This presentation provides an overview of the builder design pattern, including its structure and implementation in Java. The builder pattern separates object construction from representation, allowing the same construction steps to create different types of objects. The presentation defines the key components of the builder pattern - Product, Builder, Concrete Builder, and Director. It then provides a code example to illustrate these components in action, showing how a MealBuilder class can use the builder pattern to construct different meal objects.
The Builder pattern is used to generate different types of reports (Crystal, HTML, PDF) from a CRM document format, while keeping the report construction process the same. An abstract ReportBuilder interface defines common report generation steps. Concrete builders like CrystalReportBuilder, HTMLReportBuilder, and PDFReportBuilder implement these steps to produce their specific report types. A ReportDirector coordinates the building process by working with a ReportBuilder object.
The theory of SOLID principles was
introduced by Robert C. Martin in his 2000
paper “Design Principles and Design
Patterns”.
SOLID => Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, Dependency Inversion.
This document provides information about a course on design patterns taught by Dr. Asma Cherif. It includes the course code, instructor details, learning objectives, textbooks, and topics that will be covered such as architectural design, what patterns are, and different types of patterns. Design patterns provide solutions to common software design problems and promote reuse of successful designs. The course aims to help students understand design patterns, identify patterns in code and designs, and implement patterns to design and develop quality software applications.
in these slides i have explained the factory method design pattern. slides contains complete notes on this pattern from definition to implementation by code example.
Design patterns are optimized, reusable solutions to the programming problems that we encounter every day. A design pattern is not a class or a library that we can simply plug into our system; it's much more than that. It is a template that has to be implemented in the correct situation. It's not language-specific either. A good design pattern should be implementable in most—if not all—languages, depending on the capabilities of the language. Most importantly, any design pattern can be a double-edged sword— if implemented in the wrong place, it can be disastrous and create many problems for you. However, implemented in the right place, at the right time, it can be your savior.
Dependency injection, or DI, is a design pattern in which a class requests dependencies from external sources rather than creating them.
Dependency Injection is known to be a programming paradigm.
It enables the creation of dependent objects outside of a class while providing those very objects to a class in numerous ways.
The document discusses the Decorator design pattern. The Decorator pattern allows behavior to be added to individual objects dynamically at runtime without affecting other objects. This provides a flexible alternative to subclassing for extending functionality. The pattern provides classes that wrap the component class and contain it, allowing additional responsibilities to be attached. Decorators provide a way to add or remove responsibilities from individual objects.
This presentation provides an overview of the builder design pattern, including its structure and implementation in Java. The builder pattern separates object construction from representation, allowing the same construction steps to create different types of objects. The presentation defines the key components of the builder pattern - Product, Builder, Concrete Builder, and Director. It then provides a code example to illustrate these components in action, showing how a MealBuilder class can use the builder pattern to construct different meal objects.
The Builder pattern is used to generate different types of reports (Crystal, HTML, PDF) from a CRM document format, while keeping the report construction process the same. An abstract ReportBuilder interface defines common report generation steps. Concrete builders like CrystalReportBuilder, HTMLReportBuilder, and PDFReportBuilder implement these steps to produce their specific report types. A ReportDirector coordinates the building process by working with a ReportBuilder object.
The theory of SOLID principles was
introduced by Robert C. Martin in his 2000
paper “Design Principles and Design
Patterns”.
SOLID => Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, Dependency Inversion.
This document provides information about a course on design patterns taught by Dr. Asma Cherif. It includes the course code, instructor details, learning objectives, textbooks, and topics that will be covered such as architectural design, what patterns are, and different types of patterns. Design patterns provide solutions to common software design problems and promote reuse of successful designs. The course aims to help students understand design patterns, identify patterns in code and designs, and implement patterns to design and develop quality software applications.
in these slides i have explained the factory method design pattern. slides contains complete notes on this pattern from definition to implementation by code example.
Design patterns are optimized, reusable solutions to the programming problems that we encounter every day. A design pattern is not a class or a library that we can simply plug into our system; it's much more than that. It is a template that has to be implemented in the correct situation. It's not language-specific either. A good design pattern should be implementable in most—if not all—languages, depending on the capabilities of the language. Most importantly, any design pattern can be a double-edged sword— if implemented in the wrong place, it can be disastrous and create many problems for you. However, implemented in the right place, at the right time, it can be your savior.
Dependency injection, or DI, is a design pattern in which a class requests dependencies from external sources rather than creating them.
Dependency Injection is known to be a programming paradigm.
