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

learn more… | top users | synonyms (1)

0
votes
1answer
133 views

What is the correct way to bind few classes with similar functionality?

I want to do this in the right way to learn I have a few classes which have only one method. For example: public class RedColorText { public void AddRedColorText(string text) { ...
-1
votes
3answers
358 views

Which Design Pattern Is Best Suited?

I have been studying Design Patterns and I am looking to implement them into my latest project. I am working on a Windows Service that regularly checks a database table for a new entry. Depending on ...
4
votes
4answers
248 views

Dependency Inversion & Decoupling

I'm wondering if someone might explain the last paragraph written in this example on Dependency Inversion & Decoupling. http://www.springbyexample.org/examples/core-concepts.html Following the ...
1
vote
1answer
87 views

Lookup pattern as a way of passing global references

I am looking at some legacy code in java that uses the Service Locator pattern as a way of passing global references as opposed to passing them over and over again through method arguments and I am ...
1
vote
3answers
194 views

Decorator design pattern in swift

Im reading "Head first design patterns" (here you can find exact example mentioned in book) While going through Decorator design pattern, everything was crisp and clear until i stumbled into this ...
1
vote
1answer
189 views

How would a modern website like Reddit divide up its website into Django apps? [closed]

Django uses apps to divide projects into manageable and reusable chunks. All examples in tutorials use polls or articles in unrelatable circumstances. In a modern example like Reddit (or even Amazon ...
4
votes
1answer
184 views

Designing interfaces to hardware

I am writing a library in C++ that is used by customers to interface with hardware. There are many different devices that I need to support. For the sake of simplicity, assume I have 2 Widgets, ...
1
vote
1answer
215 views

Service layer - fat service classes?

Let's say that I have a service for Job Offer entity in CRM app. Job offer is related to many many things, so there will be lot of methods on service layer to interact with above. What should be ...
1
vote
1answer
322 views

Repository pattern without entity framework?

Is it possible to implement the Repository pattern without using entity framework? I am working on a small dev team of 3 on a small scale (for now) ASP.NET MVC solution. I told my manager that I ...
3
votes
1answer
105 views

Software Design: Generating Documents Of Different Formats and Different Layouts

I am currently prototyping a piece software which must be able to generate different types of documents in different file formats. The document could be a letter, or a receipt, for example, requested ...
2
votes
1answer
70 views

Combining Patterns: Fluent Builder and Null Object Pattern

I am currently wrestling around with some GUI code where I have a table whose rows correspond to some object, let's say a Person object. When the table initializes, it fills the table with the Person ...
0
votes
1answer
295 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 ...
1
vote
1answer
179 views

Does key-value observing between model and view violate MVC?

In MVC the Controller is the go-between for the View and the Model. So the Controller should be the one that observes or receives changes from the Model and View and updates the other accordingly. I ...
3
votes
1answer
156 views

Unit testing a template class after refactoring

I am cleaning up my code by way of removing duplicates, and found two classes that were almost identical, out of 55 lines, only a single predicate in an if statement differed between them. Both ...
1
vote
1answer
77 views

Possible to refactor these methods that contain the same logical flow?

I have many methods in many repositories that have the same logical flow: Retrieve value from Cache Check value If no value, fetch from Database Update Cache Return value Is there a way to ...
2
votes
1answer
314 views

Should I use foreign keys in my database if I use laravel?

I'm creating a website with Laravel for the first time. I checked relationships documentation today and it seems that Laravel just uses simple SQL queries. class User extends Eloquent { public ...
2
votes
0answers
107 views

Ways to do callback, when and where

I've recently started to do some more complicated programming with network-related work on iOS with Swift. This introduced a lot of asynchronous code not only in networking but also some exchange of ...
0
votes
0answers
65 views

Mailbox Pattern with Variable Arguments in C++

In a game I'm developing, the GUI thread is catching user actions, and the simulation thread is responsible of handling and responding to them. To minimize complexity and delay, I predefined all ...
0
votes
2answers
145 views

Flexible and easy to use settings class

I am thinking about a way to create a flexible "settings class" in C#. The question is: How to provide a confortable way to provide default values to the settings. I want the programmer to access the ...
0
votes
3answers
118 views

where should put showSchedule method in school system

In my school management system I have this partial class diagram: 1- In one use case student want to see his schedule of classes in week. this is what i suppose to do: get student object from ...
6
votes
3answers
381 views

Design solution for communicating between multiple layers

We are developing a framework that has several layers and would be deployed in a multi-threaded environment. Each layer may have its own input/output data type. The top layer takes the input, performs ...
2
votes
3answers
192 views

Design a Queuing Solution with Clustering and Multiple Consumers

It is a Design Problem which I am listing out here. I have different set of business operations that are carried out for different business entities. Operations: Operation A Operation B Operation ...
1
vote
2answers
440 views

many to many relation in database schema and oop class diagram

I have Student and Group entities. Student can have many groups and Group can have many students too. so in database I should have middle class and change many-to-many relation to one-to-many and ...
0
votes
2answers
167 views

Pattern for caching DAOs: strategy or decorator?

I'm building a php system with the Services/DAOs/Domain Models pattern, and now is the time to implement a caching system for the DAOs. Would you use a decorator pattern, or maybe the strategy ...
0
votes
1answer
248 views

How could I avoid singletons in this case? [duplicate]

Using Dart in the client part of a web app where I have an application manager that contains a List of application instances and references to services that are used by each application as in the ...
3
votes
1answer
217 views

Template pattern with varying input type in overridden method

I am trying to use template pattern to define a generic algorithm in java. But the method that needs to be overridden, takes an object as input. This object will vary depending on the concrete ...
0
votes
2answers
237 views

What design pattern for changing interface?

