Followable methods followers by Type

lib/acts_as_followable/followable.rb

@@ -1,5 +1,5 @@
 module ActsAsFollowable
-  module Followable
+  module Followable #这个是被关注
 
     def self.included(base)
       base.extend ClassMethods
@@ -8,12 +8,28 @@ module ActsAsFollowable
     module ClassMethods
       def acts_as_followable #This means can be followed - 被关注
         include ActsAsFollowable::Followable::InstanceMethods
+        include ActsAsFollowable::FollowableExt
+
+        has_many :followers, as: :followable, dependent: :destroy, class_name: 'Follow'
       end
     end
 
     module InstanceMethods
       # 1: 查看某个 模型 关注我的所有对象
       # 2: 查看某个 模型 的某个 实例 是否关注我了
+      def followers_count
+        self.followers.count
+      end
+
+      def followers(follower_type, options = {})
+        followers = follower_type.constantize.
+          joins(:follows).
+          where('follows.followable_id' => self.id,
+                'follows.followable_type' => class_name(self),
+                'follows.follower_type' => follower_type
+        )
+        return followers
+      end
     end
   end
 end

lib/acts_as_followable/followable_ext.rb

@@ -0,0 +1,10 @@
+module ActsAsFollowable
+  module FollowableExt #这个是被关注
+    private
+
+    #  有可能有STI的情况出现
+    def class_name(obj)
+      obj.class.superclass != ApplicationRecord ?  obj.class.superclass.name : obj.class.name
+    end
+  end
+end