It enables the creation of dependent objects outside of a class while providing those very objects to a class in numerous ways.
The document discusses the Decorator design pattern. The Decorator pattern allows behavior to be added to individual objects dynamically at runtime without affecting other objects. This provides a flexible alternative to subclassing for extending functionality. The pattern provides classes that wrap the component class and contain it, allowing additional responsibilities to be attached. Decorators provide a way to add or remove responsibilities from individual objects.
The document discusses the flyweight pattern, which uses sharing to efficiently support large numbers of fine-grained objects. An application may use many objects, but most objects' state can be made extrinsic. By removing extrinsic state and replacing groups of objects with relatively few shared objects, storage costs can be reduced. The flyweight pattern defines an interface for flyweights to receive extrinsic state, with concrete flyweights implementing storage for intrinsic state. A flyweight factory manages the shared flyweight objects.
The document discusses three design patterns: Singleton, Observer, and Factory. The Singleton pattern ensures that only one instance of a class can exist and provides a global access point. The Observer pattern defines a subscription mechanism so that multiple objects can be notified of changes to an object they are observing. The Factory pattern provides an interface for creating objects but leaves the concrete class unspecified. Real-world examples and implementations of each pattern are provided.
This document discusses the facade design pattern. The facade pattern provides a simplified interface to a more complex subsystem. It decouples the subsystem from the client and makes the subsystem easier to use. A facade acts as a front-facing interface that hides the underlying complexities of the subsystem and delegates client requests to appropriate subsystem classes. This reduces dependencies between subsystems and promotes loose coupling. The facade pattern is useful for layering subsystems and simplifying access to them through a single interface.
The Bridge Pattern decouples an abstraction from its implementation so that they can vary independently. It allows multiple dependent implementations to share a single independent interface. This pattern is used when an abstraction has many implementations and it is difficult to extend and reuse the abstraction and implementations independently with inheritance. The bridge pattern involves an abstraction, refined abstraction, implementor, and concrete implementor. The abstraction maintains a reference to the implementor interface and the concrete implementor implements that interface. This pattern improves extensibility by allowing the abstraction and implementation hierarchies to vary independently.
The builder pattern is a design pattern used to separate the construction of a complex object from its representation. It allows the same construction process to create different representations. The document describes the builder pattern using the example of building computers. It defines classes for components like CPU, motherboard, drives, and their assembly into computer objects using either a general ComputerBuilder or specialized builders for desktop and laptop computers. The builder pattern participants are the builder, concrete builders, director and product, and their collaboration is described.
The document discusses the decorator design pattern. The decorator pattern allows adding new behaviors to existing objects at runtime by placing them inside decorator objects that contain the original object. This allows functionality to be added without changing the object's class. Some key points made are: the decorator pattern adds functionality at runtime through composition; decorations are independent and can be mixed; and it is used to attach additional responsibilities to objects without subclassing. An example using shapes and color decorators is provided to demonstrate implementation.
The document discusses various design patterns. It begins by explaining that design patterns represent best practices used by experienced software developers to solve common problems. It then discusses the Gang of Four (GOF) patterns, which were identified in 1994 and include creational, structural, and behavioral patterns. Creational patterns like Singleton, Factory Method, Abstract Factory, and Prototype are covered. Structural patterns like Adapter, Bridge, Composite, Decorator, Facade, Flyweight, and Proxy are also introduced. Behavioral patterns like Chain of Responsibility, Command, Interpreter, Iterator, Mediator, Memento, Observer, State, Strategy, Template Method, and Visitor are briefly mentioned as well. The document then discusses some Java Enterprise
This document discusses design patterns, beginning with how they were introduced in architecture in the 1950s and became popularized by the "Gang of Four" researchers. It defines what patterns are and provides examples of different types of patterns (creational, structural, behavioral) along with common patterns in each category. The benefits of patterns are that they enable reuse, improve communication, and ease the transition to object-oriented development. Potential drawbacks are that patterns do not directly lead to code reuse and can be overused. Effective use requires applying patterns strategically rather than recasting all code as patterns.
This document discusses dependency injection in .NET. It defines dependency injection as a set of principles and patterns that enable loosely coupled code. Some benefits of loose coupling are that it is easy to extend, test, maintain, and facilitates parallel development and late binding. Common dependency injection patterns include constructor injection, property injection, and method injection. Popular dependency injection containers for .NET include Autofac, Ninject, Unity, and Castle Windsor. The document provides an example of tightly coupled code and how to make it loosely coupled using dependency injection by adding abstractions, constructor injection, and object composition.
