Questions about interface related design considerations, such as programming to the interface.
5
votes
5answers
182 views
Is there something wrong with having one interface to be implemented multiple times in inheritance chain?
interface IUser {}
interface IConcreteUser : IUser {}
abstract class UserBase : IUser {}
class ConcreteUser : UserBase, IConcreteUser {}
As you can see, ConcreteUser inherits IUser two times - one ...
1
vote
1answer
56 views
Is Design by Contract the same as using Interfaces to create a “contract”?
Does an OOP design that uses a Design by Contract mean the designer is using interfaces to create a "contract." The term "contract" is used quite often when discussing OOP interfaces, so I didn't ...
3
votes
1answer
51 views
Message publishing interface when deferring until transaction is committed
Suppose I have the following interface used for publishing messages onto a message queue:
interface IMessageProducer
{
void Publish<TMessage>(TMessage message);
}
Normally, an implementer ...
3
votes
1answer
154 views
When adding a property to an interface in C#, is that consider major, minor, or patch using semantic versioning?
My team and I are trying to follow semantic versioning 2.0.0 to keep tabs on our library versions. We primarily use C# for our development and are currently in a situation where we are going to add a ...
159
votes
9answers
26k views
I changed one method signature and now have over 25,000 errors. What now?
I started a new job recently where I am working on a very large application (15M loc). In my previous job we had a similarly large application but (for better or for worse) we used OSGi, which meant ...
0
votes
0answers
42 views
Entity Framework - Old school save/update advice?
I've a query for you relating to best use of EF6 when using Winforms yet not having justification for changing things to something more modern.
I've got half a dozen classes that are based on ...
4
votes
4answers
240 views
Evolving an interface that is not supposed to be implemented by the client
I'm about to write a Java library. Basically, this library provides something like this to its user:
interface Foo {
void doA();
boolean aWorked();
void doB(int value);
}
The user is not ...
7
votes
3answers
373 views
Is it OK for interfaces to depend on concrete classes?
I am creating interface in Java for custom error handler.
Want to pass an argument error object but I need it to be child of Exception class.
Is it okay to use my defined class name in an interface ?...
4
votes
2answers
341 views
Is it ok to have an empty abstract class to make concrete classes polymorphic
BEFORE:
I have an interface that has one method definition
public interface IDockable
{
void Dock(DockerContainerConfig config);
}
Everything is ok for my first implementation
public class ...
2
votes
3answers
151 views
What does the following definition of an interface mean?
I am reading Real-Time UML Workshop for Embedded Systems and I do not understand what they are saying here. I have bolded the parts of the text that I do not fully understand. I am trying to ...
2
votes
0answers
102 views
Is Pairing a bloated interface with an Enum a good idea?
At work we have an interface that is getting bloated. The interface is designed to be easily implemented by an immutable object. So it looks something like this:
//there is no behavior here, just ...
0
votes
0answers
69 views
Should I replace native JavaScript exceptions with a foreign concept?
I have a case where I would like to avoid using exceptions for validation errors in my function's callback parameter. These errors are not really exceptional, and try...catch can prevent a JS engine ...
0
votes
0answers
38 views
Sending events down a tunnel, and bubbling them back up
I am working on developing an HTML canvas application, where I need to be able to do my own UI event processing. That's where the stem of this question comes from, but I'd really like to understand ...
1
vote
2answers
74 views
General approach to an interface that will resolve a dependency to a database library
Background
I often write software for systems that are responsible for testing manufactured products. For every product that gets tested, we have to generate a report for the test-results. The way ...
12
votes
3answers
3k views
Is this bad OOP design for a simulation involving interfaces?
I am designing my own little OOP program to simulate Vampires, Wolves, Humans and Trucks and am trying to implement my own limited understanding of Interfaces.
(I am still abstracting here and have ...
3
votes
2answers
176 views
How to bring others to understand your interface
I'm working in a corporation that has two products. One is a desktop application the other is a web-application. I'm in on the part as backend-engineer on the web-application. I design the web-...
