coreblueltd/electron-cgi-dotnet

.Net Standard Library to enable a DotNet console application to interact with a NodeJs process

Electron CGI

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Update version 0.0.5

• Duplex: ability to send requests from both .Net and Node.js

Update version 0.0.2

• Ability to serve request concurrently (uses System.Threading.Tasks.DataFlow)

Next steps

• Add the ability to send requests form .Net to Node
• Instead of making the process fail when there's an exception in a handler, serialise the exception and "surface" it in Node

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Electron CGI is a library that enables sending request form NodeJs and have them served by .Net.

The npm package is called electron-cgi.

The nuget package is called ElectronCgi.DotNet.

Here's an example of how you can interact with a .Net application from Node:

In NodeJs/Electron:

const { ConnectionBuilder } = require('electron-cgi');

const connection = new ConnectionBuilder()
        .connectTo('dotnet', 'run', '--project', 'DotNetConsoleProjectWithElectronCgiDotNetNugetPackage')
        .build();

connection.onDisconnect = () => {
    console.log('Lost connection to the .Net process');
};

connection.send('greeting', 'John', theGreeting => {
    console.log(theGreeting); // will print "Hello John!"
});

connection.close();

And in the .Net Console Application:

using ElectronCgi.DotNet;

//...
static void Main(string[] args)
{
    var connection = new ConnectionBuilder()
                        .WithLogging()
                        .Build();

    // expects a request named "greeting" with a string argument and returns a string
    connection.On<string, string>("greeting", name =>
    {
        return $"Hello {name}!";
    });

    // wait for incoming requests
    connection.Listen();        
}

How does it work?

Electron CGI establishes a "connection" with an external process. That external process must be configured to accept that connection. In the example above that's what the Listen method does.

In Node we can "send" requests (for example "greeting" with "John" as a parameter) and receive a response from the other process.

The way this communication channel is established is by using the connected process' stdin and stdout streams. This approach does not rely on staring up a web server and because of that introduces very little overhead in terms of the requests' round-trip time.