The Singleton pattern ensures that only one instance of a class is created, and provides a global access point to that instance. There are many objects that only need a single instance, such as thread pools, caches, and objects used for logging or managing preferences. The Singleton pattern solves problems that could occur from instantiating multiple instances of these objects, such as inconsistent behavior or wasted resources. It works by having a class define a static method that returns its sole instance, which is created the first time the method is called.
Quick introduction to Spring Framework. Following are the topics I have included in this presentations:
1. Introduction to Software Framework
2. What is Spring Framework?
3. Spring Framework History
4. Spring Framework Architecture
5. Why Spring?
6. Spring Framework Ecosystem
The document discusses the facade design pattern, which hides the complexities of a system and provides a simpler interface to clients. It defines the facade pattern and provides examples of its use in Java APIs like HttpSession and HttpServletRequest to simplify accessing sessions and requests. The document also notes benefits like simplifying a complex subsystem and consequences like tighter coupling, and encourages viewing a demo of the facade pattern in action.
Repository Pattern with c# and Entity FrameworkImtiaj Ahammad
Repository pattern concept and implementation in asp.net MVC with C# and entity framework
source code: https://github.com/imtiajahammad/RepositoryPatternWithCSharpAndEntityFramework
#imtiajLearnings
#imtiajFables
The Command design pattern encapsulates requests as objects, allowing for the parameterization of clients with different requests, queues of requests, and undo functionality. It decouples the invoker of a request from the receiver that performs it. Some key elements are the Command interface that declares an execute method, ConcreteCommand classes that link Receivers to their actions, and an Invoker that asks Commands to carry out requests. The pattern supports adding new commands without changing existing code but can lead to many command classes cluttering the design. It is used when objects need to issue parameterized requests without coupling to receivers or timing of requests.
The document discusses the SOLID principles of object-oriented design:
1. The Single Responsibility Principle states that a class should have one, and only one, reason to change.
2. The Open-Closed Principle states that software entities should be open for extension but closed for modification. Behavior is changed through inheritance and composition rather than direct modification.
3. The Liskov Substitution Principle states that subclasses must behave in the same way as the base class so that the base class can be substituted wherever the subclass is expected.
4. The Interface Segregation Principle states that interfaces should be small and focused so that client classes do not depend on methods they do not use.
An introduction to structural design patterns in object orientation. Suitable for intermediate to advanced computing students and those studying software engineering.
This document discusses various structural design patterns including Adapter, Bridge, Composite, Decorator, Facade, Flyweight, and Proxy. It defines each pattern, provides examples of how and when to use each pattern, and in some cases includes UML diagrams. The document also discusses how the Decorator pattern can be used to solve the problem of creating specialized robot doctors in an automated hospital that each perform a core set of functions plus additional specialized functions.
The document provides an introduction and overview of design patterns. It defines design patterns as common solutions to recurring problems in software design. The document discusses the origin of design patterns in architecture, describes the four essential parts of a design pattern (name, problem, solution, consequences), and categorizes patterns into creational, structural, and behavioral types. Examples of commonly used patterns like Singleton and State patterns are also presented.
The document discusses design patterns, which are reusable solutions to common software design problems. It provides examples of different types of patterns, including creational (Factory Method, Abstract Factory, Builder, Prototype, Singleton), structural (Adapter, Bridge, Composite, Decorator, Facade, Flyweight, Proxy), and behavioral (Chain of Responsibility, Command, Interpreter, Iterator, Mediator, Memento, Observer, State, Strategy, Template Method, Visitor) patterns. Each pattern is defined and an example problem and solution using the pattern is described.
The document provides an overview of design patterns, including what they are, why they are used, how to apply them, examples of common patterns, and an example application to expense reporting. Design patterns solve common programming problems by describing core solutions that can be reused in different situations, with the intent of increasing code reuse and flexibility. The document discusses several fundamental design patterns including creational, structural, and behavioral patterns, provides UML diagrams to illustrate the relationships between pattern participants, and gives a detailed example of how patterns could be applied to validate expense reports against business policies.
The document discusses the flyweight pattern, which uses sharing to efficiently support large numbers of fine-grained objects. An application may use many objects, but most objects' state can be made extrinsic. By removing extrinsic state and replacing groups of objects with relatively few shared objects, storage costs can be reduced. The flyweight pattern defines an interface for flyweights to receive extrinsic state, with concrete flyweights implementing storage for intrinsic state. A flyweight factory manages the shared flyweight objects.
