Questions tagged [object-oriented]
A methodology that enables a system to be modeled as a set of objects that can be controlled and manipulated in a modular manner
3,335
questions
0
votes
2
answers
118
views
For non-container classes, are "better naming" and "ready for commented codes" good reasons not to declare the most abstract type?
According to Why define a Java object using interface (e.g. Map) rather than implementation (HashMap), I know I should declare the most abstract type possible, but the question is about template class ...
- 5,732
4
votes
4
answers
3k
views
Are "need to call objects in parent object" and "avoid circular dependency" reasons to avoid "Tell, don't ask"?
According to Explanation on how "Tell, Don't Ask" is considered good OO, I know I should avoid get the state of an object and then decides the actions to take to that object, eg:
Bad:
...
CommunityBot
- 1
12
votes
7
answers
10k
views
Structured programming versus OO programming
I am making a presentation that shows the differences between structural and object oriented programming and I want to illustrate why people need OOP with an example where applying OOP concepts will ...
- 273
2
votes
6
answers
515
views
From the perspective of OOP, taking performance into account - should a database connection be a static field, an instance field, or a local variable?
When methods use a database connection, should the connection be a static field, an instance field, or a local variable?
Here are my doubts. I dithered which are correct and which are baseless. I ...
- 111
2
votes
3
answers
5k
views
What would the best way to design a giant API wrapper class with multiple 'sections'?
Here's the problem I'm trying to solve:
There's a rather large API I'm trying to write a wrapper class around. The simplest approach would be to make one class with a method representing each ...
202
votes
14
answers
140k
views
When are Getters and Setters Justified?
Getters and setters are often criticized as being not proper OO. On the other hand, most OO code I've seen has extensive getters and setters.
When are getters and setters justified? Do you try to ...
- 42.7k
1
vote
6
answers
311
views
How encapsulating what varies can help us?
I have a question about encapsulation and I read these two topic (this & this) but I got more confused.
I've been reading Head First Object-Oriented Analysis and Design book and I'm trying to ...
- 45.5k
4
votes
6
answers
2k
views
How exactly are getters and setters defined?
Note: Questions with similar title have been asked before, but please read the full text before claiming that this is a duplicate.
Since everybody in OOP uses the terms getter and setter, I would ...
CommunityBot
- 1
2
votes
3
answers
153
views
Is it necessary or "class obsession" (opposite to primitive obsession) to create classes for non-business fields?
I know there are some posts talk about primitive obsession : When is primitive obsession not a code smell?, Is "avoid the yo-yo problem" a valid reason to allow the "primitive obsession&...
- 634
-2
votes
0
answers
55
views
Design a grading system for the institutions/Govt on an event of exam cancellation like the one happend in 2021 [closed]
can you please help me solve below object oriented design problem? basically requirement is to design classes and their interactions. It was asked to me in an interview and I was rejected in that ...
- 97
2
votes
1
answer
215
views
In poltergeist, whats wrong with "solely to trigger or initialize several other objects"? Isn't it is a good use of encapsulation and reuse?
After reading What differentiates function objects from poltergeists?, according to the definition of poltergeist, I still don't understand why would "poltergeist" be a bad pattern:
A ...
- 201k
7
votes
5
answers
14k
views
Should I use friend classes in C++ to allow access to hidden members?
Here is my situation (a simple example).
Say I have a class called HiddenData
Then I have another class called StoreHiddenData
And finaly a class called OperateHiddenData
Here's the thing, my ...
- 42.7k
6
votes
4
answers
6k
views
When should the builder design pattern be used?
I am currently learning about various object oriented design patterns. I came across a pattern called the builder pattern which is basically where you build a complex object through the use of ...
- 273
66
votes
8
answers
13k
views
When to *not* use SOLID principles
Coming from a math background, counterexamples are equally, if not more, helpful to me for understanding concepts than examples. I've seen many, many examples of when and how to use the SOLID ...
- 1,048
0
votes
2
answers
83
views
Where to put factories that depend on the application layer?
I am a frontend developer (currently working with Vue and TS), and I have been searching for better organization of the frontend code and recently I got to know DDD a bit. I know DDD is mostly used ...
- 4,490
0
votes
2
answers
68
views
How to structure a cart with cart products object
I am new to DDD and I am having trouble structuring an object. I have a cart, where I can add products to it. Each product has some properties like image, title, price, etc. Whenever a product is ...
