X-ray StoneAssemblies.MassAuth with NDepend

Introduction

A long time ago, I wrote this post Why should you start using NDepend? which I consider as the best post I have ever written or almost ;)

NDepend is a static analysis tool for .NET, and helps us to analyze code without executing it, and is generally used to ensure conformance with the coding guidelines. As its authors use to say, it will likely find hundreds or even thousands of issues affecting your codebase.

After the first pre-releases of StoneAssemblies.MassAuth I decided to X-ray it with NDepend. I attach a new NDepend project to StoneAssemblies.MassAuth solution, filter out the test and demo assemblies, and hit the analyze button.

Attach new NDepend Project to Visual Studio Solution 

Now, I invite you to interpret some results with me. So, let's start.

Interpreting the NDepend analysis report

One of the outputs of the analysis is a web report. The main page includes a report summary with Diagrams, Application Metrics, Quality Gates summary, and Rules summary sections.

NDepend Report Summary

Navigation Menu

It also includes a navigation menu to drill through  more detailed information including Quality Gates, Rules, Trend Charts, Metrics, Dependencies, Hot Sports, Object-Oriented Design, API Breaking Changes, Code Coverage, Dead Code, Code Diff Summary, Build Order, Abstractness vs. Instability and Analysis Log.

But let's take a look at these summary sections.

Diagrams

The diagrams section includes Dependency Graph, Dependency Matrix, Treemap Metric View and Abstractness vs. Instability. 

Dependency Graph

Dependency Matrix

Treemap Metric View (Color Metric Coverage)

So far I understand these metrics, actually, I can interpret them relatively easily. 

But, wait for a second. What is this Abstractness versus Instability? 

Abstractness versus Instability

According to the documentation the Abstractness versus Instability diagram helps to detect which assemblies are potentially painful to maintain (i.e concrete and stable) and which assemblies are potentially useless (i.e abstract and instable).

Abstractness: If an assembly contains many abstract types (i.e interfaces and abstract classes) and few concrete types, it is considered as abstract.

Instability: An assembly is considered stable if its types are used by a lot of types from other assemblies. In this context stable means painful to modify.

Component	Abstractness (A)	Instability (I)	Distance (D)
StoneAssemblies.MassAuth	0	0.96	0.03
StoneAssemblies.MassAuth.Rules	1	0.4	0.28
StoneAssemblies.MassAuth.Messages	0.43	0.62	0.04
StoneAssemblies.MassAuth.Hosting	0.14	0.99	0.09
StoneAssemblies.MassAuth.Rules.SqlClient	0.17	1	0.12
StoneAssemblies.MassAuth.Server	0	1	0
StoneAssemblies.MassAuth.Proxy	0	1	0

None of StoneAssemblies.MassAuth's components seem potentially painful to maintain or potentially useless. But, I have to keep my eyes on StoneAssemblies.MassAuth.Rules, because of the distance (D) from the main sequence. Actually, another candidate to review is StoneAssemblies.MassAuth.Messages since ideal assemblies are either completely abstract and stable (I=0, A=1) or completely concrete and instable (I=1, A=0).

Application Metrics 

The application metrics section shows the following summary.

Application Metrics

Looks like some metrics depend on a codebase. Since this is the first I run NDepend's analysis over StoneAssemblies.MassAuth code, it hasn't noticed any difference with previous executions. But this help me to be alert about the low 66.99% value for the tests coverage, the 3 failures for quality gates, the violations of 2 critical rules and 15 high issues.

Quality Gates

In this section is possible to view more details on the failing quality gates. The percentage of coverage, the critical rules violated and the debt rating per namespace.

Quality Gates

Wait for a second again. What is debt rating per namespace means? 

According to the documentation the rule is about to forbid namespaces with a poor debt rating. By default, a value greater than 20% is considered a poor debt rating.

Namespaces	Debt Ratio	Issues
StoneAssemblies.MassAuth.Services	39.01	8
StoneAssemblies.MassAuth.Services.Attributes	37.62	3
StoneAssemblies.MassAuth.Server	23.67	6
StoneAssemblies.MassAuth.Rules.SqlClient .Rules	36.24	3

Rules summary

The final section is the Rules summary. It listed the issues per rules in the following table. 