The document discusses three design patterns: Singleton, Observer, and Factory. The Singleton pattern ensures that only one instance of a class can exist and provides a global access point. The Observer pattern defines a subscription mechanism so that multiple objects can be notified of changes to an object they are observing. The Factory pattern provides an interface for creating objects but leaves the concrete class unspecified. Real-world examples and implementations of each pattern are provided.
This document discusses the facade design pattern. The facade pattern provides a simplified interface to a more complex subsystem. It decouples the subsystem from the client and makes the subsystem easier to use. A facade acts as a front-facing interface that hides the underlying complexities of the subsystem and delegates client requests to appropriate subsystem classes. This reduces dependencies between subsystems and promotes loose coupling. The facade pattern is useful for layering subsystems and simplifying access to them through a single interface.
The Bridge Pattern decouples an abstraction from its implementation so that they can vary independently. It allows multiple dependent implementations to share a single independent interface. This pattern is used when an abstraction has many implementations and it is difficult to extend and reuse the abstraction and implementations independently with inheritance. The bridge pattern involves an abstraction, refined abstraction, implementor, and concrete implementor. The abstraction maintains a reference to the implementor interface and the concrete implementor implements that interface. This pattern improves extensibility by allowing the abstraction and implementation hierarchies to vary independently.
The builder pattern is a design pattern used to separate the construction of a complex object from its representation. It allows the same construction process to create different representations. The document describes the builder pattern using the example of building computers. It defines classes for components like CPU, motherboard, drives, and their assembly into computer objects using either a general ComputerBuilder or specialized builders for desktop and laptop computers. The builder pattern participants are the builder, concrete builders, director and product, and their collaboration is described.
The document discusses the decorator design pattern. The decorator pattern allows adding new behaviors to existing objects at runtime by placing them inside decorator objects that contain the original object. This allows functionality to be added without changing the object's class. Some key points made are: the decorator pattern adds functionality at runtime through composition; decorations are independent and can be mixed; and it is used to attach additional responsibilities to objects without subclassing. An example using shapes and color decorators is provided to demonstrate implementation.
The document discusses various design patterns. It begins by explaining that design patterns represent best practices used by experienced software developers to solve common problems. It then discusses the Gang of Four (GOF) patterns, which were identified in 1994 and include creational, structural, and behavioral patterns. Creational patterns like Singleton, Factory Method, Abstract Factory, and Prototype are covered. Structural patterns like Adapter, Bridge, Composite, Decorator, Facade, Flyweight, and Proxy are also introduced. Behavioral patterns like Chain of Responsibility, Command, Interpreter, Iterator, Mediator, Memento, Observer, State, Strategy, Template Method, and Visitor are briefly mentioned as well. The document then discusses some Java Enterprise
This document discusses design patterns, beginning with how they were introduced in architecture in the 1950s and became popularized by the "Gang of Four" researchers. It defines what patterns are and provides examples of different types of patterns (creational, structural, behavioral) along with common patterns in each category. The benefits of patterns are that they enable reuse, improve communication, and ease the transition to object-oriented development. Potential drawbacks are that patterns do not directly lead to code reuse and can be overused. Effective use requires applying patterns strategically rather than recasting all code as patterns.
This document discusses dependency injection in .NET. It defines dependency injection as a set of principles and patterns that enable loosely coupled code. Some benefits of loose coupling are that it is easy to extend, test, maintain, and facilitates parallel development and late binding. Common dependency injection patterns include constructor injection, property injection, and method injection. Popular dependency injection containers for .NET include Autofac, Ninject, Unity, and Castle Windsor. The document provides an example of tightly coupled code and how to make it loosely coupled using dependency injection by adding abstractions, constructor injection, and object composition.
The Singleton pattern ensures that only one instance of a class is created, and provides a global access point to that instance. There are many objects that only need a single instance, such as thread pools, caches, and objects used for logging or managing preferences. The Singleton pattern solves problems that could occur from instantiating multiple instances of these objects, such as inconsistent behavior or wasted resources. It works by having a class define a static method that returns its sole instance, which is created the first time the method is called.
Quick introduction to Spring Framework. Following are the topics I have included in this presentations:
1. Introduction to Software Framework
2. What is Spring Framework?
3. Spring Framework History
4. Spring Framework Architecture
5. Why Spring?
6. Spring Framework Ecosystem
The document discusses the facade design pattern, which hides the complexities of a system and provides a simpler interface to clients. It defines the facade pattern and provides examples of its use in Java APIs like HttpSession and HttpServletRequest to simplify accessing sessions and requests. The document also notes benefits like simplifying a complex subsystem and consequences like tighter coupling, and encourages viewing a demo of the facade pattern in action.
