Writing Unit Test for SMTP Component


I was working on a notification system that allows users to subscribe an email notification based on the status of the database record. An email will be sent to the destination whenever the status is satisfied.

As the system is providing various of email templates for users to choose when they’re defining the subscription. So the challenge to the development team is writing the unit test for each template and ensure the code coverage is more than 90% according to the DevOps strategy.

Writing this post, I would like to share the experience to write the unit tests for SMTP and how to perform the system integration test (SIT) without Exchange Email Server.

I. Writing Unit Tests For SMTP

As in the email template, I allow users to add some predefined parameters into email subject and body as the sample below:

  •  [DateTime]: before delivery email to destinations the system will transform this token to current date time.
  • [RecordId]: the system will pick up the primary key value of the record and replace to this token.
  • [CreatedBy] or [UpdatedBy]: if these tokens are in email subject it will be transformed to account email from active directory. If it is in email body then will be transferred to account name instead.

The requirement of the unit test for this system is able to verify not only template transformation but also the SMTP communication in order to limit the number of the code issues bugs leaking to SIT and UAT.

I found a useful open source library named netDumbster allows to simulate an SMTP service for developers to write the unit tests for SMTP module. This module allows running the unit tests in any build server without any additional installation needed.

Below is the source code for a sample notification service

And here is the unit test for this service.

The configuration of the Unit Test project.

You may face below issue when using this library. Because the SMTP is not stopping property and the unit tests process is still running.

To resolve this issue just simply force stop below processes in the Task Manager and then run the unit tests again.

Here is the result when running the auto build on the VSTS.

I would recommend using [AssemblyInitialize] and [AssemblyCleanup] to start and stop the SMTP emulator instead of [TestInitialize] and [TestCleanup] because start and stop the emulator is taking time and sometimes the SMTP is not stopped properly and keep holding the port 25 so that the next instance is not able to initialize for the second test method.


II. The SMTP Emulator for SIT and UAT.

There are so many reasons that we don’t want The testers using the real Product exchange server to perform the SIT or UAT testing. I don’t want to list out the reason here. However, if you are looking for an alternative solution that allows testers testing the SMTP without exchange server then there is a free and open source tool for that purposes.

The Papercut is an SMTP emulator that saving the incoming emails to a location instead of delivery to the real destinations. This tool provides a WinForms application that allows tester verify the email directly.

There is a Papercut service allows you host the SMTP emulator on to a server in the test environment and share across to all application.

III. Source Code

You can download the demo source code here.

HBD.Mef.Mvc Enhancement For WebApi


Like the previous post, I have introduced a Workspace for Web Mvc and along with the post, AzureNotes Module was provided as an example.

Now in this post, I would like to update you the new version 1.0.5 of HBD.Mef.Mvc. From this version, it will support the WebApi technology that allows developing a similar Workspace for Web API.

The HBD.Api.Shell

Similarly to HBD.Mvc.Shell, the HBD.Api.Shell is the Workspace allowing to develop a WebApi module in the different project and deploy to the Workspace lately.

Develop a WebApi module is simpler than develop a module for Wb Mvc because WebApi doesn’t have any resources (views, CSS files, and JavaScript files) other than controllers. Hence, deployment a module into the Shell is just copying the binaries and config files only.

To simplify the life, I have provided a general routing for all Modules including the Workspace as below.

This route is applying for all modules and all controllers. Hence, the pathway to access to a controller is api/{area}/{controller}{id} which {area} is Module’s name, {controller} is the controller name and {id} is optional.

The module registration also simplified instead of providing the Module Name and custom routing. Promptly with API module requires the name only. Below is sample code to register an API module.

The HBD.Mef.Mvc will base on the registered named and select the appropriate controller for the request. If there is no controller found for an appropriate request the HttpResponseException with 404 status code will be thrown.

Mef Controller Resolver Service

Please note that this registration is for Api modules only. There is nothing changed on the Mvc module registration that had been introduced on the previous post.

The AzureNoteApi

I would like to show you a similar module for HBD.Api.Shell called AzureNoteApi; this module is just exposing all actions of AzureNote in the previous post as WebApi. Below is the details information the Apis. You can use Postman to try out with my live demo.

Live Demo

The HBD.Api.Shell is also published on to Azure you might have a try by using Postman with the following API.

  • HBD.Api.Shell API

  • AzureNote API

Source Code

The latest source codes had been uploaded to Github you can download here.

Why Workspace? Why Mef? What HBD?


As recently, I’d shared a few libraries that allow developing a Workspace, and many people asked me, What is Workspace and Why should We care about it?

So, I come up with this post to share a few advantages of the Workspace. I’m not talking about disadvantage here because every Framework has the pros and cons itself. However, We choice it because it was suitable for our company, our departments and our teams or in other words is our customers choice it.

