Electron.NET with a Web API

This post will be expanding on the introduction to Electron.NET that I did here to add in a Web API hit to pull some data as well as the UI on the Electron side to use this data. The code before any changes can be found here.

API Creation

To create the API I used the following from the command prompt in the folder where I wanted the new project to be created.

API Data

Now that the API project is created we need to add in the ability to interact with a database with Entity Framework Core. Adding in Entity Framework Core ended up turning into a post of its own when you can read here.

The model and DB Context of the API project match what was in the blog post I linked above, but I am going to include them here. The following is the model.

Next, is the DB Context, which is empty other than the DB Set for the contacts table.

With our model and context setup, we can run the following two commands to add the initial migration and apply the migration to the database.

API Endpoints

The API is just going to handle the basic CRUD (create, read, update, delete) operations for contact. Instead of hand coding the controller we are going to use some code generation provided by Microsoft. First, we need to add the  Microsoft.VisualStudio.Web.CodeGeneration.Design NuGet package to the API project using the following command in a command prompt set to the root of the API project.

Now with the above package installed, we can use the following command to generate a controller with the CRUD operations already implemented.

There is a lot of switches when using  aspnet-codegenerator. The following is a rundown of the ones used above.

  • controller tells the code generator we are creating a controller
  • name defines the name of the resulting controller
  • model is the model class that will be used for the generation
  • dataContext is the DB Context that will be used for the generation
  • outDir is the directory the output will be in relative to the current directory of your command prompt
  • api tells the code generator this controller is for a REST style API and that no views should be generated

With the code generation complete the API should be good to go.

Electron Model

Over in the Electron project, we need a model to match the data the API is returning. This could be the point where a third project is added to allow the API and the Electron app to share common items, but just to keep the example simple I’m just going add a copy of the contact model from the API project to the Electron project.  The following is the full contact model class.

Electron Views

Now that we have a model in our Electron project we need to create the views that go along with it. Start by adding the code generation package like we did above using the following command.

Unfortunately, controller generation needs a DBContext to work which our project doesn’t have, so we have to take the long way about to generate our views and then manually create a controller to go with them. In order to get view generation to work, I had to add references to the Entity Framework Core Tools package using the following command.

In the  csproj file add the following .NET CLI tool reference.

Now the project is ready to use the command prompt to generate the views we will need for our CRUD operations related to our contacts. Use the following commands to create the full range of views needed (Create, Edit, List, Delete, Details).

Again there is a lot of switches when using  aspnet-codegenerator. The following is a rundown of the ones used above.

  • view  tells the code generator we are creating a view
  • the next two items are the name of the view and the name of the view template
  • model is the model class that will be used for the generation
  • useDefaultLayout uses the default layout (surprise!)
  • outDir is the directory the output will be in relative to the current directory of your command prompt

The Index.cshtml generated above comes with links for Edit, Details, and Delete that won’t work as generated. Open the file and make the following changes to pass the key of the contact trying to be opened.

Electron Controller

With the views complete let’s add a  ContactsController.cs to the  Controllers directory. The code for the controller follows, but I’m not going to go into the details. I took a controller from another contact base project and just replaces all the Entity Framework stuff with calls to the API we created above. Please don’t use this as an example of how something like this should be done it is just quick and dirty to show that it can work.

Electron Add Link To Navigation

The final step to add a link to the list of contacts to the navigation bar of the application. Open the  _Layout.cshtml and in the unordered list for the nav bar add the following line.

Wrapping Up

That is all the changes to get the application up and running. If you run the API and then use  dotnet electronize start from a command prompt in the ElectronTest project root all should be good to go.

The completed code can be found here.

Run Multiple Projects in Visual Studio Code

While expanding the sample used in the Electron.NET post to include an API I hit a snag with Visual Studio Code. I have used multiple projects with Visual Studio Code before, but never two distinct applications that I need to run at the same time.  Sample code that contains the two projects, but before any modifications covered in this post can be found here.

