template-method-pattern

问题 The template method pattern provides that the abstract base class has a not overridable method: this method implements the common algorithm and should not overridden in the subclasses. In Java the template method is declared final within the abstract base class, in C# the sealed keyword has a similar meaning, but a not overridden method can not be declared sealed . public abstract class Base { protected abstract AlgorithmStep1(); protected abstract AlgorithmStep2(); public sealed void

问题 The template method pattern provides that the abstract base class has a not overridable method: this method implements the common algorithm and should not overridden in the subclasses. In Java the template method is declared final within the abstract base class, in C# the sealed keyword has a similar meaning, but a not overridden method can not be declared sealed . public abstract class Base { protected abstract AlgorithmStep1(); protected abstract AlgorithmStep2(); public sealed void

问题 I am building an open source library that I can sum up to something like that: class SuperThing { public function doStuff($object) { // ... } } I want to offer the possibility to the user of the library to add custom behavior. For example, he might want to insert some logging at specific points in the operation, or he might want to modify the object at a certain point. I see 2 ways of doing it: the template method pattern seems appropriate, but it will force me to add a lot of protected

问题 Can anyone let me know some example situations where Template Method - pattern should be used? Give me some real-world use from your own experience. (I have so far found it useful only for mapping data in the DA layer. Sorry!!!) 回答1: I tried to give you some real-world examples, and some common situations where Template Method pattern should be used. When you want your program be "Open For Extension” and also “Closed for Modification”. This means that the behavior of the module can be

问题 I have a problem with deciding about class responsibilities. I have 3 html-forms: For each form there is a html template containing some text and a marker for the form to be included Each form needs to be validated, if there is an error the template and the form from (1) needs to redisplayed, together with some error messages. Only some fields are common across the different forms. If there are no errors a result message needs to be mailed. For each form there is a result mail template. I

问题 I was reading about design patterns, in particular about the template method, when my attention was caught by this question on SO. After reading the explanation and specific code I am still wondering why this is an example of the 'Template method' design pattern. According to GoF, the intent of this pattern is: “Define the skeleton of an algorithm in an operation, deferring some steps to subclasses. Template Method lets subclasses redefine certain steps of an algorithm without changing the

问题 From what I understand, Template method is nothing but ordinary method that calls virtual or abstract methods defined in child class. Am I right, or is there something else important about this pattern that I miss? abstract class Foo { public void IamTemplateMethod() { // which will be called in child class object method1(); // because this... method2(); // ...or this method was called in me } public virtual void method1() { ... } // to be overriden in child class public abstract void method2

问题 GOF talks about frameworks for "Factory method" pattern. Frameworks need objects but implementation of objects depends upon application hence an abstract method to create the object is created. Also as return type is needed so interface for the object needed is defined, it defines the apis needed for the object. Actual objects are created by subclasses (concrete Application) . This is a creational pattern. For Template pattern the only change is that the encapsulating class does not know the

问题 Edit: Found duplicate I've whittled down some problem code to the simplest working case to illustrate the following: my typedef in a pure abstract base class is not being inherited by the derived class. In the code below I'd like to inherit the system_t typedef into the ConcreteTemplateMethod : #include <iostream> // pure abstract template-method template <typename T> // T == Analyzer<U> class TemplateMethod { public: typedef T system_t; virtual void fn (const system_t& t) const = 0; };

问题 I have a base abstract class that needs an algorithm for Authentication. I have two implementations of this, one will hash a password and compare it to a stored hash, the other will use windows active directory. But before actually doing the hash check or the windows authentication, I have extra workflow logic that must absolutely be implemented. So things like failedPasswordCount, lastAuthenticationAttemptDate, IsUserApproved, etc. must always be modified or used in the same way no matter