The Advantages Of the Workspace

  1. When developing a new application, we need to build the framework, define the project’s structure, the theme and layout in the IDE and beside of that we need to implement the services that will be used in the application as authentication service, workflow service, input, and output services. What happen if there are so many applications are developing on the different teams in your department, and eventually, each team come up with an application that has difference theme, layout, and components. Just consider Workspace is a Framework and it will help to manage the layout, theme, services consistently between the development teams. It also advises removing the duplication efforts when two or three teams are implementing the similar components.
  2. The other case. In your department, there are a hundred websites are operating and now your company just released a new logo and requested to replace the logo on all application. So, how many teams need to involve and how long it take? As you know re-branding is not only a logo but also the theme, color table, and fonts of the application are getting changed. However, if you have a Workspace you just need to enhance and re-deploy it again without impact to the modules.
  3. Let’s see, If your department already had the Workspaces. So when any team wants to build a new application they can use that Workspace as a framework and start to develop their modules instead of taking time for solution structure, framework defination, theme, and layout creation for the application.

The other Advantages already shared on the previous post. I would like to bring them here so that We will have a general view on it.

  1. Let’s imagine, if you have many development teams and tring hard to make the teams work independently and parallely. However, if three or four teams are working a the significant changes of a complex application and that application does not support modularization. So when any team needs to deploy the changed to the Stagings or Production environments, they need to inform all the other teams to ensure there is no conflict between the teams. After deployed, the other teams need to merge the changes into their source code branches. Managing this situation is a nightmare for the project manager.
  2. The other scenario, if the application doesn’t support modularization, so any change even the small one you need to conduct the System Integration Test (SIT) and User Acceptant Test (UAT) for the whole system because of the impact and the efforts will charge back to the business. You know, the business users may surprise why the simple change is costly?
  3. Micro-Services adoption: as you know, Micro-service is new technology that structures an application as a collection of loosely coupled services, which implement business capabilities. The microservice architecture enables the continuous delivery/deployment of large, complex applications. It also enables an organization to evolve its technology stack.

Why’s Mef

I’ve worked on many Dependency Injections as Ninject, AutoFax, Unity, QuickInject and StructureMap.

The functionality of them is the same because they have been implemented based on Ioc, Dependency Injection concepts. Similarly, The Mef had been released sine the .Net Framework 4.0

Only one thing different between the libraries is the way to import the type mapping and export the objects from the DI container.

If you ask me Why I like Mef? The answer is because of Love. The crazy love without reason. I think the accepted answer is because She is Microsoft’s daughter.

Hope the answer satisfies you.

What is HBD?

HBD (Hoang Bao Duy) is just a lazy, foolish developer, and all his projects were supposed for personal used only.

All HBD projects had been developed by himself. Obviously, There are a lot of silly code in his projects. If you found it, please help to point it out, that is the way you help him grow.

He is not recommending to use his library on your company projects because the enterprise project framework should be verified carefully by the professional development and testing teams.

Saying that doesn’t mean the libaries were came up with poorly quality. Just want to share more information about HBD libraries, all had been tested carefully before publishing, beside that the vulnerability scanning, code quality scaning are applied by using Sonarqube.comWhitesource-Bolt. The unit tests, code UI tests also a part of his projects in order to ensure all functionality of the libraries are working as expected. Furthermore the author had trying his best to improve the libraries, add new features and hotfix the defects promptly.

However, if you want to implement something but don’t know how to start or you want to have some referent code then the HBD open source projects are for you.

Source Code

All HBD projects had been published in here.

The Mef for MVC and Azure DocumentDb Demonstration 


As I’d already shared the Mef libraries for WPF, WinForms and Console Application. So In this post, I would like to share one more Mef library for .Net MVC.

As you may know, The MVC is supporting Areas that allow developing a set of Views, Controllers, and Resources (Images, CSS and Javascript) inside Areas folder. However, the areas are still a part of MVC application, and the resources need to be imported into the _Layout view manually and deploy along with the application. Beside of that, if any changes in the areas may impact to the whole application and need to be tested carefully before going live.

I. HBD.Mef.Mvc Introduction

PM> Install-Package HBD.Mef.Mvc

The Definition.

  • Workspace: this is an MVC website (a Shell) considering as Module container that allows deploying and run multi modules separately.
  • Module: this is a loosely couple MVC area that is implementing independently with Workspace and able to deploy into the Workspace lately.

So, get used of Area in MVC, I would like to introduce my HBD.Mef.Mvc library, it had been implemented based on the Mef technology allows you to build and manage the MVC areas as a module not only in a separate folder but also in different projects.

Before going to details of the library implementation, I would like to discuss a few questions below.

Why do we need the Modularization application?

