. It has been discovered that inheritance alone is not sufficient to express the structure of object oriented applications and their implementations. This has led to the development of generic software architectures as object oriented frameworks (Johnson, 1997) and of design patterns (Gamma et al. 1995) describing known ways to design solutions to related problems in the implementation of software components. We propose to explore to use a similar approach and to target at the discovery of reoccuring structures of management of dependencies. We see ....

Johnson, R. E. (1997). Frameworks = (Components + Patterns). Communications of the ACM, 40(10):39--42.

....Lesson 11. Explicit problem analysis is needed to build up a shared view on the problems to be addressed. Lesson 12. The research agenda should be set by a negotiation process that takes researchers interest and expertise, product developer need, and company strategic goals into account [11]. Lesson 13. Planning as well as monthly progress meetings are an opportunity to explain your research to management: this is technology transfer. Unfortunately, individual researchers tend to resist planning passionately. Researchers are soloists, who enjoy their freedom. They have their own ....

....the case studies and pilots themselves. Production software, on the other hand, needs to be a team effort, will be used intensively, needs to be consistent, deploying a small set of coherent technologies, and needs to be customizable, maintainable, and testable. Therefore, Scholtz [17] and Johnson [11] argue in favor of a clear separation between research and development. Johnson emphasizes that you will need your researchers for other purposes than development: Lesson 44. Treating researchers as extra developers is like eating seed corn, sacrificing the future for short term gain [11] In ....

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J. Johnson. R D, not R&D. Communications of the ACM, 39(9):32--34, September 1996.

....of several components [GS93] Similarly design patterns [GHJV95] package lower level design information for reuse. Several benefits of design reuse are presented in the literature [BMR 96] Pre95] GHJV95] Despite of the well known advantages of design reuse versus plain code reuse [BP89] Joh97] several problems occur, when design information is visible in the units of reuse [GAO95] One of the expected major benefits of software components is, that a software component is deployable in several different design contexts. Therefore, design decisions have to be encapsulated and hidden ....

....to components that is not available in any of the underlying infrastructure components. Frameworks are an attempt to reuse designs manifested in code. Frameworks are enhanced to a specific application by providing specific modules which are plugged in certain defined interfaces of the framework [Joh97] Unfortunately, the interface descriptions do not contain enough information, so that a compiler can translate an uninstantiated framework into binary code. As a consequence most frameworks are delivered in source code. The relations between components and frameworks are many fold. With an ....

Ralph E. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10):39--42, October 1997.

....of several components [GS93] Similarly design patterns [GHJV95] package lower level design information for reuse. Several benefits of design reuse are presented in the literature [BMR 96] Pre95] GHJV95] Despite of the well known advantages of design reuse versus plain code reuse [BP89] Joh97] several problems occur, when design information is visible in the units of reuse [GAO95] One of the expected major benefits of software components is, that a software component is deployable in several different design contexts. Therefore, design decisions have to be encapsulated and hidden ....

....to components that is not available in any of the underlying infrastructure components. Frameworks are an attempt to reuse designs manifested in code. Frameworks are enhanced to a specific application by providing specific modules which are plugged in certain defined interfaces of the framework [Joh97] Unfortunately, the interface descriptions do not contain enough information, so that a compiler can translate an uninstantiated framework into binary code. As a consequence most frameworks are delivered in source code. The relations between components and frameworks are 12 many fold. With an ....

Ralph E. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10):39--42, October 1997.

....like UML and toolindependent languages. Executable components, on the other hand, can sometimes be used in different tools, but they are platform specific and not easily adaptable. 4. #Components and frameworks Frameworks are often regarded as an environment for the reuse of components ( 3] and [7]) Therefore, it is useful to explore how components and frameworks are related. A framework consists of a number of concrete and abstract classes and a definition of the way instances of these classes collaborate. The concrete classes implement the collaboration of the classes. The abstract ....

Ralph E. Johnson. Frameworks = (Components + Patterns). Communications of the ACM 40, 10 (1997). pp. 39-42.

....for monitoring and management tools are very diverse, especially when allowing to observe heterogeneous components simultaneously, there is no common de nition of tool functionality or behavior. Therefore, the MIMO approach is based on de ning a general infrastructure, i.e. a framework [5] for tools. This framework consists of basic monitoring system components which o er de ned and generic interfaces both for tools and middleware platforms. Furthermore, access patterns de ning how to make use of the components and interfaces are de ned. This combination of components and patterns ....

