The object model

The object model is the collection of all the interfaces and related data types that are implemented by the services. I chose to put all of them in a single package: github.com/the-gigi/delinkcious/pkg/object_model. It contains two files: interfaces.go and types.go.

The interfaces.go file contains the interfaces for the three Delinkcious services:

package object_model

type LinkManager interface {
   GetLinks(request GetLinksRequest) (GetLinksResult, error)
   AddLink(request AddLinkRequest) error
   UpdateLink(request UpdateLinkRequest) error
   DeleteLink(username string, url string) error
}

type UserManager interface {
   Register(user User) error
   Login(username string, authToken string) (session string, err error)
   Logout(username string, session string) error
}

type SocialGraphManager interface {
   Follow(followed string, follower string) error
   Unfollow(followed string, follower string) error

   GetFollowing(username string) (map[string]bool, error)
   GetFollowers(username string) (map[string]bool, error)
}

type LinkManagerEvents interface {
   OnLinkAdded(username string, link *Link)
   OnLinkUpdated(username string, link *Link)
   OnLinkDeleted(username string, url string)
}

The types.go file contains the structs that are used in the signatures of the various interface methods:

package object_model

import "time"

type Link struct {
   Url         string
   Title       string
   Description string
   Tags        map[string]bool
   CreatedAt   time.Time
   UpdatedAt   time.Time
}

type GetLinksRequest struct {
   UrlRegex         string
   TitleRegex       string
   DescriptionRegex string
   Username         string
   Tag              string
   StartToken       string
}

type GetLinksResult struct {
   Links         []Link
   NextPageToken string
}

type AddLinkRequest struct {
   Url         string
   Title       string
   Description string
   Username    string
   Tags        map[string]bool
}

type UpdateLinkRequest struct {
   Url         string
   Title       string
   Description string
   Username    string
   AddTags     map[string]bool
   RemoveTags  map[string]bool
}

type User struct {
   Email string
   Name  string
}

The object_model package is just using basic Go types, standard library types (time.Time), and user-defined types for the Delinkcious domain. It is all pure Go. At this level, there is no dependency or awareness of networking, APIs, microservices, or Go kit.