RexMorgan/IPartialActionExtension.cs

## IPartialActionExtension.cs
public interface IPartialActionExtension<T>
    where T : class
{
    T Modify(T model);
}

## IPartialActionExtensionGraph.cs
public interface IPartialActionExtensionGraph<T> : IPartialActionExtension<T>
     where T : class
{
}

## MasterLoginLogout.aspx
<%@ Page Language="C#" CodeBehind="MasterLoginLogout.aspx.cs" Inherits="Project.Web.Shared.Partials.Views.MasterLoginLogout" %>
<%@ Import Namespace="Project.Web.Models.Users" %>
<% if (Model.IsAuthenticated) {%>
    <a href="<%=Urls.UrlFor(new UserLogoutGetModel())%>">Logout</a>
<% } else { %>
    <a href="<%= Urls.UrlFor(new UserLoginGetModel()) %>">Login</a>
<%} %>

## MasterLoginLogout.aspx.cs
public class MasterLoginLogout : FubuPage<MasterLoginLogoutModel>
{
}

## MasterLoginLogoutModel.cs
[PartialModel]
public class MasterLoginLogoutModel
{
    public bool IsAuthenticated { get; set; }
}

## MasterLoginLogoutPartialActionExtension.cs
public class MasterLoginLogoutPartialActionExtension : IPartialActionExtension<MasterLoginLogoutModel>
{
    private readonly IAuthenticationManager _authenticationManager;

    public MasterLoginLogoutPartialActionExtension(IAuthenticationManager authenticationManager)
    {
        _authenticationManager = authenticationManager;
    }

    public MasterLoginLogoutModel Modify(MasterLoginLogoutModel model)
    {
        model.IsAuthenticated = _authenticationManager.LoggedIn;

        return model;
    }
}

## PartialAction.cs
public class PartialAction<T>
    where T : class
{
    private readonly IPartialActionExtensionGraph<T> _graph;

    public PartialAction(IPartialActionExtensionGraph<T> graph)
    {
        _graph = graph;
    }

    public T Execute(T input)
    {
        return _graph.Modify(input);
    }
}

## PartialActionExtensionGraph.cs
public class PartialActionExtensionGraph<T> : IPartialActionExtensionGraph<T>
    where T : class
{
    private readonly IContainer _container;

    public PartialActionExtensionGraph(IContainer container)
    {
        _container = container;
    }

    public T Modify(T model)
    {
        _container.GetAllInstances<IPartialActionExtension<T>>()
            .Each(extension => model = extension.Modify(model));

        return model;
    }
}

## PartialActionsSource.cs
public class PartialActionsSource: IActionSource
{
    public IEnumerable<ActionCall> FindActions(TypePool types)
    {
        return types
            .TypesMatching(t => t.HasAttribute<PartialModelAttribute>())
            .Select(m =>
                        {
                            var actionType = typeof(PartialAction<>).MakeGenericType(m);
                            return new ActionCall(actionType, actionType.GetExecuteMethod());
                        });
    }
}

## Site.master
<%@ Master Language="C#" AutoEventWireup="true" CodeBehind="Site.master.cs" Inherits="Project.Web.Shared.Master.Site" %>
<%@ Import Namespace="FubuCore" %>
<%@ Import Namespace="Project.Web.Shared.Partials.Models" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <title>Project Master Page</title>
    </head>
    <body>
        <% this.Partial<MasterLoginLogoutModel>(); %>
    </body>
</html>
	public interface IPartialActionExtension<T>
	where T : class
	{
	T Modify(T model);
	}
	<%@ Page Language="C#" CodeBehind="MasterLoginLogout.aspx.cs" Inherits="Project.Web.Shared.Partials.Views.MasterLoginLogout" %>
	<%@ Import Namespace="Project.Web.Models.Users" %>
	<% if (Model.IsAuthenticated) {%>
	<a href="<%=Urls.UrlFor(new UserLogoutGetModel())%>">Logout</a>
	<% } else { %>
	<a href="<%= Urls.UrlFor(new UserLoginGetModel()) %>">Login</a>
	<%} %>
	public class MasterLoginLogout : FubuPage<MasterLoginLogoutModel>
	{
	}
	[PartialModel]
	public class MasterLoginLogoutModel
	{
	public bool IsAuthenticated { get; set; }
	}
	public class MasterLoginLogoutPartialActionExtension : IPartialActionExtension<MasterLoginLogoutModel>
	{
	private readonly IAuthenticationManager _authenticationManager;

	public MasterLoginLogoutPartialActionExtension(IAuthenticationManager authenticationManager)
	{
	_authenticationManager = authenticationManager;
	}

	public MasterLoginLogoutModel Modify(MasterLoginLogoutModel model)
	{
	model.IsAuthenticated = _authenticationManager.LoggedIn;

	return model;
	}
	}
	public class PartialAction<T>
	where T : class
	{
	private readonly IPartialActionExtensionGraph<T> _graph;

	public PartialAction(IPartialActionExtensionGraph<T> graph)
	{
	_graph = graph;
	}

	public T Execute(T input)
	{
	return _graph.Modify(input);
	}
	}
	public class PartialActionExtensionGraph<T> : IPartialActionExtensionGraph<T>
	where T : class
	{
	private readonly IContainer _container;

	public PartialActionExtensionGraph(IContainer container)
	{
	_container = container;
	}

	public T Modify(T model)
	{
	_container.GetAllInstances<IPartialActionExtension<T>>()
	.Each(extension => model = extension.Modify(model));

	return model;
	}
	}
	public class PartialActionsSource: IActionSource
	{
	public IEnumerable<ActionCall> FindActions(TypePool types)
	{
	return types
	.TypesMatching(t => t.HasAttribute<PartialModelAttribute>())
	.Select(m =>
	{
	var actionType = typeof(PartialAction<>).MakeGenericType(m);
	return new ActionCall(actionType, actionType.GetExecuteMethod());
	});
	}
	}
	<%@ Master Language="C#" AutoEventWireup="true" CodeBehind="Site.master.cs" Inherits="Project.Web.Shared.Master.Site" %>
	<%@ Import Namespace="FubuCore" %>
	<%@ Import Namespace="Project.Web.Shared.Partials.Models" %>

	<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
	<html xmlns="http://www.w3.org/1999/xhtml">
	<head>
	<title>Project Master Page</title>
	</head>
	<body>
	<% this.Partial<MasterLoginLogoutModel>(); %>
	</body>
	</html>