Ralph E. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10):39-42, Oct 1997.

....include connection objects that enable the user interface to communicate with the database server. 4.3 Framework Design Several definitions of object oriented frameworks have appeared in literature. A framework is a reusable, semi complete application [14] or the skeleton of an application [15] that can be specialized by developers to produce custom applications. Another definition of frameworks that captures the structural composition of a framework defines a framework as a reusable design of all or part of a system that is represented by a set of abstract classes and the way their ....

....by developers to produce custom applications. Another definition of frameworks that captures the structural composition of a framework defines a framework as a reusable design of all or part of a system that is represented by a set of abstract classes and the way their instances interact [15]. The object oriented view of the Input Forms presented in the previous subsection adheres to the first definition of frameworks in that it describes skeleton classes for an Input Form; the classes need to be specialized to generate a specific application. The object oriented view, however, is ....

Ralph E. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10):39-- 42, October 1997.

....need to speed up the implementation process and to facilitate the maintenance and extension of the system to be built has inspired the development of software design methods in the 90 s. Examples of these methods are object oriented analysis and programming [2, 9] design patterns and frameworks [6, 7, 10]. Frameworks are software structures developed for a specific application domain, which can be re used in the implementation of various different concrete systems in this domain. Experience with the use of frameworks has shown that they can increase the effectiveness of the implementation process ....

....Frameworks are software structures developed for a specific application domain, which can be re used in the implementation of various different concrete systems in this domain. Experience with the use of frameworks has shown that they can increase the effectiveness of the implementation process [7, 10]. Our work considers the implementation of protocols from their specifications. Different alternative notations can be used to specify a protocol, whereas each of these notations is based on a specific design model. A design model consists of a set of design concepts and the rules for combining ....

R.E. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10): 39-42, October 1997.

....based on the kinds of artifacts, and on the kinds of software development phases, where components are reused. Along the artifacts axis, we may distinguish executable objects, class descriptions, patterns of reusable knowledge, frameworks in the sense of patterns with inversion of control [10], and whole executable programs. Along the phases axis, reusability may occur during all software development phases ranging from requirements specification to implementation. An interesting topic of research remains to look into each combination of the two dimensions and investigate their ....

Johnson, R.E.: Frameworks = Components + Patterns. Communications of the ACM, 40 (10), p. 39-42 (October 1997)

....we had gained little in terms of the time to debug a Java form over the time for its equivalent Oracle based implementation. Common Patterns. At this point in the project we advanced from using a simple object oriented approach to one in which our goal was to create an object oriented framework [14, 15]. Software developers have a variety of definitions and conceptualizations of frameworks. The description that is closest to our use of the term is that a framework is a reusable, not fully specified application that can be specialized to produce custom applications. It embodies both design and ....

....of the framework that was not apparent before. Such periodic maintenance of frameworks has been cited as one of its weakness; such modifications, however, have been minimal for us. Another commonly cited problem with frameworks is the lack of suitable documentation for new users of the framework [15]. While the documentation of the framework code is available via this document and online, we have also documented the process of using the framework to generate a new Input Form. 4 We had an opportunity to ask students who had not been involved in the development of the framework to use the ....

Ralph E. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10):39-- 42, October 1997.

....It was a requirement to build a framework which can be used as a research vehicle in a number of research projects. By Framework we refer to a software environment that is designed to simplify the development and management of hypermedia applications [2] by supporting re use of existing components [11]. In particular, we want to research issues such as streaming content data and its synchronisation with link data, the use of computations for content based retrieval and navigation, and adjust the architecture to different configurations in order to e.g. address scalability [1] 2 Description of ....

Ralph E. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10):39--42, October 1997.

....significant differences between ACE and ACT are: 1. Framework structure ACT has a core skeleton around which customized components are added to build functional communication system [3] This approach facilitates rapid building of communication systems using an application framework such as ACT [8]. In addition to the customized components the skeleton is designed and implemented to provide little overhead. The framework offers a layered design that allows having more than one implementation at the same time, tuned to different requirements. 2. Protocol support 10 ACT provides extensive ....

