abstract

Testing a method used from an abstract class

I have to Unit Test a method (runMethod()) that uses a method from an inhereted abstract class to create a boolean. The method in the abstract class uses XmlDocuments and nodes to retrieve information. The code looks somewhat like this (and this is extremely simplified, but it states my problem) namespace AbstractTestExample { public ab...

Is there a way to make sure classes implementing an Interface implement static methods?

First of all, I read erickson's useful reply to "Why can’t I define a static method in a Java interface?". This question is not about the "why" but about the "how then?". Edit: my original example was ill-posed, but I'll leave it bellow. While I am now convinced that in most cases what I want to do is overkill, there is one scenario wh...

Java - abstract class, equals(), and two subclasses

Hello, I have an abstract class named Xpto and two subclasses that extend it named Person and Car. I have also a class named Test with main() and a method foo() that verifies if two persons or cars (or any object of a class that extends Xpto) are equals. Thus, I redefined equals() in both Person and Car classes. Two persons are equal wh...

How to create a dynamic array of an Abstract class?

Lets say I have an abstract class Cat that has a few concrete subclasses Wildcat, Housecat, etc. I want my array to be able to store pointers to a type of cat without knowing which kind it really is. When I try to dynamically allocate an array of Cat, it doesn't seem to be working. Please help? Cat* catArray = new Cat[200]; ...

How to persist a very abstract data type between sessions: PHP

I have an abstract data type that behaves much like stack. It represents a history of "graph objects" made by a particular user. Each "graph object" holds one or more "lines", a date range, keys, and a title. Each "line" holds a sql generator configured for a particular subset of data in my db. I would like for these "histories" to b...

Best method of including an abstract in a latex 'book'?

Hello there. I've been looking for the answer to this question for a while now but can't seem to find it, so I'm hoping someone on here can help me. I'm writing up a thesis in Latex, and really like the \frontmatter, \mainmatter and \backmatter ability when using the "book" environment. However I need to add an abstract and the \begin...

Visual Studio: Design a UserControl class that derives from an abstract base class

Hi All, I want to have an abstract base class for some of my custom UserControl's. The reason is obvious: they share some common properties and methods (a basic implementation of some elements of an interface actually), and I want to implement them only once. I have done this by defining my abstract base class: public abstract class V...

Can i override an abstract method written in a parent class, with a different name in a child class?

abstract class SettingSaver { public abstract void add(string Name, string Value); public abstract void remove(string SettingName); } class XMLSettings : SettingSaver { public override void add(string Name, string Value) { throw new NotImplementedException(); } ...

When using the getInstance() method of the abstract java.text.NumberFormat class, what is the actual class of the return value?

This question expands upon the one at abstract-class-numberformat-very-confused-about-getinstance. I feel that this question is different enough to merit being asked on its own. In the answers to that question, it was stated that a code statement such as NumberFormat en = NumberFormat.getInstance(Locale.US); returns an object that is...

Why can't you call abstract functions from abstract classes in PHP?

I've set up an abstract parent class, and a concrete class which extends it. Why can the parent class not call the abstract function? //foo.php <?php abstract class AbstractFoo{ abstract public static function foo(); public static function getFoo(){ return self::foo();//line 5 } } class C...

Django: Inherit Permssions from abstract models?

Is it possible to inherit permissions from an abstract model in Django? I can not really find anything about that. For me this doesn't work! class PublishBase(models.Model): class Meta: abstract = True get_latest_by = 'created' permissions = (('change_foreign_items', "Can change other...

C# - What should I do when every inherited class needs getter from base class, but setter only for ONE inherited class

Hello, I have a abstract class called WizardViewModelBase. All my WizardXXXViewModel classes inherit from the base abstract class. The base has a property with a getter. Every sub class needs and overrides that string property as its the DisplayName of the ViewModel. Only ONE ViewModel called WizardTimeTableWeekViewModel needs a se...

Why does C# allow abstract class with no abstract members?

The C# spec, section 10.1.1.1, states: An abstract class is permitted (but not required) to contain abstract members. This allows me to create classes like this: public abstract class A { public void Main() { // it's full of logic! } } Or even better: public abstract class A { public virtual void Ma...

django modeling

Concept: Drinks are made of components. E.g. 10ml of Vodka. In some receipt the component is very particular (10ml of Finlandia Vodka), some not (10 ml of ANY Vodka). I wonder how to model a component to solve this problem - on stock I have particular product, which can satisfy more requirements. The model for now is: class Receipt(m...

How can I make an "abstract" enum in a .NET class library?

I'm making a server library in which the packet association is done by enum. public enum ServerOperationCode : byte { LoginResponse = 0x00, SelectionResponse = 0x01, BlahBlahResponse = 0x02 } public enum ClientOperationCode : byte { LoginRequest = 0x00, SelectionRequest = 0x01, BlahBlahRequest = 0x02 } That wo...

How to use reflection to get a default constructor?

I am writing a library that generates derived classes of abstract classes dynamically at runtime. The constructor of the derived class needs a MethodInfo of the base class constructor so that it can invoke it. However, for some reason Type.GetConstructor() returns null. For example: abstract class Test { public abstract void F(); } ...

Scala's sealed abstract.

What is the difference between sealed abstract and abstract Scala class? ...

A problem with .NET 2.0 project, using a 3.0 DLL which implements WCF services.

I made a client for accessing my WCF services in one project, and all classes that work with services inherit from this class: public abstract class ServiceClient<TServiceClient> : IDisposable where TServiceClient : ICommunicationObject This class is where I do stuff like disposing, logging when the client was called, etc. some common...

Java abstract visitor - guarantueed to succeed? If so, why?

I was dealing with hibernate, trying to figure out the run-time class behind proxied instances by using the visitor pattern. I then came up with an AbstractVisitable approach, but I wonder if it will always produce correct results. Consider the following code: interface Visitable { public void accept(Visitor v); } interface Visito...

Python virtual classes: doing it right ?

I have been reading documentation describing class inheritance, abstract base classes and even python interfaces. But nothing seams to be exactly what I want. Namely, a simple way of building virtual classes. When the virtual class gets called, I would like it to instantiate some more specific class based on what the parameters it is giv...