Building Multiple Projects

The first issue to tackle was getting both projects to build since they are technically independent. As I’m sure you are aware VS Code doesn’t need a solution file like full Visual Studio does. What I learned during this process was that while a solution file isn’t required once can be used to ensure multiple projects all get built. Using VS Code’s Terminal I ran the following commands to create a new solution and add my two projects to that solution.

With the solution file in place, I then opened the tasks.json file found in the .vscode directory. In the build task, I removed the path to a specific csproj file and just used the workspace folder.

This is just one option on how to handle the builds. I believe another way would be to have two build tasks (one for each project) and use the individual build task in your launch configurations (which we are going to talk about next).

Debugging Multiple Projects

Open up your launch.json file in the .vscode directory. By default you will see a couple of configurations more than likely you will see one named .NET Core Attach and another named .NET Core Launch (web). It is the .NET Core Launch (web) configuration that we are interested in. This configuration controls how our application is launched. If you notice the program property points to the dll created during the build process, in the sample code this is  ${workspaceFolder}/src/ElectronTest/bin/Debug/netcoreapp2.0/ElectronTest.dll. This is all fine but doesn’t give us a way to run both of our projects. Let’s tweak the env property to set the ASPNETCORE_URLS which will control the URL the application is launched with.

Now that the original application’s launch configuration is set we need to add a second launch configuration for our second application. The following is the full configuration section for my second application (the API).

I started with a copy of the original application and just modified a couple of things. First, the name property is now .NET Core Launch (API) which will help us know which application we are launching later. In the launchBrowser section, I set enabled to false since this is an API and I don’t need to launch the browser when the application starts. The final difference is in  ASPNETCORE_URLS to make sure the URLs of the two applications are different. I used http://localhost:5000 in this example.

Now that all our configurations are good to go hop over to the debug section in VS Code.

On the debug you will notice that both of our launch configurations are listed. If you select the API one and hit the green play button it will start the API. With the API running you can then select the web configuration and hit the green play button and you will have both of your applications running in debug mode.

Wrapping Up

While it is not obvious at all how to get multiple applications to run in a single instance of VS Code the process isn’t hard after you do it the first time. I think my Visual Studio experience made figuring this out harder than it should have been. My key to learning how to get this going was on this GitHub issue.

Hopefully, this saved you some of the struggles I went through. Please leave a comment if there are different ways to accomplish this. The code with the final configuration can be found here.

Create a Desktop Application using ASP.NET Core and Electron.NET

Electron is a cross-platform (Windows, Linux, and Mac) library for building desktop applications using JavaScript, HTML, and CSS. Even if you have never head of Electron I’m sure you have used some of the desktop applications it has been used to build such as Visual Studio Code, Atom, Slack.

Electron.NET provides a wrapper around Electron with an ASP.NET Core MVC application in the mix. Here is the reason why this was done from the creates of the project.

Well… there are lots of different approaches how to get a X-plat desktop app running. We thought it would be nice for .NET devs to use the ASP.NET Core environment and just embed it inside a pretty robust X-plat enviroment called Electron. Porting Electron to .NET is not a goal of this project, at least we don’t have any clue how to do it. We just combine ASP.NET Core & Electron.

Project Creation

Seems only fitting to use VS Code for this post since it is built using the same base library. From the command line create a new ASP.NET Core MVC application using the following command.

Make note that it is important at this time that you use the MVC template when attempting this and not a Razor Page application. This is more of a warning if you are using Visual Studio to do your project creation and not the CLI command above.

Next, we need to reference the ElectronNET.API NuGet package which can be added using the following command.

Then, open the csproj and add a reference for the Electron.NET CLI tool which should match the following.

After that make sure and restore packages using the following command.

Wire-up Election.NET

Open Program.cs and add UseElectron(args) to the WebHost builder chain.

Net, open Startup.cs and add the following line to the bottom of the Configure function. This is what will open the Electron window on startup.

Finally, run the following from the command prompt to get the project ready to run under Electron. This should only need to be done once.

