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

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1answer
157 views

C++11 freeRTOS questions about queue usage and object design

Background I'm writing C++ firmware with freertos to penplottingrobot. It's a makeblock XYplotter and the firmware is connecting to mDraw software for command instructions thru USB drivers. MDraw ...
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2answers
395 views

Is it bad practice when an Object has to be aware of another Object

I was reading this page and came across this sentence in the accepted answer: I don't like A directly knowing about B. But that's a DIP thing not a POJO thing. What if you can't abstract out B ...
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6answers
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continuous integration for scientific software

I'm no software engineer. I'm a phd student in the field of geoscience. Almost two years ago I started programming a scientific software. I never used continuous integration (CI), mainly because at ...
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3answers
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OOP and class that inherit from many classes

In OOP, is it possible to have a class that inherits from multiple other classes? And if yes, how is this situation called? For example, suppose I have the following classes: Eye Nose Mouth Eyebrow ...
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1answer
66 views

Should I group all sound file definitions together? Or define some of them locally, if possible?

For example, suppose my application have some sound files, now I define all sound file references in a single class: public class SoundHelper{ public static Sound buttonSound=new Sound("(some url)...
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2answers
181 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 "quick" release. ...
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1answer
46 views

Accessing an object accross different view functions in Flask

I am experimenting with an web app for searching and buying bus tickets. I came up with a few objects like RequestedRoute, Passenger, and Ticket: I have some Flask view functions as well. The home ...
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0answers
36 views

Splitting aggregate leads to inconsistencies in data

What I'm going for is something like GNUCash or any type of personal finance tracking software that looks similar to this: That is the main page listing all your accounts; then when you click an ...
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1answer
149 views

Why is using an internal attribute to filter objects considered OK, but when I use a map to filter based on attributes, it's considered a code smell?

A long time ago I asked about using an enum to essentially use as a poor version of instanceof to make decisions about an object. As stated in this answer: When your weapon types enum just mirrors ...
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1answer
125 views

Have an object communicate with another object

I asked similar question earlier this morning, and for whatever reason, I'm not getting a complete answer to my question. I'll ask it a different way. I was attempting to understand Eric Lippert's ...
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2answers
107 views

Using a Collection with Attributes to Check and Make Decisions

I was reading on this SESE page about using a variable to indicate the object type, more specifically, an enum. The accepted answer states: When your weapon types enum just mirrors the class ...
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4answers
117 views

High class cohesion violates ubiquitous domain language

Originally posted at CodeReview, but it was brought up that this would be better posted here. The other question has been deleted. Creating some personal finance software, but running into an ...
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3answers
253 views

Why is the Command desing pattern useful for game AI?

I'm trying to learn the Command design pattern and apply it to the game I'm working on. First I read about the general implementation, and I feel like I understand it pretty well. Now I want to know ...
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1answer
470 views

Why do we imlpement the Command design pattern like this?

I trying to learn the Command design pattern, I already know how it works and where it is used, but I'm a little bit confused about the implementation. So I know we need to set the context by ...
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2answers
86 views

Appropriate design for restoration of previous states

This is a very common feature in software, and I am sure there is a whole deal written about it, but I really don't know what the technical term is, so here I am: I am talking about giving your ...
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0answers
228 views

Separate business logic from ORM models in SQLAlchemy

I have a Flask application with tens of complex models, almost all of them related to each other. A simple pseudo-schema of some of them: +----------------+ | FoodGroup | +-------+--------+ ...
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2answers
103 views

Performing serial communication in constructor to initialize an object

I have a class UnitInfo which represents a collection of unit information with methods to get the unit information in a structured way, such as a specific encoding, etc. This unit info consists of ...
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0answers
78 views

Expected behavior from client when thinking about design patterns?

I'm confused about the behavior I should expect from a client when thinking about design patterns. To be more precise, I'm reading the Head First Design Patterns book, and on the difference between ...
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2answers
81 views

Is it a good idea to let database surrogate key values spill out into other aspects of code (HTML, Controllers, Model, Repository layer)?

Is it acceptable to use id in HTML forms and subsequent code processing (controller, view, model, repository layers)? For example I need to show something like this on a web page: Select Motor ...
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1answer
181 views

Is this a 'proper' use of a trait in PHP?

In Laravel 5.6 an Illuminate\Database\Eloquent\Relations\BelongsTo relation was given the ability to support default models. This allows a model that will be returned if the relationship is empty. ...
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1answer
63 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 ...
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0answers
70 views

Hierarchy of models while designing a client for a RESTful service

I am trying to write a client for a restful service. I am confused in designing the models. Below are the details: I have a Model named UnicastMessageRequest, it's definition is like this: ...
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2answers
202 views

Verifying Parameters in Constructor or Service

I was reading on this SO page about when to check parameters when constructing an object. The accepted answer suggests throwing the exception from the constructor so that an invalid object cannot be ...
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2answers
2k views

How is bad declare public static variable and use it in other classes?

GOAL: to have a main class which has some global variables which need to be modified by other classes. I have a class with a structure like below public class ClassName { public static ...
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4answers
601 views

Proper way to name a class which has just methods and not fields

GOAL: naming a class which has the responsibility to save data in Android database. The class structure is like this ClassName { public void saveSync(...){ /* implementation*/ } public ...
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2answers
103 views

How would you design the abstraction/class(es)/component(s) of a third-party service/api used in your application?