Repository Pattern with c# and Entity FrameworkImtiaj Ahammad
Repository pattern concept and implementation in asp.net MVC with C# and entity framework
source code: https://github.com/imtiajahammad/RepositoryPatternWithCSharpAndEntityFramework
#imtiajLearnings
#imtiajFables
The Command design pattern encapsulates requests as objects, allowing for the parameterization of clients with different requests, queues of requests, and undo functionality. It decouples the invoker of a request from the receiver that performs it. Some key elements are the Command interface that declares an execute method, ConcreteCommand classes that link Receivers to their actions, and an Invoker that asks Commands to carry out requests. The pattern supports adding new commands without changing existing code but can lead to many command classes cluttering the design. It is used when objects need to issue parameterized requests without coupling to receivers or timing of requests.
The document discusses the SOLID principles of object-oriented design:
1. The Single Responsibility Principle states that a class should have one, and only one, reason to change.
2. The Open-Closed Principle states that software entities should be open for extension but closed for modification. Behavior is changed through inheritance and composition rather than direct modification.
3. The Liskov Substitution Principle states that subclasses must behave in the same way as the base class so that the base class can be substituted wherever the subclass is expected.
4. The Interface Segregation Principle states that interfaces should be small and focused so that client classes do not depend on methods they do not use.
An introduction to structural design patterns in object orientation. Suitable for intermediate to advanced computing students and those studying software engineering.
This document discusses various structural design patterns including Adapter, Bridge, Composite, Decorator, Facade, Flyweight, and Proxy. It defines each pattern, provides examples of how and when to use each pattern, and in some cases includes UML diagrams. The document also discusses how the Decorator pattern can be used to solve the problem of creating specialized robot doctors in an automated hospital that each perform a core set of functions plus additional specialized functions.
The document provides an introduction and overview of design patterns. It defines design patterns as common solutions to recurring problems in software design. The document discusses the origin of design patterns in architecture, describes the four essential parts of a design pattern (name, problem, solution, consequences), and categorizes patterns into creational, structural, and behavioral types. Examples of commonly used patterns like Singleton and State patterns are also presented.
The document discusses design patterns, which are reusable solutions to common software design problems. It provides examples of different types of patterns, including creational (Factory Method, Abstract Factory, Builder, Prototype, Singleton), structural (Adapter, Bridge, Composite, Decorator, Facade, Flyweight, Proxy), and behavioral (Chain of Responsibility, Command, Interpreter, Iterator, Mediator, Memento, Observer, State, Strategy, Template Method, Visitor) patterns. Each pattern is defined and an example problem and solution using the pattern is described.
The document provides an overview of design patterns, including what they are, why they are used, how to apply them, examples of common patterns, and an example application to expense reporting. Design patterns solve common programming problems by describing core solutions that can be reused in different situations, with the intent of increasing code reuse and flexibility. The document discusses several fundamental design patterns including creational, structural, and behavioral patterns, provides UML diagrams to illustrate the relationships between pattern participants, and gives a detailed example of how patterns could be applied to validate expense reports against business policies.
The document discusses design patterns used in object-oriented programming. It describes common design patterns like factory method, singleton, observer, and adapter patterns. It also discusses principles for assigning responsibilities to objects like high cohesion and low coupling. The document provides examples of applying these patterns and principles to design software objects and systems.
The document provides an overview of design patterns, including creational patterns. It defines the Abstract Factory pattern, which provides an interface for creating families of related or dependent objects without specifying their concrete classes. The Abstract Factory pattern allows for creating objects in a generic way and enforces creation constraints. It works by having a super-factory that creates other factories to generate related object types. The document outlines the intent, structure, collaboration and consequences of applying the Abstract Factory pattern, as well as how to implement and apply it to solve object creation problems in a flexible manner.
Lecture two,
An introduction to Design Pattern
History
Pattern Language,
Categorization according to GoF
MVC
Creational Design Patterm
Factory Method
Abstract Factory
Singleton
Builder
This document discusses design patterns and provides examples of implementing some common patterns in C#. It begins with an introduction to design patterns, their history and types. It then demonstrates implementing singleton, prototype, facade and decorator patterns in C#, including class diagrams and implementation steps. It discusses advantages of design patterns and hints for advanced development, like making patterns thread-safe. The document concludes with a thank you.