Run the application

At this point, the application is ready to go. The neat part is you can just hit F5 and it will run like any normal ASP.NET Core application (this would change when you get into Electron specific calls I’m sure) or if you run the following command it will run inside of the Electron shell.

Wrapping up

It was surprisingly simple to get a new application up and running, of course so far the app isn’t anything other than a web site hosted in Electron. My plan is to take this base application and create my normal basic contacts application, which will be the next post. From there I may look into layering in some Electron features.

The completed code can be found here.

Refit Basics

A few weeks ago I was watching this episode of the ASP.NET Community Standup and they had Ryan Nowak on to talk about the new HttpClientFactory coming in the 2.1 release and a question came up about compatibility with Refit. I had been meaning to check out Refit but had honestly forgotten about it. This post is going to be a very basic introduction to Refit.

What is it?

In the author’s (Paul Betts) words, Refit is the automatic type-safe REST library for .NET Core, Xamarin and .NET. Cool, but what does that mean? Basically, Refit allows you to define an interface for an API that your application wants to call and using that is hides way all the HTTP and JSON serialization/deserialization bits.

Sample project creation

To test Refit out I created a very simple .NET Core console application. To do the same open a command prompt in the directory you want the project using the following command.

For this project, I am using Visual Studio Code as my editor. Since VS Code doesn’t have a NuGet UI build in (maybe there is an extension?) I used the following command to add Refit to the project.

Or if you prefer you can add the following to your csproj file.

The API

Instead of creating an API I searched the internet for a free one I could use. I ended up using CountryAPI. The following is a sample of what a response from the API looks like.

Classes

Now that we know what the API response looks like classes can be created to match its structure. In this case, I have two classes one for response and one for the actual country data.

API Interface for Refit

With the classes for the response setup, we can now define the interface that will be used by Refit when calling the API. The following interface defines a function to get all countries and another function that gets countries that speak a specific native language.

The attributes on the functions are part of the magic of Refit. In the cases above both of the calls are HTTP Get requests which is why they are using the  Get attribute. Refit does support other verbs as well.

The other thing of note here is the  AliasAs on the parameter of the second function call. This attribute can be used to control what gets put in the query string and keeps cryptic names from the API from spreading to other places in your code.

Calling the API

The following is the full code from my Program class that shows the usage of Refit with both of the API calls defined above.

The following line is defining a call to a rest API for a specific interface.

Now that we have a reference to the API it can be called asynchronously to get the data from the API.

The rest of the app is more of the same just using the other API call.

Gotchas

In order to use  async Task Main a change is needed to the project file to set the  LangVersion. I just set it to latest, but I believe the minimum for this feature is 7.1.

If you are using VS Code and are using  Console.ReadLine() like I am above then a change will be needed for the  launch.json file found in the  .vscode directory. Look for the  console property and set the value to either  integratedTerminal or  externalTerminal otherwise, the app will be connected to the debug console which will show the output of the application, but doesn’t allow for input.

Wrapping up

Using Refit to makes using APIs super simple. There is a level of magic that I would like to dig into more. I would also like to see how it handles issues and what sort of hooks are provided to address those issue. Based on the Github page Paul has addressed a wide range of the challenges faced with dealing with an API.

As part of writing this posts, I came across two other posts on Refit that might be helpful, one by Jerrie Pelser and the other from Scott Hanselman.

 

Swagger and Swashbuckle: Disable Try It Out

In last week’s post, I walked through adding Swagger support to an ASP.NET Core 2 API using the Swashbuckle. One of the awesome things about Swashbuckle is it provides an integration with swagger-ui.

Try it out!

One of the features of the UI integration is the ability to invoke an end point using the “Try it out!” button. This feature is awesome during development but may not be something you want to allow, depending on the use case, for a production end point.

Disable Try it out!

I tried googling lots of different things to find the option to disable the “Try it out” button and had a really hard time finding an answer. It didn’t help that I want the button text to be “Try it now” for some reason. Thankfully it truly was a failure on my part and there is a provided way to disable “Try it out” and it is much more flex able than what I was initially looking for.