R. Johnson. Frameworks = Patterns + Components. Communications of the ACM, 40(10), October 1997.

....significantly reduce development costs, maintenance costs, and unrealizable schedules. Software reuse has repeatedly been suggested as a means for successfully combating the software crisis: the problem of building large and reliable software systems at a reasonable cost (Krueger, 1992; Mellor Johnson, 1997). Reusability is widely believed to be a key to improving software development quality (Biggerstaff Richter, 1997) Reuse results in a completed systems containing fewer total symbols with less time having been spent on the symbols organization. Therefore, in a sense, reuse enhances software ....

....specific needs. 4. Integration allows developers to combine their specialized components into a new software system. There are many techniques which when utilized help foster software reuse. Some of the main techniques are the use of architectural styles, design patterns, and objects (Mellor Johnson, 1997). Each of these will be discussed at length below in conjunction with a description of how ConAg uses them. 4. ConAg s Architectural Style Building on the findings that object oriented development has been shown to significantly increase productivity, ConAg is developed in Java using object ....

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Johnson, Ralph. (1997). Frameworks = (components + patterns). Communications of the ACM, 40 (10), 39-42.

....based on the kinds of artifacts, and on the kinds of software development phases, where components are reused. Along the artifacts axis, we may distinguish executable objects, class descriptions, patterns of reusable knowledge, frameworks in the sense of patterns with inversion of control [10], and whole executable programs. Along the phases axis, reusability may occur during all software development phases ranging from requirements specification to implementation. An interesting topic of research remains to look into each combination of the two dimensions and investigate their ....

Johnson, R.E.: Frameworks = Components + Patterns. Communications of the ACM, 40 (10), p. 39-42 (October 1997)

.... and have to scale in several different directions (e.g. number of processing nodes in a distributed environment, number of continuous media streams) Consequently, various techniques that emphasize reuse (e.g. application frameworks [1, 5, 9] design patterns [4, 2] software components [8]) and provide scalable software solutions are attracting the interest of the industry. In this paper we present a component based model applicable to continuous media processing. The model is based on four software patterns that express expert knowledge about software construction. Systems ....

R. E. Johnson. Frameworks=(Components + Patterns). Communications of the ACM, 40(10), October 1997.

....domain that need to be kept flexible must be identified. These areas are called hot spots and a well designed framework should include a sufficient number [22] Insufficient consideration of hot spots limits a frameworks re usability. The disadvantages of frameworks identified by Johnson [10] include; ffl they are complex and therefore difficult to learn; ffl they are hard to develop and therefore cost more and have a longer development time than normal applications; ffl using a particular language to implement a framework limits its applicability only to systems supporting that ....

D.E. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10):39--42, October 1997.

....community with regard to the development of applications in general. Reuse is regarded as the key for improving quality and productivity of software development [8] with a primary focus on the potential contributions of the object oriented (OO) paradigm and derived methods and technologies [37, 40, 30, 31]. Frameworks are an object oriented reuse technique. A framework [16, 52, 28, 31, 40, 22] can be regarded as a high level application or subsystem architecture, consisting of a set of classes that are specifically designed to be refined and used as a group. A framework represents a generic ....

....is regarded as the key for improving quality and productivity of software development [8] with a primary focus on the potential contributions of the object oriented (OO) paradigm and derived methods and technologies [37, 40, 30, 31] Frameworks are an object oriented reuse technique. A framework [16, 52, 28, 31, 40, 22] can be regarded as a high level application or subsystem architecture, consisting of a set of classes that are specifically designed to be refined and used as a group. A framework represents a generic solution for the development of applications in a specific domain (e.g. graphical editors [29] ....

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JOHNSON, R.E. Frameworks = components + patterns. Communications of the ACM, 40(10): 39-42, Oct. 1997.

....Parallel Programming Frameworks Another approach to parallel programming is frameworks, a concept similar to templates and that can be related to design patterns. A framework is an extendible set of classes that implements the basic structure for solving problems, usually in a specific domain [21]. This solution may or may not implement some templates or patterns, although doing so provides a good way of describing how a user can interact and extend the framework. A user uses a framework by specifying a set of components or objects that the computational portion of the framework uses. If ....

R. E. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10):39--42, October 1997.

....wrappers. Although there are similarities between ACT and ACE, there are also major differences. ACT has a core skeleton around which customized components are added in order to build a functional communication system (Figure 8) This approach facilitates rapid building of communication systems [8]. ACT layers are encapsulated and each layer provides well defined functionality. A layer can have several implementations at the same time, tuned to different requirements. ACT provides extensive support for integration of user defined application level protocols, multithreading policies, and ....

