About the project

This is an experimental library. I tried to implement observer pattern in go without looking at existing solutions.

One can say that it's not "go way". We'll see. I want to implement couple of solutions and compare them.

How to use

See examples directory for more details.

package main

import (
	"errors"
	"fmt"
	"github.com/beono/godispatcher"
	"github.com/beono/godispatcher/examples/manager"
)

func validateUser(event *godispatcher.Event) error {
	if user, ok := event.Data.(*manager.User); ok {
		if user.Email == "" {
			return errors.New("email can't be empty")
		}
	}
	return nil
}

func main() {

	dispatcher := godispatcher.New()
	dispatcher.On(manager.UserUpdateBefore, validateUser)

	UserManager := manager.UserManager{
		Observer: dispatcher,
	}

	newUser := manager.User{
		ID:    0,
		Email: "",
	}

	fmt.Println(UserManager.Update(newUser)) // prints "email can't be empty"
}