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

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How to show someone of the power of model-view-controller design pattern?

I've been working with a friend on a project that we've taken over, and I've realized that we have a big problem implementing the model-view-controller design pattern due to the way that the project ...
-1
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0answers
18 views

I should expose Cursor object to the view object to use it? [on hold]

I developed from the Web to Android Development is doing a App, the need to use SQLite and AdapterView. I wanted to write a DAO class to do all the work associated with the database query and populate ...
0
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1answer
624 views

What pattern to use for this 'constructor'? Decorator vs Factory?

I'm developing a program to generate LARP characters in java and I've hit a snag. Initially I had planned to use a decorator to iterate through the potential 'roles' (effectively classes), and then ...
0
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2answers
43 views

How to maintain atomicity with a service like pattern

Imagine a route in an MVC web project which handles editing a user of your product. You can do things like change their name, their email, their group, their roles and so forth. This data is put in a ...
0
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1answer
54 views

How do you name the Visitor implementation? [on hold]

I was reading about Visitor pattern and was a little wondering about naming of the methods. Assume we have the implementation of the pattern as follows: public interface Entity{ public void ...
7
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3answers
4k views

Is the Entity Component System architecture object oriented by definition?

Is the Entity Component System architecture object oriented, by definition? It seems more procedural or functional to me. My opinion is that it doesn't prevent you from implementing it in an OO ...
2
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1answer
100 views

Builder design patterns: passing parameters from client to the builder

Does the builder design pattern allow passing parameters? If yes, what is right way to achieve it? Overview The builder pattern is about hiding the details of object constructon, it places two ...
0
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1answer
74 views

DI container with multiple instances of same object

I'm looking for idea to make a DI container that can store multiple instances of the same object. Usually, a DI container should store either a single instance of the object, or create new object each ...
3
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3answers
320 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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0answers
43 views

Partially Fulfilled Specification Pattern

We have a model (IPayableModel) with a boolean property indicating that a user may or may not pay for the item. A set of specifications defining criteria that would disqualify the model from payment ...
2
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3answers
91 views

Architecture: Are form default values considered business logic and where should the logic to calculate them be placed?

An example of default form values on a search form might be: Start Date - Today End Date - The last day of the next month Obviously, these are fairly simple examples, but default values can get a ...
0
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1answer
239 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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0answers
82 views

How to to log clicks for a Pay-Per-Click software?

Let say you have a Website with advertising, and each time a user clicks on it, you want to charge an advertiser the amount he bids (basically, a pay-per-click system, like Adswords, with a different ...
0
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1answer
135 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 ...
0
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2answers
165 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 ...
0
votes
1answer
182 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. ...
0
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1answer
259 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
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1answer
167 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 ...
0
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1answer
493 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 ...
0
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0answers
57 views

When should i sync my data from parse.com to my android app [on hold]

I'm making an android application whith parse.com. Here is the situation : I have an offline part on my android app and i'm using LDS (LocalData Storage) to stock my data and send them to parse.com. ...
5
votes
1answer
95 views

Role-based REST API?

I'm building a REST API for which several users with different roles will have access to the resources it contains. To keep the scope simple let's take the "student/teacher/class" domain: GET ...
1
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1answer
205 views

mySQL / PHP design pattern - one function multiple queries

So here's the gist of it. I'm looking for a design pattern where I can have one function, say queryHandler that gets the query and the parameters from a number of different functions and returns the ...
0
votes
1answer
87 views

Design Pattern for Filtering [closed]

I have a requirement where I get a list of objects say List. Now I have filter Criteria which I need to apply to filter out the objects in the list. Currently I am thinking of using chain of ...
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3answers
261 views

PHP - Repository matrix pattern?

I'm trying really hard to refactor some of my legacy code in the project using best practices and design patterns + DDD so I'd love some feedback on an issue I'm currently having. Let's assume that I ...
0
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2answers
58 views

Client-Server Application Object with child Objects

Actually I'm going to build an Client Server Application, at the Login I recive the User Object from the Server. An user has a List of tasks, but I don't want to load them at the Login. So what would ...
14
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4answers
3k views

Does anyone have a specific example of using the Flyweight Pattern?

