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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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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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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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 ...
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DI or Factory Pattern ? Both ? or a different apprach?

Lets say we have an abstract class called BaseSwitch, inherited by concrete implementations Switch A and Switch B, Each Switch representing a real-life switch (A telephony tool which among its ...
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Reducing Coupling in a Series of Tasks

I am working on some code right now that involves processing user requests. Each request requires going through an approval. When a request is made, one or more records are created on the database ...
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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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What am I missing in my (mis)understanding of IoC/DI/Castle Windsor?

Okay, so here's how I understand IoC and DI in Web API to work when using Castle Windsor. Note, though, that my confidence that I understand it as I should, though, falls somewhere between my ...
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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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Loose coupling and shuffling dependencies

I have a bunch of classes that look something like this: public class MyGame() { private Graphics graphics; private Player player; public MyGame() { graphics = new ...
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Can I use Dependency Injection without breaking Encapsulation?

Here is my Solution and projects: BookStore (solution) BookStore.Coupler (project) Bootstrapper.cs BookStore.Domain (project) CreateBookCommandValidator.cs CompositeValidator.cs IValidate.cs ...
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Loading data for ShoppingCart item

I'm currently trying to cover our shopping cart with unit tests. Class ShoppingCartItem has property Term. It also loads available terms for this item upon object creation. Currently this is done ...
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How to refactor out static members of basic classes

Currently I am working on C++ project, which can be classified as "legacy" project. A lot of poor written code was committed because of lack of experience and under the pressure of deadlines. When I ...
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Factory Pattern and/or Dependency Injection?

I understand the concept and can use both the Factory Pattern and Dependency Injection, however they seem a little at odds with each other conceptually. Is it a case of using one over the other? Or ...
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High Level Configuration of Constructor Injection in C++

My questions are specifically dealing with dependency injection through the constructor. I understand the pros/cons of service locator pattern, constructor/setter injection, and their flavors, however ...
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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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Why does the modifier access for the properties need to be public with Unity?

Why does the modifier access for the properties need to be public with Unity? I'm very interested in a detailed explanation for my question. I read about tips to do it in other ways, but not a ...
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235 views

it is a good approach to implement dependency injection in a desktop app?

Well, the thing is that I am just about to create a Desktop App (with .NET windows forms) And now I just wonder if it would be really a wise choise to use any IoC (StructureMap,Ninject,Spring .Net), ...
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Can Dependency Injection used as an alternative to Reflection for creating instances

There is a piece of .net C# code which use Reflection to create an instance using Activator.CreateInstance(). This is an old piece of code and runs on the top of Enterprise Library. Is it a better ...
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Service layer coupling

I am working on writing a service layer for an order system in php. It's the typical scenario, you have an Order that can have multiple Line Items. So lets say a request is received to store a line ...
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MVVM and service pattern

I'm building a WPF application using the MVVM pattern. Right now, my viewmodels calls the service layer to retrieve models (how is not relevant to the viewmodel) and convert them to viewmodels. I'm ...
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Dependency injection: At what point am I allowed to create a new object?

I am refactoring a PHP application, and I am trying to do has much dependency injection (DI) as possible. I feel like I've got a good grasp of how it works, and I can certainly see my classes ...
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Dependency injection with Finite State Machines and the Interface Segregation Principle

I am trying to figure out what is the best way to setup a FSM and also keep my interfaces clean and use an IOC container to use DI. Let's just visit the Head First design pattern textbook example of ...
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Inject specific classes or not

I have a TableSqlBuilder interface which has a method getCreateTableSql. This interface is used in some other class as follows: function createTable( $tableDefinition ) { $sql = ...
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The Nature of Spring [duplicate]

Is it accurate to say that dependency injection manually using java (without spring) is nothing but implementing the strategy pattern (as per this example)? Furthermore, is it correct to say that ...
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Generics vs IoC [closed]

One of the "Service Locator" pattern drawbacks is that a caller can be misleaded about dependencies of a callee. Ok, but what if I put dependencies as generic parameters at a class level: class ...
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Is Dependency Injection worth it outside of UnitTesting

Given a constructor that will never, ever, have to use any different implementations of several objects that it initializes, is it still practical to use DI? After all, we might still want to unit ...
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MVC Models instantiation

Where should the Models be instatiated in a MVC arhitecture? I understand the preferred way would be outside controllers, in a bootstrap file and injected using a Dependecy Injection Container. But ...
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MVVM application architecture, where to put dependency injection configuration class, BusinessLayer and Common interfaces?