Rules summary

NDepend indicates to me that I violated 2 critical rules. One to avoid namespaces mutually dependent and the other to avoid having different types with the same name. That sounds weird, but who knows, even I can make mistakes ;)

What's next?

I the near future, I will be integrating the NDepend analysis as part of the build process, therefore I could easily share with you the evolution of this library in terms of quality. If you are interested in such an experience wait for the next post.

As you already know, StoneAssemblies.MassAuth is a work in progress, which includes some unresolved technical debts. But, as I told you once, it is possible to make mistakes (critical or not), but be aware of your code quality constantly makes the difference between the apparent and intrinsic quality of your sources. If you are a dotnet developer, NDepend is a great tool to be aware of your code quality. 

Yeah, you are right, I have some work to do here in order to fix this as soon as possible but also remember, StoneAssemblies.MassAuth is also an open-source project, so you are welcome to contribute ;)

StoneAssemblies.MassAuth Hands-on Lab

A few days ago, I introduced you StoneAssemblies.MassAuth as a  Gatekeeper implementation.

Today, as promised, I bring you a hands-on lab that consists of the following steps:

1. Set up the workspace
2. Contract first
3. Implementing rules
4. Implementing services
5. Hosting rules
6. Build, run and test

So, let’s do this straightforward. 

Prerequisites

• Visual Studio 2019 (16.9.3)
• Docker (2.3.0.4)
• Cake (1.1.0)
• Tye (0.9.0-alpha.21380.1)

Step 1: Set up the workspace

To set up the workspace, open a PowerShell console and run the following commands:

After executing these commands, StoneAssemblies.MassAuth.QuickStart.sln Visual Studio solution file is created, which includes the following projects:

• StoneAssemblies.MassAuth.QuickStart.Messages:  Class library for messages specification. 
• StoneAssemblies.MassAuth.QuickStart.Rules: Class library to implement rules for messages.
• StoneAssemblies.MassAuth.QuickStart.Services: Web API to host the services that require to be authorized by rules.
• StoneAssemblies.MassAuth.QuickStart.AuthServer: Authorization server to host the rules for messages. 

The commands also add the required NuGet packages and project references.

If you review the content of the StoneAssemblies.MassAuth.QuickStart.AuthServer.csproj project file, you should notice a package reference to StoneAssemblies.Extensibility. This is required because all rules will be provisioned as plugins for the authorization server. 

The extensibility system is NuGet based, so we need to set up the build to provision the rules and messages as NuGet packages. For that is the purpose, this workspace configuration includes two more files. The build.cake, a cake based build script to ensure the required package output,  

and the tye.yaml that will help us to run and debug the solution.

 

Step 2: Contract first

Let's add a bit of complexity to the generated problem, related to the weather forecast. For instance, let's say we will allow requesting forecasts from a certain date, as some forecasts may not be available due to the complexity of the calculations.

For that purpose, we will add the following class to the message project, to request the weather forecast with the start date as an argument.

Step 3: Implementing rules

Now we are ready to implement some rules for such a message. Continuing with our scenario, let's say the forecast data is only available from today and up to 10 days. This operation could be more complex through a query to an external database, but for simplicity, it will be implemented as follows.

Step 4: Implementing services

It's time to complete the WeatherForecastController implementation in the service project. It should look like this. 

Notice the usage of AuthorizeByRule attribute on the Get method, to indicate that the input message WeatherForecastRequestMessage must be processed and validated by the authorization engine before the method execution.

We also have to update the Startup class implementation.

  

Basically, the AddMassAuth service collection extension method is called to register the library services and also ensure communication through the message broker. Remember, StoneAssemblies.MassAuth is built on top of MassTransit.  Finally, to read the configuration via environment variables we must update the Program class to this. 

Step 5: Hosting rules

To host rules, we provide a production-ready of StoneAssemblies.MassAuth.Server as docker image available in DockerHub. But for debugging or even for customization purpose could be useful build your own rule host server. So, in the server project, we also have to update the Startup class implementation, to initialize the extensibility system and load rules. 

