Object-oriented design is the process of planning a system of interacting objects for the purpose of solving a software problem.

learn more… | top users | synonyms

2
votes
5answers
1k views

Lots of classes with only one single static method with same name as class - Code smell? [duplicate]

I'm trying to follow the single responsibility principle (SRP) in my applications. I have lots of CRUD classes I just name xxxxxManager. Following the SRP, I made 4 classes for each one : ...
1
vote
3answers
560 views

Where to Populate Objects

As mentioned in this question, I am moving our team towards objects (as opposed to just throwing DataTables and variables around everywhere). I have picked a suitable spot for the project that ...
3
votes
3answers
4k views

Empty virtual method on base class VS abstract methods

I couldn't find a question that was not too specific to some case, so I'll try to make this very generic. We need an extractor base class to a set of documents, for example. Each document has its ...
2
votes
3answers
1k views

Design for creating a menu based on user type

Problem I am building a PHP application which has a main menu, which in turn contains various "sections" or "subheadings" with various links. There are several user types such as SuperAdmin, Admin, ...
5
votes
4answers
685 views

Design pattern for bidirectional signals/events

This problem feels rather basic, yet I've never known a great solution. I'm looking for a way for components in an application to notify each other while being as decoupled as possible (both at build/...
2
votes
3answers
386 views

Basic OOP Question for a Report

I'm in development of a sample project in Android for a friend's phone that keeps track of his sales. At first, one of the requirements was to create yearly reports of this sales data. This would be ...
1
vote
1answer
272 views

Should an object update itself?

I'm working on Ruby on Rails. There is a feature in our app where doctors can "claim" cases for themselves. I can either have the doctor perform the action and update the plate, or I can have the ...
1
vote
2answers
1k views

Is this proper OO design for C++?

I recently took a software processes course and this is my first time attempting OO design on my own. I am trying to follow OO design principles and C++ conventions. I attempted and gave up on MVC for ...
0
votes
1answer
257 views

Convert to Object Oriented Programming

I am currently working on a project that is fairly small for the time being. There was a recent change to implement 3-tier architecture, such that the code is now split up appropriately to data ...
1
vote
1answer
445 views

Binary Tree/Knowledge Base design C++

Currently I have a binary tree template setup where my main is using it with strings to make a question/answer game. I'm using a knowledge base that works as an interface to the binary tree that main ...
0
votes
3answers
398 views

Software architecture which allows for growth, real life situation [closed]

I know of Interfaces, Abstract classes that serve as Base class, I've been reading up on loose coupling, ... But I can't come up with a decent solution when a property of a class changes, and the new ...
3
votes
2answers
202 views

OO design for a Windows application that communicates with an external machine via RS232

I'm after a bit of OO design advice... I'm about to start developing a Windows application that communicates with an external machine via RS232. The machine has an onboard "system controller" ...
1
vote
2answers
2k views

Where should the ACL handler be called in a MVC architecture?

Thinking about Access Control Lists bound to a web MVC architecture, I have a doubt on where the verification should be done. Within Models? Controllers? FrontController? Imagine a multiple module ...
0
votes
4answers
652 views

What is this design pattern called? [closed]

I have some code: /// <summary> /// Represents Record Locator class /// </summary> public class RecordLocator : IRecordLocator { /// <summary> /// The Record Locator string, ...
2
votes
2answers
428 views

Updating an Entity through a Service

I'm separating my software into three main layers (maybe tiers would be a better term): Presentation ('Views') Business logic ('Services' and 'Repositories') Data access ('Entities' (e.g. ...
2
votes
1answer
169 views

Is it bad practice to encapsulate a single operation in a class? [duplicate]

I recently had a back and forth over at StackOverflow about my answer to this question. The question was simple. The author wanted to transform a number into an abbreviated version that appended a K, ...
1
vote
1answer
235 views

Names for generic classes - how to avoid naming them just “object”? Use synonyms?

