Quick Start

You will build a simple web application with Procyon.

What You Need

• About 15 minutes
• A favorite text editor or IDE
• Golang version 1.19.4 or above.

Create a New Project

First we need to create a Procyon application, which can be done in a number of ways.

Using command line

The Procyon CLI is a command line tool that you can use to bootstrap a new project.

Use the following command to Install the Procyon CLI.

$ go get -u codnect.io/procyon/...

Once you have installed the CLI, you can run he below command to verify our installation process.

$ procyon version
Procyon CLI v0.5.3

The init command lets you create a new project. The following example generates a project named simple-procyon-webapp.

$ procyon init simple-procyon-webapp

Using Goland or Intellij IDEA

To make the project creation from Goland or Intellij IDEA possible, we need to install a plugin from the marketplace called Procyon. It makes it easier for you to create a new project.

Once you have installed the plugin, you will see a project generator named Procyon in the New Project dialog. Select Procyon to create a new project.

Write Your First Router

Let’s create a simple router to display Hello World!.

pkg/routers/hello.go

package main

import (
	"codnect.io/procyon/web/http"
	"codnect.io/procyon/web/http/router"
)

type HelloRouter struct {
	
}

// Create a constructor function returning the instance of the HelloRouter
func NewHelloRouter() *HelloRouter {
    return &HelloRouter{}
}

// Implement the Router interface and define the routes
func (r *HelloRouter) Routes() *router.Routes {
	routes := router.Route()
	
	// Route GET '/hello' requests to SayHello handler
	routes.GET("/hello", http.Handle(r.SayHello))
	
	return routes
}

func (r *HelloRouter) SayHello(ctx http.Context) error {
	response := ctx.Response()
	response.SetHeader("Content-Type", "text/plain")
	_, err := response.Writer().Write([]byte("Hello World!"))
	return err
}

The above example includes a single endpoint.

• When an HTTP GET request is sent to the URL /hello
  • Hello World! is written to the HTTP response.
• If the request method is not GET or the URL is not /hello, no route matches and an HTTP 404 is returned.

Register Router

Everything in Procyon is component. You must register your router by using the component.Register function, so it can be managed by the Procyon Framework.

cmd/app/main.go

package main

import (
	"codnect.io/procyon/component"
)

func main() {
	// Run your application
	procyon.New().Run()
}

func init() {
	// Register your constructor function
	component.Register(NewHelloRouter)
}

Run the Application

Now we are ready to run our application:

$ go run main.go

or

$ procyon run

If you open a web browser to http://localhost:8080/hello, you should see output similar to the following:

Hello World!

To gracefully exit the application hit Ctrl-C.