  1. Let’s imagine, if you have many development teams and try to make the teams are working independently and separately as much as possible. However, if three or four teams are working a the significant changes of a complex application and that application does not support modularization. So when any team needs to deploy the changed to the Stagings or Production environments, they need to inform all the other teams to ensure there is no conflict between the teams. After deployed,  the other teams need to merge the changes into their source code branches. Managing this situation is a nightmare for the project manager.
  2. The other scenario, if the application doesn’t support modularization, so any change even the small one you need to conduct the System Integration Test (SIT) and User Acceptant Test (UAT) for the whole system because of the impact and the efforts will charge back to the business. You know, The business users may surprise why the simple change is costly?
  3. Micro-Services adoption: as you know, Micro-service is new technology that structures an application as a collection of loosely coupled services, which implement business capabilities. The microservice architecture enables the continuous delivery/deployment of large, complex applications. It also enables an organization to evolve its technology stack.
Micro Service Architecture

So the advantage of the Modularization application:

  • Allow the teams are working on the modules independently, parallelly.
  • Speed up and enable continuous development, delivery process: In term of the Agile development process. Normally, the sprint time is two weeks, and the recommendation to the development team is releasing a small workable feature of the application and demo to the Business users on the Sprint demonstration meeting.
  • Help to scale down the impact of the changes and increase the scalability, flexibility, and stability of the application.
  • Developing and maintain the automation tests or UI tests for a module is much easier for the whole complex application.

What is Mvc Module?

As you know, develop a Module is not just a Views and Controllers but also the settings, configuration, resources, Business and Data logics also. On the next sections, I will show you how to build a Workspace and create a module for that Workspace separately by using HBD.Mef.Mvc.

II HBD.Mef.Mvc Features

1. Navigations

Along with a Module is a set of navigation that We need to add into the top menu of the Workspace to allow users to navigate and using your modules functions. Let’s see, if developing a module and the navigation are adding directly to the _Layout view of the Workspace, and overwriting the  _Layout file of the Workspace in every deployment. In this case, the dependence happens again if there are more than one development teams are working the same Workspace and on each team, they also maintain a different version of _Layout view on their modules.

  • INavigationService

So in this library is provided an INavigationService allows registering the navigations into the Main Menu of Workspace dynamically.

Currently, the Main menu is supported two level only. You can add a navigation link directly in the main menu, or add a menu and navigation links are children of that menu.

  • IFooterNavigationService

Similarly, the IFooterNavigationService allows registering the links into Footer portion of the Workspace dynamically.

  • Navigation and Authorization

In the MVC some controller actions are required a particular Roles for the execution. So if the current user doesn’t have the necessary Roles, she is not able to execute that actions. In this case, the Workspace will hide all the navigation related to that actions automatically. If there are no visible children of a menu, the Workspace will hide the parent menu as well. It will help to save the main menu space for the other modules.

2. Resource Bundle Handling.

Working with MVC, you will know that the framework provides a feature called Bundle to allows to import the CSS and javascript files into the views.

Similar to navigation. Including all resources into the _Layout view of the Workspace is not recommended and it may conflict with the resources of the other Areas.

To resolve this issue. I have implemented a helper class in the library allows to register the module resources into the bundles and manage to render that bundles when accessing the module viewsIt means the Workspace will present the resources of the accessing module into the _Layout page at runtime. This feature will ensure that no CSS or java scripts conflicts between the Modules.

3. Controllers scanning.

You may be aware that, if we want to export a class into Mef container, we need to mark the class with Export attribute. What happens if you forgot to mark this attribute to the controllers? No worry this case had been covered in this library. It will scan all controllers in your binaries and export into Mef container automatically.

4. Configuration management.

As you know, running a .Net website the AppSettings and ConnectionStrings will be loaded into ConfigurationManager class of System.Configuration.

Definitely, on each Module, it will have a separate set of App Settings and Connection strings. Instead of adding the configuration into Workspace config file. You can keep it in a Wed.config and place it in the top level of your Module. The library will load and merge into the ConfigurationManager automatically.

Currently. Only AppSettings and ConnectionString sections are supporting. As the configuration will merge into Workspace configuration, so I would recommend using the Module Name as the prefix of the configuration keys.

The sample code to show you how to use all features above will be provided on the Module development below.

III. Develop a new Workspace.

The idea to implement an MVC Workspace as a core foundation application, that allows to add-in the modules and services independently.

I have developed a Workspace named HBD.Mvc.Shell using HBD.Mef.Mvc and published to Github, if you want to develop a new Workspace by yourself you can reference my source code in here.


However, I would like to highlight a few things as below.

1. Bootstrapper class in the App_Start folder.

After installed HBD.Mef.Mvc from Nuget, a new Bootstrapper class, will be added to App_Start folder automatically.

Only one thing you need to do is overwrite the RegisterMainNavigation method and add the navigation of Workspace in. Because the Menu bar, Footer bar will be rendering from INavigationService and IFooterNavigationService instead of maintaining the menus manually.

The rest of configuration, modules loading, resources management will be done automatically by Bootstrapper itself. However, all methods of Bootstrapper are in virtually so in case you want to customize the logic you can overwrite them easily.

Please note that the DisplayAt and AlignAtRight only supported int the root menu level for both The main menu and Footer navigation.