Sorry guys, I should have clarified the fact that the modified method is abstract in Father. Then if the method signature changes, all its implementations in SonX shall also change(at least the ...
1
vote
1answer
54 views

Is having a parent controller to manage a set of tabbed sections an anti-pattern for an angular application?

A lot of times, I have long forms that I divide into multiple tabbed sections. Each section is managed by it's own controller and there is a parent controller that manages the whole view. I use ...
2
votes
1answer
170 views

Why use a enum to create the singleton pattern [duplicate]

Why would you use an enum to create a singleton pattern? To what purpose would it serve over a conventional singleton pattern? I have seen the above used. The code uses an enum to create this pattern ...
2
votes
1answer
127 views

Applying initialization-on-demand holder idiom at variable level rather than class

I was looking for the idiomatic way to implement thread-safe lazy initialization for a configuration collection retrieved from the DB inside a Spring bean. I decided to adapt the ...
0
votes
1answer
162 views

Is this a pattern? If so, which one? (Contexts, Requests and Responses) [closed]

In most of my code nowadays, I adapted to an approach which I think I read in the context of "Clean Code". It was some years ago and I cannot find the source again, so I would like to know what the ...
0
votes
2answers
224 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. ...
3
votes
1answer
97 views

How should I represent composeable, associative computations to be repeatedly applied to units of data?

Spoiler My question is the following: Are there any design patterns for representing chainable functions that are for the problem described below? High-Level Decription of the Process I'm ...
3
votes
3answers
175 views

Is it misleading to label code as a particular design pattern if it only loosely fits the definition?

Background: I have a rough, but working understanding of ~15 design patterns. It's been my experience using design patterns in my own projects that the resulting implementations usually end up as some ...
1
vote
1answer
100 views

Should make concrete factories in the same count of families of objects or according to stages in my problem?

I am programming a game. In this game I have 3 stages. In the first stage, there is a static goal and a static shooter in the game. In the second stage, the goal will move. And in the third one both ...
8
votes
2answers
619 views

How should I handle logger failures?

In several of our company's applications, we use a custom logger. It's fairly robust, though we may replace it with something like NLog in the future. One of the logger's tasks is to log any ...
2
votes
2answers
164 views

Design pattern for composition workflows

Please bear with me as I find this tricky to articulate exactly what I am after (probably not a good sign..). I have several services set up which can be combined in a particular order to create ...
2
votes
1answer
202 views

When do I reuse or create a new Builder

I've implemented a Builder Pattern in a project I'm working. I'm using this design pattern to created Fields and Components (div, tables, panel (boostrap)). So I have a Director Component class. It ...
0
votes
1answer
99 views

Can JUnit be used to test this project?

I currently have an interesting situation occurring with my code, and after hacking away at what turned out to be a dead end for the last two weeks, I'm here asking those smarter than I to educate me ...
2
votes
1answer
123 views

Is Singleton enough for a EMailUtil or there is any better implementation? [duplicate]

I am developing an application, where I have to send lots of emails for user account creations, validation, invites etc. I have implemented a static class EMailUtil which has different methods like ...
0
votes
4answers
449 views

Is it bad to use DI to inject constructor parameters at runtime?

These are two classes, the first one I inject an instance of type IEngine while the second one I inject owner's name, tickets and engine. Version 1: public class Car { public Car(IEngine ...
0
votes
1answer
75 views

How to organize conversion logic for strategy pattern?

I have a Color class. It has a property model which is a class that implements ColorModel interface, this property could be a RGB, Hex or HSL classes which implementing ColorModel interface. // ...
0
votes
1answer
189 views

Design Pattern Question

I'm relatively new to the world of OOP, and having read through some design patterns, I'm struggling with that 'aha' moment. I have the following objects Event (Single event, with start time and end ...
1
vote
1answer
88 views

Which design pattern restricts limits class creation to certain classes

I have a fairly simple application that is divided into two classes. The first class is the Manager class and the second class is the employee class. These are simple classes and do not inherit from ...
4
votes
1answer
121 views

Extend, wrap, or both to add generics to a class that should have had them?

So I'm using a C# framework that has a great example of where generics would be useful, except they weren't used. For simplicity's sake, we will say it was a list (I know C# has its own list), but ...
0
votes
3answers
142 views

Various methods manipulating same member variable versus each takes inputs and provides output [closed]

As software design paradigm which is better? to let various methods manipulate a member variable, or define each method or function to take some inputs and provide some outputs? For example class ...
-1
votes
1answer
126 views

Front-end or Back-end Implementation of API? [closed]

Lets say I want to implement an API from an external website, for example like Dribbble or Last.fm. I'm fairly new to this new generation of front-end MVC's (angular, etc), and most example's I've ...
0
votes
1answer
116 views

Should Form Object be considered a DTO?

I got this from one of online video tutorials. Author binds form data not to Value Object directly, but first to validable DTO, and THEN to Value Object, using service. Example: package ...
2
votes
1answer
110 views

In a Table Data Gateway, where do I put queries that use joins

The book Pattern of Enterprise Application Architecture has the following description over the Table Data Gateway pattern: “A Table Data Gateway holds all the SQL for accessing a single table or ...
3
votes
2answers
136 views

What preconditions should be checked while adding/removing a listener?

Imagine the following interface: interface Service { addListener(Listener l) removeListener(Listener l) } Should I check for null values while add/remove? Is it a good idea on remove to ...