Problem#comments counter cache

Marcin Ciunelis
1 parent 695de2bb
Showing 6 changed files with 53 additions and 2 deletions Show diff stats
app/models/comment.rb
app/models/problem.rb
app/views/errs/_table.html.haml
db/migrate/20111019163257_add_problem_comments_count.rb
spec/factories/comment_factories.rb
spec/models/problem_spec.rb
@@ -2,12 +2,25 @@ class Comment
   include Mongoid::Document
   include Mongoid::Timestamps
+  after_create :increase_counter_cache
+  before_destroy :decrease_counter_cache
+
   field :body, :type => String
   index :user_id
-  belongs_to :err
+  belongs_to :err, :class_name => "Problem"
   belongs_to :user
   validates_presence_of :body
+
+  protected
+    def increase_counter_cache
+      err.inc(:comments_count, 1)
+    end
+
+    def decrease_counter_cache
+      err.inc(:comments_count, -1) if err
+    end
+
 end
@@ -21,6 +21,7 @@ class Problem
   field :user_agents, :type => Array, :default => []
   field :messages, :type => Array, :default => []
   field :hosts, :type => Array, :default => []
+  field :comments_count, :type => Integer, :default => 0
   index :app_id
   index :app_name
@@ -26,7 +26,7 @@
           %td.message
             = link_to trucated_err_message(problem), app_err_path(problem.app, problem)
             %em= problem.where
-            - if problem.comments.any?
+            - if problem.comments_count > 0
               - comment = problem.comments.last
               %br
               .inline_comment
@@ -0,0 +1,10 @@
+class AddProblemCommentsCount < Mongoid::Migration
+  def self.up
+    Problem.all.each do |problem|
+      problem.update_attributes(:comments_count => problem.comments.count)
+    end
+  end
+
+  def self.down
+  end
+end
 \ No newline at end of file
 Factory.define :comment do |c|
   c.user       {|u| u.association :user}
   c.body       'Test comment'
+  c.err        {|e| e.association :problem}
 end
@@ -276,5 +276,31 @@ describe Problem do
     end
   end
+  context "comment counter cache" do
+    before do
+      @app = Factory(:app)
+      @problem = Factory(:problem, :app => @app)
+    end
+
+    it "#comments_count returns 0 by default" do
+      @problem.comments_count.should == 0
+    end
+
+    it "adding a comment increases #comments_count by 1" do
+      lambda {
+        Factory(:comment, :err => @problem)
+      }.should change(@problem, :comments_count).from(0).to(1)
+    end
+
+    it "removing a comment decreases #comments_count by 1" do
+      comment1 = Factory(:comment, :err => @problem)
+      lambda {
+        @problem.reload.comments.first.destroy
+        @problem.reload
+      }.should change(@problem, :comments_count).from(1).to(0)
+    end
+  end
+
+
 end
	@@ -2,12 +2,25 @@ class Comment		@@ -2,12 +2,25 @@ class Comment
2	include Mongoid::Document	2	include Mongoid::Document
3	include Mongoid::Timestamps	3	include Mongoid::Timestamps
4		4
		5	+ after_create :increase_counter_cache
		6	+ before_destroy :decrease_counter_cache
		7	+
5	field :body, :type => String	8	field :body, :type => String
6	index :user_id	9	index :user_id
7		10
8	- belongs_to :err	11	+ belongs_to :err, :class_name => "Problem"
9	belongs_to :user	12	belongs_to :user
10		13
11	validates_presence_of :body	14	validates_presence_of :body
		15	+
		16	+ protected
		17	+ def increase_counter_cache
		18	+ err.inc(:comments_count, 1)
		19	+ end
		20	+
		21	+ def decrease_counter_cache
		22	+ err.inc(:comments_count, -1) if err
		23	+ end
		24	+
12	end	25	end
13		26
	@@ -21,6 +21,7 @@ class Problem		@@ -21,6 +21,7 @@ class Problem
21	field :user_agents, :type => Array, :default => []	21	field :user_agents, :type => Array, :default => []
22	field :messages, :type => Array, :default => []	22	field :messages, :type => Array, :default => []
23	field :hosts, :type => Array, :default => []	23	field :hosts, :type => Array, :default => []
		24	+ field :comments_count, :type => Integer, :default => 0
24		25
25	index :app_id	26	index :app_id
26	index :app_name	27	index :app_name
	@@ -26,7 +26,7 @@		@@ -26,7 +26,7 @@
26	%td.message	26	%td.message
27	= link_to trucated_err_message(problem), app_err_path(problem.app, problem)	27	= link_to trucated_err_message(problem), app_err_path(problem.app, problem)
28	%em= problem.where	28	%em= problem.where
29	- - if problem.comments.any?	29	+ - if problem.comments_count > 0
30	- comment = problem.comments.last	30	- comment = problem.comments.last
31	%br	31	%br
32	.inline_comment	32	.inline_comment
	@@ -0,0 +1,10 @@		@@ -0,0 +1,10 @@
		1	+class AddProblemCommentsCount < Mongoid::Migration
		2	+ def self.up
		3	+ Problem.all.each do \|problem\|
		4	+ problem.update_attributes(:comments_count => problem.comments.count)
		5	+ end
		6	+ end
		7	+
		8	+ def self.down
		9	+ end
		10	+end
0	\ No newline at end of file	11	\ No newline at end of file
1	Factory.define :comment do \|c\|	1	Factory.define :comment do \|c\|
2	c.user {\|u\| u.association :user}	2	c.user {\|u\| u.association :user}
3	c.body 'Test comment'	3	c.body 'Test comment'
		4	+ c.err {\|e\| e.association :problem}
4	end	5	end
5		6
	@@ -276,5 +276,31 @@ describe Problem do		@@ -276,5 +276,31 @@ describe Problem do
276	end	276	end
277	end	277	end
278		278
		279	+ context "comment counter cache" do
		280	+ before do
		281	+ @app = Factory(:app)
		282	+ @problem = Factory(:problem, :app => @app)
		283	+ end
		284	+
		285	+ it "#comments_count returns 0 by default" do
		286	+ @problem.comments_count.should == 0
		287	+ end
		288	+
		289	+ it "adding a comment increases #comments_count by 1" do
		290	+ lambda {
		291	+ Factory(:comment, :err => @problem)
		292	+ }.should change(@problem, :comments_count).from(0).to(1)
		293	+ end
		294	+
		295	+ it "removing a comment decreases #comments_count by 1" do
		296	+ comment1 = Factory(:comment, :err => @problem)
		297	+ lambda {
		298	+ @problem.reload.comments.first.destroy
		299	+ @problem.reload
		300	+ }.should change(@problem, :comments_count).from(1).to(0)
		301	+ end
		302	+ end
		303	+
		304	+
279	end	305	end
280		306