The FontAwesome and Glyphicon icons also supported on both levels of menu. If you want to display an image on the menus instead, you can replace the Glyphicon with a virtual path of the image location. When rendering the Workspace will scan the image from both Area and global Workspace folders and display the image properly.

2. Main menu and Footer partial views.

In HBD.Mvc.Shell Workspace, I had moved the main menu and footer of _Layout view to the partial views. So, in future if any changes on the menu rendering we just need to re-deploy the small part view files instead of a whole _Layout file. This will help to minimize the impact of the changes to the Workspace.


Navigation Partial Views

3. Navigation Authorization.

As mentioned above. The navigations are supporting the Authorization, and I would like to move to a separate section to show you how the navigation can pick up the Roles from a controller, or you can specify the Roles manually.

  • Auto Pickup the Roles from Authorize attribute.

The sample code to add a navigation for a controller action

With above code, we will add a navigation titled Import Account From File for the ImportFromFile action of ImportController and below is controller code.

The For extension method will check the Authorize attribute of ImportFromFile action to whether any Authorize with Roles had been specified and pick up the Roles for the navigation automatically. If there is no Authorize attribute had been found it will check at the Controller level for the same.

Note that this automation only happens when there is no Roles had been provided. It means if you already provided the Roles for navigation the auto role pick up won’t be executed.

  • Specify the Roles manually.

Below code is a sample for the manual Role specification:

The WithAuthorize is an extension method that allows you to determine the Roles for navigation. If calling WithAuthorize without any parameter provided, it means the navigation just require the current user is authorized.

IV. Quick start Module development.

To prove my library is working. I have implemented a simple module named Azure Notes. This module is a personal notebook and using Azure DocumentDb to store the note items.

Before starting with the Module implementation, we need to create the Azure DocumentDb first. There is two option for the developers.

1. Setup DocumentDb on Azure Portal

If you already had the Azure Subscription, you can log in to the portal and create a DocumentDb account and then create a collection with the following information.

  • Database name: AzureNotes
  • Collection Id: AzureNotes
  • Partition Key: AzureNotes
  • Storage Capacity: 10GB.
  • Throughput Capacity: 400 RU/s

If you don’t have Azure Subscription, you can install Azure DocumentDb Emulator here, and the create a similar collection as above.

2. Module Implementation

  • Create new Module

Create new Mvc Web application and install the latest version of HBD.Mef.Mvc from nuget. After installed you can delete all the redundant files and just keep the below folders and files.

  • Content folder
  • Controllers folder
  • Views folder
  • Scripts folder
  • all configuration files.

And then add a new class named <YourModuleName>AreaRegistration and then inherited from MefAreaRegistration in HBD.Mef.Mvc this class will help to register your module as an Area in the Workspace application.

Your module should look similar as below.

  • Register Module Routing

  • Register Main Menu Navigation

  • Register Footer Navigation

  • Register Module Bundles

  • Update the App Settings of Web.config file
    • Using Azure DocumentDb Emulator

    • Using Azure DocumentDb

The DocumentDB Account URL and Key can be found in the DocumentDb Account Keys

  • Controller and Views Implementation

You shall continue to implement your controllers and views logics as usually. However, remember to add the Export attribute to your Controllers.

3. Module Deployment

To deploy your module into Workspace. All the folder below need to be copied into Areas\<YourModuleName>\ folder. All binaries of your module will be copied to the bin folder of Workspace.

  • Debug Mode

Running your module on the localhost, you can use set below command line into the post-build event of your module. It helps to copy the necessary files and folders into the Workspace on every build.

  • Deploy to Production

Package your module as the structure below for the production deployment. So that, IT guys can help to copy the folder and files quickly or use the auto deployment tool to deploy the zip file into Workspace application.

  • AzureNotes.zip
    • Areas
      • AzureNote
        • Content: all CSS files of your module.
        • Scripts: all javascript files of your module.
        • Views: all *.cshtml files and folders of your modules.
        • Web.config
    • bin
      • AzureInterfaces.dll
      • AzureNote.dll
      • AzureNoteEntities.dll
      • AzureStorage.dll
      • DocumentDB.Spatial.Sql.dll
      • Microsoft.Azure.Documents.Client.dll
      • Microsoft.Azure.Documents.ServiceInterop.dll

After deployed, just recycle the application pool to re-initialize the Workspace to load new module and displayed on the screen.

4. Live Demo

I have hosted the HBD.Mvc.Shell and Azure Notes module onto my Azure, you may want to take a look at the link below. I just have 25$ on my subscription. So hopefully It is not going to down soon.

V. Source Code

  1. HBD.Mef.Mvc
  2. HBD.Mvc.Shell
  3. AzureNotes

The WPF Workspace – Quick Start


Nuget Package:

PM> Install-Package HBD.WPF.Shell

As the Workspace for WPF had been introduced a few day back. So is this post I would like to show you how to get started with that application.