Lets say you were designing a Twitter client for people with people could see tweets and post tweets? How would you design the twitter api abstraction? Many of the api wrappers I've seen feature an ...
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1answer
137 views

Repository that performs API calls internally - DDD

Please note: although my question relates to DDD, I am also interested in this from an architectural and OO design perspective. This question may also be a simple case of CQRS and/or interface ...
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1answer
147 views

OOP Encapsulation Philosophy

Is it fair to say that it is good practice to default everything to private up when defining a class? For example, for my public interface I would set my class something like this: class foo { ...
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1answer
97 views

What to do if some parameters become constants inside a particular class

I'm sure there's some programming paradigm to cover this case, but I can't find the correct wording for it, and therefore my Google-fu is worthless. I have a class called SimpleWorld that has methods,...
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1answer
94 views

Should I “Connect->To controller A”, or “To controller A->Connect”?

For example, suppose I have a shopping app, which has a user info page to show user info: class UserInfoController{ toPurchaseRecord(){ } } and a purchase record page to show purchase record,...
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2answers
146 views

Design Pattern to extract arbitrary field from arbitrary file format

Lets say I have multiple file types: .json, .csv ... etc These file types come in different formats: Second json structure Extra column added to csv etc. I need to extract fields from these files;...
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4answers
866 views

struct with nonsensical default value

In my system I frequently operate with airport codes ("YYZ", "LAX", "SFO", etc.), they are always in the exact same format (3 letter, represented as uppercase). The system typically deals with 25-50 ...
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2answers
170 views

Strategy/domain object responsibilities

Assume we are in the world of car rental application :) Let's say that I have 3 types of cars with 2 categories of price: Car type Price category ------------------------------ Sport ...
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3answers
515 views

What is the name of this pattern (if any)?

There's a sort of pattern that I've sort of stumbled myself into "discovering" that seems extremely useful, but I've never seen it described before. It's sort of a way of achieving inheritance through ...
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4answers
283 views

Passing around large value objects vs converting to smaller value objects

Let's say I have a project that needs to do the following: Multiple calls to read from the database where each call is a different query and returns back a value object (just has getters/setters). ...
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1answer
58 views

Using a class as an attribute in another class or just one value?

I have a PHP script which has a group class and a component class. Each group consists of several components. My group has attributes groupName, groupId and componentList. My component has a ...
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5answers
167 views

Is a point drawn on a canvas considered an entity in domain driven design?

I'm reading on DDD and came across this excerpt: Let’s consider a drawing application. The user is presented a canvas and he can draw any points and lines of any thickness, style and color. It is ...
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1answer
51 views

Creating objects from a class/classes with different fixed values which can be easily expandable by a user

I am creating a program, and I would like to know the best practice for creating a class which defines different fuel types For instance, I have the following class that I have written in python: ...
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3answers
141 views

Process an undefined number of class states

Let's say I have an entity Foo. That entity could have a 5 states: A, B, C, D, E(in real application number of statuses can be larger). I store that entity in a database and map it to class. Every day ...
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2answers
369 views

Difficulty making this class open-closed

Here is my problem: I want to read input from different HID devices such as a gamepad, racing well, joystick, etc. Pretty much any game controller. The issue is that they all have different inputs. ...
2
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1answer
92 views

Configurable sorting strategies

I need to be able to sort an object by multiple conditions, and these sorts need to be configurable from the application.properties file (as in it should be possible to specify in the file the sorts ...
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3answers
101 views

POLA, Constructor and Getters

As a followup to this question and one I asked a while ago, suppose if I had an Author class structured like this: class Book { private String title; private Set<Author> authorsSet; ...
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3answers
388 views

Is calling .sort() in the constructor a violation of the guideline that a constructor shouldn't do work?

Suppose I have the following List to hold a list of fruits. Example: def fruits = ["Apple", "Orange", "Grapes"] def fruitsBowl = ["Apple", "Grapes", "Orange"] // Will print false println(fruits....
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2answers
70 views

Factories and event binding

Factories are used to create objects. I was wondering if it's against the purpose of a factory, if I would bind couple of objects together in the factory. Let me illustrate this with an example. Let'...
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3answers
133 views

How to untangle a data class where annotations from different frameworks mix?

The framework mix problem I'm using two frameworks -- PingIdentity's SCIM 2 SDK and Spring LDAP -- to deserialise a SCIM resource (i.e. JSON) to a Java object then write it to an LDAP directory, and ...
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2answers
497 views

Require_once in class files

I have a big system of classes and objects which rely on each other in order to function. Should I put all of the require_once() calls for dependencies at the top of each class file? ie: <?php ...
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1answer
55 views

How to model parent/child composite when the child is related to another class

I don't know which is the correct way to model this requirement in OOD: A device has many properties, each property has exactly one device parent. There are a set of procedures and a specific ...
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1answer
75 views

Would you implement an interface to connect to a database?

I found in a book (Learning PHP Design Patterns, Chapter 2, page 25) a text explaining the importance of interfaces in OOP design. The author ended up by giving this example: <?php interface ...
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1answer
80 views

Auto-Initializable Objects Pattern

I'm working on a system where we consistently apply "patterns" or approaches such as Dependency Injection. I'd rather not expose the current underlying technology as not to get biased solutions, ...
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1answer
803 views

Architecture / Design Pattern for Login Signup

I have a multi-seller ecommerce platform, derived out of Opencart 2.3. We changed quite a bit of the core code of the Opencart to add our own customizations, including features such as Seller ...