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Business Entity (computer Science)
A business object is an entity within a multi-tiered software application that works in conjunction with the data access and business logic layers to transport data. For example, a "Manager" would be a ''business object'' where its attributes can be "Name", "Second name", "Age", "Area", "Country" and it could hold a ''1-n'' association with its employees (a collection of ''Employee'' instances). Another example would be a concept like "Process" having "Identifier", "Name", "Start date", "End date" and "Kind" attributes and holding an association with the "Employee" (''the responsible'') that started it. Function Whereas a program may implement classes, which typically end in objects managing or executing behaviours, a ''business object'' usually does nothing itself but holds a set of instance variables or properties, also known as ''attributes'', and associations with other business objects, weaving a map of objects representing the business relationships. A domain mod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multitier Architecture
In software engineering, multitier architecture (often referred to as ''n''-tier architecture) is a client–server architecture in which presentation, application processing and data management functions are physically separated. The most widespread use of multitier architecture is the three-tier architecture. ''N''-tier application architecture provides a model by which developers can create flexible and reusable applications. By segregating an application into tiers, developers acquire the option of modifying or adding a specific tier, instead of reworking the entire application. A three-tier architecture is typically composed of a ''presentation'' tier, a ''logic'' tier, and a ''data'' tier. While the concepts of layer and tier are often used interchangeably, one fairly common point of view is that there is indeed a difference. This view holds that a ''layer'' is a logical structuring mechanism for the conceptual elements that make up the software solution, while a ''tier'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software
Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work. At the lowest programming level, executable code consists of machine language instructions supported by an individual processor—typically a central processing unit (CPU) or a graphics processing unit (GPU). Machine language consists of groups of binary values signifying processor instructions that change the state of the computer from its preceding state. For example, an instruction may change the value stored in a particular storage location in the computer—an effect that is not directly observable to the user. An instruction may also invoke one of many input or output operations, for example displaying some text on a computer screen; causing state changes which should be visible to the user. The processor executes the instructions in the order they are provided, unless it is instructed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Access Layer
A data access layer (DAL) in computer software is a layer of a computer program which provides simplified access to data stored in persistent storage of some kind, such as an entity-relational database. This acronym is prevalently used in Microsoft environments. For example, the DAL might return a reference to an object (in terms of object-oriented programming) complete with its attributes instead of a row of fields from a database table. This allows the client (or user) modules to be created with a higher level of abstraction. This kind of model could be implemented by creating a class of data access methods that directly reference a corresponding set of database stored procedures. Another implementation could potentially retrieve or write records to or from a file system. The DAL hides this complexity of the underlying data store from the external world. For example, instead of using commands such as ''insert'', ''delete'', and ''update'' to access a specific table in a databas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Business Logic
In computer software, business logic or domain logic is the part of the program that encodes the real-world business rules that determine how data can be created, stored, and changed. It is contrasted with the remainder of the software that might be concerned with lower-level details of managing a database or displaying the user interface, system infrastructure, or generally connecting various parts of the program. Details and example Business logic: * Prescribes how business objects interact with one another * Enforces the routes and the methods by which business objects are accessed and updated Business rules: * Model real-life business objects (such as accounts, loans, itineraries, and inventories) Business logic comprises: * Workflows that are the ordered tasks of passing documents or data from one participant (a person or a software system) to another. Business logic should be distinguished from business rules. Business logic is the portion of an enterprise system which det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class (computer Science)
In object-oriented programming, a class is an extensible program-code-template for creating objects, providing initial values for state (member variables) and implementations of behavior (member functions or methods). In many languages, the class name is used as the name for the class (the template itself), the name for the default constructor of the class (a subroutine that creates objects), and as the type of objects generated by instantiating the class; these distinct concepts are easily conflated. Although, to the point of conflation, one could argue that is a feature inherent in a language because of its polymorphic nature and why these languages are so powerful, dynamic and adaptable for use compared to languages without polymorphism present. Thus they can model dynamic systems (i.e. the real world, machine learning, AI) more easily. When an object is created by a constructor of the class, the resulting object is called an instance of the class, and the member variabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instance Variable
