IMPLEMENTING COMPONENT GROUPINGS in VB.NET

Generator QR Code in VB.NET IMPLEMENTING COMPONENT GROUPINGS

CHAPTER 5 IMPLEMENTING COMPONENT GROUPINGS
QR Creation In Visual Basic .NET
Using Barcode encoder for .NET Control to generate, create Quick Response Code image in .NET applications.
www.OnBarcode.com
Reading QR Code In Visual Basic .NET
Using Barcode recognizer for VS .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
The client does need to know about the general workings of the various IStrategy implementations and the workings of the Algorithm class. The Algorithm class doesn t know about the different IStrategy implementations, and only knows the IStrategy interface. The individual IStrategy implementations may or may not contain state related to the operations. The individual IStrategy implementations don t know about the workings of the Algorithm class. The Algorithm class won t directly reference the IStrategy implementations (other than the pattern-defined references), and the IStrategy implementations won t directly reference the Algorithm class instance.
Drawing ANSI/AIM Code 39 In VB.NET
Using Barcode encoder for .NET framework Control to generate, create Code 39 image in .NET applications.
www.OnBarcode.com
Generating Linear In Visual Basic .NET
Using Barcode printer for Visual Studio .NET Control to generate, create Linear image in VS .NET applications.
www.OnBarcode.com
Implementing Dynamic Selection of Language Translation
PDF-417 2d Barcode Creation In Visual Basic .NET
Using Barcode creation for .NET Control to generate, create PDF-417 2d barcode image in VS .NET applications.
www.OnBarcode.com
EAN / UCC - 13 Generation In VB.NET
Using Barcode creator for .NET framework Control to generate, create EAN / UCC - 13 image in .NET framework applications.
www.OnBarcode.com
Having illustrated the different patterns, the question is which pattern should be applied to solve the problem of implementing a dynamic selection of the language used for translation. When confronted with a problem, you follow these steps: 1. Define the problem to be solved and consider what the important attributes are. 2. Pick the patterns that you think apply. 3. From the selected patterns, define the distinguishing attributes. This means pick out the attributes of the patterns that separate them from the other selected patterns. 4. Then take those attributes and compare them to the attributes you need to solve the problem. Having defined the problem and the patterns, let s start figuring out which pattern could be used and why. First, let s eliminate the patterns that don t apply and I ll explain why. Note that the explanation of why a pattern doesn t apply is as important as explaining why a pattern does apply. When a pattern isn t used, there should be a clear reason why not. Command pattern: Doesn t apply because the Command pattern is generally used for executing a number of steps after they have already been completed. The caller gives the state, and thus this single aspect negates the use of this pattern. Composite pattern: Doesn t apply because there is no hierarchical storage of objects. The requirement is to perform a single translation of a single phrase that is given by the request. Decorator pattern: Doesn t apply because the text isn t translated multiple times. The text is translated using a single language. The only exception is if concurrent translations were to be executed. For example, if you want to convert a text into five different languages at once for every request, then a Decorator pattern might be useful, as the list of languages could represent the five different languages. Three patterns were removed as being obviously incorrect, but the three left over are potential solutions. From the three, two are close solutions, but not close enough, as I explain here:
Print EAN13 In VB.NET
Using Barcode creation for VS .NET Control to generate, create EAN-13 Supplement 5 image in .NET applications.
www.OnBarcode.com
Painting Codabar In Visual Basic .NET
Using Barcode generation for Visual Studio .NET Control to generate, create Monarch image in VS .NET applications.
www.OnBarcode.com
CHAPTER 5 IMPLEMENTING COMPONENT GROUPINGS
Scanning QR Code 2d Barcode In Java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Paint QR Code In None
Using Barcode generator for Microsoft Excel Control to generate, create Denso QR Bar Code image in Office Excel applications.
www.OnBarcode.com
State pattern: The State pattern could apply, but there is a problem in that translating languages doesn t involve shifting from one language to another language. For example, the translation service wouldn t expect to have the first text translated into German and the second text translated into Japanese. The choice of translation is determined by the client, and therefore this pattern isn t applicable. Strategy pattern: The strategy pattern does apply and would work. In fact, the strategy pattern would be a natural fit. Going back to the original definition of the TranslationServices class, it represents the Algorithm class. This means that the client that consumes the TranslationServices class would have to define the language to use for translation. The reason why I didn t choose this approach relates to Figure 5-4 and Figure 5-3. In Figure 5-3, the Loader class is contained in the Form class. Then in Figure 5-4, the Loader is contained in the TranslationServices class. If the Strategy pattern were used, then the Loader class would have to be moved back to the Form class or more appropriately to the TranslationTextBox class. Remember that the TranslationServices type represents the State pattern defined Algorithm type, and therefore the client must define the translation. This means the GUI must contain application logic on which language to choose, meaning it must know, instantiate, and assign the language type. This is what we want to avoid because it violates separating GUI logic from application logic. The solution is to use the Chain of Responsibility pattern, because a configuration file could define all possible languages that would be loaded. The TranslationServices would expose a collection of available languages as a series of identifiers. Then the GUI would select a language that would be used to translate the text. The Loader class would be converted from a simple Client-Dispatcher-Server pattern to also take advantage of the Chain of Responsibility and implement the ITranslationServices interface. The new and final architecture that allows a dynamic selection of the language is illustrated in Figure 5-11.
Recognize Code39 In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Code 39 Extended Printer In None
Using Barcode generator for Software Control to generate, create Code 39 Full ASCII image in Software applications.
www.OnBarcode.com
Figure 5-11. UML definition of the final translation services architecture The Chain of Responsibility pattern is implemented using delegates because the Loader class is serving the dual purpose of implementing the Client-Dispatcher-Server pattern and the
Scan Code 128 Code Set B In VS .NET
Using Barcode scanner for VS .NET Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
UPC Code Creation In Java
Using Barcode creation for Eclipse BIRT Control to generate, create UPC Code image in BIRT reports applications.
www.OnBarcode.com
Paint Barcode In .NET Framework
Using Barcode maker for Reporting Service Control to generate, create Barcode image in Reporting Service applications.
www.OnBarcode.com
EAN13 Generator In Objective-C
Using Barcode printer for iPhone Control to generate, create EAN13 image in iPhone applications.
www.OnBarcode.com
UPC-A Supplement 5 Drawer In None
Using Barcode encoder for Font Control to generate, create UPC-A Supplement 2 image in Font applications.
www.OnBarcode.com
Code 128 Code Set C Generator In Java
Using Barcode drawer for Java Control to generate, create Code 128 Code Set B image in Java applications.
www.OnBarcode.com
Barcode Generator In None
Using Barcode maker for Online Control to generate, create Barcode image in Online applications.
www.OnBarcode.com
Painting UPC-A In Objective-C
Using Barcode creator for iPhone Control to generate, create GTIN - 12 image in iPhone applications.
www.OnBarcode.com
Copyright © OnBarcode.com . All rights reserved.