Questions about interface related design considerations, such as programming to the interface.

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3
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4answers
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Instantiating Interfaces in C#?

I am reading/learning about interfaces in C# at the moment, and thus far I managed to understand how it differs from an abstract class. In the book I am reading the author explains that interfaces are ...
1
vote
1answer
353 views

Interfaces, Adapters, exposing business objects via WCF design

I know there have been countless discussions about this but I think this question is slightly different and may perhaps prompt a heated discussion (lets keep it friendly). The scene: I am developing ...
0
votes
1answer
469 views

The real difference between web and native apps in mobile and smart devices [closed]

I still don't understand the difference between a native app and web or hybrid apps from the interface point of view. Now, apps such as Twitter, Facebook, etc. Are they native? or web? or hybrid apps? ...
2
votes
1answer
153 views

Using partially implemented interfaces

Consider the following hierarchy in C++ notation: class A { public: virtual void doStuff()=0; virtual void doOtherStuff()=0; }; class B:public A { public: ...
4
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5answers
321 views

Loose coupling and shuffling dependencies

I have a bunch of classes that look something like this: public class MyGame() { private Graphics graphics; private Player player; public MyGame() { graphics = new ...
5
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3answers
293 views

Interface at the class or function level?

I have been falling into a pattern lately where I have been defining routines that rely on an interface defined by a function that is specified as a parameter to the routine. (The language is C#, but ...
-1
votes
2answers
184 views

Programming beginner: Options for small program interfaces? [closed]

I have been a Rails developer for a year now, and I really want to start diving in to Ruby and pure programming without using a framework. However I am having trouble conceptualizing little programs I ...
2
votes
1answer
318 views

How does dependency inversion principle work in languages without interfaces?

In C#/Java, the dependency inversion principle is often demonstrated by high-level classes that depends on an interface/abstraction (that it owns). Low-level classes will implement the interface, thus ...
25
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2answers
2k views

What is the name of the following (anti) pattern? What are its advantages and disadvantages?

Over the last few months, I stumbled a few times over the following technique / pattern. However, I can't seem to find a specific name, nor am I a 100% sure about all its advantages and disadvantages. ...
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12answers
2k views

Is “If a method is re-used without changes, put the method in a base class, else create an interface” a good rule-of-thumb?

A colleague of mine came up with a rule-of-thumb for choosing between creating a base class or an interface. He says: Imagine every new method that you are about to implement. For each of them, ...
9
votes
5answers
780 views

Should I write an interface API before an implementation?

I've been delving into more "organized" programming recently and I've been learning that I should be programming to an interface, not an implementation. With that in mind, would it be better to ...
0
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0answers
80 views

Study on designing user prompts (choice of wording, response format, etc.)

Sometimes there are different ways to ask a user the same question. For example, if the user tries to exit a program without saving their file, you can ask either of these questions: Are you sure ...
1
vote
1answer
429 views

Interface Dependencies or Abstract Classes

I have a decision to make and I am wondering what would be the better solution. I am refactoring an older application and intend to really get into the nuts and bolts of it. There are 8 report types ...
2
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6answers
4k views

Design Patterns - Why the need for interfaces?

OK. I am learning design patterns. Every time I see someone code an example of a design pattern they use interfaces. Here is an example: ...
1
vote
4answers
668 views

Explanation of the definition of interface inheritance as described in GoF book

I am reading the first chapter of the Gof book. Section 1.6 discusses about class vs interface inheritance: Class versus Interface Inheritance It's important to understand the difference between ...
2
votes
2answers
357 views

Class design for calling “the same method” on different classes from one place

Let me introduce my situation: I have Java EE application and in one package, I want to have classes which will act primarily as cache for some data from database, for example: class that will hold ...
4
votes
1answer
123 views

C programming multiple storage backends

I am starting a side project in C which requires multiple storage backends to be driven by a particular piece of logic. These storage backends would each be linked with the decision of which one to ...
10
votes
4answers
6k views