I.  Module Implementation.

1. Add New Project

  • Open Visual Studio and create a new WPF User Control Library project with project name is WPF.Demo.Module.
  • Install the latest version of HBD.WPF.Shell from Nuget.
  • Add a new class named DemoStartup and inherited from HBD.WPF.Shell.Modularity.WpfModuleBase and then override 2 methods (GetStartUpViewTypes and MenuConfiguration(IShellMenuService menuSet)) as below.
  • Remember to add the ModuleExport attribute into your DemoStartup class.

2. Setup the Module_*.json

  • Add a new json named Module_Demo.json with the below content.

  • Set the build action of this config file is Copy Alway.

3. Add a new User control

  • Add a new class named ViewModel1.cs inside folder ViewModels as below.

  • Add a new User Control named View1.xaml inside Views folder with the code behind as below.

4. Setup the Public folder

  • Copy folder [Solution Directory]\packages\HBD.WPF.Shell\tools\Shell to [Solution Directory]\Published\Shell.
  • Right click on the project select Properties
  • Add below code into Post-build event

  • Set Start external program under Debug to [Solution Directory]\Published\Shell\HBD.WPF.Shell.exe
  • And set Working directory to [Solution Directory]\Published\Shell folder.
Debug Setup

5. Run the application with this Module.

  • After finished all above steps, the project shall look like below.

  • Build and Run the application you will see the new Demo menu had been added. When clicking on the child menu item the View1 will be open on the Tab control.

II. Source Code

Download the WPF.Demo.Module here.

Hope my Workspace is useful.

The Workspace for WPF Application Introduction


Nuget Package:

PM> Install-Package HBD.WPF.Shell

I. HBD.WPF.Shell Introduction

Similar with HBD.WinForms.Shell and HBD.App.Shell. In this post, I would like to introduce one more Shell Foundation for WPF Application. This open source project had been developed based on Prism and WPF technologies, that allow to add-in the Modules at run-time. So that you can use this project as a Foundation of your application and then develop and maintain your modules separately and independence.

The Main window

II. The Available Regions

When working with Prism, the region is one of the good features allow to organize display area and navigation of the controls in the application. As the screenshot above there are 7 regions are available in this Shell.

1. The Menu Region

This region will be used to display the main menu of the Shell. The main menu view will be loaded into the menu region when the application started and it can’t be replaced or deactivated and the menu view must be inherited the  HBD.Mef.Shell.Views.IShellMainView interface. So that the Shell will extract the view from Mef container based on this interface type.

The sample code of the main menu view.

The Main Menu View

2. The Right Region

This region will be used to display the notification center of the Shell. Similar to the main menu view. The notification center view will be loaded into the right region when clicked the bell icon on the menu view. However, it can be replaced or deactivated. This view also requires being inherited the  HBD.Mef.Shell.Views.IShellNotificationCenterView interface.

The Notification View

3. The Status Region

This region will be used to display the status view of the Shell. This view will be loaded at app start and can’t be replaced or deactivated. This view required to be inherited the HBD.Mef.Shell.Views.IShellStatusView interface.

4. The Main Region

This region will be used to display the Tab Control View that allows adding the custom views from the Modules. The same with Status View, This view will be loaded at app start and not allow to replace or deactivate. It also required being inherited the  HBD.Mef.Shell.Views.IShellMainView interface.

5. The Left Region

This region is available and will be shared for all modules. The look and feel are similar to the left region.

6. The Tab Region

This region must be defined in the Tab Control View to tell the Shell that all custom views from the modules will be displayed in the Tab Control.

The Tab Control View

7. The Title Region

When creating a custom view of the Module. The view header and view title need to be specified. The view title will be displayed on the Tab header and view header will be displayed in the title region.  However, only view title will be displayed when loading to the Left orRight region as the screenshot below. As the other view, this title view needs to be HBD.Mef.Shell.Views.IShellTitleView inherited the interface.

Title region

Just hightlight that all Views of this Shell had been implemented in the separate library named HBD.WPF.Shell.UI and export into Mef container. So that, you can customize the views by replace HBD.WPF.Shell.UI with the other library that content the full set of the above views.

Refer the source code of HBD.WPF.Shell.UI for more details.

III. The Built-inServices of the Shell.

Below built-in services had been developed along with this project. I will post a separate post for each service to discuss the usage and customization later. In this section just introduce the service functionality and how to use it.

Please note that all built-in service had been added into the HBD.WPF.Shell.ViewModels.ViewModelBase abstract class.  So recommend that all view model should be delivered from this class.

1. Dialog Service

The dialog service is providing the easy way to interact with the dialog as

  • Display a UserControl as dialog.
  • Open the file browser dialog
  • Open the Folder browser dialog.

The service is an instance of  HBD.WPF.Shell.Services.IDialogService interfaces and exported to the Mef container.

  • Sample code

  • Dialog screenshot

2. Message Box service

The message box service is providing the common dialog as Information, Alert, Confirm and Error message box and shared across the modules. So that message box will be displayed consistently.

