DI, dependency-injection, is a design pattern where dependencies (instances of objects, properties) of a component are set through the constructor(s), methods or fields (properties)

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C# Dependency Injection Placement

This is my first time using Unity so bear with me for a moment. I have a sample Visual Studio 2012 project with 4 projects (but only two of these projects will be used with Unity). This is the ...
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Am I following a good design thought process? Is the Abp framework overkill?

As I finish one project and start another, I have a small time window to come up with an architecture for the new. I am coming from the following design: Web applicationReceives domain models & ...
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86 views

Data serialization architecture, injection on construction vs. on function call

I am creating a data serialization/deserialization mechanism for essentially a persistent storage object. Due to the variety of systems this mechanism could run on, there needs to be a a variable ...
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284 views

when using dependency injection, should I always pass an interface

When using depending injection, you generally pass everything around as an interface (perhaps with the exception of primitives and strings). That allows you to easily chance the behavior, without ...
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I get dependency injection, but can someone help me understand the need for an IoC container?

I apologize if this seems like yet another repeat of the question, but every time I find an article regarding the topic, it mostly just talks about what DI is. So, I get DI, but I'm trying to ...
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Why do IoC containers provide public Resolve method(s)?

In my opinion it just inverses the inversion and could make new users (including myself) make incorrect assumptions about using IoC containers. It can be used for the Service Locator (anti-)pattern ...
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206 views

Should the Presenter depend on the View or the vice versa?

So far, I have used the MVP architecture pattern a few times. Every now and then, I wonder whether my Presenter should depend on my View or vice versa, that is the View depends on my Presenter. NOTE ...
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271 views

Reducing dependency cycles and reducing coupling

I'm trying to learn how to produce quality object-oriented code and have been studying concepts like SOLID. I'm currently working on an entity-component-process system for a small game engine. ...
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124 views

Value Object: static factory or assisted injection?

First let assume that everybody agree that there is nothing wrong with injecting some value object into injectable object such as service. Indeed, a service can get another service injected, but could ...
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Dependency Injection: where to store dependencies used by only one method?

I am developing a project integrated with Dependency Injection (just for reference, I'm using Unity). The problem is that I have some Manager classes with several methods and in many cases I have ...
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Questioning one of the arguments for dependency injection: Why is creating an object graph hard?

Dependency injection frameworks like Google Guice give the following motivation for their usage (source): To construct an object, you first build its dependencies. But to build each dependency, ...
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Ninject/DI: How to correctly pass initialisation data to injected type at runtime

I have the following two classes: public class StoreService : IStoreService { private IEmailService _emailService; public StoreService(IEmailService emailService) { _emailService ...
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How best to construct our test subjects in unit tests?

Some of our business logic classes require quite a few dependencies (in our case 7-10). As such when we come to unit test these the creation become quite complex. In most tests these dependencies are ...
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How to handle “circular dependency” in dependency injection

The title says "Circular Dependency", but it is not the correct wording, because to me the design seems solid. However, consider the following scenario, where the blue parts are given from external ...
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Decoupling when constructors have non-contractual parameters

By non-contractual parameters, I mean parameters that are not interfaces or service dependencies, something like class Person(string name). I am writing a webpage scraping application, and so far ...
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260 views

When to use packages or Repositories in Laravel?

I'm a Laravel (PHP) developer, and new with DI, Packages (workbench) and Repositories (Pattern). I want to know about the best concept/methodology for a more flexible design; ie. the project can grow ...
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57 views

Are the required parameters of a function called dependencies?

I'm studying dependency injection and I want to know if required function parameters can be considered dependencies. I'd just like to make sure before I go around referring to them dependencies and ...
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142 views

How should one implement the dependency-injection for a geocoding client that aggregates different coordinate provider implementations?

I am new to DI and I would like to know how DI might be used to help resolve this problem. If I have an ILatLongLocation which implements a Latitude and Longitude, then given two of these I can ...
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224 views

How can I use guice to replace code dependent on service locator implementation?

Consider I have a service called FileSystem, and that this FileSystem is used by various classes throughout the application. Typically, the service is acquired via some static class method ...
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354 views

Showing a View from another View in MVP

This question is regarding MVP triads. Lets say I have two triads and first one has View1, Mode1 and Presenter1. Second triad has View2, Model2 and Presenter2. Now what I trying to do is, I just want ...
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588 views

What complexity do DI frameworks add?

The currently most upvoted answer to a very recent question states that DI containers are an "enterprise software" pattern, used when the object graph is very large and complex. I suspect that 95% ...
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432 views

Do dependency injection frameworks pose a dependency risk?

I have been refactoring an existing system to use dependency injection, and that work has been going smoothly. After a while I noticed that a large number of in-house libraries became dependent upon ...
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How does dependecy injection increase coupling?

On the Wikipedia page on dependency injection, the disadvantages section tells us this: Dependency injection increases coupling by requiring the user of a subsystem to provide for the needs of ...
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How to properly handle conditional dependencies in a factory?