Again, to read the configuration via environment variables the Program file must be updated like this. 

Step 6: Build, run and test

Let's see if this works. So, cross your fingers first ;)

To build and run the project, open a PowerShell terminal in the working directory and run the following commands.

Open your browser and navigate to http://localhost:8000 to display the Tye user interface. 

You can see the logs of the rules host server to notice how extensibility works.

Let's do some weather forecast requests. For instance with a valid request

the output looks like this

but with an out of range request

the output shows an unauthorized response.

So, as expected, it works ;)

Closing

In case it doesn't work for you, you can always try to review the final and complete source code of this hands-on lab is in the StoneAssemblies.MassAuth.QuickStart repository is available on GitHub. 

Remember StoneAssemblies.MassAuth is a work in progress, we are continuously releasing new versions, so your feedback is welcome. Also, remember that it is an open-source project, so you can contribute too.

Enjoy «authorizing» with pleasure and endless possibilities.

Stressless in the new jungle

This is my personal journey buying in TuEnvio. 

What is TuEnvio?

Described by CIMEX itself, TuEnvio is an “E-Commerce platform created by the CIMEX corporation for the national customer, which allows online purchases from the comfort of your home”. 

But you may wonder: Why is this new? The fact is that the expansion of Internet access in Cuba is actually a new phenomenon. From almost zero, without infrastructure, in a couple of years, Internet access for many Cubans is almost a reality. Right, it is very expensive thanks to ETECSA, but it continues to expand, which is good.

Since Cubans had no internet access, “no one” worried about selling products online. At least, not for Cubans that live in Cuba. Therefore, they “invented” a service called EnviosCuba for foreign families could buy products for their national’s relatives. A kind of favor-based business model, which is very sad. An approach to only capture foreign currency instead also think in the prosperity and comfort of Cubans that live in Cuba.

But the SARS-Cov-2 arrived. They would be forced to launch a service on a scale for which they were neither technologically nor logistically prepared. Its name TuEnvio.

The new jungle

TuEnvio looked promising. Several instances of the store, distributed in some physical stores, showed its “stock” online. Users were able to navigate, search and buy. But somewhat was not right. Buying what you needed wasn't exactly that easy. Eventually, you could catch a thing but the stress began to increase. As a vigilante, to buy a high demanded product, you had to stay up late at night.

TuEnvio doesn't have a native notification system, so I started implementing something to help me stay tuned. I was at home (remember COVID19), I was bored, but most importantly I had to buy.

That was the birth of  YourShipping.Monitor as a project. 

The first step was implementing a basic scraping system to be notified of the availability of products, including some searches by keywords. To improve the notification system, I also implemented a personal Telegram Bot, that also allows me some basic interactions.

@cimex_cuba #TuEnvio #Telegram #Bot #Demo 😉

/search agua pic.twitter.com/3fTR2z3hIp

— Alexánder Fernández (@alexfdezsaucoCU) May 31, 2020

So, the idea was to create an application similar to CamelCamelCamel with target TuEnvio. But everything would change when The new jungle arises. 

Shoot first, ask later

The best description of the situation was published in this video. A "parodied" scene from The Big Bang Theory television series. By the way, to understand what is happening you need to read the subtitles in Spanish ;). I'm not sure who the original author is. But it rocks. If you know him, please just let me know to update this post.

It turns out that shopping at TuEnvio wasn't too easy. Only a few viewed the products because they accessed them at the right time. Links leak?

On the other hand, the workload generated by the simultaneous access of thousands of people was handled by DATACIMEX's developers with an incorrect caching approach. If someone doesn't see a product at the right time, should wait for the cache to be invalidated within the next 3 minutes.

This, combined with the limited offer, meaning that the majority of TuEnvio's users were unable to purchase a thing. Worse still, they didn't even see a single product.

Under these circumstances YourShipping.Monitor's goals changed. I needed the notifications. But actually, I needed to interact with the store in light speed mode to add products to the shopping cart. 

  

I almost forget that this is also a technical post. So, here we go.

Parallel web scraping

YourShipping.Monitor is being implemented using the NetCore full stack including the frontend with Blazor. It allows me to track stores, departments, and products from its uniform resource locator (URL). The user must enter the link and a background process extracts the information and also tries to interact with the options of the store with a single rule: add a product to the cart at first sight. 

