A design pattern is a general reusable solution to a commonly occurring problem in software design.

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3answers
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How to design a solution that needs dynamism using Visitor Design pattern [EDIT]

I have below code/classes/interfaces: An Interface: public interface Animal<A extends Animal<A>>{ void fight(A otherAnimal); } 2.Tiger class which is implementing Animal ...
3
votes
1answer
237 views

Pattern to use to relate multiple data sources to different user data widgets

I have an client x server intranet application the basically gets data from the server, format it and send that data to the client for display. At the server we are using ASP.NET C# running on IIS ...
28
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11answers
3k views

Constructor-only subclasses: Is this an anti-pattern?

I was having a discussion with a co-worker, and we ended up having conflicting intuitions about the purpose of subclassing. My intuition is that if a primary function of a subclass is to express a ...
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1answer
26 views

Methods accounting for all input to method

This is more of a conceptual question. Let's say that you had the following enum public enum FooEnum { ALPHA, BETA, GAMMA, DELTA; } And let's say you have the following method: ...
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0answers
37 views

Differences between books in the principles of computer programming, and in programming languages [on hold]

What are differences between books in the principles of computer programming, and in programming languages (whose purposes are not for specific languages)? I am often confused by them. I heard ...
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0answers
28 views

What design pattern is used in this delegating scenario?

I am currently having to bend some framework API to fit my usecase. The framework provides generic interfaces such as public interface Processor<T> { T process(T t); } with various ...
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0answers
12 views

Design of actions handlers requiring some order

I have a REST application where 'actions' can be executed to perform anything in the system. For example: user.save, user.get, etc... I also have pre and post execution 'handlers'. For example a ...
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4answers
194 views

2 methods that are 75% the same?

I have code that violates the DRY principle and I would like to consolidate 2 methods as much as I can, but the problem I am facing is that they have some differences, I would say they are about 75% ...
2
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0answers
70 views

What kind of programming pattern is appropriate for programming an algorithm with rules and exceptions?

I'm interested in coming up with an algorithm to solve a guessing game. The player is attempting to guess a sequence of 4 unique numbers from 1 to 9. After a guess, they are told how many numbers of ...
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1answer
41 views

Ask advice on the improvement of my code [on hold]

My original part of the code for a matrix class is like this: Matrix::Matrix(const Matrix& mat) { int i; r = mat.r; c = mat.c; d = new double [r*c]; double* p = d; double* pm = ...
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2answers
101 views

Sharing code logic between controllers, through the Model layer?

As I originally conceived my Model layer, it was only supposed to hold data and no code. I receive DTOs from web-services, they are mapped into my Model objects. Those model objects usually end up ...
2
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1answer
170 views

Reducing the complexity of over-designed code

I have just started working at a company where I have inherited a C# codebase from a previous developer. I know programming well, have an engineering degree + an (unfinished, several year long) PhD ...
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2answers
373 views

Is factory pattern a right pattern for the situation described here?

Is factory pattern a right pattern when we want to consolidate the related objects? Problem - In the Set-top box, I have a user-io, basically the interface to control the settop box - The user-io can ...
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1answer
108 views

Problems with OO design for application with pluggable components

I'm trying to refactor an ugly code and make it easly extendable in the future. The application should be nothing else but a series of components that have input(s) and output(s). The components ...
2
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2answers
121 views

Is there a name for a dictionary that returns the key as the value by default? [on hold]

A dictionary that returns the key as the value by default can be used in cases where exceptions or translation is needed. E.g. One could do i18n = SpecialDict() if spanish: i18n["Hello"] = ...
2
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0answers
60 views

Scheme/Design Pattern for allowing a certain outside class to set properties

I came up with a solution (in PHP) to a problem and am wondering if it is a named Design Pattern, and if it is good practice. I have a collection class and an item class. The collection class is the ...
2
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1answer
185 views

What is SteppedPattern?

I read this article on Jon Skeet's blog where he delves into the topic of performance on object pooling & thread safety. In the article he makes a reference to SteppedPattern: Most of our ...
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1answer
40 views

What is the better way of getting different outputs for two very simmilar related workflows

I have a very concrete scenario but I think it would be quite frequent. I'm trying to come up with a solution that it's "better" by better meaning more scalable, reusable and not smelly. I'm working ...
20
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12answers
4k views

What design patterns are the worst or most narrowly defined? [closed]

For every programming project, managers with past programming experience try to shine when they recommend some design patterns for your project. I like design patterns when they make sense or if you ...
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0answers
25 views

Find software architecture design level patterns [closed]

where can I find software architecture design level reusable components, I mean -architecture patterns repository -user interface architecture patterns repository? Thank you.
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1answer
217 views

Methods for structuring JavaScript SDKs

I've built a REST API and have been using Backbone models throughout a couple different applications to communicate to it. I would really like to build a single JS SDK that can be used in any ...
0
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1answer
66 views

Is this a good service locator, and is this service locator pattern(?) OK?