In the  Configure function of the  Startup class find the call to  app.UseSwaggerUI. Adding  c.SupportedSubmitMethods(new string[] {}); will completely disable “Try it out”. The following is the full call to  app.UseSwaggerUI just to provide context.

The great thing about the way this is set up if you can allow some actions and not others. For example, say you wanted to allow get actions but disable the rest. The following would allow for that.

One word of caution the above is case sensitive and if you use  Get instead of  get “Try it out” will remain disabled.

Swagger and Swashbuckle with ASP.NET Core 2

This post is going to be very similar to a post from last December which can be found here. A lot has changed since then and this post is going to add Swagger to an existing ASP.NET Core application using Swashbuckle much like the one from last year. The starting point of the code can be found here.

What is Swagger?

Swagger is a specification used to document an API. As I am sure we all know API documentation tends to get out of date fast and a lot of times is a low priority.  Swagger aims to help solve that problem using a format that is both human and machine readable which can be maintained in either JSON or YAML. The documentation can be auto generated using a tool like Swashbuckle which provides away to keep your consumers up to date. Check out this post by the Swagger team for the full introduction.

What is Swashbuckle?

Swashbuckle provides auto generation of Swagger 2.0, a UI, etc. The project takes all the pain out of getting going with Swagger as well as providing tools and hooks for using and customizing Swagger related items. The full description can be found here.

Adding Swashbuckle

Using your favorite method of NuGet interaction, add the  Swashbuckle.AspNetCore NuGet package to your project. Personally, I have gotten where I edit the csproj file to add new packages. If that is your style you would need to add the following package reference.

This one package provides all the functionality we will need.

Wiring up Swashbuckle

Now that the Swashbuckle package is installed, there are a few changes that are needed in the  Startup class to get everything wired up. First, in the  ConfigureServices function, the Swagger generator needs to be added to DI.

AddSwaggerGen allows for configuration of options, but here we are just setting a name and a minimal amount of information.

In the  Configure function Swagger needs to be added to the request pipeline in order to expose the Swagger generated data. I placed this after  UseMvc.

At this point, the Swagger generated JSON would be available at  {yourBaseUrl}/swagger/v1/swagger.json. To take a step further let’s expose the UI that comes with Swashbuckle. Add the following just below  app.UseSwagger().

Now a UI based on your API is available at  {yourBaseUrl}/swagger with zero extra work on your part. The following is the UI for the post contact route in the example project.

As you can see the UI provides a great view of your API as well as ways to try it out and the potential responses that should be expected from a call.

Controller Considerations

All of this wonderful functionality doesn’t come for free of course. In order for Swashbuckle to pick up your routes, your controller will need to use attribute based routing instead of depending on convention based routing.

In order for Swashbuckle to know the return types and of your controller actions may need to have some attributes added. This won’t be required if your action return a specific type, but if you are returning an  IActionResult you should attribute your action with all the  ProducesResponseType you need to cover the results of your action. For example, the following is the action definition for the Post in the screen shot above.

Wrapping up

Swashbuckle makes it easy to add Swagger to a project. I feel that it also provides a huge value for anyone trying to consume an API. It is of course not a magic bullet and communication with your API consumers about API changes will still be critical.

Microsoft’s docs have a great walk through which can be found here. It does more in-depth on customizing your setup and as far as modifying the look of the UI. I also recommend checking out the GitHub page for the project which can be found here.

The finished code can be found here.

NDepend Spotlight

Today I am going to be doing a tool spotlight on NDepend. NDepend has a ton of features to help you keep a handle on your applications including the following plus much more.

  • Code Rules
    • 200 default rules with ability to add custom rules using LINQ
  • Quality Gates
  • Visual Studio Integration
  • Build Process Integration
  • Dependency Graph
  • Dependency Matrix
  • Technical Debit Estimation

For full disclosure, NDepend reached out to me to give their tool a try. I am writing based on my experiences with their tool and will be including both the positive and negative aspects of my experience. None of the links in this post are referrals that would in any way provide me any sort of payment.