This service is an instance of  HBD.WPF.Shell.Services.IMessageBoxService interfaces and exported to the Mef container.

  • Sample code
  • Information Box
  • Alert Box
  • Confirmation Box

3. Notification Service

The notification service allows to display a notification on the screen and added into Notification automatically.  This service is an instance of  HBD.WPF.Shell.Services.INotificationService interfaces and also exported to the Mef container.

  • Sample code
  • Notification Screenshot.

4. Status Service.

The status service allows displaying the message onto the Status bar of the Shell. This service is an instance of  HBD.WPF.Shell.Services.IShellStatusService interfaces and also exported to the Mef container.

  • Sample code
  • Screenshot

5. Other Services.

  • Navigation Executer: this service will help to execute the  INavigationParameter
  • Shell Option Service: this service will save the states of the application: current position, current theme, window state and more.
  • Shell Region Navigation Service: This service provides an easy way to navigation between the views and regions.

6. Upcoming Services.

The services below are under development and hope it will be release soon.

  • Authentication service: this service will be using the Open Authentication technology that allows the application interact with the OAuth services as Google, Facebook, Outlook, Linked-In, and Twitter.
  • Module management service: that allow downloading, import and manage the Modules in the Shell.

Just hightlight that all Services of this Shell had been implemented in the separate library named HBD.WPF.Shell.Services and export into Mef container. So that, you can customize the views by replace HBD.WPF.Shell.Services with the other library that content the full set of the services above.

Refer the source code of HBD.WPF.Shell.Services for more details.

IV. Implement the new Module.

Please refer here for the quick star with Module development here.

V. Source code

You can download the full source code of this Shell here. All the controls of this Shell had been customized from the Microsoft standard controls. So that feel free to use this project for your business.

The Workspace for Console application


Nuget Package:

PM> Install-Package HBD.App.Shell


This post, I Will share the other Workspace source code for Console Shell application as well. This one will provides the core foundation for the console application. That allows building a loosely coupled, module-able and maintainable application.

How does it work?

This Shell application had been developed based on HBD.Mef library that will automatic load all modules in the defined folder at run time. This application is suitable for those who want to develop a batch job that will be triggered by the scheduler and execute the particular plugin based on the input parameters.

Quick Start

1. Add New Module

  • Open Visual Studio and create a new Class Library project example project name is Job.Module.
  • Install the latest version of HBD.App.Shell from Nuget.
  • Add a new class named Job1 and inherited from HBD.Mef.ConsoleApp.ConsoleModuleBase and then implement 2 abstract methods (Initialize and Run(params string[] args)) as below. Remember to add the ModuleExport attribute into your Job1 class.

The function of this job is writing a message to the console and log file.

2. Setup Publish Shell folder.

  • Copy folder [Solution Directory]\packages\HBD.App.Shell\tools\App.Shell to [Solution Directory]\Publish\App.Shell

3. Update project’s properties.

  • Right click on the project select Properties
  • Add below code into Post-build event
  • Set Start external program under Debug to Publish\App.Shell\HBD.App.Shell.exe
  • And set Working directory to Publish\App.Shell folder.
  • And then set the Command line arguments is -job1 param1 param2 param3.

Job Module Debug

  1. Add Module config and Debug your module.
  • Add a new Module_Job_Demo.json file with the following content.
  • Set Build action of this config file as below

Job Module Json

  • Run your module, the Shell application will display as below.

App Shell Job1

How to run multi jobs with parameters

As the Command line arguments above you will see the first parameter is the JobName and then follow by the parameters for that job. If you want to execute multi-job you can pass the Command-line arguments following this format: -JobName1 param1 param2 param3 -JobName2 param1 param2 param3

This is a screenshot when executing multi jobs. App Shell Job1 Job2

If the Environment is Debug the console window will keep open unstil you press a enter key.

Source code

You can download the Job.Module source code here in Github – Job.Module

And the source code of HBD.App.Shell in here Github – HBD.App.Shell

Hope, this Shell will help you to develop a plugin-able application faster and easier. Your feedback and ideas are much appreciated. Please feel free to drop me an email with your opinion.

The Workspace for WindowForms

Nuget Package:

PM> Install-Package HBD.WinForms.Shell


This post, I would like to share my Winforms Shell application, that provides the core foundation for the Winforms application. With this foundation, it can be load the external modules from the pre-defined folders when it started. So that you can add-in and maintenance the modules easily.

How does it work?

This Shell application had been developed based on HBD.Mef library to loading and executing external modules when it starts. For more information about HBD.Mef you can found in here.

Build-In Services

In this Shell there are a few services had been developed and exposed into Mef that helps you to interact with the Shell component. 1. The IMainMenuService will help to add Menu Item into the Menu-bar of Main window.

Menu Bar

  1. The IStatusBarService will help to set the status into the Status-Bar of Main window.

Status Bar

  1. The IMainViewService will help to interact with Tab Manager of the Main window. That allow to add/remove UserControl into TabManager.