Let's say you have a string $action run-time, that specifies which type of $object needs to be created: $dbobject, $memcacheobject, $fileobject, $xmlobject, etc. Assume also, that creation of an ...
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275 views

How to handle passing multiple dependencies in a module hierarchy

So I have my application consisting of a number of modules in a module hierarchy. Furthermore let's also assume each module is a class and we have a tree of classes where the classes at the top are ...
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272 views

Applying DDD to a simple app with a configuration twist

I’m using the light-weight PHP Fat-Free Framework as a base to form a simple MVC based app with DDD philosophy for the Model layer. I’m aware that DDD is most suitable or enterprise solutions and that ...
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Using 2 Constructors: one that injects dependencies and one that instantiates them

I started using TDD for the first time on a project I started recently. I have a few objects with dependencies and structures that look something like this: public class MyClass { private ...
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How to extend Constructor Injection?

Suppose I have MyClass with a very simple dependency. It uses constructor injection. public class MyClass : IMyClass { private IA A; public MyClass(IA a) { A = a; } } This ...
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596 views

Where should I put bindings for dependency injection?

I'm new to dependency injection and though I've really liked it so far, I'm not sure where bindings should go. I'm using Guice in Java, so some of what I say might be specific to just Guice. As I see ...
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To Repository Or Not To Repository

When I first learnt about Domain Driven Design, I was also introduced to the repository and unit of work patterns that once seemed to be top notch for the cool kids that threw SQL queries like ...
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Dependency injection for request variables in a web application

I'm working a PHP 5.5/MySQL web application. If a class depends partly on some global GET and POST variables for its members, should I just refer to them directly from within the class, or should I ...
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Spring bean injection into a hibernate validator constraint

I have a controller method like listed below whose argument is annotated with @Valid to validate PasswordChange object using a Hibernate validator @Constraint. Both PasswordChange and a sample ...
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172 views

How to design a domain entity that uses a dependency to manage a state field?

I'm new to DDD and IOC/DI and I'm having some trouble figuring out how to design an entity that needs to use a state pattern to manage its status. As the transitions are somewhat complicated, I'm ...
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357 views

Pooling (Singleton) Objects Against Connection Pools

Given the following scenario A canned enterprise application that maintains its own connection pool A homegrown client application to the enterprise app. This app is built using Spring framework, ...
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653 views

Organising data access for dependency injection

In our company we have a relatively long history of database backed applications, but have only just begun experimenting with dependency injection. I am looking for advice about how to convert our ...
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Dealing with an often occuring dependency that is not related to the class

I'm using view classes for my templating. These view classes often require the Routing class to get URI's from other pages. You could actually say that the Routing should be available to every view ...
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State Pattern Code for embedded device - Dependency Injection of Device Objects in Context and State Classes

I'm wrestling with some code and I think I've finally gotten some state pattern code working with my events. I've got a simplified system that will work like this: This is my first go with State ...
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273 views

Dependency Injection vs Mixing Levels of Abstraction

I've been reading Clean Code: A Handbook of Agile Software Craftsmanship by Robert C. Martin. One point he makes: G34 Functions should descend only one level of abstraction However, I'm ...
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Initialization of objects in a system using dependency injection

This is a follow up question to the following post: Injecting dependencies (DI) in c++ applications In a system that uses DI, someone, somewhere should be responsible to create the various objects ...
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Injecting dependencies (DI) in c++ applications

I am playing with dependency injection, but i am not sure I am doing it right. Especially, I am not sure what should be the correct way to build classes with injected dependencies. Say I have a class ...
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Logging page/session ID in an inner module

We have a C# ORM module that generates queries. It logs generated queries and other information into the error/trace file. It is used by our web application. Most of our queries are generated ...
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Does Serialization preclude the use of Dependency Injection?

Simple question: I understand that Serialization in C# requires default constructors. This would eliminate the possibility of using Constructor injected DI (which is generally the favored style of DI, ...
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2k views

Unit testing, factories, and the Law of Demeter

Here's how my code works. I have an object that represents the current state of something akin to a shopping cart order, stored in a 3rd party shopping API. In my controller code, I want to be able to ...
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Understanding dependency injection

I'm reading about dependency injection (DI). To me, it is a very complicated thing to do, as I was reading it was referencing inversion of control (IoC) as well and such I felt I was going to be in ...
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184 views

Manual dependency injection or abstract factory

We're starting to use dependency injection in a fairly large, interactive program. It's early yet, but I have a feeling that the majority of the objects being injected are going to want runtime data ...
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2answers
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How to decouple simple factory and default implementation?

I have a simple factory class (FileResources) with static factory methods providing a default implementation (DefaultFileResource). public final class FileResources { private FileResources() {} ...
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Which classes should be autowired by Spring (when to use dependency injection)?

I have been using Dependency Injection in Spring for some time now, and I understand how it works and what are some pros and cons of using it. However, when I'm creating a new class I often wonder - ...
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183 views

Application settings via constructor injection or ambient context

I am developing an application containing a class which loads application settings from a configuration file. Settings class: public sealed class MyAppSettings : IMyAppSettings { private ...
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3answers
191 views

Should I consider loosely-coupling for class methods as well? [duplicate]

I'm a fan of Dependency Injection, however I don't know how much both public and private methods inside a class should be loosely-coupled. Just to picture it better, when I have both projectId and ...
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Does Refactoring towards Looser Coupling, Smaller Functions, and Separate Classes affect System Performance? (and Should I Care)

In Computer Science field, I have noticed a notable shift in thinking when it comes to programming. The advice as it stands now is write smaller, more testable code refactor existing code into ...