What’s new in ASP.NET Core 2.2 – Web API improvements – HTTP-REPL

On September 2018, .NET Core preview 2 has been released. Dot Net team keeping the Web API improvements as a major theme for this release.

The aim of web API improvements is to make API

  • Easier to create
  • Easier test and debug
  • Easier to document
  • Easier to consume
  • Easier to secure
  • Easier to monitor

API becomes part of a major software application, this release got major improvements to develop APIs and services.

In this post, we shall discuss the improvements made to APIs in terms of creating, debugging and testing.

We can build an API from scratch and let’s view what’s new in this release.

For doing these activities, I’m using Visual studio 2017 preview 2 in my machine. So make sure you are having the similar version to experiment the same.

Create an API Project

Let’s create a new project called “APITest” using the following steps

  • File -> New Project -> Choose ASP.NET Core Web Application under Web Category

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  • And in the next prompt select ASP.NET Core 2.2 in the topmost drop-down and click.

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Now, our API gets created with the default template. We will be having a controller called ValuesController.

Additionally to that, we shall create a new controller called EventController to perform our experiments.

Model

Before creating that controller, let’s create Event model and we can generate our Controller code based on the model we create.

Our Event model will look like below,

So, we have our Model ready now. Let’s generate our Controller based on this Model.

Controller

  • Right click on Controller folder in solution explorer
  • Select Add
  • Click Controller
  • Choose Option “API Controller with actions, using Entity Framework”
  • Select Model class and DataContext using the plus symbol and Click Add

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Once we have clicked the Visual studio will start scaffolding our new controller in a few seconds. And our controller will look like below

So, all set with API setup. Whenever we create an API, we will run the application and open the API link in the browser window.

If it is a GET call its fine, but when we need to make POST call or something we need another set of tools to perform testing. In that case, the browser is not the best tool to perform testing in the API.

In .NET Core 2.2, a new tool called HTTP-REPL has been introduced. It’s a .NET Core global which we can install using the dotnet CLI.

HTTP-REPL is a command line tool to interact with API.

Right now, the tool is not shipped with this release. However, we install using the following steps.

How to install HTTP-REPL

Run the following command in command prompt to install in global level in your machine

dotnet tool install -g dotnet-httprepl --version 2.2.0-* --add-source https://dotnet.myget.org/F/dotnet-core/api/v3/index.json

Once installed, we can verify the installation using the following command

http-repl-5

we can run http-repl using the command

dotnet httprepl

And we can point to any API which has swagger enabled to try out by setting the base URL.

Let’s not do that now, we can experiment the tool with the API which we created.

Add HTTP-REPL in Web browser list

Instead of opening the command and traversing to the API URL, we can launch our application into Repl right from our Visual Studio IDE.

For that, we need to add the Repl in the Web browser list.

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To Add in web browser list, click browse with the option and click Add and fill the required as follows.

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http-repl exe will present in the following path

C:\Users\<>\.dotnet\tools\dotnet-httprepl.exe

Once added, set it as default web browser.

And update your default launchUrl as empty or remove that settings from launchSettings.json

Launch the application

As we have added EF in our API, let’s add migration before launching the application.

Run the following command in Package Manager Console (Tools->Nuget Package Manger->Package Manager Console)

Add-Migration Initial
Update-Database

Click F5 or click IIS express in the toolbar to launch

http-repl-8.png

After launching the application, we can test our API endpoint right from our Repl command prompt.

Let’s add Open API spec

To make HTTP Repl more accessible, we can add swagger Open API Spec. So that Repl will get to know the available HTTP methods and info in the application.

Let’s add swagger generation with the help open source project Swashbuckle.AspNetCore

Right click on the project and click Manage Nuget package and install Swashbuckle

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Once installed

In the ConfigureServices method of Startup.cs, register the Swagger generator, defining one or more Swagger documents.

services.AddSwaggerGen(c =>
{
    c.SwaggerDoc("v1", new Info { Title = "Events API", Version = "v1" });
});

In the Configure method, insert middleware to expose the generated Swagger as JSON endpoint(s)

app.UseSwagger();

At this point, you can spin up your application and view the generated Swagger JSON at “/swagger/v1/swagger.json.”

Optionally insert the swagger-ui middleware if you want to expose interactive documentation, specifying the Swagger JSON endpoint(s) to power it from.

app.UseSwaggerUI(c =>
{
    c.SwaggerEndpoint("/swagger/v1/swagger.json", "Events API V1");
});

All Set!!!

The command ls will list the routes API as well the HTTP methods available in that particular.

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The command UI will launch the swagger UI page and open in the browser.

https://localhost:44384/api/Events~ ui

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POST call

Let’s post some values using Repl. For making post calls we need to register some text or code editor.