0
votes
0answers
89 views
ASP.NET: Creating an interface for a controller
Would creating a controller's interface a bad idea? I have a controller that derived from ApiController, so knowing that you can only derived one class to a class but able to derived one or more ...
2
votes
3answers
182 views
How to decide, should I put methods to abstract class or to interface?
I'm writing an app it needs to have generic registration step item. It needs to be able to do some specific things (I use interface for that) and it needs to be a visual element (of Xamarin. It doesn'...
1
vote
1answer
70 views
Interface with multiple default methods OR Interface + Class
In a code base I am "starting from" there are a handful of interfaces with many default methods. They look something like this:
public interface HasXY {
double getX();
double getY();
...
2
votes
2answers
115 views
Function acting as a shortcut to object's methods
I was reading Python's requests library's code to find out how it works. Since this library has a simple usage interface, it creates a more complex object beyond. For instance:
requests.get(...)
Is ...
3
votes
3answers
181 views
Is it good practice to create interfaces that limit usage?
So I'm coding a way to send events to multiple clients, and then having the clients decide how they want to handle it. I'll exclude the bits that don't lend themselves to explaining the situation.
...
3
votes
1answer
84 views
How to properly extend an interface with immutable properties to offer mutability via another interface
The following code snippets are simplified to demonstrate the context!
The actual interfaces and classes are POCOs having additional properties. The types are part of library I am working on, the ...
1
vote
0answers
91 views
Interface Methods vs Data Objects
Building a UI editor for Android and basically there are interfaces such as this:
interface Item {
fun decorate()
fun translate(x: Int, y: Int)
fun rotate(rotation: Float)
fun scale(...
1
vote
2answers
73 views
Modifying an existing class: should I extend it to a new class?
I'm working with a library (from an online source, not authored in-house) providing an interface as well as an implementation of it:
interface FooInterface {
// ...
}
class Foo implements ...
0
votes
1answer
96 views
Force implementation of an interface to use a function, to enable functionality that's transparent to the user
I am the designer of an interface IModel, which will be used by the implementer of a the controller (MVC). The interface contains funcA().
Another programmer needs to implement a specific class for ...
0
votes
1answer
94 views
Having the implementer as a property in an interface - is it bad practice?
I have an interface IFoo that only gets implemented by objects with a fairly high level (framework) base class. It would be very useful to me to not only get the Interface members, but also the ...
2
votes
1answer
91 views
Leo Brodie's “Interface Component”
On page 85 of Leo Brodie's book, Thinking Forth, he describes a component which he calls the "Interface Component." He describes its differences from, and benefits over a standard interface as follows:...
-3
votes
1answer
116 views
Interface methods vs abstract methods [duplicate]
I have one abstract class having two abstract methods, and I don't need to add any non abstract methods in this case why we need interface? In this scenario both interface methods and abstract methods ...
9
votes
1answer
260 views
Now that not all method declarations in a Java Interface are public abstract, should the methods be declared with these modifiers?
Starting with Java 8, default methods were introduced into interfaces. Effectively, this means that not all methods in an interface are abstract.
Starting with Java 9 (maybe), private methods will be ...
0
votes
1answer
86 views
Is this a good way to keep track of subscription cycles and figure out if we need to charge the subscriber?
I'm working in PHP and building a subscription management system from scratch.
I'm trying to figure out the required functions for the Subscription interface (OOP) that need to be implemented by ...
1
vote
1answer
177 views
What are mIa, mId and dIa interfaces?
This document on European Telecommunications Standards Institute website describes some Machine2Machine (M2M) communications protocols. I've seen mIa, mId and dIa interfaces in some research papers, ...
3
votes
2answers
160 views
Java redeclare inherited interfaces?
While working on a small class called FractionNumber I found asking myself if I should implement an interface that I am already implementing. Sounds stupid, I know, but bear with me.
My class ...
1
vote
2answers
64 views
Defining reusable components while having a specific application in mind
Over the past several months I have learned a lot in software design and practices across several languages and frameworks. To me, the most attractive and useful designs patterns are those that follow ...