I have been studying design patterns and came accross the fly weight pattern. I have been trying to see opportunities to use the pattern in my applications but I am having trouble seeing how to use ...
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3answers
169 views

C# Subject Observer Architecture question

I'm making a C# application using the Subject Observer design pattern in a slightly different way. I am passing the Provider Class, implementing IObservable (this has the OnNext() method that ...
2
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1answer
91 views

Is it OK to deprecate methods that need to be public due to the packaging model but are not to be used outside the codebase in Java?

I am currently working on a semi-large project that has several packages. There are 3 main packages, a "client" package, a "server" package and a "common" package. There are two jars, one for the ...
119
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11answers
22k views

How accurate is “Business logic should be in a service, not in a model”?

Situation Earlier this evening I gave an answer to a question on StackOverflow. The question: Editing of an existing object should be done in repository layer or in service? For example ...
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0answers
330 views

Online stores service design [duplicate]

I am designing an online store service app with rails. Everyone who wants to make his/her own store can do it with this app by just signing up and choosing a domain. I want to make it as SaaS as it ...
3
votes
1answer
130 views

Recursively parse without resorting to ugly design patterns

I'm currently building a crochet pattern parser in Java, and I've hit upon some trouble. I'll call the language used for input Crochet Pattern Code (CPC). I have a rather large writeup on the ...
9
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7answers
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Is there any design pattern except MVC for web?

I want to know are there any design patterns for web besides MVC? I know there are design patterns as: Registry, Observer, Factory, ActiveRecord ,... and MVC a set of other design patterns and folder ...
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1answer
205 views

How to avoid big class complexity while keeping encapsulation?

I'm developing a PHP library to work with big numbers (at this moment only with a "Decimal" class, but I want to add new classes, to handle Integers, Rationals, and Complex numbers). In any case, the ...
5
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2answers
370 views

Why should ViewModel route actions to Controller when using the MVCVM pattern?

When reading examples across the Internet (including the MSDN reference) I have found that code examples are all doing the following type of thing: public class FooViewModel : BaseViewModel { ...
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Is this MEAN stack design-pattern suitable at the 1,000-10,000 user scale?

Let's say that when a user logs into a webapp, he sees a list of information. Let's say that list of information is served by one of two dynos (via heroku), but that the list of information ...
0
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1answer
92 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 ...
31
votes
1answer
10k views

Communication between nested directives

There seem to be quite a few ways of communicating between directives. Say you have nested directives, where the inner directives must communicate something to the outer (e.g. it's been chosen by the ...
2
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1answer
98 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 ...
0
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4answers
196 views

Fixing class Hierarchy design mistakes due to incorrect inheritance

I have a code like this. My derived class man, may not properly have a member function declared pure virtual higher up the hierarchy. eg. WagTail here class mammal{ public: virtual void WagTail() ...
0
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1answer
37 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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1answer
203 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 ...
2
votes
1answer
223 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
votes
2answers
105 views

What kind of base for Decorator: interface, abstract class, non-abstract

What should be at the top of inheritance tree of Decorator design pattern? I mean the base for both components and decorators non-abstract class: has data fields, implements methods abstract class: ...
1
vote
3answers
179 views

Pass the whole object to a method or just parts?

I have an object that has about 50 properties, but one of my methods only uses about 3 of these properties. Is it still better to pass the whole object or parts. A scenario would be were I am using ...
3
votes
2answers
255 views

implementing dynamic query handler on historical data

EDIT : Refined question to focus on the core issue Context: I have historical data about property (house) sales collected from various sources in a centralized/cloud data source (assume info ...
0
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0answers
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What is the best way to create DTOs from entities and update entities from DTOs in a layered architecture? [duplicate]

Option 1: At first I would make a call to my service layer, which served as an API for my core domain, to get a domain object or a list of domain objects and then pass them into the assembler which ...
0
votes
1answer
121 views

What is the best way to create DTOs from entities and update entities from DTOs in a layered architecture?

Option 1: At first I would make a call to my service layer, which served as an API for my core domain, to get a domain object or a list of domain objects and then pass them into the assembler which ...
3
votes
1answer
280 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 ...
9
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1answer
4k views

Understanding Visitor Pattern

I have a hierarchy of classes that represents GUI controls. Something like this: Control->ContainerControl->Form I have to implement a series of algoritms that work with objects doing various ...
3
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1answer
277 views

Beginner Facade Pattern Example

I came across this article: http://didawiki.cli.di.unipi.it/lib/exe/fetch.php/magistraleinformatica/tdp/dp-l10a-facade2014.pdf At the end, it has a question asking: One common problem ...