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

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Why do code-bases in n-tier development have an equal amount of, if not more, JavaScript code now?

I've been doing web programming for a long time now, and somewhere, I lost track of why we are doing what we are doing today (or how did we come to do things this way)? I started out with basic ASP ...
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1answer
224 views

How do you keep control in a large software project? [duplicate]

I've a large-ish software project that I'm the sole developer for (~80KLOCS and counting - I know there are much larger projects out there, but it's an order of magnitude larger than I've ever had to ...
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1answer
56 views

Duplicate method in spring services, how to refactor?

ServiceOne.java private void doStuff(){} ServiceTwo.java private void doStuff() Where to put common code ? Shall I create a new service, but then what interface will it implement ? Or shall I ...
4
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1answer
142 views

Designing a better performing total permissions setup for multiple permission levels

We've got a global system that we are attempting to solve a permissions issue around. Currently, our system serves a number of different applications out to our clients and each client has their own ...
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43 views

Choosing a pattern for domain logic on top of ORM model

I am using Python and ORM, particular SQLAlchmey. I have an ORM model which implements data mapper pattern. The model has a field state, which can take one of several states, let's say NEW, CANCELLED, ...
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0answers
169 views

C# structure needed for dynamic behaviour

I am using Unity to build a visualisation of a serious game. I am using the C# programming language. My problem is that I receive data from a JSON and I parse it and I end up with a list of different ...
1
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1answer
158 views

Program Architecture: How to manage objects that are interdependent

Consider the following case, image I making a simple chat program; I want it to be extensible such that it would be fair easy to add add different scripting and user interfaces. I want the core ...
3
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2answers
191 views

How and Why should class modifiers enforce or prevent inheritance and the ability to override

This isn't really related to anything I am working on currently, its more of a question I really couldn't find an answer for. Class modifiers like MustInherit or NotOverridable to me, seem like they ...
0
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2answers
376 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 ...
2
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1answer
225 views

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 ...
0
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1answer
124 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 ...
0
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0answers
19 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 ...
0
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1answer
253 views

Good design pattern for linq to sql

I currently have a linq to sql project that was used for one project and not much work was put into it, only the generated context and entities were used. Since then the project has started to become ...
3
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2answers
1k 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 ...
0
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0answers
35 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, ...
1
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4answers
442 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 ...
1
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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 ...
5
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2answers
325 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
81 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). ...
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0answers
124 views

Should you register other services in ViewModelLocator in MVVM light?

I'm new to MVVM Light and SimpleIoC. My question is, should all the registration of view models and other services be done in the ViewModelLocator class? Or should ViewModelLocator be used only for ...
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0answers
43 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 ...
3
votes
2answers
338 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 ...
14
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4answers
629 views

Proper Model-View-_____ design

I've been reading up about Model View Controller, Model View Presenter, Model View ViewModel, and so on, and generally, the underlying concept seems pretty simple to understand: keep the pretty ...
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0answers
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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 ...
-4
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1answer
121 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
166 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 ...
0
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1answer
260 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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7answers
494 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 ...
3
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3answers
235 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. ...
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0answers
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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 ...
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2answers
218 views

How does the consumer-producer solution work?

I'm only a beginner, and my book doesn't cover this subject. I have researched my problem and found that an implementation of the consumer-producer pattern is the ideal solution, and have Googled it, ...
1
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1answer
205 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 ...
3
votes
3answers
691 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
242 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 ...
0
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2answers
137 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 ...
4
votes
2answers
151 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 ...
0
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1answer
142 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
165 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
54 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
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0answers
166 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 ...
3
votes
1answer
88 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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0answers
78 views

Environment that enables variable constraint checking and creation

Currently I'm working on a system that enables users to add Tag's to available TagTypes on specific pages. For instance, we would have a TagType called "Installer" and the user wants his name ...
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 ...
1
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1answer
240 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
vote
3answers
248 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
votes
1answer
91 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 ...
1
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3answers
281 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? ...
2
votes
1answer
104 views

Pattern to gain abstraction over assembly with no abstraction

I'm interacting with a large code base (in a single assembly) written by another department (let's call it BusinessAssembly). Precious few of the objects we need to use in that assembly use ...
2
votes
3answers
169 views

Disallow non-local storage of an object

I need to write a class in C++ that acquires a hardware resource and releases it again when it is destroyed. Basically that can be done in the constructor and destructor of the class. The difficulty ...
3
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2answers
203 views

IoC as service locator

I have been wondering for quite some time on some issues while using dependency injection: In a layered application, I normally inject repositories into the application service using constructor ...