Software Design Patterns. Part I :: Structural PatternsSergey Aganezov
In a nutshell, software design patterns are generally reusable solutions to a commonly occurring problems. And this says it all! We are going to learn when it is completely unnecessary for you to reinvent the wheel, and what are the best ways to approach each particular problem during software development process.
Design patterns are optimized, reusable solutions to the programming problems that we encounter every day. A design pattern is not a class or a library that we can simply plug into our system; it's much more than that. It is a template that has to be implemented in the correct situation. It's not language-specific either. A good design pattern should be implementable in most—if not all—languages, depending on the capabilities of the language. Most importantly, any design pattern can be a double-edged sword— if implemented in the wrong place, it can be disastrous and create many problems for you. However, implemented in the right place, at the right time, it can be your savior.
In software engineering, a design pattern is a general reusable solution to a commonly occurring problem within a given context in software design. A design pattern is not a finished design that can be transformed directly into source or machine code. It is a description or template for how to solve a problem that can be used in many different situations. Patterns are formalized best practices that the programmer can use to solve common problems when designing an application or system. Object-oriented design patterns typically show relationships and interactions between classes or objects, without specifying the final application classes or objects that are involved. Patterns that imply object-orientation or more generally mutable state, are not as applicable in functional programming languages.
Design patterns reside in the domain of modules and interconnections. At a higher level there are architectural patterns that are larger in scope, usually describing an overall pattern followed by an entire system.[1]
There are many types of design patterns, for instance
Algorithm strategy patterns addressing concerns related to high-level strategies describing how to exploit application characteristics on a computing platform.
Computational design patterns addressing concerns related to key computation identification.
Execution patterns that address concerns related to supporting application execution, including strategies in executing streams of tasks and building blocks to support task synchronization.
Implementation strategy patterns addressing concerns related to implementing source code to support
program organization, and
the common data structures specific to parallel programming.
Structural design patterns addressing concerns related to high-level structures of applications being developed.
The document introduces design patterns and their key elements. It discusses how design patterns help address common object-oriented design problems like determining appropriate objects, object granularity, specifying interfaces, and implementations. Key points made include: design patterns make reuse easier, express proven techniques, help choose reusable designs, and get a design "right" faster. Each pattern has a name, problem description, solution, and consequences. Patterns are organized by purpose (creational, structural, behavioral) and scope (class, object).
This document introduces design patterns and their key elements. Design patterns help designers solve common problems in object-oriented software design and make reusable designs more accessible. A pattern has four elements - a name, the problem it addresses, the solution, and consequences of applying the pattern. Patterns are organized based on their purpose (creational, structural, behavioral) and scope (object, class, etc.). The document outlines 23 classic design patterns organized in a catalog.
The document discusses several creational design patterns including Singleton, Abstract Factory, Builder, and Prototype patterns. It provides definitions and examples of how each pattern works, including ensuring a class only has one instance (Singleton), creating object factories without specifying classes (Abstract Factory), constructing complex objects step-by-step (Builder), and copying existing objects (Prototype). The document is intended for teaching software design patterns to students.
The document discusses object-oriented programming concepts including objects, classes, message passing, abstraction, encapsulation, inheritance, polymorphism, and dynamic binding. It provides examples and definitions for each concept. It also discusses how to represent real-world entities like a person or place as objects with states (attributes and values) and behaviors (methods). Classes are defined as blueprints that specify common properties and functionality for objects. The relationships between classes and objects are demonstrated.
Fundamentals of OOP (Object Oriented Programming)MD Sulaiman
The document discusses object-oriented programming concepts including objects, classes, message passing, abstraction, encapsulation, inheritance, polymorphism, and dynamic binding. It provides examples and definitions for each concept. It also covers basic class concepts like defining classes, creating objects, using constructors, and accessing instance variables and methods. The document appears to be teaching material for an introductory object-oriented programming course.
Object oriented programming concepts such as abstraction, encapsulation, inheritance and polymorphism are supported in .NET languages like C# and Visual Basic. Encapsulation groups related properties and methods into a single object. Inheritance allows new classes to be created from an existing class. Polymorphism allows multiple classes to be used interchangeably even if they implement properties or methods differently.
Patterns (contd)Software Development ProcessDesign patte.docxdanhaley45372
Patterns (contd)
Software Development Process
Design patterns used to handle change
More time extending and changing code than developing it.
The Strategy design pattern handle change by selecting from a family of external algorithms rather than rewrite.