The term “interface” in C++

Java makes a clear distinction between class and interface. (I believe C# does also, but I have no experience with it). When writing C++ however there is no language enforced distinction between class ...
4
votes
2answers
184 views

Is excessive indirection and/or redundant encapsulation a recognized concept? [closed]

I'm curious if there's a series of tendencies or anti-patterns when programming whereby a developer will always locally re-wrap external dependencies when consuming them. A slightly less vague ...
0
votes
1answer
74 views

Inject specific classes or not

I have a TableSqlBuilder interface which has a method getCreateTableSql. This interface is used in some other class as follows: function createTable( $tableDefinition ) { $sql = ...
2
votes
3answers
168 views

Is it good practice to not filter values according to nullability?

Sometimes when I create an API that should enable getting a single value or all values I use the following pattern (passing NULL to the API, means get all rows): @Usernames - comma separeted list of ...
1
vote
3answers
222 views

How do I support interfaces for different devices in the same input scenario?

I asked this question on SO but someone pointed out that I would be better off here. He's most likely right. So here I go! So I just wanted an opinion. I have 2 different ways to approach the ...
2
votes
0answers
148 views

ActiveX, OLE, COM explanation or informative links

I've been programming a lot with C# on Visual Studio and many minor/other languages, but I'm having a really hard time to get the grasp of ActiveX, OLE, COM interfaces. All I got is that they're like ...
1
vote
1answer
92 views

Generic service control interface

I need an interface to a back-end service, mostly for control commands (stop, status, cancel, reload config). The service might be in Python, Perl, Java, or whatever, and runs continuously. The ...
2
votes
1answer
178 views

Design of interface for finding one of something or a list

I am developing a telephony call model and thinking about how best to design the interface. One basic idea is that a call has a unique call identifier. I have a list of calls and finding a specific ...
4
votes
3answers
195 views

Where should I place my interface?

I have an interface to communicate with a DB (actually it is not a database, but this is to give a concrete example): interface DbInterface{ Result sendQuery(Query q); } And I am trying to ...
0
votes
0answers
157 views

Pattern or solution for using classes with different interface the same way

What I would like to achieve is to use classes (now two, later more) with different interface the same way, so I would like avoid using decisions based on the interface on upper levels for instance, I ...
2
votes
4answers
247 views

Why should IQueryProvider implementations throw NotSupportedExceptions?

Searching the web, we can find plentiful examples of various ORMs (nHibernate, EF, LinqToSql, etc.) that implement but don't actually support the full IQueryable<T> interface, throwing ...
3
votes
2answers
1k views

C++ class with only pure virtual functions: what's that called?

So i'm looking for some input/consensus on what terminology we should be using to describe something that looks like this: class Printable { public: virtual void printTo(Printer *) = 0; ...
2
votes
1answer
95 views

What to name a new interface that is replacing an existing one?

We're redesigning our application's plugin interface, so we're using the Adapter pattern with our proof-of-concept design to show that the new interface will function without committing to using it in ...
4
votes
1answer
321 views

Is using protected inheritance to hide (but exploit) implemented interface from the public ok?

Recently, we had a discussion about code using protected inheritance in order to hide the fact (to client code) a class inherits from a specific base class but to exploit this fact in the ...
3
votes
2answers
764 views

Collection interfaces in C#, coming from Java

In Java, I'm used to declaring collections using the most-abstract interface possible and then constructing them using the concrete implementation that makes sense at the time. It usually looks ...
3
votes
4answers
7k views

Abstract class + Inheritance vs Interface

Hello fellow programmers, I am reading a book on C# and the author is comparing Abstract classes and Interfaces. He claims that if you have the following "abstract class:" abstract class ...
12
votes
5answers
2k views

What is the functional-programming alternative to an interface?