For example, using the following command we can set a default editor

pref set editor.command.default "C:\Windows\System32\notepad.exe"

Once we have set the default editor, we can make post call as follows by typing command POST

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The target editor will default placeholder to fill the data, we can fill up the JSON data, save the file and close it. And also we set header with command line argument -h, the tool got some nice autocomplete feature.

Once closed, the POST call gets called with the data we submit.

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Get call

We can make GET call as follows,

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Cool! That’s it for now. we can discuss API Analyzer in the next post.

Happy Coding!

ASP.NET Core 2.2.0-preview1 – Web templates update

The first preview of the next minor release of ASP.NET Core and .NET Core is available from Aug 21, 2018. The new .NET Core SDK of 2.2.0-preview1 can be downloaded from here.

We need Preview of Visual Studio 2017 – 15.9 Preview 1 to work with .NET Core 2.2 projects.

Whats new in 2.2?

.NET Core listed the following features in their documentation. Now, there is no much information regarding the features in details. They will be publishing detailed information about features soon and hyperlinking that documentation in the same release page.

The new features have been discussed in the ASP.NET Community Standup call.

 

In this post, I would like to discuss updated web templates. Even though we need Visual Studio Preview to work with ASP.NET Core Projects. I have used VS Code to discuss the web templates in this post.

Current Version

Before upgrading the SDK, I wanted to check the current version of the .NET Core with the command.


dotnet --version

version

We can download the .NET Core 2.2 SDK from the link,

https://www.microsoft.com/net/download/dotnet-core/2.2

We can download and start Installation based on our system environment.

SDK

Once installed we can check whether the latest version is available or not with the same command which we have earlier in this post.

SDK2

Now, dotnet version is updated the 2.2.1 preview 🙂

Let’s create a web application

Using dotnet CLI, we can create the application from the command prompt right away. Following is the syntax to create an application


dotnet new  [--force] [-i|--install] [-lang|--language] [-n|--name] [--nuget-source] [-o|--output]
[-u|--uninstall] [Template options]
dotnet new  [-l|--list] [--type]
dotnet new [-h|--help]

 

If we have any doubts in the arguments we can use flag –help to list the available arguments to that particular command. dotnet template engine will display the commands.

For example,

dotnet new --help

The above command lists the available templates in this version

args.png

Using the help of commands, we can create n number of application with the various application with different themes.

MVC web templates

For now, let’s explore whats new in MVC and angular web templates.

To explore MVC web templates, we can go ahead and create an MVC application using dotnet CLI from the and prompt with the owing command.


dotnet new mvc

Once the command executed, the CLI will create the required files for the MVC application and it will start to restore the dependencies as the post-creation actions.

mvc

The files have been generated with the following structure,

mvc-2.png

DotNet completed optimized this folder and file structure, and they have placed an only minimal code in the starter template. The main aim of this optimization is to provide a quick starter template for the user to get started with the project.

Even though we have a separate template to create an empty project, its always good to have a very minimal set of code with some working example in the project.

So the team has provided the very small set of code in this latest version templates if the user wants to override or delete the existing pages and getting started with the new project. That can be achieved with less number of deleting the existing code.

Let’s run the application and see how the new UI has been designed with command

dotnet run

 

mvc-3

The latest UI looks so clean, there are no such components – Jumbotron in the first half of page, 4 or 5 pages with user login feature. We are having only 2-page links here.

And as you see there is a default option to place the cookie accept policy details. Once the user clicks the Accept button, the message gets hidden and a flag is getting added in the browser cache. Until the user clears the browser for this particular web page, the message won’t show to the user again. That’s a helpful feature IMHO.

We 2 links called page 1, page 2 here, but those are not working in this preview release. In the standup call, the team provided the news that it will be fixed in the main release. And the team is looking for the feedback from the community to improve the templates.

I think we should add sidebar as an optional flag, we can let the user decide whether they need it or not. We don’t have to put it in the default templates page.

 

Angular web templates

Now, let’s explore the angular application web template.

We can follow the same approach

dotnet new angular
dotnet run

 

The angular web templates come up with following folder structure

spa.png

When we run the latest angular application template, we have got following UI pages,

angularangular1angular2

In the Home page, we have information about the single page application on what are all the UI framework and technology used in the application like –

In the counter page, we have a button and counter whenever we click the button the counter provides the number of clicks information.

In the Fetch date page, we have a table with bootstrap styles.

 

Bootstrap is fine here, but I wish the angular material design should get included as an optional flag. It will be great if have the material design support in the dotnet CLI itself.

That’s for now, thanks for reading.

Happy Coding!