This is an add-in for Fody

It extends Nancy with a way to modify models after a route has been executed, but before they are serialized

Nuget

Nuget package http://nuget.org/packages/Nancy.ModelPostprocess.Fody

To Install from the Nuget Package Manager Console

PM> Install-Package Nancy.ModelPostprocess.Fody

Why create this package?

Nancy is a very flexible framework, which offers a variety of extension points. One such extension point is the AfterRequest pipeline

pipelines.AfterRequest += (ctx) => {
	// Modify ctx.Response
};

The problem is that ctx.Response holds serialized value (JSON. HTML, etc) of a response ready to be sent back to the client. Currently though there is no way to modify a model outside of a NancyModule. There is a question on StackOverflow about this here

How this works

Nancy.ModelPostprocess.Fody is a Fody add-in, which means that extra code is injected to the modules so that the models returned from routes can be modified before thay are serialized.

Usage

Module

Your code

You implement your modules as usual

public class SampleModule : NancyModule
{
    public SampleModule()
    {
        Get["Model"] = p => new SampleModel { SomeValue = "Original value" };
    }
}

What gets compiled

public class SampleModule : NancyModule
{
    public SampleModule(IModelPostprocessor processor)
    {
		var route = new Func<dynamic, dynamic>(
			p => new SampleModel { SomeValue = "Original value" }
		);
        Get["Model"] = route.WrapRoute(processor, this);
    }
}

Bootstrapper

In Bootstrapper you register the IModelPostprocessor and handlers for specific model types

public class SampleBootstrapper : DefaultNancyBootstrapper
{
    protected override void ApplicationStartup(
    	TinyIoCContainer container, 
		IPipelines pipelines)
    {
        base.ApplicationStartup(container, pipelines);

        var postprocessor = new ModelPostprocessor();
        postprocessor.RegisterModelHandler(new SampleModelHandler());
        container.Register<IModelPostprocessor>(postprocessor);
    }
}

The model handler

Model handlers are classes implementing IModelHandler<T> interface, which has a single method

public class SampleModelHandler : IModelHandler<SampleModel>
{
    public void Postprocess(SampleModel model, NancyModule module)
    {
        model.SomeValue = "I can modify my model here :)";
    }
}

ModelPostprocessor class

The default implementation of IModelPostprocessor

1. holds instances of model handlers and passes matching models for processing,
2. has a built-in handler for the Negotiator class, which handles model(s) returned for Content Negotiation,
3. currently requires that handlers are registered manually and as concrete instances

Russian Doll designed by [Simon Child](http://www.thenounproject.com/Simon Child) from the Noun Project