If I want to program in a "functional" style, with what would I replace an interface? interface IFace { string Name { get; set; } int Id { get; } } class Foo : IFace { ... } Maybe a ...
-3
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3answers
612 views

Programming to interface in Java [duplicate]

What is the real use of interfaces in Java? What is meant by programming to interfaces? I heard these things several times but I don't know what it is and why it is used.
2
votes
3answers
101 views

Can certain expectations of behavior be part of an interface's contract?

Given the following code: public interface IUserDataProvider { ICollection<SomeClass> getSomeClassRecordsForUser(int idUser); } Is it possible to define (via documentation) an ...
8
votes
3answers
8k views

Difference between various Collection Generic Interfaces in C#

I have been playing around with C# for Windows and ASP.net MVC development for some time now. But I am still unclear on a few areas. I am trying to understand the basic difference between and ...
7
votes
3answers
350 views

How do you find your way in deeply nested, interfacey code? [duplicate]

I know most people hate flat and long functions, and hate when code is not full of ISomethings. The problem is that I guess my mind works in different way, and I always have problems with that type ...
21
votes
9answers
2k views

Interface naming: prefix 'Can-' vs suffix '-Able'

It's common to use '-able' as a suffix for interfaces e.g. Serializable Printable Enumerable Drinkable Shootable Rotatable I was thinking that 'Can-' might better because it may be more descriptive. ...
9
votes
4answers
1k views

When to use interfaces (unit testing, IoC?)

I suspect I've made a schoolboy error here, and am looking for clarification. A lot of the classes in my solution (C#) - dare I say the majority - I've ended up writing a corresponding interface for. ...
9
votes
4answers
8k views

Who extends interfaces? And why?

AFAIK, my class extends parent classes and implements interfaces. But I run across a situation, where I can't use implements SomeInterface. It is the declaration of a generic types. For example: ...
33
votes
4answers
4k views

What did Rich Hickey mean when he said, “All that specificity [of interfaces/classes/types] kills your reuse!”

In Rich Hickey's thought-provoking goto conference keynote "The Value of Values" at 29 minutes he's talking about the overhead of a language like Java and makes a statement like, "All those interfaces ...
2
votes
2answers
2k views

Programming against a protocol in Objective-C

I stumbled accross the SOLID principles. There is one burning question. Should I always use protocols? I never saw someone using them in the way that a Java developer would use them. I tried it in a ...
7
votes
4answers
3k views

Can I consider interface methods as abstract methods?

I was thinking about that, and I had some doubts. When I declare an interface, for example: public interface MyInterface { public void method1(); public void method2(); } Could these ...
29
votes
12answers
9k views

Why does PHP have interfaces?

I noticed that as of PHP5, interfaces have been added to the language. However, since PHP is so loosely typed, it seems that most of the benefits of using interfaces is lost. Why is this included in ...
4
votes
5answers
416 views

How does the concept of a class change when passing data to the constructor instead of method parameters?

Let's say we're making a parser. One implementation could be: public sealed class Parser1 { public string Parse(string text) { ... } } Or we could pass the text to the ...
1
vote
1answer
135 views

How do you distinguish your public API interfaces from the interfaces you use for testing/mocking?

Mocking frameworks are useful for creating mock objects that isolate the code under test from its surrounding software environment. Some mocking frameworks cannot mock non-virtual methods, so they ...
1
vote
2answers
227 views

Violating the Interface Segregation Principle?

I currently have an interface named InternalEntityIdTransformer, which has a getInternalId method, that given an external id returns the corresponding internal one. Now I am working on functionality ...
3
votes
4answers
312 views

As a tooling/automation developer, can I be making better use of OOP?

My time as a developer (~8 yrs) has been spent creating tooling/automation of one sort or another. The tools I develop usually interface with one or more API's. These API's could be win32, WMI, ...
5
votes
3answers
537 views

Switching from abstract class to interface

I have an abstract class which has all abstract methods except one which constructs objects of the subclasses. Now my mentor asked me to move this abstract class to an interface. Having an interface ...