2
votes
3answers
255 views
Preemptive interfaces in Java - good, bad or “a matter of taste”
I frequently come across projects that strictly define an interface for each and every class. 90% of those interfaces feature only a single implementation. Proponents of these "preemptive interfacs" ...
0
votes
0answers
137 views
What is the meaning of the different interface types in Ian Sommervilles's Software Engineering?
Reading Ian Sommervilles's Software engineering, he mentiones there are following interfaces:
Paramater interface: data or functions are passed from one component
to another
Shared memory interface: ...
0
votes
0answers
86 views
Using java interfaces to narrow the classes public interface
There is a lot of content on the web discussing if it is worth defining an interface if only one class implements it. The answers are mostly either "Yes, because you probably need to mock it anyways" ...
1
vote
3answers
340 views
Is interface containing every method of given class a good thing?
I'm trying to write a simple game and I really want to finally create something that would be "programmatically correct". I stuck with a problem like this: I have class
public abstract class ...
1
vote
1answer
196 views
Inheritance is better or composition design pattern in this scenario?
Design and implement Cash Register:
Given a number of items you will be required to calculate the total bill.
Items are charged for in a couple of different ways:
A given price for each item, e.g. ...
1
vote
1answer
172 views
Should we “prefer composition over multiple interface”?
Should we avoid multiple interface if possible? Because I think at most cases a class with multiple interfaces can be replaced with another version with composition and single interface only e.g.:
...
2
votes
2answers
184 views
Java: Composition of classes implementing same interface
Let's consider an example wherein I have to model the following:
Class to schedule exams for a Student, lets call it StudentExamScheduler
Class to schedule exam for a Class. Let's call it ...
0
votes
0answers
58 views
Code Duplication After Dependency Injection Instead Of Inheritance
I'm applying Dependency Injection instead of Inheritance. But now, I've the problem of code duplication.
Main Controller
final class PreferenceController implements PreferenceInterface
{
...
0
votes
0answers
62 views
Heuristics/rules for programming to an interface [duplicate]
I am struggling with applying the "programming to an interface" guideline because I can't seem to decide in which situations it is necessary and in which ones it's overkill (or even counter productive)...
0
votes
1answer
174 views
Should I force “composition over inheritance” rule to class members?
As I know, according to "composition over inheritance" rule, we should avoid reuse a method by inheritance, but how about class members? Suppose I have parent and child classes:
public class Animal{
...
0
votes
0answers
90 views
Can I keep my code loosely coupled with public-facing enums?
I have some enums in a concrete API/library that will be publicly used by application projects. My problem here, is that I cannot write an interface to these enums (that I know of). I should have ...
0
votes
1answer
147 views
Isn't instantiating an object of type Interface illegal?
This answer describing how Spring for Java works instantiates an object of type Interface which is illegal yet it received 21 upvotes. Why is this answer upvoted for illegal behavior?
Spring contains ...
6
votes
2answers
316 views
Why generic interface cannot implement dynamic type?
If it possible:
IList <dynamic> = new List <dynamic>;
or:
class A <T>
{
A(T){}
}
class B: A <dynamic> {}
. Why it is not possible to do this:
class U: IEnumerable <...
1
vote
3answers
353 views
Same class and namespace name
I have a problem how to go about naming my namespaces and classes. I already figured they shouldn't both have the same name, as it causes all kinds of problems. Most notable problem for me is that I ...
1
vote
2answers
134 views
Will it be okay for an interface to take a dependency on an interface in this situation?
Background
I have an interface defined for a circular-buffer called ICircularBuffer in a separate project. This ICircularBuffer is something that we use all over the place, so it resides in the ...
2
votes
2answers
112 views
Revisiting Fowler's “Public versus Published Interfaces” article with regard to versioning and microservices
In this short article Public versus Published
Interfaces from 2002, Martin Fowler distinguishes between easily changeable "public interfaces" and harder to change "published interfaces":
The key ...
5
votes
1answer
153 views
Inheritance from children to parents?
Seeing this UML class diagram :
FileHandler, Uploader and Deleter are abstract classes.
The four bottom classes are implementations. They extend on FileHandlerInterface which requires a handle method ...