When programming, I often end up naming some generic class (think of an abstract base class for stuff you manage in your project) something like FooObject, FooComponent or FooItem (where Foo is an ...
3
votes
2answers
555 views

Object-Oriented design and proper Java architecture for my program

This is the very first time that I think I want to create a program which really uses OOP principles and I want to do it in the most effective and efficient way. First of all we are given this (great)...
2
votes
2answers
201 views

Handling “unspecified” values in software

So I'm working on a software product where we have a number of fields that the customer can leave blank, some of which are numeric. To persist these in the database we use nullable columns. Easy peasy....
30
votes
8answers
4k views

Are classes with only a single (public) method a problem?

I am currently working on a software project that performs compression and indexing on video surveillance footage. The compression works by splitting background and foreground objects, then saving the ...
1
vote
3answers
234 views

A pattern to “atomically” update a pair of objects

Is there a standard pattern in OOP to kind of "atomically" update a pair of objects, like a pair of bank accounts on a transaction? I would like to have somehow a single public method exposed that ...
2
votes
2answers
629 views

C# Design Issue [closed]

I am building a small application and I am trying to understand the best way to approach the design. I am looking for some guidance/advice how best to approach the following issue. What I have is ...
0
votes
2answers
231 views

How to remove redundant code that enables button. Or “if” statement

I got probably "micro optimization" problem. I got "History number", "Next Number", "Reset" buttons, as well "label" for text. Every time I click At "Next number" button I would like to show random ...
2
votes
3answers
148 views

Refactor an old model of a LastUser Modification on every Object?

I have a software requirement, that needs to store the user that made the last modification to another object, for every object (assume that all objects are already mapped and into a BD). So we have ...
2
votes
1answer
620 views

What kind of object relational mapping is appropriate here?

In my database I have a table that looks like this Master(ID, Name, Attr1...). Every ID will have at least 1 entry in additional tables that have additional attributes. Those tables specialize the ...
2
votes
1answer
98 views

Are there any known effects on cognitive load of many files with one file per object?

There has been a trend in the Ruby/Rails community to create lots of objects that have very small functionality (SRP anyone?) and live in their own file. These are often extracted from large, bloated ...
25
votes
10answers
7k views

Can we live without constructors?

Let's say in some reason all objects are created this way $obj = CLASS::getInstance(). Then we inject dependencies using setters and perform starting initialization using $obj->initInstance(); Are ...
5
votes
2answers
633 views

How to handle status integers from database in object oriented code?

Consider a database table of Items that have a status flag represented by an integer. A few of the status might be: 0 - Past Storage; 1 - Current Inventory; 5 - Scrap; 6 - Rework; 15 - Processing; ...
4
votes
3answers
238 views

Benefits of using config files over making many small classes?

My friend and I are building a mobile game and ran into the following design problem: We will have many different types of units all with different stats and abilities. However, all unit types ...
3
votes
1answer
223 views

How can I structure my code when I have orthogonal arrays of features?

Example: You have a game with different schools of magic (fire, ice, etc). Each school has a set of properties that pertain to independent features of the game, such as: strings to be displayed on ...
3
votes
3answers
192 views

How do I recreate this Access Control/Group/ whatever methodology in OO/MVC

I am looking at trying to rewrite an application that is mostly procedural to an MVC/OO approach in order to teach myself a deeper understanding of both. BUT, I am having some conceptual issues with ...
8
votes
2answers
5k views

Open Close Principle (OCP) vs Dependency Inversion Principle (DIP)

I was trying to understand the difference between Open Closed Principle (OCP) and Dependency Inversion Princible (DIP). Based on research I've made on the internet so far, I came to the conclusion ...
1
vote
3answers
799 views

Service method, bean as an argument and mandatory attributes

There is a service: createUser(User user) where you can create a new user, with so many attributes (name, address lines...). Now, some user attributes are mandatory. Other attributes are not ...
0
votes
1answer
185 views

Boolean properties in Class A control availability of members in Class B: Design Pattern?

