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

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2
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2answers
276 views

Does it make sense to use interfaces if you don't have polymorphism?

Suppose I have distinct classes that have the same behavior, which can be represented like this: public interface Behavior { void operationA(); } public class ImplementerA implements Behavior { ...
1
vote
2answers
97 views

How specific should be an interface about its implementation details?

Perhaps I should have picked a better title, but anyway... Basically what to do with two or more implementations that have the same public interface, but they are meant for slightly different ...
3
votes
3answers
565 views

Why not apply Interface Segregation Principle to “extreme”

Providing that clients would typically consume just one method, though methods would be conceptually related, why not always apply the Interface Segregation Principle to the extreme and have [many] ...
41
votes
9answers
4k views

Programming for future use of interfaces

I have a colleague sitting next to me who designed an interface like this: public interface IEventGetter { public List<FooType> getFooList(String fooName, Date start, Date end) ...
5
votes
2answers
2k views

Code re-use in C++, via multiple inheritance or composition? Or…?

I originally asked this question on StackOverflow, but I was directed here, and I think my problem is perhaps as much conceptual as technical, so here goes. If you’re defining a hierarchy of abstract ...
0
votes
3answers
389 views

Why do APIs generally consist of interfaces? [duplicate]

I am starting out in Java API design and in reading existing code bases, I have found that most APIs consist of interfaces only with their implementations bundled in a different package. Having read ...
6
votes
4answers
611 views

Split up large interfaces

I'm using a large interface with about 50 methods to access a database. The interface has been written by a colleague of mine. We discussed this: Me: 50 methods is too much. It's a code smell. ...
2
votes
0answers
165 views

The inheritance argument of zope.interface (providedby vs isinstance)

What limitations does inheritance of an interface through an abstract base class present that are addressed by zope.interface? In the following talk given in 2010 by Jeff Rush about interfaces, at ...
1
vote
4answers
332 views

Combinatorial explosion of interfaces: How many is too many?

I'm a relative newcomer to OOP, and I'm having a bit of trouble creating good designs when it comes to interfaces. Consider a class A with N public methods. There are a number of other classes, B, C, ...
1
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2answers
78 views

Creating an Interface To a Language's Standard Library?

In the process of learning test-driven development, I've been introduced to dependency injection and the use of interfaces, and have started using these concepts in my own PHP code in order to make it ...
5
votes
1answer
76 views

Designing communications for extensibility

I am working on the design stages of an application that will a) collect data from various sources (in my case that's scientific data from serial ports), keeping track of the age of the data, b) ...
0
votes
2answers
273 views

Java best practice Interface - subclasses and constants

In the case where a couple of classes implements an interface, and those classes have a couple of constants in common (but no functions), were should I put this constant ? I've had this problem a ...
3
votes
2answers
158 views

Design for an interface implementation that provides additional functionality

There is a design problem that I came upon while implementing an interface: Let's say there is a Device interface that promises to provide functionalities PerformA() and GetB(). This interface will ...
0
votes
1answer
115 views

Should interface only be used for behavior and not to show logical data grouped together? [duplicate]

Should an interface only be used to specify certain behavior? Would it be wrong to use interface to group logically related data? To me it looks like we should not use interface to group logically ...
0
votes
2answers
164 views

Is using interfaces on internal code a good idea? [duplicate]

I'm working on a set of automated tests that we use internally at work. Lately, we've been designing classes that implement interfaces in addition to inheritance. As I understand it, interfaces in ...
7
votes
2answers
317 views

How to hide AOP implementation dependency without breaking encapsulation?

I have the concept of a SlowLoading thing: public interface SlowLoading { boolean hasLoaded(); } I also have a component MyComponent: public interface myComponent{ void doSomething(); } My ...
0
votes
2answers
243 views

c# naming - What are common conventions for a suffix to distinguish between read-only and writable interfaces [closed]

Assume an interface that allows queries on a spatial tree public ISpatialTree { int FindChildIndex(Vector point); bool IsLeaf { get; } ICollection<ISpatialTree> Children { get; } } ...
3
votes
1answer
182 views

Interface hierarchy design for separate domains

There are businesses and people. People could be liked and businesses could be commented on: class Like class Comment class Person implements iLikeTarget class Business implements iCommentTarget ...
5
votes
5answers
1k views

How to enforce implementation of interface to behave a certain way

Suppose you had the following interface public interface IUserRepository { User GetByID(int userID); } How would you enforce implementers of this interface to throw an exception if a user is ...
0
votes
2answers
185 views

Interface method signature not restrictive enough

I wrote a piece of code at my job sometime ago. While writting the code I wrote few interfaces who would allow me to add more flexibility and at that time I was also trying to understand OOP concept ...
13
votes
3answers
1k views

Why are interfaces more helpful than superclasses in achieving loose coupling?

(For the purpose of this question, when I say 'interface' I mean the language construct interface, and not an 'interface' in the other sense of the word, i.e. the public methods a class offers the ...
3
votes
1answer
198 views

Different scoring algorithms for different competition elements

I am creating a scoring system for a competition that is somewhat obscure, but it resembles the Olympics in terms of its high-level structure. Therefore, I will ask my question in terms of an ...
3
votes
2answers
293 views

How to manage memory in C interface for C++ implementation considering c++11?

I have a library implemented in C++ which has a C interface. This C interface is, for all intents and purposes, the only way to use this library. C++11 seems to discourage the use of raw pointers but ...
1
vote
1answer
238 views

Should I use inheritance or an interface?

So in a nutshell I have an abstract class : public abstract class Member { public string PCode { get; set; } public string Reference { get; set; } public DateTime? ElectedDate { get; set; } } And ...
1
vote
3answers
336 views

Empty superclass for Collection of derived classes

Basically, what I would like to obtain is a way to iterate through ONE list, and call methods specific to the interface the objects in the collection implement. In my Java project, it would result in ...
0
votes
2answers
214 views

UML Class Diagram: Abstract or Interface?