Design point: Make code closed for modification of code, but open for extension
Problem
Computer object created
Description Method returns
Getting a Computer
Problem
Program has to change every time
Customer changes options
Decorator Pattern
Wrapper code used to extend your core code
Extend a class dynamically at runtime
Decorator uses wrapper code to extend core functionality - decorating the code
Decorator Pattern
description() returns “You are getting a computer”
Wrapper description() returns
“You are getting a computer and a disk”
Wrapper description() returns
“You are getting a computer and a disk and a monitor”
Decorator Pattern
Core component: Computer
Variables holding computer objects should also be able to hold objects that wrap computer objects.
Extend the wrapper classes from the Computer class.
Abstract class cannot be instantiated
Ensures all wrappers are consistent
Developers have to provide their own description
Decorator Pattern
Method calls the core computer object’s
description method and adds “and a disk”
Decorator Pattern
Method calls the core computer object’s
description method and adds “and a disk”
Extend the core object by wrapping it in decorator wrappers. Avoids modification of the core code.
Each successive wrapper called the description method of the object it wrapped and added something to it.
Factory Pattern
Based on type, call the
Connection method
Factory Pattern
Create a method that returns the
correct connection type
Factory Pattern
New operator used to create OracleConnection objects.
New operator used to create SqlServerConnection objects, and MySqlConnection objects.
New operator to instantiate many different concrete classes
Code becomes larger and needs to be replicated in many places
Factor that code out into a method.
Code keeps changing
Encapsulate code into a factory object
Goal: Separate out the changeable code and leave the core code closed for modification
Building the Factory
Creating the Factory
FirstFactory class encapsulates the connection object creation
Pass to it the type of connection (“Oracle”, “SQL Server”,)
Use the factory object to create connection objects with a factory method named createConnection
Building the Factory
Create the FirstFactory class.
Save the type of the database, passed to the FirstFactory class’s constructor.
Object-creation code changes
Check which type of object to be created
(OracleConnection, SqlServerConnection,
and then create it.
Factory Class
Create the Abstract Connection Class
Core code should not be modified or has to be modified
as little as possible.
Using the connection object returned by the
new factory object
Use t.
Accident detection system project report.pdfKamal Acharya
The Rapid growth of technology and infrastructure has made our lives easier. The
advent of technology has also increased the traffic hazards and the road accidents take place
frequently which causes huge loss of life and property because of the poor emergency facilities.
Many lives could have been saved if emergency service could get accident information and
reach in time. Our project will provide an optimum solution to this draw back. A piezo electric
sensor can be used as a crash or rollover detector of the vehicle during and after a crash. With
signals from a piezo electric sensor, a severe accident can be recognized. According to this
project when a vehicle meets with an accident immediately piezo electric sensor will detect the
signal or if a car rolls over. Then with the help of GSM module and GPS module, the location
will be sent to the emergency contact. Then after conforming the location necessary action will
be taken. If the person meets with a small accident or if there is no serious threat to anyone’s
life, then the alert message can be terminated by the driver by a switch provided in order to
avoid wasting the valuable time of the medical rescue team.
Digital Twins Computer Networking Paper Presentation.pptxaryanpankaj78
A Digital Twin in computer networking is a virtual representation of a physical network, used to simulate, analyze, and optimize network performance and reliability. It leverages real-time data to enhance network management, predict issues, and improve decision-making processes.
Determination of Equivalent Circuit parameters and performance characteristic...pvpriya2
Includes the testing of induction motor to draw the circle diagram of induction motor with step wise procedure and calculation for the same. Also explains the working and application of Induction generator
Build the Next Generation of Apps with the Einstein 1 Platform.
Rejoignez Philippe Ozil pour une session de workshops qui vous guidera à travers les détails de la plateforme Einstein 1, l'importance des données pour la création d'applications d'intelligence artificielle et les différents outils et technologies que Salesforce propose pour vous apporter tous les bénéfices de l'IA.