Installation

The download is a zip file that you then have to find out what you want to do with. This was the first negative I hit with the product. While it isn’t hard to figure out it would be much nicer if this were an installer where I could select what I wanted to install instead of having to look at the getting started docs right away. For non-build usage, the options to run the tool is either via a Visual Studio extension (NDepend.VisualStudioExtension.Installer) or as a stand alone application (VisualNDepend.exe).

I chose to go explore with the Visual Studio extension. As a hint that I didn’t notice until later, VisualNDepend provides an option to install the Visual Studio extension in addition to providing all the functionality of the Visual Studio extension.

Visual Studio Extention

After installing the NDepend extension there will be a new top level NDepend menu in Visual Studio.

With the solution you want to analyze already open select the NDepend > Attach New NDepend Project to Current VS Solution.

This will launch a dialog that allows you to select which assemblies you would like to analyze preloaded with the assemblies for the current application.

As you can see from the dialog there are a lot of options. If your project has other assemblies or solutions that you would like to be included as part of the analyses they are easy to add. When finished adding items to analyze click the Analyze button at the bottom. I am using a small project for this entry and the process took less than 10 seconds. I also tried it on a large project (500k+ lines of code) and it took less than 30 seconds.

After the analyses are complete the extension shows a dialog asking what to do next as well as launching a web page with the results of the analyses if you kept the Build Report check box checked. Following are the options in the dialog.

From here I chose to View NDepend Dashboard, but also make sure and check out the report that the analyses generated as it provides a great summary at the end of all the issues found. The following is a part of the dashboard.

There is a ton of data provided. If you notice at the top there is a Choose Baseline option which would allow comparisons of solutions over time. I can see this view of a project over time is very helpful, but not a feature I will get to explore here.

Exploration

Exploration of the data NDepend provides is something I could spend hours looking at even on a small project. For example, the following is an output to HTML (their output is much prettier than the version that is shown here) of the issues that make up the critical group in the Rules box in the dashboard above.

4 rules Issues Debt Annual Interest Breaking Point Category Full Name
Avoid methods with too many parameters 1 issue 1h 9min 5min 4 522d Project Rules \ Code Smells Rule
Avoid non-readonly static fields 12 issues 32min 4h 0min 48d Project Rules \ Immutability Rule
Avoid namespaces mutually dependent 2 issues 30min 1h 1min 179d Project Rules \ Architecture Rule
Avoid having different types with same name 3 issues 30min 1h 0min 182d Project Rules \ Naming Conventions Rule
Sum: 18 2h 41min 6h 6min 4 933d
Average: 4.5 40min 1h 31min 1 233d
Minimum: 1 30min 5min 48d
Maximum: 12 1h 9min 4h 0min 4 522d
Standard deviation: 4.39 16min 1h 28min 1 899d
Variance: 19.25 34d 979d overflow

Here is the same view inside the Queries and Rules Edit window.

Double click any line will take you to a detail view showing a listing of the rule broken down by project, namespace, and class.

The same window also shows the query that was used to find the rule violations. For example, the above is powered by the following query.

The above is CQLinq or Code Query LINQ which is used to query the code model that the NDepend analysis creates. The detail of CQLinq are outside the scope of this post, but based on the above you can see how powerfully this could be.

Other considerations

Based on my usage to get the best value from NDepend your whole team would need to be licensed and making sure new code satisfies with all the rules your team wishes to follow. NDepend has a component that can be used as part of server based build processes which is needed, but I would want to use that component as a fail safe, not as a way to avoid buying licenses. If you use multiple computers it seems that you will need multiple licenses which will cause issues for some users.

Wrapping up

After trying NDepend out for awhile I am still amazed at the amount of data it provides. Not to mention the ability to add new queries and rules of your own. One blog post is never going to be enough to cover even a fraction of what this tool does. It feels like Resharper in it does so much that it takes a lot of time to learn and take advantage of the full set of features it provides.

Swagger and Swashbuckle with ASP.NET Core API

This post is going to walk through adding Swagger to an existing ASP.NET Core API application using Swashbuckle. The starting point for the code can be found here.

