Added arn to the main repository

arn/HasPosts.go

@@ -0,0 +1,65 @@
+package arn
+
+import (
+	"sort"
+)
+
+// HasPosts includes a list of Post IDs.
+type hasPosts struct {
+	PostIDs []string `json:"posts"`
+}
+
+// AddPost adds a post to the object.
+func (obj *hasPosts) AddPost(postID string) {
+	obj.PostIDs = append(obj.PostIDs, postID)
+}
+
+// RemovePost removes a post from the object.
+func (obj *hasPosts) RemovePost(postID string) bool {
+	for index, item := range obj.PostIDs {
+		if item == postID {
+			obj.PostIDs = append(obj.PostIDs[:index], obj.PostIDs[index+1:]...)
+			return true
+		}
+	}
+
+	return false
+}
+
+// Posts returns a slice of all posts.
+func (obj *hasPosts) Posts() []*Post {
+	objects := DB.GetMany("Post", obj.PostIDs)
+	posts := make([]*Post, 0, len(objects))
+
+	for _, post := range objects {
+		if post == nil {
+			continue
+		}
+
+		posts = append(posts, post.(*Post))
+	}
+
+	return posts
+}
+
+// PostsRelevantFirst returns a slice of all posts sorted by relevance.
+func (obj *hasPosts) PostsRelevantFirst(count int) []*Post {
+	original := obj.Posts()
+	newPosts := make([]*Post, len(original))
+	copy(newPosts, original)
+
+	sort.Slice(newPosts, func(i, j int) bool {
+		return newPosts[i].Created > newPosts[j].Created
+	})
+
+	if count >= 0 && len(newPosts) > count {
+		newPosts = newPosts[:count]
+	}
+
+	return newPosts
+}
+
+// CountPosts returns the number of posts written for this object.
+func (obj *hasPosts) CountPosts() int {
+	return len(obj.PostIDs)
+}