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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Acceptable placement of the composition root using dependency injection and inversion of control 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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76 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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6answers
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Dependency injection ; good practices to reduce boilerplate code

I have a simple question, and I'm not even sure it has an answer but let's try. I'm coding in C++, and using dependancy injection to avoid global state. This works quite well, and I don't run in ...
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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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1answer
51 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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1answer
230 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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1answer
164 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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How to inject a .net Provider (OAuthAuthorizationServerProvider)? [migrated]

I'm looking for a solution how to inject IApplicationUserManager into a OAuthAuthorizationServerProvider.cs This is the sample I'm looking at now: ...
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220 views

How should dependencies be managed across a modular application?

Let's say that we have a structure like this: Application -- Modules --Module1 -- Controller -- PublicHelper --Module2 -- Controller ...
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2answers
57 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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48 views

Save database changes in service layer or controller mvc .net

I have recently been using a service layer to abstract away alot of the business logic of my application. However I've come into an issue where I'm not sure what is best practice on doing the actual ...
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68 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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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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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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374 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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1answer
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What are Dependency Injections and why are they useful? [closed]

I have heard of ninject and I have to build a lot of apps that have to integrate with other tools. SO i was wondering what this was and how it is used.
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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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1answer
90 views

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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171 views

Passing a dependency to a controller class

I'm looking for an approach to the following problem: I have a reusable library. It contains a controller class, in the MVC sense. Let's say it's called UserAdministrationController, and it's for ...
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1answer
84 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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1answer
136 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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3answers
133 views

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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2answers
78 views

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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420 views

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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80 views

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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195 views

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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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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59 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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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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2answers
157 views

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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204 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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2answers
181 views

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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2answers
115 views

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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82 views

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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2answers
556 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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6answers
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What does the Spring framework do? Should I use it? Why or why not? [closed]

So, I'm starting a brand-new project in Java, and am considering using Spring. Why am I considering Spring? Because lots of people tell me I should use Spring! Seriously, any time I've tried to get ...
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5answers
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What does Dependency Injection mean by saying it can inject on runtime?

I understand that the dependency injection is something done by coding and its all done at compile time. And that Dependency injection coding is easily done now by helper tools like Ninject. However ...
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1answer
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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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3answers
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Should IoC container be part of portable library?

I am seeing the benefits of Portable Class Libraries for centralizing Models and ViewModels to a single code-base. Where should dependency injection management (IoC container) take place, though? My ...
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7answers
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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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Customizing configuration for PHP will Laravel 4 IoC be useful?

This topic has been discussed in this post: Customizing configuration with Dependency Injection However - I couldn't find one for PHP syntax and since one of the answers was to use a specific ASP.net ...
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239 views

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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109 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
84 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
163 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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2answers
321 views

Help With Dependency Injection

I am still very confused as to why and when to use Dependency Injection. If anyone could explain maybe using the below example that would be great, any other explanations would be appreciated. Lets ...
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Should you implement a repository pattern with an MVVM javascript framework?

When coding a MVVM pattern I use Dependency Injection (DI) and try and code against interfaces. One of the common patterns is a Repository pattern, so I can swap my data storage provider. If I'm ...
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6answers
4k views

Should I use Dependency Injection or static factories?

When designing a system I am often faced with the problem of having a bunch of modules (logging, database acces, etc) being used by the other modules. The question is, how do I go about providing ...
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1answer
181 views

Practical Use of Depency Injection (IoC) Container

I am creating a MVC-ish framework in PHP. I am trying to implement a DI Container to allow the creation of controller objects (among others). My MVC framework is pretty typical. Each module (or ...
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1answer
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What is the clean way to pass my LoginContext down through the layers to the data access layer?

I have inherited an API implemented using ASP.NET WebApi 2. The actions on the controllers are all like this: public object Get(long id) { LoginContext loginDetails = GetLoginDetails(); if ...