I am modeling a class diagram and have spotted an opportunity to simplify it slightly. What I want to know is, would this it be better to implement an abstract class or an interface? The scenario is ...
1
vote
2answers
306 views

Go-like interfaces + multi-methods make sense?

Thinking about the design of a potential new language, I wonder how related are the concepts of built a OO similar to GO interfaces and multi-methods (I get this from ...
0
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1answer
133 views

When is it suitable to use inheritance [duplicate]

I recently had a small "argument" about inheritance with a friend. I think people overuse it a lot. Intuition tells me that that the only good reason for class inheritance is polymorphism - when there ...
0
votes
4answers
254 views

Can a Java interface declaration enforce parameter properties?

As far as I know, declaring an interface is like so: public interface Roots_Squares { public double square_root( double value ); } Now... how do you enforce value to have non-negative values? ...
1
vote
3answers
221 views

Necessity of Interfaces for Small Projects

Is it necessary to use interfaces for small projects? I work at a shop writing small custom applications for clients, primarily data manipulation. I'm mostly self-taught but also took some programming ...
2
votes
2answers
133 views

Segregating interfaces/concerns to a tree

When working with a single object there are a number of ways to segregate interfaces to it. Breaking it into smaller components that can be treated independently. Breaking it into simpler ...
1
vote
3answers
341 views

Why are inheritance and interfaces restricted to instance members?

Disclaimer: I think the rules are almost the same in most OO languages, but since I'm most familiar with C# I'll be relating to this specific language. I think that the use of attributes and ...
0
votes
3answers
158 views

Is declaring STL variables in a class definition too revealing?

If you are trying to hide implementation, would declaring STL variables be too revealing? // in Word_Bucket.h class Word_Bucket { private: std::vector<std::string> contents; ...etc } ...
0
votes
1answer
714 views

How to use namespaces to separate interface from implementation, in c++?

As far as I can tell, you can make your interface known to others by providing your .h file. Your .cpp is the implementation. Then they can see the function names, the parameter types, the return ...
3
votes
2answers
707 views

Implementing the Interface Segregation Principle

Does this IConvertible interface satisfy the Interface Segregation Principle (ie. the "I" in SOLID)? Here is the definition: public interface IConvertible { TypeCode GetTypeCode(); bool ...
0
votes
1answer
83 views

Inverse of Extract Interface refactoring

I'm working with a Java project that has several interfaces, many of which have only one implementation. (See related question) For a given revision of the software, one could think this acceptable ...
0
votes
0answers
50 views

What should I do with too much interfaces needed for a dialog

Let me start by doing a small summary of the changes we did in our code in the last year. We have a software (VERY big) that is used to visualize multiples underground networks, enter data in the ...
49
votes
10answers
10k views

Is better Show() + Hide() or SetVisible(bool visible)?

What is better and why? (From interface-design point of view) : a) To have two Show() and Hide() functions b) To have one SetVisible(bool visible) function EDIT: For example some object have ...
19
votes
4answers
15k views

Why were default and static methods added to interfaces in Java 8 when we already had abstract classes?

In Java 8, interfaces can contain implemented methods, static methods, and the so-called "default" methods (which the implementing classes do not need to override). In my (probably naive) view, there ...
2
votes
4answers
1k views

Understanding “programming to an interface”

I have come across the term "programming to an interface instead of an implementation" a lot, and I think I kind of understand what it means. But I want to make sure I understand it's benefits and ...
-1
votes
3answers
216 views

Regarding interfaces of classes in OOP

When one says "a class' interface": Does he/she refer to all of the get and set methods - or do they refer only to the methods' signatures and return types, without the inner implementation of these ...
0
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2answers
132 views

Using interfaces as part of encapsulation

I'm creating interfaces for a number of our existing classes for mocking reasons. Many of these classes also have package scope methods as an attempt to give some level of encapsulation by ensuring ...
0
votes
1answer
384 views

Does it make sense to break fluid interface if a bad argument is passed?

If I chain some setters together and one of them does not return $this, then I will get a fatal error. But maybe that is a good thing. $object = new object(); ...
-4
votes
1answer
774 views

what is the main utility of Interface in real world programming (OOPS) [duplicate]

what is the main utility of Interface. we know that we can implement dynamic behavior using interface but i guess it is not only the utility. so i like to know when we have to write interface and when ...
-1
votes
1answer
36 views

delivering ebook throught mobile app [closed]

I have designed the interface of a mag app which would deliver digitized magazine in the size of A3 paper to the mobile phone. My choice of fileformat is jpg of each of the pages, but is there any ...
0
votes
0answers
49 views

Use Objective-C protocols like Java interfaces [duplicate]

I'm a Java developer moving to Objective-C. So far in Objective-C I've seen protocols used extensively to implement the delegate pattern, but I haven't seen then to add a layer of abstraction in the ...
1
vote
3answers
170 views

Refactoring - Utility classes behavior under a common interface

I was suggested to put my question here, so I'm doing so ;) I need a common interface which represents some specific behavior: public interface Contract(){ public void methodA(); public void ...
1
vote
2answers
776 views

Interface Segregation Principle - type hinting multiple interfaces

The question is about typehinting of the role interfaces. The code example has two DataMappers which typehint the interface they need in the constructor, FooDataMapper type hints the Preparable ...
0
votes
3answers
150 views

Naming interfaces for persistent values

I have 2 distinct types of persistent values that I'm having trouble naming well. They're defined with the following Java-esque structure, borrowing Guava's Optional for the example and using generic ...
0
votes
1answer
655 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? ...