But what if I'm looking to the wrong department? What if one product is available in the very same second as another. This is why it was important to send as many requests as possible at the same time. Using the asynchronous capabilities of C# in combination with AsyncEnumerable library, I was able to do it, just like this. 

But it wasn't just me. A community of Cuban developers launched several applications to help people to buy. Even when such applications required user interaction, the workload affected the store's servers a lot. So, CIMEX responded with an anti-scraping approach.

Fighting against the anti-scraping system

One day the scraper stopped working. All requests were redirected to a page to execute this JavaScript code.

It could be easy to figure out what is happening. They expect a cookie, with a value generated in that JavaScript. I'm already using AngleSharp to explore the DOM elements. It might be possible to evaluate such a function, to acquire the value of the cookie, using the same library? The answer is yes. AngleSharp.Js is an experimental extension that allows you to run simple JavaScript functions. So, after capturing the parameters with regex, I was able to call the function to capture the cookie value as well.

Moving to unattended mode 

At this point, I was creating the session with the browser, saving the cookies.txt file, and making it available to the scraping server (a.k.a. YourShipping.Monitor.Server). The main reason, the captcha. But TuEnvio's captcha looks like this.

Actually, it doesn't look like a very hard captcha. Nothing that has not been broken before with tesseract-ocr. So, just added the reference to a .NET wrapper of tesseract and wrote down this

and you know what? It worked.

Final thoughts  

I know, this doesn't seem a bit stressful, but yeah, now it is. With YourShipping.Monitor and a bit of luck, I have been able to capture something in TuEnvio's stores. There is no guarantee, so I always insist that ETECSA should not charge for access to virtual stores. Someone can spend more money trying to buy than buying.

Recently,  CIMEX released the store's opening schedule. So now, with the effective combination of my command-line tool nauta-session, to manage Nauta Hogar sessions, I can already go to sleep, stressless 😉.

Me cuadró. Ya me puedo acostar a dormir 😉. pic.twitter.com/Xe1UwFYnPC

— Alexánder Fernández (@alexfdezsaucoCU) September 25, 2020

Getting started with Blorc.PatternFly

Original Published on PatternFly Medium Publication

If you’re a developer who loves hands-on tactical tutorials, then read on. Today, we’re covering Blorc.PatternFly.

First off, the basics: What is Blorc.PatternFly? Standing for Blazor, Orc, and PatternFly, Blorc.PatternFly is a library with the ultimate goal of wrapping all PatternFly components and making them available as Blazor components.

Now let’s jump into a tutorial. Keep in mind that this tutorial isn’t meant as an overview of Blazor — you’ll need some basic knowledge of Blazor before diving in.

You’ll also need to have these tools handy:

• Visual Studio 2019 (16.4.2)
• Blazor (3.1.0-preview4.19579.2)

Step 1: Creating the project

First, go through the Get started with ASP.NET Core Blazor tutorial for Blazor WebAssembly experience. You’ll create the Blazor project in this tutorial, and you’ll only have to convert the Bootstrap to PatternFly. For the purpose of this guide, use Blorc.PatternFly.QuickStart as the project name.

Follow the on-screen instructions of the Visual Studio project:

Create a new project.

Configure your new project.

Create a new Blazor app with Blazor WebAssembly experience.

The Blazor template is built on top of Bootstrap. So the resulting app looks like this:

Index.razor and SurveyPrompt.razor

Counter.razor

FetchData.razor

From here, you’ll replace the Bootstrap look and feel with the PatternFly one.

Step 2: Startup configuration

Once the project has been created, add Blorc.PatternFly as a package reference via NuGet. At the time of writing this article (which I hope you’re enjoying!), this package is only available as prerelease. To install the latest prerelease version, check the Include prerelease option in the Package Manager.

Adding latest prerelease of Blorc.PatternFly package

Also, it’s mandatory to register the Blorc.Core services in the ConfigureServices method of the Startup class, shown below:

Once the Blorc services are registered, it’s time to start replacing the UI elements, starting with the content of the index.html and site.css files.

