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

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Is the application architecture of Facebook Flux a new idea?

Facebook announced that it's using the architecture they call Flux to develop their projects. It consists of a single direction dataflow, and concepts like a Dispatcher, Stores and Actions (well ...
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2answers
131 views

At what granularity are events recorded in Event Sourcing?

I'm growing my understanding of event sourcing. My understanding is that it provides a means of recording events as they happen so that given a common beginning state and an audit log of recorded ...
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1answer
78 views

Communication between Multiple Presenters in MVP

I'm designing an application using the MVP pattern, but a few of the edge cases for the system rely on communication between multiple presenters. View 1 calls Presenter 1 which does Operation A ...
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4answers
3k views

Which design pattern is more suitable for logging?

I should log some events in a program but as far as I know it would be better to keep the logging code outside the program because it is not about the real functionality of the program. So may you ...
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0answers
18 views

Determining proximity of entities based on multiple measures

I have a database table set up like so: Table: entities name - varchar score - int category - varchar value - int value2 - int depth - float ... etc. Example: name ...
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8answers
3k views

Does MVC apply only to web

It is almost and instantaneous whenever I talk to developers about Model View Controller (MVC) they say you make a request to a url the server builds a entity (MODEL) and provides you with visual ...
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2answers
752 views

Is performance the only reason not to use SignalR (websockets) entirely in lieu of a traditional REST API?

I have used SignalR to achieve real-time messaging functionality in several of my projects. It seems to work reliably and is very easy to learn to use. The temptation, at least for me, is to abandon ...
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7answers
425 views

What is the simplest way to broadcast data from application to other applications in .Net

I want to send information from one .Net application to multiple other .Net applications. I want the applications to be loosely coupled. The number of applications receiving the information could ...
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2answers
222 views

Why use Creational patterns in Java?

How are Creational patterns useful? Most of the material I came across explains the use case to "solve common problems associated with object creation, improve flexibility". I can think of just two ...
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31 views

passing different models to view based on razor theme engine

I'm using a pattern similar to the one here to implement a Themed View Engine. Basically instead of having a View folder, I have a Theme folder and inside different themes: default, red, blue, green, ...
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1answer
70 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 ...
5
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2answers
318 views

What is a good design pattern for multi-mode software?

I will explain my question by way of example, but I'd love a general solution. I am writing a JavaScript application that needs to function differently depending on its run-time context. To handle ...
0
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1answer
79 views

How to compute data for charting?

I'm building a charting component that displays data directly from the raw data records. It should be able to filter data (subset) and then perform some rudimentry maths on the data (sum, avg, etc). ...
3
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1answer
113 views

Difference between patterns: Specification, Guarding, Conditions, Monads, Validation,

I'm currently trying to get my head around a few patterns (especially the ones mentioned in the title above) that are made to address different problems and are being used in different parts of the ...
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0answers
42 views

How to clean composition root from anything other than object construction?

I'm doing poor man's DI (manual injection) in my application. My (pseudo-) composition root looks something like this: var connectionSettings = new Settings(SqlParameters) var dataLoader = new ...
4
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2answers
967 views

How does MVC work with the principle “Tell, Don't ask”?

Procedural code gets information then makes decisions. Object-oriented code tells objects to do things. — Alec Sharp So, when a view wants to display some information that is suppose to be ...
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2answers
304 views

How do you apply Single Responsibility principle to a repository

I am trying to apply "SOLID" whenever I can and try to use common sense and avoid a pattern when I see that a pattern is creating more problems than it's trying to solve. I don't want to apply a ...
3
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3answers
231 views

Interface to enumerate over files

I'm trying to design a generic interface for enumerating over a list files. Each iteration will open a file, allow the consuming code to access the file to perform some task, and then close the file. ...
65
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10answers
7k views

Are design patterns really essential nowadays?

I was reading "Coders at Work" and have faced the fact that some of the professionals interviewed in the book are not so enthusiastic about design patterns. I think that there are 2 main reasons for ...
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0answers
30 views

What is the best way to initialize a child's reference to its parent? [duplicate]

I'm developing an object model that has lots of different parent/child classes. Each child object has a reference to its parent object. I can think of (and have tried) several ways to initialize the ...
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0answers
117 views

Callback pattern handling exceptions - Best practices in .NET 3.5

I am looking to implement the callback pattern with error handling such that error is caught and pass to the callback code with the response. Since I am using .NET 3.5, I cant use Task (TAP) pattern ...
46
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6answers
37k views

Why should I use an MVC pattern?

It seems everyone doing web applications nowadays wants to use MVC for everything. I find it hard to convince myself to use this pattern, however. I understand the general idea is to separate the ...
0
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1answer
193 views

Object in Business layer same as DTO with logic?

