这里有课，我需要收集一些关于喜欢、评论、内容、视图的统计信息
class UsersActivityTable
def initialize(user_ids, content_ids, start_date, end_date)
@user_ids, @content_ids, @start_date, @end_date = user_ids, content_ids, start_date, end_date
end
def rows
@rows ||= @user_ids.map do |user_id|
OpenStruct.new( :full_name => sum_users(user_id),
:contributed => sum_contributed(user_id),
:interacted => sum_interacted(user_id)
)
end
end
private
def sum_users(user_id)
@sum_users ||= Hash[ User.value_of(:id, :first_name, :last_name).map{|usr| [usr[0], "#{usr[1]} #{usr[2]}"] } ]
@sum_users[user_id]
end
def sum_contributed(user_id)
@sum_contributed ||= Content.where(:user_id => @user_ids, :id => @content_ids)
.where('date(created_at) between ? and ? ', @start_date, @end_date)
.group(:user_id)
.count
@sum_contributed[user_id].to_i
end
def sum_interacted(user_id)
sum_comments(user_id).to_i + sum_views(user_id).to_i + sum_likes(user_id).to_i
end
def sum_comments(user_id)
@sum_comments ||= Comment.where(:user_id => @user_ids, :content_id => @content_ids)
.where('date(created_at) between ? and ? ', @start_date, @end_date)
.group(:user_id)
.count
@sum_comments[user_id]
end
def sum_likes(user_id)
@sum_likes ||= Like.where(:user_id => @user_ids, :content_id => @content_ids)
.where('date(created_at) between ? and ? ', @start_date, @end_date)
.group(:user_id)
.count
@sum_likes[user_id]
end
def sum_views(user_id)
@sum_views ||= View.where(:viewable_type => 'Content', :user_id => @user_ids, :viewable_id => @content_ids)
.where('date(created_at) between ? and ? ', @start_date, @end_date)
.group(:user_id)
.count
@sum_views[user_id]
end
end
如您所见，有一些重复：
.where('date(created_at) between ? and ? ', @start_date, @end_date)
.group(:user_id)
.count
我为每个实体执行它。有什么方法可以应用条件 lambda 之类的吗？
我认为是可能的 - 在集合实例上定义方法并调用它：
# pseudo code
group_results = lambda{|el| el.where('date(created_at) between ? and ? ', @start_date, @end_date)
.group(:user_id)
.count }
Content.where(...).tap{|collection| collection.defune_method .... }.group_results