filmov
tv
Factory Design Pattern Introduction
Показать описание
Text version of the video
Healthy diet is very important both for the body and mind. If you like Aarvi Kitchen recipes, please support by sharing, subscribing and liking our YouTube channel. Hope you can help.
Slides
Design Patterns Tutorial playlist
Design Patterns Text articles and slides
All Dot Net and SQL Server Tutorials in English
All Dot Net and SQL Server Tutorials in Arabic
In this session we will learn
1. What is Factory Design Pattern
2. Implementation Guidelines
3. Simple factory implementation
What is Factory Design Pattern : Gang of Four Definition
Define an interface for creating an object, but let subclasses decide which class to instantiate. The Factory method lets a class defer instantiation it uses to subclasses
Factory pattern is one of the most used design patterns in real world applications. Factory pattern creates object without exposing the creation logic to the client and refer to newly created object using a common interface
Implementation Guidelines
We need to choose Factory Pattern when
1. The Object needs to be extended to subclasses
2. The Classes doesn’t know what exact sub-classes it has to create
3. The Product implementation tend to change over time and the Client remains unchanged
Simple Factory Example : Business Requirement
Differentiate employees as permanent and contract and segregate their pay scales as well as bonus based on their employee types
We can address the above requirement with the below implementations
1. Implement without Factory Pattern
2. Use a Simple Factory
3. Enhance Simple factory to Factory Method Pattern
We will be working on the Employee Portal that we used in the Singleton tutorials. Please refer to them before proceeding
Prerequisite steps
1. Enhance the DB model to add Employee_Type Table
2. Add Permanent and Contract Employees as Master Data.
3. Add new columns EmployeeTypeID, Bonus, HourlyPay to Emplyee Table and add Foreign key constraint to the Emp
4. Update the Emloyee Model edmx file with the latest changes.
5. Create new BaseController and Move the Singleton Exception logic to the base controller
public class BaseController : Controller
{
private ILog _ILog;
public BaseController()
{
_ILog = Log.GetInstance;
}
protected override void OnException(ExceptionContext filterContext)
{
_ILog.LogException(filterContext.Exception.ToString());
filterContext.ExceptionHandled = true;
this.View("Error").ExecuteResult(this.ControllerContext);
}
}
6. Regenerate the EmployeesController and its corresponding views
7. Comment the code in Create and Update views which accepts inputs for Bonus and HourlyPay
Solution 1: Implement without Factory Pattern
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include = "Id,Name,JobDescription,Number,Department,HourlyPay,Bonus,EmployeeTypeID")] Employee employee)
{
if (ModelState.IsValid)
{
if (employee.EmployeeTypeID == 1)
{
employee.HourlyPay = 8;
employee.Bonus = 10;
}
else if (employee.EmployeeTypeID == 2)
{
employee.HourlyPay = 12;
employee.Bonus = 5;
}
db.Employees.Add(employee);
db.SaveChanges();
return RedirectToAction("Index");
}
ViewBag.EmployeeTypeID = new SelectList(db.Employee_Type, "Id", "EmployeeType", employee.EmployeeTypeID);
return View(employee);
}
The above code introduces
1. Tight coupling between Controller class and Business logic
2. For any new employee type addition, we end up modifying the controller code adding extra over heads in the development and testing process
Using a simple factory eliminates the above drawbacks.
Solution 2: Implement with Simple Factory
1. Add new Manager folder and add the below interface and classes
public interface IEmployeeManager
{
decimal GetBonus();
decimal GetPay();
}
Healthy diet is very important both for the body and mind. If you like Aarvi Kitchen recipes, please support by sharing, subscribing and liking our YouTube channel. Hope you can help.
