Categories
Azure Azure Functions

Building Azure Functions in the Rider IDE

Many people now use Rider as their integrated development environment editor for .NET. However, when it comes to using it for developing Azure Functions, the out-of-the-box experience is (currently) less than ideal.

I say currently, because in the next update to the Azure Toolkit plugin for Rider Functions support has been added. This’ll make running and debugging function apps a breeze.

Until then though, here’s how you can run a functions app from Rider.

How to run Azure functions in Rider

First, you’ll need to install the function CLI (see creating an Azure function for the Mac).

Then, open your functions app in Rider by selecting the project or solution.

Create a Properties folder in the root directory if you don’t have one already, and then inside of that create a new JSON file called launchSettings.json.

Inside the JSON file, place the following object:

{  "profiles": {    "functions": {      "commandName": "Executable",      "executablePath": "func",      "commandLineArgs": "start --port 7071 --pause-on-error"    }  }}

You should see Rider now refresh, and add the configuration profile to your configurations with a little rocket icon. Click run, and your function app should start running within Rider.

Note that debugging is a little tricker for now. On Windows, once your function app is running you can go “Run” > “Attach to process” and choose your function app to listen to. But on a Mac, this has had mixed results.

Categories
.NET Core

Understanding the Newtonsoft JSON Token

One of the concepts worth understanding when writing a custom converter for the popular Newtonsoft JSON framework is that of the JsonToken, and the role it plays in helping you understand the JSON being read.

The JsonToken documentation for Newtonsoft is relatively sparse – in part because once you understand it, it’s a relatively simple concept.

Effectively, when you’re attempting to deserialise a string representation of a JSON object, such as in the ReadJson method of a custom JsonConverter, the JsonToken represents each element or component (token if you prefer) of the object as it’s deserialised.

So for example, if you have the following JSON and implement the ReadJson method:

{	"message": "Hello world"}

When you first get the reader.TokenType value you’ll get JsonToken.StartObject back – this represents that the { implies that you’re first reading an object element.

If you were to then call reader.ReadAsync(), and then subsequently request the reader.TokenType again now you’ll get JsonToken.PropertyName in response. This is because the next element within the JSON string is the property name (in other words, the “message” key).

Lastly, if you were to call reader.ReadAsync() for a third time, you’d get back JsonToken.String as the value of the property is a string (“Hello world”). NewtonSoft will try and parse the value into a representation of a type – so for example, if that was a number, you’d get back Integer of Float, and if it was a Boolean you’d get back Boolean.

Categories
Azure Azure Functions

Create an Azure Function App using a Mac

In this post, we’ll take a look at how you can quickly create an Azure Function when using a Mac. In particular, we’ll be using the Azure Functions command line tools to create our functions app.

Getting started

Before you can create a function, you’ll need to install the Azure Function command line tools. But before you can continue, you need to make sure that you have installed Brew. If you’re not familiar with it, Brew is a package manager for the Mac – similar to NPM for Node.Js projects.

Once you’ve installed Brew, make sure you have the latest .NET Core SDK installed. If you’re not sure, open Terminal and run:

dotnet --version

If you do get a version back, make sure it’s at least 2.0.0 or above. If you get an error, you’ll need to install it using the following Brew commands:

brew tap caskroom/caskbrew cask install dotnet

Run the same dotnet version command again to ensure the install was successful.

Now we need to install the Azure Function Core Tools:

brew tap azure/functionsbrew install azure-functions-core-tools

Once the install has finished, you’re now ready to go creating your first function!

Creating the function app

Now that we’ve got all the dependencies installed, it’s time to create our function app. Open Terminal, and navigate to a directory where you’d like your app to be created (in our case, we’re going to create it from the root Documents folder).

cd ~/Documents

Now let’s get started creating the app! First lets initialise the project:

func init MyFirstFunctionApp --source-control true --worker-runtime dotnet

This will create a folder called MyFirstFunctionApp inside your Documents folder. It will be initialised as a git repository (the source-control parameter) and have a dotnet runtime. If you’d prefer a Node.Js function or a Python function, you can replace dotnet with either node or python respectively.

You’ll now have your project – but at this point, it’ll be empty with no functions. To add your first function, we need to run the following command to generate a function called MyFirstFunction:

 func new --name MyFirstFunction

It’ll then ask you what type of template you’d like to use. A template is effectively a trigger – what will cause your function to start running? We’ll choose #2 (HttpTrigger) for now, as this will enable you to easily run your function via Curl, Postman or by visiting a page in your web browser. You can provide this in the previous command as —template, or select from the list.

You’ll now have your first function and function app created! You can run it by entering:

func start

Once it’s started, you should see the a message with the function URL, like this:

The sample function expects a name parameter to be provided, so open up your web browser and go to http://localhost:7071/api/MyFirstFunction?name=Bob. You should get a response like:

Hello, Bob

Summary

So that’s how easy it is to get started with an Azure Function app on a Mac. Microsoft has done a lot of work around the tooling to make it as straightforward as possible.