To make sure that no unused dependencies are being deployed, remove the bootstrap and open-iconic directories from the wwwroot/css directory.

Step 3: Updating pages and components

The time has come to update the components. You should be able to update the content of the razor files with references to the available Blorc.PatternFly components.

You can do this yourself by following the steps below or you can clone the repository with the source code of this tutorial.

For instance, the MainLayout component must inherit from PatternFlyLayoutComponentBase, and you can use the Page component as follows:

For the NavMenu, you could use the Navigation component and update the razor file as shown below:

Finally, update the content of the Counter and FetchData pages.


And that’s it! Great work. Your application should now look like the screenshots below:

Index.razor and SurveyPrompt.razor

Counter.razor

FetchData.razor

Send us your feedback

Keep in mind that the library is a work in progress, and there are still a few PatternFly components being implemented. We are continuously releasing new versions. The good news is that Blorc.PatternFly is open source, and the sources are available on GitHub.

If you would like support for any new component, contribute to the Blorc.PatternFly library on GitHub. You can get in touch by:

• Creating tickets.
• Contributing by pull requests.
• Contributing via Open Collective.

Finally, if you want to see the latest develop branch of Blorc.PatternFly in action, you can browse to the live demo with a full overview of all the PatternFly components already available for Blazor. And you’ll probably agree: PatternFly and Blazor are awesome — and combined, they are a beautiful pair.

Interested in contributing an article to the PatternFly Medium publication? Great! Submit your topic idea, and we’ll be in touch.

What about Catel.Fody and computed read-only properties change notifications?

In my last post, I covered the implementation of INotifyPropertyChanged interface when using SheepAspect as an AOP library. In the end, I also implemented an approach to notify changes of computed read-only properties. This approach has a downside, the dependent properties discovering process must be done in run-time.

Such a journey recalls us that Catel.Fody didn’t have support for notifying property changes of computed read-only properties. How could such a thing ever be possible? Obvious, “the shoemaker's son always goes barefoot” ;). But don’t worry: the feature is here, moving the dependent properties discovering process to build-time, thanks to Fody.

As you probably know by now, Catel.Fody will rewrite all properties on the DataObjectBase and ViewModelBase. So, if a property is written like this:

public string FirstName { get; set; }

will be weaved into

public string FirstName
{
    get { return GetValue<string>(FirstNameProperty); }
    set { SetValue(FirstNameProperty, value); }
}

public static readonly PropertyData FirstNameProperty = RegisterProperty("FirstName", typeof(string));

But now we added a new feature to Catel.Fody. If a read-only computed property like this one exists:

public string FullName
{
    get { return string.Format("{0} {1}", FirstName, LastName).Trim(); }
}

the OnPropertyChanged method will be also weaved into

protected override void OnPropertyChanged(AdvancedPropertyChangedEventArgs e)
{
    base.OnPropertyChanged(e);
    if (e.PropertyName.Equals("FirstName"))
    {
        base.RaisePropertyChanged("FullName");
    }
    if (e.PropertyName.Equals("LastName"))
    {
        base.RaisePropertyChanged("FullName");
    }
}

This feature is already available in the latest beta package of Catel.Fody.

Try yourself and let us know.

Implementing notify property changed with SheepAspect

Introduction

I spend some time looking for AOP options for .NET.  All references point to PostSharp as the coolest option - even when you have to pay to use it - due to its features, starting from the way it works – in build time and static – plus a lot of build-in “advice” and extensions points.

There are also several run time and dynamic options such as Castle, Unity, etc., but I prefer the build time and static approach.  Indeed I use Fody - as an alternative to PostSharp - even when I have to write down custom plugins directly in IL.

But all of these AOP-like libraries and tools for .NET do not allow you to handle exactly the all the AOP concepts such as pointcut, join-point, and advice.

But recently I found a project in CodePlex, named SheepAspect with an introductory statement that includes the following words “…was inspired in AspectJ”. So, I just installed the package from NuGet and started to write in C# a notify property changed proof of concept with a friend of mine (Leandro).

