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POStack overflow when resolving services with Ninject
 

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  1. POStack overflow when resolving services with Ninject
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    <p>I'm trying to resolve a known fixed list of Foo services (in singleton scope) using NInject; this resolution happens in a FooProvider's constructor. The problem is that each Foo will need this provider as well. </p> <pre><code>public interface IFoo { } public interface IFooProvider { } public class Foo : IFoo { private readonly IFooProvider _provider; public Foo(IFooProvider provider) { _provider = provider; } } public class FooProvider : IFooProvider { private List&lt;IFoo&gt; _allFooServices; public FooProvider(IKernel kernel) { _allFooServices = kernel.GetAll&lt;IFoo&gt;().ToList(); } } public class Program { private static void Main(string[] args) { var IoC = new StandardKernel(); IoC.Bind&lt;IFoo&gt;().To&lt;Foo&gt;().InSingletonScope(); IoC.Bind&lt;IFooProvider&gt;().To&lt;FooProvider&gt;().InSingletonScope(); var foo = IoC.Get&lt;IFoo&gt;(); } } </code></pre> <p>There is a logical cyclic loop here, and obviously the stack overflow shows its going down it. However, I have both interface bound to singletons. </p> <p>Thinking about it; we try to resolve IFoo, which then needs resolution of IFooProvider, itself needing a list of IFoo... but we haven't resolved for any IFoo singletons yet because we're still trying to resolve it!</p> <p>So how could I work around this? </p> <p>[Edit] Possible solution; delay buffering of IFoo service instances. </p> <pre><code>public FooProvider(IKernel kernel) { _kernel = kernel; } public IFoo Find(object context) { if (_allFooServices == null) _allFooServices = _kernel.GetAll&lt;IFoo&gt;().ToList(); return _allFooServices.Where(... </code></pre> <p>[Why?]</p> <p>The general idea is to avoid the service locator pattern, as I've seen it described as an anti-pattern. So, rather than try to resolve services through the dependency injector during run time; you try to get a list of services during setup. The problem with this though, is that if any of your services want to find other services, you have the above problem.</p>
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    1. USMeirion Hughes
    1. USMeirion Hughes
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    1. COSo why does `Foo` need an instance of `FooProvider`? If in fact `FooProvider` is a factory to create `Foo`'s it should be readily available another way yes?
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      1. USMike Perrenoud
    2. COAll Foo are services, the FooProvider is trying to get a (resolved) list of all Foo services at injection time. If any foo needs to find another foo (specific to context) during run-time it can ask the FooProvider at run time.
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      1. POStack overflow when resolving services with Ninject
      1. USMeirion Hughes
    3. COSo shouldn't `FooProvider` be a singleton that's easily resolved via dependency injection by all other `Foo`'s?
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      1. USMike Perrenoud
 

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