https://github.com/ypankaj007/design-patterns-in-go

Implementation of design patterns in Golang
https://github.com/ypankaj007/design-patterns-in-go

design-pattern go

Last synced: 25 days ago
JSON representation

Implementation of design patterns in Golang

• Host: GitHub
• URL: https://github.com/ypankaj007/design-patterns-in-go
• Owner: ypankaj007
• Created: 2019-06-18T11:17:48.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2020-03-05T10:06:10.000Z (almost 5 years ago)
• Last Synced: 2024-06-21T04:58:39.525Z (7 months ago)
• Topics: design-pattern, go
• Language: Go
• Homepage:
• Size: 77.1 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

        

# Observer Design Pattern in GO

The observer pattern is a software design pattern in which an object, called the subject, maintains a list of its dependents, called observers, and notifies them automatically of any state changes, usually by calling one of their methods.

# Example

 - In the code, I took a simple message posting example over social media (Linkedin, Facebook and Twitter).

 -  User will input the message by command line and it will observer in all social media portal.

 

# Implementation

  - import observer package in our application 

  - Create Event and Register Observer

  - Resiter observer 

    ```sh

    privatePortal.Attach(observer) // observer defines Observer object 

    ```

- Remove observer 

    ```sh

    privatePortal.Detach(observer) // observer defines Observer object

    ```

    - Notify to observer 

    ```sh

    privatePortal.Notify(e) // e defines Event object

    ```

  

```sh

package main

import (

	"bufio"

	ob "design-patterns-in-go/behavioral/observer"

	"fmt"

	"os"

)

func main() {

	fmt.Println("Observer application .......")

	// Initialize notifier

	privatePortal := ob.Initialize()

	fmt.Println("Registering linkedin observer")

	privatePortal.Attach(&ob.Linkedin{})

	fmt.Println("Registering facebook observer")

	privatePortal.Attach(&ob.Facebook{})

	fmt.Println("Registering twitter observer")

	privatePortal.Attach(&ob.Twitter{})

	scanner := bufio.NewScanner(os.Stdin)

	for scanner.Scan() {

		e := ob.Event{Message: scanner.Text()}

		privatePortal.Notify(e)

	}

	fmt.Println(scanner.Err())

}

```