Slides
Design Patterns Tutorial playlist
Design Patterns Text articles and slides
All Dot Net and SQL Server Tutorials in English
All Dot Net and SQL Server Tutorials in Arabic
In this session we will learn
1. What is Factory Design Pattern
2. Implementation Guidelines
3. Simple factory implementation
What is Factory Design Pattern : Gang of Four Definition
Define an interface for creating an object, but let subclasses decide which class to instantiate. The Factory method lets a class defer instantiation it uses to subclasses
Factory pattern is one of the most used design patterns in real world applications. Factory pattern creates object without exposing the creation logic to the client and refer to newly created object using a common interface
Implementation Guidelines
We need to choose Factory Pattern when
1. The Object needs to be extended to subclasses
2. The Classes doesn’t know what exact sub-classes it has to create
3. The Product implementation tend to change over time and the Client remains unchanged
Simple Factory Example : Business Requirement
Differentiate employees as permanent and contract and segregate their pay scales as well as bonus based on their employee types
We can address the above requirement with the below implementations
1. Implement without Factory Pattern
2. Use a Simple Factory
3. Enhance Simple factory to Factory Method Pattern
We will be working on the Employee Portal that we used in the Singleton tutorials. Please refer to them before proceeding
Prerequisite steps
1. Enhance the DB model to add Employee_Type Table
2. Add Permanent and Contract Employees as Master Data.
3. Add new columns EmployeeTypeID, Bonus, HourlyPay to Emplyee Table and add Foreign key constraint to the Emp
4. Update the Emloyee Model edmx file with the latest changes.
5. Create new BaseController and Move the Singleton Exception logic to the base controller
public class BaseController : Controller
{
private ILog _ILog;
public BaseController()
{
_ILog = Log.GetInstance;
}
protected override void OnException(ExceptionContext filterContext)
{
_ILog.LogException(filterContext.Exception.ToString());
filterContext.ExceptionHandled = true;
this.View("Error").ExecuteResult(this.ControllerContext);
}
}
6. Regenerate the EmployeesController and its corresponding views
7. Comment the code in Create and Update views which accepts inputs for Bonus and HourlyPay
Solution 1: Implement without Factory Pattern
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include = "Id,Name,JobDescription,Number,Department,HourlyPay,Bonus,EmployeeTypeID")] Employee employee)
{
if (ModelState.IsValid)
{
if (employee.EmployeeTypeID == 1)
{
employee.HourlyPay = 8;
employee.Bonus = 10;
}
else if (employee.EmployeeTypeID == 2)
{
employee.HourlyPay = 12;
employee.Bonus = 5;
}
db.Employees.Add(employee);
db.SaveChanges();
return RedirectToAction("Index");
}
ViewBag.EmployeeTypeID = new SelectList(db.Employee_Type, "Id", "EmployeeType", employee.EmployeeTypeID);
return View(employee);
}
The above code introduces
1. Tight coupling between Controller class and Business logic
2. For any new employee type addition, we end up modifying the controller code adding extra over heads in the development and testing process
Using a simple factory eliminates the above drawbacks.
Solution 2: Implement with Simple Factory
1. Add new Manager folder and add the below interface and classes
public interface IEmployeeManager
{
decimal GetBonus();
decimal GetPay();
}
0:22:43
Factory Design Pattern Introduction
0:08:28
The Factory Method Pattern Explained and Implemented in Java | Creational Design Patterns | Geekific
0:10:38
Factory Design Pattern Explained: Introduction and Fundamentals
0:07:23
Factory Design Pattern
0:27:21
Factory Method Pattern – Design Patterns (ep 4)
0:11:40
Factory Design Pattern
0:09:28
Factory, Abstract Factory, Factory Method - Design Pattern (C#)
0:08:50
Factory Design Pattern in Java
0:03:14
Factory Design Pattern in Java Theory
0:11:03
Factory Method Design Pattern [An Introduction for .NET Developers (using C#)]
0:15:35
Factory Design Pattern - Why and How with Code!!
0:15:07
How to use Factory Method Design Pattern to design a course website like Udacity, Edx, Coursera...
0:11:04
10 Design Patterns Explained in 10 Minutes
0:14:53
Design Patterns | Factory Design Pattern | What, Why and How
0:09:46
Factory Pattern - DESIGN PATTERNS (C#/.NET)
0:10:37
Factory Design Pattern Introduction
0:09:47
8 Design Patterns EVERY Developer Should Know
0:26:55
Factory Method Design Pattern
0:01:57
Design Pattern - Introduction
0:07:27
Abstract Factory Design Pattern Explained: Introduction and Fundamentals
0:00:58
What is the factory design pattern?
0:28:50
27. All Creational Design Patterns | Prototype, Singleton, Factory, AbstractFactory, Builder Pattern
0:12:54
Factory Pattern in C#: Creating Objects with Ease
0:02:46
2 The Factory Design Pattern Introduction
Комментарии