Planning my architecture for an MVVM application I come to this: MyApp.UI View MyApp.BusinessLayer ViewModel MyApp.DataAccessLayer RepositoryImplEF MyApp.DomainLayer DomainObject ...
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Main method templating

Now that I've gotten into a dependency injection groove, I find main methods for different applications all look basically the same. This is similar to stuff you might find on the Guice documentation, ...
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Factory for arrays of objects in python

Ok, the title might be a little misleading. I have a Window class that draws widgets inside itself in the constructor. The widgets are all of the same type. So I pass a list of dictionaries, which ...
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366 views

Architecting Domain Layer and other modules with dependency injection in mind

I am currently new to Dependency Injection pattern. I am influenced by link by Mark Seemann. I have a confusion regarding whether an interface for an agent class of some agent module should be ...
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244 views

Unused dependencies and constructor injection

I have a class that has 3 dependencies. WritabbleDBConnection, ReadOnlyDBConnection and a QueryFilter utility object. I want to do constructor Injection so my class would look something like this. ...
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Very-Loose Coupling and Dependency Injection for Database Management

I'm currently setting up a MongoDB database for a web-app. I'm running node.js and using Mongoose to help manage mapping, validation ect. I'm wondering if it's a good idea to really decouple MongoDB ...
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DI / IoC Abstract Factory Galore

Given a project architecture as follows, where each box represents an assembly (all are class libraries), and each arrow stands for a dependency: Might be worth nothing that this project is massive ...
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When to use interfaces (unit testing, IoC?)

I suspect I've made a schoolboy error here, and am looking for clarification. A lot of the classes in my solution (C#) - dare I say the majority - I've ended up writing a corresponding interface for. ...
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558 views

Configuring DI in a decoupled app

I'm reading through Mark Seeman's Dependency Injection in .NET (excellent read so far) and something is escaping me. If the application's architecture is like [DAL] => [BLL] <= [UI], with the ...
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Dependency Injection Confusion

I think I have a decent grasp of what Dependency Inversion principle (DIP) is, my confusion is more around dependency injection. My understanding is the whole point of DI is to decouple parts of an ...
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1answer
185 views

Reducing repetitive DI code

I have a method which constructs dependencies using Unity. Currently, all of the calls do pretty much the same thing: Registers 2 repository object and 2 'App Part' objects. My issue is, there's a lot ...
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Passing a Context around with dependency injection

In the project I'm working on, I'm using Guice and trying to do as much as possible with Dependency Injection. However, there's one little snag; many of my objects rely on an object Context. This is ...
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623 views

DB connection Dependency Injection and static creator methods

I often use static "factory" methods to create objects from database. class Job { protected $objDb; public function __construct($objDb) { $this->objDb = $objDb; } public static function ...
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Pattern to use for different Stages in a software

I am developing a software for a laboratory to test some devices. To test each device there are multi subtests which should be done to reach to the final result.To perform a complete test, the ...
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How is dependency injection not just moving the complexity into a separate class?

I've been looking into using the Typhoon framework for dependency injection this week. I get that separating the construction of objects is beneficial for replacing arbitrary components with mocks ...
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Should a repository be passed in to the User Interface

In Mark Seeman's Dependency Injection in .NET he injects a repository into his UI layer. I believe that he is doing this so that he can store everything in the UI configuration, however this just ...
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when to mock in unit testing [duplicate]

I am trying to write unit tests in javascript for an application made in nodejs. What I want to know is - Say there is a class Vehicles which is dependent on another class Roads. Should I mock the ...
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3answers
291 views

Dependency injection and ease of use

I'm writing a handy library (we'll call it Thinger) that goes off and fetches an XML document, does some X-Path query on it and does something helpful with the result of that. (What I'm actually doing ...
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Single write, multiple read of stateful objects

Scenario: One data input feed (call this Source) Multiple objects (call these Layer1) read this Source, and analyze the feed. This analysis is stateful. Layer1 objects have configuration parameters. ...
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How to 'convert' a Static Access style project to IoC/DI style?

Are there any best approaches for refactoring a programming project that has previously been written with the static reference anti-pattern (the majority of classes refer at some point to a static ...
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284 views

Is it a bad design to specify default bindings when using Inversion of Control (IOC) containers and dependency injection (DI)?

I'm using Ninject, but this is not a Ninject-specific question. I'm wondering if the advanced and flexible capabilities of the IoC container are giving me enough rope to hang myself with a bad ...
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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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What's the practical difference between the styles of dependency injection?

I'm new to dependency injection and I have a few questions about which style I shouldI use in my applications. I've just read Inversion of Control Containers and the Dependency Injection pattern by ...