- 45.5k
0
votes
1
answer
65
views
REST - Adding a new field
I have an object with fields like ID, CODE, NAME, etc., and it has its own database table with each field. And I am working on implementing the REST API for this object. I want to expose all these ...
- 72.5k
14
votes
6
answers
2k
views
Clean OOP way of mapping an object to its presenter
I am creating a board game (such as chess) in Java, where each piece is its own type (like Pawn, Rook etc.). For the GUI part of the application I need an image for each of these pieces. Since doing ...
- 273
1
vote
5
answers
299
views
Specialization and LSP violation?
I have Document and ExternalDocument classes in my system, where ExternalDocument extends Document. The main distinction is that ExternalDocument holds onto externalDocumentId and externalEventId data ...
- 71k
0
votes
2
answers
94
views
Logical architecture based on modules and SPI
I'm looking for the most proper way to design a modular application with ServiceLoader.
--MAIN IDEA--
module app.view | exports app.view.View interface that defines UI api
module app.engine | exports ...
- 638
3
votes
5
answers
617
views
Is "avoid feature envy" violating "open closed principle"?
After reading
What is a" feature envy" code and why is it considered a code smell?"
I know the following code is suffering from "feature envy":
public class Garden{
...
- 203
1
vote
3
answers
867
views
Safety of magic setters in PHP
I don't know how in else languages, but in PHP seems to me that they are very unsafe way how to set value of any member variable - because one setter cannot easily validate input for many variables (...
CommunityBot
- 1
1
vote
2
answers
73
views
MVVM: How and should I expose view models' models to other view models?
Many times while writing MVVM apps in C# I've come across this sort of problem where I need to expose the model in a view model so that I can get it in another view model and do something with it.
...
- 21
2
votes
1
answer
115
views
OO vs FP: What is a good approach to understanding if heavy wrapper classes should be used?
Consider a processing system which ingests objects from an external source and performs extensive processing. One example could be objects detected by a computer vision system which are then fed into ...
- 103k
5
votes
2
answers
281
views
What is the difference between detailed design and design for construction?
I am currently reading Code Complete. And I was confused when the author in one case uses the term "detailed design", and in the other "design for construction". What is their ...
- 201k
1
vote
2
answers
192
views
Composition over inheritance: how data are accessed in the composition case?
I've been reading this Wikipedia article Composition over inheritance. It gives a code example of inheritance first, and then a code example of composition. In case of inheritance there are data that ...
- 25.1k
0
votes
1
answer
135
views
Is "Wrap child class operation into a function, then return the object, in order to declare most abstract type" necessary or over-engineering?
According to Why define a Java object using interface (e.g. Map) rather than implementation (HashMap), I should declare the most abstract type as possible. However, in some cases I remember, ...
0
votes
4
answers
238
views
Single responsibility principle - Classes with operator overload
I've been reading a bit through Clean Code and I came across the Single Responsibility Principle. The principle states that every class should have only one responsibility.
An example taken from ...
- 74.8k
17
votes
8
answers
12k
views
Why is "diamond problem" a problem? Why doesn't the child simply call both parent's methods sequentially? Why is a thing with solutions a problem?
I know there have been many post about diamond problem, one of it: Why do you reduce multiple inheritance to the diamond problem?. But I'm not asking what it is or what is the solution of the problem. ...
- 215
1
vote
1
answer
59
views
Is using an UId to hash Mutable Entities an anti-pattern?
In the context of an object-oriented language, such as Dart, I have an abstract entity which has a single property called id (which is incrementally uniquely generated to make sure there are no-...
- 201k
0
votes
0
answers
43
views
How to handle multiple-state domain object?
Let's take an example of Order.
An order can have the state new, canceled, shipped, or processing.
The new order can be processed.
The new order can be canceled.
The processing order can be shipped.
...
14
votes
3
answers
4k
views
How do you approach class design in OOPs?
When I try to design an OO solution ,I generally use the CRC modelling wherein I list the class names (nouns), what they do(verbs) and how they collaborate with other classes.
This blog has the below ...
- 113
0
votes
1
answer
200
views
Validation in a simple DDD example
I'm doing a simple project that represents a CI Pipeline in a low scale. So I'm trying to model "the best way possible" to practice DDD.
Basically I have the following information:
...