What is Swagger?

Swagger is a specification on documentation an API. As I am sure we all know API documentation tends to get out of date fast and a lot of times is a low priority.  Swagger aims to help solve that problem using a format that is both human and machine readable which can be maintained in either JSON or YAML and can be auto generated using a tool like Swashbuckle. Check out this post by the Swagger team for the full introduction.

What is Swashbuckle?

Swashbuckle provides auto generation of Swagger 2.0, swagger-ui integration, etc. The project takes all the pain out of getting going with Swagger as well as providing tools and hooks for using and customizing Swagger related items. The full description can be found here.

Adding Swashbuckle to the project

There are lots of ways to get a new package into an ASP.NET Core application and the following covers the NuGet UI, Package Manager Console and Project.json. Pick one of them to use.

NuGet UI

Right click on the project Swashbuckle is going to be added to, Contacts in the case of the sample code, and select Manage NuGet Packages.

swashbuckleprojectmenu

Select the Browse tab, check the Include prerelease checkbox and search for Swashbuckle. Prerelease is need to get the version that works with ASP.NET Core.

swashbucklenuget

Finally click the Install button and work though any confirmation dialog screens that might show.

Package manager console

From the package manager console run  Install-Package Swashbuckle -Pre.

Project.json

Open porject.json and in the  dependencies section add  "Swashbuckle": "6.0.0-beta902".

Add and configure Swashbuckle

In the  ConfigureServices function of the  Startup class add the following. I added it as the end, but placement shouldn’t matter.

Next in the  Configure function after  app.UseMvc add the following.

The first line enable serving of the Swagger JSON endpoint and the second enables the swagger-ui.

Test it out

Running the application will now provide two new routes one or each of the items added to the  Configure function above.

The first is  http://localhost:13322/swagger/v1/swagger.json (your base URL may differ if not using the sample procject) and it exposes the Swagger compliant JSON.

The second URL is  http://localhost:13322/swagger/ui and it provides a very readable view of the documented API along with examples and options to try the API out. The following as an example of what the current version outputs.

swaggeruiexample

Wrapping up

Swashbuckle make it easy to add Swagger to a project. I feel that it also provides a huge value for anyone trying to consume an API. It is of course not a magic bullet and communication with your API consumers about API changes will still be critical.

Microsoft’s docs has a great walk through which can be found here. It does more in-depth on customizing your setup and as far as modifying the look of the UI.

The code for this post in it’s finished state can be found here.

Tool Spotlight – Add New File and Open Command Line Visual Studio Extentions

Tool Spotlight is a new type of post that I am trying out to bring attention to tools that I find useful and worth sharing. These entries will not be on any sort of schedule and will get posted anytime I come across a tool worth mentioning.

This post is going to cover two Visual Studio extensions that I find very helpful especially in the context of writing ASP.NET Core applications. Both of today’s extensions were written by Mads Kristensen.

 Add New File

The Add New File extension provides a simple way of adding new files without having to go through Visual Studio’s add new item dialog. Visual Studio’s dialog is great when I need it, but a lot of times I am adding a html or JavaScript file and just want a blank file and this extension provides a mechanism to do just that.

Lets look at the difference in the two dialogs. Here is Visual Studio’s dialog:

defaultAddNewFile

And here is what the add new file’s dialog looks like:

addNewFile

As you can see the extension’s dialog is much simpler. After the extension is install simply hit Shift+F2 to show the above dialog, enter a file name and click Add file to create a file in the current directory. Directories will also be crated as needed.

Open Command Line

The Open Command Line extension provides a way to open a console from within Visual Studio. The default console application is configurable with options from cmd and PowerShell to cmder and custom user defined applications. Opening the default console to the current directory of the selected item in Visual Studio’s solution explorer can be triggered using the Alt+Space shortcut. The extension also adds an Open Command Line option to the right click menu in solution explorer.

openCommandLineRightClick

Thoughts and Suggestions

Leave any thoughts on if this sort of post is helpful, your favorite tools or suggestions for future topics in the comments.