https://github.com/devenock/let-s-go

Let's Go Book code documentation
https://github.com/devenock/let-s-go

Last synced: 6 days ago
JSON representation

Let's Go Book code documentation

• Host: GitHub
• URL: https://github.com/devenock/let-s-go
• Owner: devenock
• Created: 2024-09-23T20:58:44.000Z (3 months ago)
• Default Branch: main
• Last Pushed: 2024-09-30T09:54:33.000Z (3 months ago)
• Last Synced: 2024-12-10T20:40:29.604Z (14 days ago)
• Language: CSS
• Size: 8.79 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

        
# Let's Go

* [Let's Go](#lets-go)

  * [chapter 1: INTRODUCTION](#chapter-1-introduction)

  * [chapter 2: FOUNDATIONS](#chapter-2-foundations)

  * [chapter 3: CONFIGURATION AND ERROR HANDLING](#chapter-3-configuration-and-error-handling)

  * [chapter 4: DATABASE-DRIVEN RESPONSES](#chapter-4-database-driven-responses)

  * [chapter 5: DYNAMIC HTML TEMPLATES](#chapter-5-dynamic-html-templates)

  * [chapter 6: MIDDLEWARE](#chapter-6-middleware)

  * [chapter 7: RESTFUL ROUTING](#chapter-7-restful-routing)

  * [chapter 8: PROCESSING FORMS](#chapter-8-processing-forms)

  * [chapter 9: STATEFUL HTTP](#chapter-9-stateful-http)

  * [chapter 10: SECURITY IMPROVEMENTS](#chapter-10-security-improvements)

  * [chapter 11: USER AUTHENTICATION](#chapter-11-user-authentication)

  * [chapter 12: USING REQUEST CONTEXT](#chapter-12-using-request-context)

  * [chapter 13: TESTING](#chapter-13-testing)

  * [chapter 14: CONCLUSION](#chapter-14-conclusion)

  * [chapter 15: APPENDICES](#chapter-15-appendices)

  * [chapter 16: GUIDED EXERCISES](#chapter-16-guided-exercises)

    * [Path Types](#path-types)

## chapter 1: INTRODUCTION

## chapter 2: FOUNDATIONS

You can check your Go version after a successful installation by running : `go version`

To create a new project in Go, create a new directory anywhere on your computer and initialize a module

by running: `go mod init `

The module path is just the canonical name or identifier for your project.

To know more about your Go current installation and environment, open the terminal and run: `go env `

To create a web application in Go, we need 3 most essential components:

1. **Handler**: If you're from the MVC background, you can think of them as controllers. They are responsible

for executing your application logic and for writing HTTP response headers and bodies.

2. **Router**: It is also known as _**servemux**_ in Go.

3. **Web server**: This is the last thing that we need and you can always establish a web server and listen to it 

natively without importing any third-party package.

`http.Handle()` and `http.HandleFunc()` allows you to create routes without declaring a servemux.

`http.HandleFunc("/", home) `

`http.HandleFunc("/snippet", showSnippet)`

Behind the scenes, these functions register their routes with something called `DefaultServeMux` which is just a regular

servemux which is initialized by default and stored in the `net/http` package.

## chapter 3: CONFIGURATION AND ERROR HANDLING

## chapter 4: DATABASE-DRIVEN RESPONSES

## chapter 5: DYNAMIC HTML TEMPLATES

## chapter 6: MIDDLEWARE

## chapter 7: RESTFUL ROUTING

## chapter 8: PROCESSING FORMS

## chapter 9: STATEFUL HTTP

## chapter 10: SECURITY IMPROVEMENTS

## chapter 11: USER AUTHENTICATION

## chapter 12: USING REQUEST CONTEXT

## chapter 13: TESTING

## chapter 14: CONCLUSION

## chapter 15: APPENDICES

## chapter 16: GUIDED EXERCISES

### Path Types

**Fixed path:** has no trailing slash

**Subtree path:** has a trailing slash(/)

To make a check for the paths, just include a check of the URL path inside the handle function.

[//]: # (checks)

It is possible to call `w.WriteHeader()` method just once per response and it should always be called 

before `w.Write()`. This is because if the later is called first, it will send a status code of 200

to the use but if you want to send a status code different from 200, then call the `w.WriteHeader()` before.

`package main

import (

"fmt"

"log"

"net/http"

"strconv"

)

//define route handlers`

`// home handler

func home(w http.ResponseWriter, r *http.Request) {

//assertains the path

if r.URL.Path != "/" {

http.NotFound(w, r)

return

}

w.Write([]byte("Let's Go!"))

}`

`// snippet handler

func showSnippet(w http.ResponseWriter, r *http.Request) {

//to get query params from a URL string

id, err := strconv.Atoi(r.URL.Query().Get("id"))

fmt.Println(id, err)

if err != nil || id < 1 {

http.NotFound(w, r)

return

}

w.Write([]byte("This is your code snippet!"))

}`

`// create snippet

func createSnippet(w http.ResponseWriter, r *http.Request) {

        //check for the write HTTP method

        if r.Method != http.MethodPost {

        //set allowed method

        w.Header().Set("Allow", http.MethodPost)

		//other helper functions from w.Header method

		w.Header().Set("Cache-Control", "public, max-age=31536000")

		//add appends the headers

		w.Header().Add("Content-Type", "text/plain")

		w.Header().Add("Cache-Control", "public")

		w.Header().Add("Cache-Control", "max-age=31536000")

		//del, deletes the headers

		w.Header().Del("Cache-Control")

		//set status code explicitly

		//w.WriteHeader(405)

		//w.Write([]byte("Method not allowed"))

		//replaces the above method calls and calls them behind the scene

		http.Error(w, "Method not allowed", 405)

		return

	}

	w.Write([]byte("Create your code snippet!"))

}`

`func main() {

	//initialize a server

	mux := http.NewServeMux()

	mux.HandleFunc("/", home)

	mux.HandleFunc("/snippet", showSnippet)

	mux.HandleFunc("/snippet/create", createSnippet)

	//	listen to port

	log.Println("Listening on port :4000")

	err := http.ListenAndServe(":4000", mux)

	log.Fatal(err)

}

`