Let's say I have a Spring MVC project, in which I'm using DTO to get data from a database and to pass data to the UI. Let's suppose that I have a UserDTO and in my business layer I have to do ...
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2answers
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Design Pattern for Data Validation

What would be the best design pattern for this problem: I have an Object A. Object A can either be registered or deleted from the database depending on the user request. Data validation is performed ...
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1answer
114 views

Creating n tier application [closed]

I am new to design patterns. I want to learn constructing 3 tier architecture. I have searched but confused at some points. In this article ...
0
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1answer
145 views

IOC Between Presentation and Infrastructure Layer

Question: I would like to set forth dependency mapping from a *.config file from a project that has no reference to the project that contains the concrete class. Scenario: I'll be using terms from ...
89
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10answers
43k views

What is MVC, really? [closed]

As a serious programmer, how do you answer the question What is MVC? In my mind, MVC is sort of a nebulous topic — and because of that, if your audience is a learner, then you're free to ...
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4answers
834 views

Acceptable placement of the composition root using dependency injection (DI) and inversion of control (IoC) containers

I've read in several sources including Mark Seemann's 'Ploeh' blog about how the appropriate placement of the composition root of an IoC container is as close as possible to the entry point of an ...
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2answers
430 views

DTO - service layer - statelessness best practices interfering with each other

I am designing a REST API coupled with a service layer that takes DTOs as input and produces them as output. This works fine for most service calls where the DTO is used to access an underlying ...
12
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3answers
5k views

How do I set up MVP for a Winforms solution?

I have used MVP and MVC in the past, and I prefer MVP as it controls the flow of execution so much better in my opinion. I have created my infrastructure (datastore/repository classes) and use them ...
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1answer
204 views

Should I couple these classes?

I am programming in Python. I have several complicated/hard-to-understand XML files that describe the structure of an election. I am trying to write a python wrapper that makes it easy to access this ...
58
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11answers
5k views

“Everything is a Map”, am I doing this right?

I watched Stuart Sierra's talk "Thinking In Data" and took one of the ideas from it as a design principle in this game I'm making. The difference is he's working in Clojure and I'm working in ...
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2answers
136 views

Should I have an object as attribute or primitive id? [duplicate]

I am wondering which principle should I use. Here is my situation. I have a class named TravelOffer. This class looks like this: public class TravelOffer { private final long id; private ...
3
votes
3answers
490 views

Should service layer catch all dao exceptions and wrap them as service exceptions?

I have three layer Spring web app: dao, service and controllers. A controller never calls directly the dao, it does it through the service layer. Right now, most of the time if there is dao exception ...
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3answers
233 views

Implements > extends, but what about variables?

It's preferable to write programs that depend on interfaces rather than on superclasses, but what when you want a class to have certain variables? Sometimes you want a class to implement a certain ...
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0answers
162 views

Lightweight data modeling vs traditional classes [closed]

I've heard a lot of talk about using lightweight data modeling as of late. Especially in relation to the Clojure programming language. What is it and how it differs from traditional classes regarding ...
10
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4answers
2k views

In MVC, can/should basic data retrieval from the Model be done in the View?

Given the concept of 'skinny controllers, fat models' and the general acceptance that Views can directly call on Models when requiring data for output, should one consider handling the 'get and ...
0
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1answer
141 views

What should be in a PIMPL?

I am kinda trying to implement a windowing library in C++, the circumstances are forcing me to implement it all myself, that's not the point of this question however. My question is: What should be ...
2
votes
2answers
148 views

Designing an API with access tokens, how to handle GET requests?

I am building an API that will utilize access tokens so that I can track usage among various departments and for access control. My plan is to utilize the HTTP verbs appropriately - GET will retrieve ...
0
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1answer
51 views

How to save entities relations using unit of work pattern

I use Unit of work pattern to commit all new, dirty, deleted entities to the DB (using a db_mapper). Example of entities are: Student and Class So Student->registerDirty() will add this entity to ...
3
votes
1answer
83 views

Design Question - System Integration

Guidance on good application architecture / design is not in short supply however most of the examples focus on some business object, like Customer and its behaviour and persistence. There is little ...
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3answers
227 views

Pattern / methodology for representing large database records as objects

A bit of background information: We have an old database application written in Access that lets users monitor their workload, and the code is... 'procedural' might be too kind. The vast majority of ...
2
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5answers
328 views

Relative encapsulation design

Let's say I am doing a 2D application with the following design: There is the Level object that manages the world, and there are world objects which are entities inside the Level object. A world ...
1
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1answer
178 views

Pass Event between Systems in a multi-threaded Entity-Component-System

Is there a way to pass Events between Systems in a multi-threaded Entity-Component-System that realizes the benefits of saving on system resources? I've read a german article about the ...
1
vote
1answer
231 views

Designing classes the right way [closed]

I am trying to design my classes in the optimal way for the following scenario. A city has metro lines covering a number of stations.There are 4 lines represented by 4 colors.The user has to enter ...
1
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1answer
68 views

Where to perform datatype.ParseString (MVC)

Using the MVC pattern, asume a simple situation where you want to send a number (for example the number of pages in a book) with a controller to a setter. Now, the set method looks like this public ...
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3answers
244 views

Decorator Pattern: can it solve issues arising from changes to underlying code?

I understand that decorators solve the problem of needing to mix and match behaviors, but it was suggested that I could use the decorator pattern to solve issues of brittleness that might arise due to ...
2
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1answer
88 views

Is there a limitation when using the Bloch's Builder Pattern with mandatory fields?

Background I have a class TextDrawable which draws text on top of a shape. There are a number of properties that can be set while creating a TextDrawable object. Mandatory Properties: Text Shape ...
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2answers
367 views

Factory Method vs. Factory Method design pattern

I am currently studying design patterns from the book (which, although I didn't try anything else, I find excellent) Head First Design Patterns. I'm confused about two concepts: The Factory Method, ...
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68 views

Is Factory method subclass of Abstract factory in essence [duplicate]

Is it correct to say that factory method is essentially just a particular case of the abstract factory which produces the only one object not a group? I know that classic realizations assumes the ...