Web application development in Go language

While hands-on with the contents of this reference book, I have summarized the parts that are lacking in understanding. https://www.oreilly.co.jp/books/9784873117522/ The sample program is provided on GitHub. https://github.com/oreilly-japan/go-programming-blueprints/tree/master/chapter1/chat

Outline to create a chat application

-Create a web server that provides HTML ・ Add a function to exchange chat messages

Summary of usage packages

Package name	Details
net/http	Provides HTTP client and server implementations
text/template	Implemented a data-driven template to generate text output
html/template	Implemented a data-driven template to generate HTML output that is safe for code injection
path/filepath	Implemented utility routines for manipulating filename paths in a way that is compatible with operating system-defined file paths
sync	Provides basic synchronization primitives such as mutual exclusive locks

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

This notation is often used when processing HTTP requests.

Difference between text/template and html/template

They do the same thing, except that the html/template package is context sensitive. It has the advantages of avoiding attacks that embed malicious scripts and encoding characters that cannot be used in URLs.

What is sync.Once type ??

A type that can guarantee that a function will only be executed once.

Impressions

I felt it was a reference book for intermediate users. There are many places where understanding cannot catch up, so it is quite difficult ... I will do my best to finish the first lap for the time being! !!