I'm working in Zend framework 1 and was using Zend_Registry to store objects so that I could replace them in my controllers while unit testing: $auth = Zend_Registry::get('Auth'); // set in ...
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2answers
71 views

Design Pattern for Removing Default Listeners

We have a standard GUI control with a bunch of default listeners like that: class OurControl extends Control { OurControl() { addMouseWheelListener(new DefaultMouseWheelListener()); ...
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1answer
44 views

Pattern for separating UI code from logic in Wicket

I'm using Apache Wicket for developing web apps, I have developed a few for the last year and it has been great; today I was looking at a few pages and most of them look like this: public class ...
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1answer
82 views

Consuming a rest API that exposes nested objects

I have a series of nested objects, exposed over a REST API, like so: class Categories { int id; string name; List<Subcategories> subcategories; } class Subcategories { ...
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2answers
97 views

Design pattern for canceling a long task in a sub-thread

Suppose we have a file copy program. It has two threads, a UI thread displaying the progress of the copy operation and a work thread copying the file. The UI has a button for canceling the process. ...
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1answer
121 views

Better pattern than large if/else if/else for checking conditionals [duplicate]

I've got a fairly large set of booleans I'm checking in javascript, and then using them to alter the state of a layout in my React app. The whole thing is unwieldy, difficult to read, inelegant, and ...
16
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1answer
691 views

When to use prototypical programming in JavaScript

I've spent a good bit of time developing simple widgets for projects in the following way: var project = project || {}; (function() { project.elements = { prop1: val1, prop2: val2 } ...
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0answers
62 views

Design pattern for large data handling and transport in Java [closed]

Need to find best design pattern to implement the following: There's a queue of multiple Object A. Each Object A needs to be updated/modified by multiple other Objects, let's say Object B and C. ...
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0answers
32 views

Strategies for maintaining backwards compatibility when persisting objects to XML [duplicate]

I am using XStream to persist Java objects to files. This works fine and so far I have had no problems. However, in the course of development, the objects have changed. Some new properties have been ...
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73 views

Choosing the right design pattern/architecture for a scenario

I have a situation, in which I would like your opinion about the best approach that I should take. Let's consider 10 classes (obj001, obj002 etc.) all which represent some business entities, and are ...
3
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3answers
279 views

Best approach for tracking dependent state

Let's pretend I work on a project tracking application. The application is a database backed, server hosted, web application. In this application there are Projects which have many Activities which ...
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1answer
90 views

Software to access GSM Terminal, sending and receiving AT commands, validating results

I am currently implementing a software that uses a GSM terminal to perform actions. Actions can be sending messages, checking balance, receiving status report messages, setting the pin, ... The ...
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1answer
114 views

Why use the Singleton pattern over class functions and fields? [duplicate]

I'm going to start by saying that I understand that programming in mostly class functions and variables can be harmful to object-orientation, and that most of the time an instance is preferred. I'll ...
0
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1answer
193 views

Where and how to reference composite MVP components?

I am learning about the MVP (Model-View-Presenter) Passive View flavour of MVC. I intend to expose events from view interfaces rather than using the observer pattern to remove explicit coupling with ...
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1answer
81 views

How can I decouple query and context in a “query object” scenario?

I'm using a query object pattern (similar to this) to manage disparate queries while avoiding bloaded facades/repositories. A query object takes a number of constructor parameters, representing query ...
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0answers
36 views

Injecting data processing logic into class

I want find more elegant and appreciate way to inject processors into CommandProcessorDispatcher class. Or it can be another one solution (the goal is separate each command processing logic to ...
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4answers
187 views

What is the efficient way to eliminate duplication? Design patterns?

I have a helper class which has a method that perform some checks against a field in a model. I have two models, ModelA and ModelB, they have some similarities but not all. One of them is they both ...
0
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1answer
209 views

DRYest approach to “rendering” drag-and-drop template editor results to HTML

I'm in the process of designing a browser based system that will allow non-technical users to quickly and easily change the content of certain parts of a web page via a WYSIWYG template-based ...
0
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1answer
127 views

Dealing with several custom getters

I have a data structure with data units containing different types of data. I've wrapped the data in "Field" objects so that each field is able to independently parse user input in a desired way. ...
26
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8answers
6k views

Are utility classes with nothing but static members an anti-pattern in C++?

The question Where should I put functions that are not related to a class has sparked some debate over whether it makes sense in C++ to combine utility functions in a class or just have them exist as ...
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2answers
120 views

Which design (pattern) would be suitable to abstract logging platforms?

I need to create a simple system to abstract logging platforms. The idea is that I'd like to be able to exchange or activate a logging platform (nlog, log4net, enterprise library) via some ...
0
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0answers
45 views

Possible way to make java class builder more abstract by using interface required keys

I'm looking for a more abstract pattern for builders that handles required fields without the need of writing a validator that checks if all requried fields are set. I like this builder. But is ...
0
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1answer
430 views

Interface questions for using Command Pattern and Dependency Injection together

I have many projects that have essentially the same high level requirement: test all hardware on a device. Each device can have a different communication protocol, requires different test equipment to ...
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1answer
98 views

Design pattern where decorated object may ask for things like “status updates” from the decorator to perform it's role?

Here's an situation that has haunted one of my open-source projects for quite some time. Imagine if you could represent every front-end input form with a single backend object? An object that ...
2
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0answers
228 views

Which patterns/architecture to apply for “Import Data, Process Data, Export Result”

I was wondering which architecture/patterns to choose for the following problem divided into three steps: Import TestScript Description from File (e.g. .xls, .txt) Process Described TestScript ...
1
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3answers
279 views

Best OOP pattern to use for creating a commandline SQL API for a proprietary json based company datastore

We need to create a SQL commandline tool for querying a proprietary json based datastore. I'll be using java. Any suggestions on the primary OOP design pattern I should use for building this API? ...
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0answers
40 views

Design pattern for multiple companies in AngularJS

We are on the verge of launching v3 of our in-house product. v2 was written completely in AngularJS and V3 will be the same, but written completely in Typescript. We have a few customers that have ...
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1answer
171 views

Should I use Strategy Pattern for this task?

I'm setting up a data validator that will iterate through the rows of a spreadsheet, and for each column, perform a validation check. I was thinking that this might be an appropriate task for the ...
9
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3answers
745 views

What is a good design pattern for generating an Excel (xlsx) file in code?

See my Update at the bottom for more. I occasionally have projects where I have to output some data as an Excel file (xlsx format). The process is usually: User clicks some buttons in my ...