CommunityBot
- 1
2
votes
1
answer
184
views
Domain models: Can they be an abstract class
When talking about having a rich domain model successfully, in real applications, it needs to, somehow, access some abstraction of complex functionality (instead of being a row state calculator the ...
- 34.3k
1
vote
1
answer
355
views
MVC-like architecture: Model-Controller communication of results/status
I'm struggling on designing a solid architecture for my project.
In particular, I don't know how to handle the communication between the models and the controllers.
My goals are:
Following the ...
CommunityBot
- 1
0
votes
1
answer
66
views
Creating Controllers and Repositories without corresponding Models
I have to create a system to interview people on a few topics where they have to answer both objective and discursive questions, where questions may change between interviews. I structured the ...
- 74.8k
0
votes
1
answer
241
views
Could this be considered a valid State GoF Pattern implementation?
For teaching purpose, I would like to create a simple implementation of State Pattern using PHP 7.4.
So, I've tried to create a simple "document state machine" starting with Draft, sending to review ...
CommunityBot
- 1
0
votes
1
answer
150
views
Clean architecture - how to manage use cases that depends on external apis
How to apply clean architecture concepts in a software that depends on External APIs.
Example:
A business that offers some kind of subscription to its users.
Its convinient to store some subscription ...
- 103k
0
votes
1
answer
156
views
Using the objects retrieved at the time of request validation
I hope the question title already answers the subject here. Lets say I have a number of ids that needs to be validated in a request.
Example:
request uri:
[POST] /album/{album_id}/song
Request ...
CommunityBot
- 1
6
votes
2
answers
32k
views
Are Spring beans declared as static a poor design choice?
The question is pretty straightforward, I'll try to explain why I want some explanations.
(All of this is my 1½-year junior Java developer opinion, which may be more than incomplete. Which is why I ...
0
votes
1
answer
73
views
Mapping list to another list dynamically
I had an idea for a piece of software using .NET C# as technology.
Basically, in my idea Im thinking of using reflection to do the mapping between a class to another class using interactivity with a ...
- 45.5k
0
votes
0
answers
46
views
Should I add new method to the interface to use it more commonly or just separate the new logic completely
I have a CouponReservationService in an e-commerce project.
It is called when a coupon is reserved to be applied to a basket. It checks that whether the coupons are already reserved. If they are ...
- 101
3
votes
9
answers
604
views
Can a Domain Object always be "completely ignorant of persistence" and yet still possible to persist?
Domain Object, while not necessarily a design pattern, can at least be considered as a design "concept", and one of its points is:
https://wiki.c2.com/?DomainObject
Domain objects should ...
- 447
13
votes
3
answers
3k
views
Applying SOLID principles
I am quite new to the S.O.L.I.D. design principles. I understand their cause and benefits, but yet i fail to apply them to a smaller project which I want to refactor as a practical exercise to use the ...
- 243
2
votes
1
answer
272
views
How to restrict the construction of a domain object to an external service?
I have this object
RelativeFoo{int relativeCode, Origin relativeTo}
And I want to map it to this other object
AbsoluteFoo{int absoluteCode}
In order to do this, I need to use a service whose ...
CommunityBot
- 1
11
votes
3
answers
4k
views
Is there any point in using builders and fluid interfaces with object initialisers?
In Java and C#, you can create an object with properties that can be set at initialisation by either defining a constructor with parameters, defining each property after constructing the object, or ...
- 678
1
vote
2
answers
193
views
Is "declaring most abstract type" suffers from the same problem as "primitive obsession"?
According to Why define a Java object using interface (e.g. Map) rather than implementation (HashMap), when creating objects, I should declare the most abstract type, eg : Map hashMap=new HashMap(). ...
- 71k
1
vote
3
answers
636
views
Architecture for slot machine game
I am building a slot machine game for a client (virtual money, not real-money gambling). They started out with a template game and hired me to reskin it and make "minor" changes for a "...
- 71k
111
votes
13
answers
61k
views
Why is C not considered an 'object-oriented' language?
It seems that C has its own quasi-objects such as 'structs' that can be considered as objects (in the high-level way that we would normally think).
And also, C files themselves are basically separate ...
- 251
0
votes
2
answers
82
views
Where to specify UI views in a hierarchy of model objects?
In a Flutter app I'm developing, I have a class hierarchy of model objects of a certain base class. To take a typical example, the abstract base class could be Vehicle. Then I have a (pretty much) ...
CommunityBot
- 1