how-i-design-my-code--blog-architecture.go

package blog

import "time"

// Article is our beloved article struct.
// This struct can be moved to another package,
// such as `package entity`.
// But, I choose to put it here because
// of readability reason.
type Article struct {
	// ID is article's unique identifier.
	ID int
	// Body is the content of the article.
	Body string
	// CreatedAt is the time when the article was created.
	CreatedAt time.Time
}

// Blog is the main business process(es).
type Blog interface {
	// CreateArticle persists an article then publish it.
	CreateArticle(article Article) error
	// GetArticles retrieves an article based on its id.
	GetArticle(id int) (Article, error)
}

// ArticleProvider provides data interchange between
// application and provider.
// The provider could be any persistent data storage,
// such as MySQL, Postgres, Cassandra or anything
// as long as it implements this interface.
type ArticleProvider interface {
	// SaveArticle persists an article.
	SaveArticle(article Article) error
	// GetArticle retrieves an article.
	GetArticle(id int) (Article, error)
}

// ArticlePublisher publishes article.
// Publisher could be Kafka, Rabbitmq, or anything
// as long as it implements this interface.
type ArticlePublisher interface {
	// PublishArticle publishes an article.
	PublishArticle(article Article) error
}

// GoBlog implements Blog interface.
type GoBlog struct {
	ArticlePvd ArticleProvider
	ArticlePub ArticlePublisher
}

// CreateArticle creates and publishes article.
func (g GoBlog) CreateArticle(article Article) error {
	if err := g.ArticlePvd.SaveArticle(article); err != nil {
		return err
	}
	return g.ArticlePub.PublishArticle(article)
}

// GetArticle gets a certain article.
func (g GoBlog) GetArticle(id int) (Article, error) {
	return g.ArticlePvd.GetArticle(id)
}