Building Nodes

Flowgear Nodes are the building blocks of an integration. The Flowgear Nodes Test Harness makes it easy for developers to build and debug Nodes.

You will need

• Visual Studio 2022

Creating a Project

You can see a complete demo Node at https://github.com/Flowgear/flowgear-samples/blob/master/custom-nodes/DemoNode.

1. Create a Class Library project in Visual Studio targeting .NET Framework 4.8. This will be the assembly that contains your Node (or Nodes).
2. Create a second Console Application project in the same solution, it also needs to target .NET Framework 4.8
3. Reference the Class library project in your Console Application project
4. In your Class Library project, add a nuget reference to Flowgear.Sdk. To do this, locate the Package Manager Console in Visual Studio and enter the command install-package Flowgear.Sdk
5. Sign both projects. (You do not need to use your production certificate. Signing the projects up-front ensures that they can only reference signed assemblies).
6. Add a 16x16 PNG to the Class Library, this will be the icon used to represent your Node. Set the Build Action to Embedded Resource
7. Create the structure of your Node using the template shown below
8. In your Console Application, add the loader code shown below
9. Set the Console Application to be the Startup Project for the Solution and launch the project

Harness Loader Code

Place the Harness reference code in the Main method of your C# Console Application project.

See the Harness code sample

Example Node Class

Place the Custom Node reference code in its own class in a C# Console Application

See the Node code sample or see the complete sample Node

Special Node Features

Creating Samples

Samples cause the ListSamples method to be invoked in the Node thereby allowing samples to be generated that are specific to the endpoint defined in the Connection. For details of how to implement this, refer to the ListSamples method in the Node code sample.

Implementing support for OAuth2

Flowgear Nodes allow you to implement support for OAuth2 directly. Refer to the Interact and refreshToken methods in the Node code sample methods for further details.

Publishing Your Node

1. In the Console, click ⚙ → Nodes, then + to publish your Node.
2. Select the Account you would like to publish the Node from and then point to a Zip archive of the binaries for the Node (typically, the contents of the bin\Release folder should be placed into a zip file).
3. Click Submit.

Once a Node has been uploaded, you can access it from the Nodes Pane where you will see an Owned label against the Node.