A high-Speed Communication System is based on the Design of a Bi-NoC Router, ...DharmaBanothu
The Network on Chip (NoC) has emerged as an effective
solution for intercommunication infrastructure within System on
Chip (SoC) designs, overcoming the limitations of traditional
methods that face significant bottlenecks. However, the complexity
of NoC design presents numerous challenges related to
performance metrics such as scalability, latency, power
consumption, and signal integrity. This project addresses the
issues within the router's memory unit and proposes an enhanced
memory structure. To achieve efficient data transfer, FIFO buffers
are implemented in distributed RAM and virtual channels for
FPGA-based NoC. The project introduces advanced FIFO-based
memory units within the NoC router, assessing their performance
in a Bi-directional NoC (Bi-NoC) configuration. The primary
objective is to reduce the router's workload while enhancing the
FIFO internal structure. To further improve data transfer speed,
a Bi-NoC with a self-configurable intercommunication channel is
suggested. Simulation and synthesis results demonstrate
guaranteed throughput, predictable latency, and equitable
network access, showing significant improvement over previous
designs
Open Channel Flow: fluid flow with a free surfaceIndrajeet sahu
Open Channel Flow: This topic focuses on fluid flow with a free surface, such as in rivers, canals, and drainage ditches. Key concepts include the classification of flow types (steady vs. unsteady, uniform vs. non-uniform), hydraulic radius, flow resistance, Manning's equation, critical flow conditions, and energy and momentum principles. It also covers flow measurement techniques, gradually varied flow analysis, and the design of open channels. Understanding these principles is vital for effective water resource management and engineering applications.
2. Intent
Decorator is a structural design pattern.
Attach additional responsibilities to an object dynamically. Decorators
provide a flexible alternative to sub classing for extending functionality.
Also Known as
Wrapper
Decorator Design Pattern- Dr. S. Neelima 2
3. Motivation
Imagine that you’re working on a notification library which lets other
programs notify their users about important events.
The initial version of the library was based on the Notifier class that had
only a few fields, a constructor and a single send method.
Decorator Design Pattern- Dr. S. Neelima 3
6. The client code would need to wrap a basic notifier object into a set of
decorators that match the client’s preferences. The resulting objects will
be structured as a stack.
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7. Motivation
2.
For example, suppose we have a TextView object that displays text
in a window. TextView has no scroll bars by default, because we might not
always need them. When we do, we can use a ScrollDecorator to add
them. Suppose we also want to add a thick black border around the
TextView. We can use a BorderDecorator to add this as well. We simply
compose the decorators with the TextView to produce the desired result.
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9. Applicability
• Use the pattern to add responsibilities to individual objects
dynamically and transparently, that is, without affecting other objects.
• Use the pattern for responsibilities that can be withdrawn.
• Use the pattern when it’s awkward or not possible to extend an object’s
behavior using inheritance.
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11. Participants
• Component (VisualComponent)
• Concrete Component (TextView)
• Decorator
• ConcreteDecorator
Decorator Design Pattern- Dr. S. Neelima 11
Collaborations
Decorator forwards requests to its Component object. It may optionally
perform additional operations before and after forwarding the request.
12. Consequences
Pros
• You can extend an object’s behavior without making a new subclass.
• You can add or remove responsibilities from an object at runtime.
• You can combine several behaviors by wrapping an object into multiple
decorators.
• Single Responsibility Principle. You can divide a monolithic class that
implements many possible variants of behavior into several smaller
classes.
Cons
• It’s hard to remove a specific wrapper from the wrappers stack.
• It’s hard to implement a decorator in such a way that its behavior
doesn’t depend on the order in the decorators stack.
• The initial configuration code of layers might look pretty ugly.
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13. Implement
• Make sure your business domain can be represented as a primary
component with multiple optional layers over it.
• Figure out what methods are common to both the primary component
and the optional layers. Create a component interface and declare those
methods there.
• Create a concrete component class and define the base behavior in it.
• Create a base decorator class. It should have a field for storing a
reference to a wrapped object. The field should be declared with the
component interface type to allow linking to concrete components as
well as decorators. The base decorator must delegate all work to the
wrapped object.
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14. Implement ….
• Make sure all classes implement the component interface.
• Create concrete decorators by extending them from the base decorator.
A concrete decorator must execute its behavior before or after the call to
the parent method (which always delegates to the wrapped object).
• The client code must be responsible for creating decorators and
composing them in the way the client needs.
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15. Known Uses
Decorator Design Pattern- Dr. S. Neelima 15
• InterViews ,ET++ and the ObjectWorksSmalltalk class library.
• More exotic applications of Decorator are the DebuggingGlyph from
InterViews and the PassivityWrapper from ParcPlace Smalltalk.
16. Related Patterns
• Adapter changes the interface of an existing object,
while Decorator enhances an object without changing its interface.
• Composite and Decorator have similar structure diagrams since both
rely on recursive composition to organize an open-ended number of
objects.
• Decorator lets you change the skin of an object, while Strategy lets
you change the guts.
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