Tab Manager

  1. The NavigationManager will provide the details in the below section. # Quick Start – Develop a new module for HBD.WinForms.Shell

1. Add New Module

  • Open Visual Studio and create a new Class Library project example project name is Demo.Module.
  • Install the latest version of HBD.WinForms.Shell from Nuget.
  • Add new class named StartupDemoModule and inherited from HBD.Mef.WinForms.Modularity.WinFormModuleBaseand  then implement 2 abstract methods (GetStartUpViewTypes and MenuConfiguration(IMainMenuService menuSet)) as below. Remember to add the ModuleExport attribute into your StartupDemoModule class.
  • Add 2 new User Controls Named View1 and View2 as below.

Demo Module Views

  • On each view overwrite the Text property and return the View Title and add the Export attribute as below.

2. Setup Publish Shell folder.

  • Copy folder [Solution Directory]\packages\HBD.WinForms.Shell\tools\WinForms.Shell to [Solution Directory]\Publish\WinForms.Shell 

3. Update project’s properties.

  • Right click on the project select Properties
  • Add below code into Post-build event
  • Set Start external program under Debug to Publish\WinForms.Shell\HBD.WinForms.Shell.exe
  • And set Working directory to Publish\WinForms.Shell folder.

Demo Module Debug

4. Add Module config and Debug your module.

  • Add a new Module_Demo.json file with the following content.
  • Set Build action of this config file as below

Demo Module Json

  • Run your module the Shell application will display as below.

Demo Shell

Navigation between the Views.

From version 1.0.1 a new interface had been added into HBD.Mef.WinForms.Common to provide the communication channel between the views. So that the view and navigate to the other view with the parameters.

1. Implementation.

If your view wants to be navigated from the other view you need to implement the INavigationAware interface and handle OnNavigatedTo(WinformNavigationContext navigationContext) method, This method will be called when navigating from the other view.

  • The interface
  • The view implementation

2. Using NavigationManager

The sample code below will handle the button event and navigate to the other view

Navigation Manager

When running the application and click the button. View2 will be open and display the message was passed from View1.

3. Recommendation

There are 2 base classes had been provided in HBD.Mef.WinForms for your Forms and Views. So that when you create a new Form or View, it can be inherited from this form instead.

  • The FormBase
  • The ViewBase
  • The Form implementation
  • The View implementation

Demo.Module source code

You can download the Demo.Module source code here in Github

Hope this Shell will help you to develop a plugin-able application faster and easier. Your feedback and ideas are much appreciated. Please feel free to drop me an email with your opinion.Nuget Dependences

Anti Forgery Token and Machine Key


If working on Asp.Net MVC, you will know the anti-forgery token that helps to protect our website against cross-site request forgery.

To use this feature, call the AntiForgeryToken method from a form and add the ValidateAntiForgeryToken attribute to the action method that you want to protect.

  • Call AntiForgeryToken from a form

  • Add ValidateAntiForgeryToken attribute to the post action

How does it work?

When calling the AntiForgeryToken method inside a form, the AspNet will generate an encrypted AntiForgeryToken, pub into a hidden field and then send to the browser. When the browser submits the form back to the server, the token will be decrypted and validated to ensure that the request is genuine before execute the destination action method as long as the action method had been marked by ValidateAntiForgeryTokenAttribute.

The generated token looks like this:

What is the issue?

When deploy the website into an environment that has multi servers are load balancing together (web farm) you may facing with below issue when click the submit button.

The anti-forgery token could not be decrypted. If this application is hosted by a Web Farm or cluster, ensure that all machines are running the same version of ASP.NET Web Pages and that the configuration specifies explicit encryption and validation keys. AutoGenerate cannot be used in a cluster.

Why did this issue happen?

Assume that the environment has two servers are load balancing as the below diagram:

Farm servers diagram

Internally, the AspNet will use two keys (decryptionKey and validationKey) for token encryption/description and validation token. By default, these keys will be generated randomly when website start.

So, looks at the diagram above there are two instances of the website are hosting on different web servers in the single web farm. So that when both of them start a set of keys will be generated for each instance are differently.

Now, a request from user A had been redirected to the server 1 by the load balancer, the website in will response a view with an encrypted AntiForgeryToken. Later on, user A submits back the form to the load balancer and hopefully that the form will be captured and to be processed by the server 1.

Unfortunately, the load balancer now redirects that request to the server 2 instead and definitely, the token that had been encrypted by the server 1 can’t be decrypted on the server 2 because the keys are different. So the error was thrown.

The idea to fix this issue is ensuring all instances of the website using the same set of keys for the encryption/description and validation in the single web farm.

  • The keys should be different on each website on the same server. So if you have multi websites are hosting on the same server they keys should be unique.
  • The keys should be different on each environment for the same website. So if your website is hosting in multi-environments ensure that the keys on each environment are differently as well.