In class-based, object-oriented programming, an instance variable is a variable defined in a class (i.e. a member variable), for which each instantiated object of the class has a separate copy, or instance. An instance variable has similarities with a class variable, but is non-static. An instance variable is a variable which is declared in a class but outside of constructors, methods, or blocks. Instance variables are created when an object is instantiated, and are accessible to all the constructors, methods, or blocks in the class. Access modifiers can be given to the instance variable. An instance variable is not a class variable although there are similarities. It is a type of class attribute (or class property, field, or data member). The same dichotomy between ''instance'' and ''class'' members applies to methods ("member functions") as well; a class may have both instance methods and class method A method in object-oriented programming (OOP) is a procedure associate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Property (programming)
A property, in some object-oriented programming languages, is a special sort of class member, intermediate in functionality between a field (or data member) and a method. The syntax for reading and writing of properties is like for fields, but property reads and writes are (usually) translated to 'getter' and 'setter' method calls. The field-like syntax is easier to read and write than many method calls, yet the interposition of method calls "under the hood" allows for data validation, active updating (e.g., of GUI elements), or implementation of what may be called " read-only fields". See an instructive example for C# language below. Support in languages Programming languages that support properties include ActionScript 3, C#, D, Delphi/Free Pascal, eC, F#, Kotlin, JavaScript, Objective-C 2.0, Python, Scala, Swift, Lua, and Visual Basic. Some object-oriented languages, such as Java and C++, do not support properties, requiring the programmer to define a pair of '' acce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Association (object-oriented Programming)
In object-oriented programming, association defines a relationship between classes of objects that allows one object instance to cause another to perform an action on its behalf. This relationship is structural, because it specifies that objects of one kind are connected to objects of another and does not represent behaviour. In generic terms, the causation is usually called "sending a message", "invoking a method" or "calling a member function" to the controlled object. Concrete implementation usually requires the requesting object to invoke a ''method'' or ''member function'' using a reference or pointer to the memory location of the controlled object. The objects that are related via the association are considered to act in a role with respect to the association, if object's current state in the active situation allows the other associated objects to use the object in the manner specified by the role. A role can be used to distinguish two objects of the same class when describi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domain Model
In software engineering, a domain model is a conceptual model of the domain that incorporates both behavior and data.Fowler, Martin. ''Patterns of Enterprise Application Architecture''. Addison Wesley, 2003, p. 116. In ontology engineering, a domain model is a formal representation of a knowledge domain with concepts, roles, datatypes, individuals, and rules, typically grounded in a description logic. Overview A domain model is a system of abstractions that describes selected aspects of a sphere of knowledge, influence or activity (a domainEvans, Eric ''Domain-Driven Design: Definitions and Pattern Summaries''. Domain Language Inc., 2006, p. 3.). The model can then be used to solve problems related to that domain. The domain model is a representation of meaningful real-world concepts pertinent to the domain that need to be modeled in software. The concepts include the data involved in the business and rules the business uses in relation to that data. A domain model levera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anemic Domain Model
The anemic domain model is described as a programming anti-pattern where the domain objects contain little or no business logic like validations, calculations, rules, and so forth. The business logic is thus baked into the architecture of the program itself, making refactoring and maintenance more difficult and time-consuming. Overview This pattern was first described by Martin Fowler, who considers the practice an anti-pattern. He says: In an anemic domain design, business logic is typically implemented in separate classes which transform the state of the domain objects. Fowler calls such external classes ''transaction scripts''. This pattern is a common approach in Java applications, possibly encouraged by technologies such as early versions of EJB's Entity Beans, as well as in .NET applications following the Three-Layered Services Application architecture where such objects fall into the category of "Business Entities" (although Business Entities can also contain behavior). F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martin Fowler (software Engineer)
Martin Fowler (18 December 1963) is a British software developer, author and international public speaker on software development, specialising in object-oriented analysis and design, UML, patterns, and agile software development methodologies, including extreme programming. His 1999 book ''Refactoring'' popularised the practice of code refactoring. In 2004 he introduced a new architectural pattern, called Presentation Model (PM). Biography Fowler was born and grew up in Walsall, England, where he went to Queen Mary's Grammar School for his secondary education. He graduated at University College London in 1986. In 1994 he moved to the United States, where he lives near Boston, Massachusetts in the suburb of Melrose.Martin Fowler at martinfowler.com. Retrieved 2012-11-15. Fowler started working with software in the early 1980s. Out of un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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