Introducing NotifyPropertyChanged aspect

The very first step is to write a NotifyPropertyChangedAspect class. It’s important to get related with SAQL in order to query the right properties from the right types, and with the usage of the SheepAspect attributes. For this particular example the pointcut includes “all public property setters of types that implement System.ComponentModel.INotifyPropertyChanged” and look like this:

[Aspect]
public class NotifyPropertyChangedAspect
{
    [SelectTypes("ImplementsType:'System.ComponentModel.INotifyPropertyChanged'")]
    public void NotifiedPropertyChangedTypes()
    {
    }

    [SelectPropertyMethods("Public & Setter & InType:AssignableToType:@NotifiedPropertyChangedTypes")]
    public void PublicPropertiesOfTypesThatImplementsINotifyPropertyChangedInterfacePointCut()
    {
    }
}

Now, I just needed to add the notify property changed behavior as around advice just as follow:

[Around("PublicPropertiesOfTypesThatImplementsINotifyPropertyChangedInterfacePointCut")]
public void AdviceForPublicPropertiesOfTypesThatImplementsINotifyPropertyChangedInterface(PropertySetJointPoint jp)
{
    object value = jp.Property.GetValue(jp.This);
    if (!object.Equals(value, jp.Value))
    {
        jp.Proceed();
        jp.This.RaiseNotifyPropertyChanged(jp.Property);
    }
}

As you should notice, to implement this, I also introduce a couple of extension methods TryGetPropertyChangedField and of course the RaiseNotifyPropertyChanged itself:

public static bool TryGetPropertyChangedField(this Type type, out FieldInfo propertyChangedEvent)
{
    propertyChangedEvent = null;
    while (propertyChangedEvent == null && type != null && type != typeof(object))
    {
        propertyChangedEvent = type.GetField("PropertyChanged", BindingFlags.Instance | BindingFlags.NonPublic);
        if (propertyChangedEvent == null)
        {
            type = type.BaseType;
        }
        else if (!typeof(MulticastDelegate).IsAssignableFrom(propertyChangedEvent.FieldType))
        {
            propertyChangedEvent = null;
        }
    }

    return propertyChangedEvent != null;
}

/*...*/

public static void RaiseNotifyPropertyChanged(this object instance, PropertyInfo property)
{
    FieldInfo propertyChangedEvent;
    if (instance.GetType().TryGetPropertyChangedField(out propertyChangedEvent))
    {
        var propertyChangedEventMulticastDelegate = (MulticastDelegate)propertyChangedEvent.GetValue(instance);
        var invocationList = propertyChangedEventMulticastDelegate.GetInvocationList();
                
        foreach (var handler in invocationList)
        {
            MethodInfo methodInfo = handler.GetMethodInfo();
            methodInfo.Invoke(handler.Target, new[] { instance, new PropertyChangedEventArgs(property.Name) });
        }
    } 
}

Now, if a class that implements or inherits from a class that implements INotifyPropertyChanged interface is added, just like this one:

public class Person : INotifyPropertyChanged
{
        public event PropertyChangedEventHandler PropertyChanged;

        public string FirstName { get; set; }

        public string LastName { get; set; }

        public string FullName
        {
            get
            {
                return string.Format(CultureInfo.InvariantCulture, "{0} {1}", this.FirstName, this.LastName).Trim();
            }
        }
}

and a program like this one is written:

this.person.PropertyChanged += (sender, args) =>
                {
                    object value = sender.GetType().GetProperty(args.PropertyName).GetValue(sender);
                    Console.WriteLine("Property Changed => '{0}' = '{1}'", args.PropertyName, value);
                };

this.person.FirstName = "Igr Alexánder";
this.person.LastName = "Fernández Saúco";

then the output will be:

Property Changed => 'FirstName' = 'Igr Alexánder'
Property Changed => 'LastName' = 'Fernández Saúco'

Uhmm! But what about with the computed read-only properties like FullName?

Notifying property changes of computed read-only properties.