The solution for IIS

The idea is how to share the set of keys across the servers in the farm. So that the encrypt and decrypt process can happen on any server successfully.

Fortunately, When hosted an AspNet MVC website on IIS you can generate a set of keys by below steps

  1. Click on the website on IIS.
  2. Double click on Machine Key
  3. Uncheck all checkboxes and click Generate button at the right side and then click apply.
  4. The keys will be saved into the web.config file of the website.
  5. Open the web.config file, copy that keys and apply across to all website instances on the single farm.

Now, try the submit your website again. The issue should be resolved.

Iphone App and Azure Web Api


In this post, I would like to share with you How to develop a native cross platform mobile application that interacts with Azure Web service.

I. Requirement.

As an account manager, I would like to request a mobile application that allows connecting to Azure web service to add, update, delete and view user accounts remotely.

The user account information need be captured as below:

  • First name: the first name of user
  • Last name: the last name of user
  • Account: the account of the user that can be used to login to our systems.
  • Description

II. Build Azure service

1. Configuration Azure Web app and SQL Database.

  • First, I will create an Azure SQL Database named AzureMobileDemo with Basic pricing tier because this is just a sample database for demonstration purpose so no need a powerful one.
  • And then create new Web App + SQL named HBDMobileService in Azure with App server plan is F1 Free and lets it connect to AzureMobileDemo database that created in the previous step.

    Until now, we shall have an HBDMobileServer that connecting to AzureMobileDemo SQL database on the Azure portal. The Application Settings should be shown as below. Please ensure that the connection name is DefaultConnection if not just click on the connection string and rename it. Because we will config this name into the WebApi project later on next section.

2. Develop Web API

Below are tool and libraries I’m using for this project.

  • Tool: Visual Studio 2017
  • Framework: .NetCore 1.1
  • Libraries: EntityFrameworkCore
  • Project Type: Web API

A new Web API project named AzureMobileService had been implemented as the class diagram below.

There is a UserController had been created which exposed all needed actions:

  • Get all users in the database.
  • Get user by primary key.
  • Add new user.
  • Update the existing user.
  • Delete the existing user by primary.

This controller will user MobileDbContect to interact with Database. MobileDbContext is an instance of DbContext in EntityFrameWorkCore that’s using User as data model to transfer the information.

Please note that the name of connection string needs to be provided in the Startup class as below.

As I’m using code first in this project and wishing to execute the database migration automatically when applicate start in the Staging or Production environment. So, I updated the Startup.Configure method as below.

3. Deploy AzureMobileService to Azure.

Before deploying AzureMobileService to Azure we need config the publish profile for this project. The publish setting can be downloaded from HBDMobileService as screenshot bellow.

Right click on the AzureMobileService and click on publish, select import profile and then click create profile button to import the publish profile file. After imported, the Publish configuration should be shown as bellow.

Now, click the Publish button to deploy the web service to your Azure portal. After deployed you can use Postman to verify the Web API to ensure it’s working properly.

Take note the Site URL in the screen shot above we will need it for the iPhone application on next section.

III. Build iPhone application

As the Visual studio 2017 already interested with Xamarin and able to develop a cross-flat form application that can be run on IOS, Android and Window Phone. However, if you want to build an IOS app on Window you still need to link Visual Studio with a Mac that installed XCode and Xamarin. So for simply, I will using Visual Studio for Mac to develop it instead and below is tool and libraries were used to develop this project.

  • Tool: Visual Studio for Mac
  • Framework: .NetCore 1.1
  • Libraries: Xamarin Forms
  • Project Type: Multiplatform – Connected App (Forms)
Open visual studio and create a new solution named AzureDemo the visual studio will create 4 projects:
  • AzureDemo: this is the main project we will implement the views and the logic of the app.
  • AzureDemo.Droid: this project will port the AzureDemo to Android application.
  • AzureDemo.iOS: similar with Droid project, this project will be port the AzureDemo to an iOS application.
  • AzureDemo.Service: this project can be removed as we already develop the Azure service above. The reason I’m using Window to develop the Azure service because Visual Studio for Mac is still previewed version and it is not fully supported Azure deployment.

The implementation of AzureDemo as below:

 There are 3 Views had been implemented:
  • UsersPage: Display the list of users.
  • UserDetailPage: Display details information of Use.
  • NewUserPage: Allow to add new or Edit User information.

The screenshots on iOS

The screenshots on Android

Before running the source code you should update the AzureMobileAppUrl in App class with your Azure service url mentioned above.

IV. Source code

  • Download source code here
  • Report issue here

As you see in the current Web Api source code all APIs are opening for everyone without any restriction. This is bad idea that any application can access your production data. So the recommendation is using Filtering to secure your Web Api? I will post a separate topic to discusing How to secure the Web Api soon.

In these projects, I’m trying to keep the source code as simple as possible for those who want to start learning Azure and Mobile development can catch up easily.

Please feel free to comment your opinion or email to me via [email protected]