R. Johnson. Frameworks = Patterns + Components. Communications of the ACM, 40(10), October 1997.

....connection of several components [GS93] Similarly design patterns [GHJV95] package lower level design information for reuse. Several benefits of design reuse are presented in the literature 96] Pre95] GHJV95] Despite of the well known advantages of design reuse versus plain code reuse [BP89] [Joh97], several problems occur, when design information is visible in the units of reuse [GAO95] One of the expected major benefits of software components is, that a software component is deployable in several different design contexts. Therefore, design decisions have to be encapsulated and hidden ....

....components that is not available in any of the underlying infrastructure components. 12 Frameworks are an attempt to reuse designs manifested in code. Frameworks are enhanced to a specific application by providing specific modules which are plugged in certain defined interfaces of the framework [Joh97]. Unfortunately, the interface descriptions do not contain enough information, so that a compiler can translate an uninstantiated framework into binary code. As a consequence most frameworks are delivered in source code. The relations between components and frameworks are many fold. With an ....

Ralph E. Johnson. Frameworks = (components + patterns). Communications of the ACM, 40(10):39--42, October 1997.

....recurring solutions that have stood the test of time. A single framework usually contains many 2 F. Tarpin Bernard, B.T. David P. Primet patterns, so these patterns are smaller than frameworks. Therefore, they are also more abstract. They are the micro architectural elements of frameworks (Johnson, 1997). But for many authors, since some frameworks have been implemented several times, they represent a kind of pattern, too. For instance, Model View Controller is a user interface framework that is described as a pattern in Bushmann al. 1996) whereas Johnson considers that it can be decomposed ....

Johnson R.E. (1997), Frameworks = Components + Patterns, Communications of the ACM, Oct., Vol 40. n10, 39-42.

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Johnson R. Frameworks = Components + Patterns. Communication of the ACM. Volume 40, Number 10, pages 39-42. October 1997.

....the software under development reuses 1 functionality already available, or built from scratch where the software under development is augmented with new functionality. Work, both at a theoretical and practical level, aims at making the componentoriented development of software systematic [6, 11, 13, 18]. We develope complex interactive systems from simple components by extending an existing logic programming framework, presented in [22 26] based on games. This framework was introduced to address inadequacies of existing logic programming approaches to develop interactive systems, particularly ....

....to be created and stored in the database of the back end. We represent the state term of the Vector 5 Entry game by a set of assertions. For example, to represent internally the entry of a vector with name x var1 and values 1 2 4 6 9, we write: vector entry(v1) name(v1, x var1) values(v1, [1,2,4,6,9]) Additional state properties required to describe the game are represented in the same way; for example the last move made by a player is also kept as part of the state in this game. We can now show how to specify the legal moves of the game by specifying necessary and possible moves. The ....

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R. Johnson, Frameworks = (Components + Patterns), Communications of the ACM, Vol. 40, No 10, October 1997.

....reusable software; and they act as building blocks from which more complex designs can be built. 11, 4] Design patterns are the micro architectural elements of frameworks. For example, Model View Controller can be decomposed into three major design patterns, and several less important ones. [12] It uses the Observer pattern to ensure the views picture of the model is up to date, the Composite pattern to nest views, and the Strategy pattern to cause views to delegate responsibility for handling user events to their controller. Object oriented patterns [5, 6, 10, 9, 13] are invariably ....

Johnson R. Frameworks = (Components + Patterns). Communications of the ACM, Vol. 40, No. 10, pages 39-42, October 1997.

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Johnson, R.E.: Frameworks = (components + patterns). Communications of the ACM 40 (1997) 39--42

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R. Johnson. Frameworks=(components + patterns). Communications of the ACM, 40(10):39--42, October 1997.

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R. E. Johnson. Frameworks = (Components + Patterns). Communications of the ACM, pages 39 -- 42, October 1997.

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[Johnson, 1997] Johnson, R., Frameworks = Components+ Patterns, Communications of the ACM, October 1997, Vol. 40, No. 10

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Johnson, R.E. Frameworks = (Components + Patterns). Communications of the ACM (CACM), Volume 40, Number 10, Oktober 1997.

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