In order to notify changes of computed read-only properties, an inspection of the IL code is required. The .NET native reflection API is limited. From the PropertyInfo is only possible to get the IL byte array from the get method body, and nothing more. Therefore, I just switched to the Mono.Cecil reflection API to be able to complement the existing RaiseNotifyPropertyChanged extension method with the following extension methods:

public static bool ExistPropertyDependencyBetween(this Type type, PropertyInfo dependentProperty, PropertyInfo propertyInfo)
{
    AssemblyDefinition assemblyDefinition = new DefaultAssemblyResolver().Resolve(type.Assembly.FullName);
    TypeDefinition typeDefinition = assemblyDefinition.MainModule.GetType(type.FullName);
    PropertyDefinition dependentPropertyDefinition = typeDefinition.Properties.FirstOrDefault(definition => definition.Name == dependentProperty.Name);
    
    bool found = false;
    if (dependentPropertyDefinition != null)
    {
        MethodDefinition definition = dependentPropertyDefinition.GetMethod;
        if (definition.HasBody)
        {
            ILProcessor processor = definition.Body.GetILProcessor();

            int idx = 0;
            while (!found && idx < processor.Body.Instructions.Count)
            {
                Instruction instruction = processor.Body.Instructions[idx];
                
                MethodDefinition methodDefinition;
                if (instruction.OpCode == OpCodes.Call && (methodDefinition = instruction.Operand as MethodDefinition) != null && methodDefinition.DeclaringType.IsAssignableFrom(typeDefinition) && methodDefinition.Name == string.Format(CultureInfo.InvariantCulture, "get_{0}", propertyInfo.Name))
                {
                    found = true;
                }
                else
                {
                    idx++;
                }
            }
        }
    }

    return found;
}

/*...*/

public static IEnumerable<PropertyInfo> GetDependentPropertiesFrom(this Type type, PropertyInfo property)
{
    List<PropertyInfo> dependentPropertyInfos = type.GetProperties(BindingFlags.Instance | BindingFlags.Public).Where(dependentProperty => property != dependentProperty && dependentProperty.CanRead && type.ExistPropertyDependencyBetween(dependentProperty, property)).ToList();
    for (int i = 0; i < dependentPropertyInfos.Count; i++)
    {
        foreach (PropertyInfo info in type.GetDependentPropertiesFrom(dependentPropertyInfos[i]))
        {
            if (!dependentPropertyInfos.Contains(info))
            {
                dependentPropertyInfos.Add(info);
            }
        }
    }

    return dependentPropertyInfos;
}

just like this:

public static void RaiseNotifyPropertyChanged(this object instance, PropertyInfo property)
{
    FieldInfo propertyChangedEvent;
    if (instance.GetType().TryGetPropertyChangedField(out propertyChangedEvent))
    {
        var propertyChangedEventMulticastDelegate = (MulticastDelegate)propertyChangedEvent.GetValue(@this);
        var invocationList = propertyChangedEventMulticastDelegate.GetInvocationList();
                
        foreach (var handler in invocationList)
        {
            MethodInfo methodInfo = handler.GetMethodInfo();
            methodInfo.Invoke(handler.Target, new[] { instance, new PropertyChangedEventArgs(property.Name) });
        }

        foreach (PropertyInfo propertyInfo in instance.GetType().GetDependentPropertiesFrom(property))
        {
            foreach (var handler in invocationList)
            {
                MethodInfo methodInfo = handler.GetMethodInfo();
                methodInfo.Invoke(handler.Target, new[] { instance, new PropertyChangedEventArgs(propertyInfo.Name) });
            }
        }
    }
}

So, now the program output is:

Property Changed => 'FirstName' = 'Igr Alexánder'
Property Changed => 'FullName' = ' Igr Alexánder' 
Property Changed => 'LastName' = 'Fernández Saúco'
Property Changed => 'FullName' = ' Igr Alexánder Fernández Saúco'

Conclusion

At this point, you should be worried about the performance and a lot of reflection API calls. I'm pretty sure that this issue could be handle with the right caching approach ;).

I didn’t know why I never heard about SheepAspect before. Probably no one trust in something called “Sheep”, but believe me SheepAspect rocks!

Wait for a second! Right now I'm reading about something called mixing. Probably I can get a more declarative approach to implement this, just like the Fody or PostSharp home page examples. But I'm not sure right now, so, you have to wait for my next post to know about it ;).