Given the following code: class AnimalDescriptor { String species; boolean hasLegs; boolean hasTeeth; boolean hasHair; public AnimalDescriptor(String species, boolean hasLegs, ...
0
votes
1answer
349 views

Flexible / Dynamic object creation or Alternative to list of lists [closed]

I have a xlsx file, that has some tabs with different data. I want to be able to save each row of a tab in a list. The first thing that comes to mind is a list of lists, but I was wondering if there ...
1
vote
3answers
380 views

Add behavior without changing existing class

I have a class Container, which represents wrapper around std::list. This class contains following public methods: void add(Shape *item) void next() void setBegin() Shape* curr() and protected ...
14
votes
5answers
3k views

Should a class know about its subclasses?

Should a class know about its subclasses? Should a class do something that is specific for a given subclass for instance? My instincts tells me that is a bad design, it seems like an anti-pattern of ...
1
vote
3answers
313 views

Problems with Facades and then evolution in software

I initially started a project with Facades and Polymorphism as a way to create simple extensible design following SOLID Principles. Here is a sample code: public interface IInterface { void ...
8
votes
2answers
2k views

What is the difference between self-types and trait inheritance in Scala?

When Googled, many responses for this topic come up. However, I don't feel like any of them do a good job of illustrating the difference between these two features. So I'd like to try one more time, ...
1
vote
1answer
685 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 ...
0
votes
3answers
2k views

Requirement gathering and use cases examples [closed]

I've heard a lot about requirement gathering and use cases in theory, but in practice often happens that we ask ourselves "should we include this? should this be a use case? in which language should ...
4
votes
4answers
515 views

How would you model an objects representing different phases of an entity life cycle?

I believe the scenario is common mostly in business workflows - for example: loan management the process starts with a loan application, then there's the loan offer, the 'live' loan, and maybe also ...
7
votes
4answers
642 views

Is throwing an error in unpredictable subclass-specific circumstances a violation of LSP?

Let's say I wanted to create a Java List<String> (see spec) implementation that uses a complex subsystem, such as a database or file system, for its store so that it acts as a persistent ...
2
votes
4answers
1k views

Explanation needed, for “Ask, don't tell” approach? [duplicate]

I'm taking a course on design patterns in software engineering and here I'm trying to understand the good and the bad way of design relating to "coupling" and "cohesion". I could not understand the ...
8
votes
4answers
1k views

How do we keep dependent data structures up to date?

Suppose you have a parse tree, an abstract syntax tree, and a control flow graph, each one logically derived from the one before. In principle it is easy to construct each graph given the parse tree, ...
54
votes
10answers
3k views

What is meant by, “A user shouldn't decide whether it is an Admin or not. The Privileges or Security system should.”

The example used in the question pass bare minimum data to a function touches on the best way to determine whether the user is an administrator or not. One common answer was: user.isAdmin() This ...
5
votes
3answers
526 views

How to conciliate OOAD and Database Design?

Recently I've studied object oriented analysis and design and I liked a lot about it. In every place I've read people say that the idea is to start with the minimum set of requirements and go ...
0
votes
3answers
385 views

When should method overloads be refactored?

When should code that looks like: DoThing(string foo, string bar); DoThing(string foo, string bar, int baz, bool qux); ... DoThing(string foo, string bar, int baz, bool qux, string more, string ...
0
votes
4answers
571 views

Does it make sense to generate java classes from class diagram?

As we do design & analysis before development, wouldn't be convenient to be able to generate Java classes from a class diagram? This would promote more exhaustive design and better codes, right? ...
1
vote
3answers
237 views

Law of Demeter in MVC regarding Controller-View communication

The scenario: Having a Controller that controls a view composed of complex subviews. Each one of those subviews is a separated class in a separate file. For example, one of those subviews is called ...