Merge pull request #1 from robschwartz/master

Added List to ignore when merging 2 documents

README.md

@@ -122,6 +122,19 @@ B attributes will be merged into A.
 
 B is also destroyed after the merge has been successful.
 
+## Testing
+
+In the terminal, you'll need to start a mongoDB connection
+
+To do this, you'll need to run `mongod` while specifying a local folder
+
+EX:
+
+    $ mkdir tmpdb
+    $ mongod --dbpath ./tmpdb
+
+Open another tab and run `rspec`
+
 
 That's all folks!
 

lib/merge-mongoid.rb

@@ -5,8 +5,9 @@ module Document
     module Mergeable
 
       # Merge a mongoid document into another.
+      # ignored_attributes: Array of attributes you want to ignore when merging 2 documents
       # A.merge!(B)
-      def merge!(another_document, arr_of_hash_uniq = {})
+      def merge!(another_document, arr_of_hash_uniq = {}, ignored_attributes = [])
         if another_document.nil?
           raise "Cannot merge a nil document."
         elsif (self.class <=> another_document.class).nil?
@@ -20,13 +21,18 @@ def merge!(another_document, arr_of_hash_uniq = {})
           #
           # We iterate on B attributes :
           another_document.attributes.keys.each do |key|
-            self[key] = merge_attributes(self[key],another_document[key],arr_of_hash_uniq[key])
-            #mongoid dirty checks don't always work correctly for arrays and maybe hashes, so we'll give it a little help
-            if self[key].is_a? Array
-                self.changed_attributes[key] = nil
-            elsif self[key].is_a? Hash
-                self.changed_attributes[key] = nil
-            end 
+            # If the current key is included in the ignore list, skip it.
+            if ignored_attributes.include?(key)
+              next
+            else
+              self[key] = merge_attributes(self[key],another_document[key],arr_of_hash_uniq[key])
+              #mongoid dirty checks don't always work correctly for arrays and maybe hashes, so we'll give it a little help
+              if self[key].is_a? Array
+                  self.changed_attributes[key] = nil
+              elsif self[key].is_a? Hash
+                  self.changed_attributes[key] = nil
+              end
+            end
           end
 
           # saving the A model

spec/merge_spec.rb

@@ -199,5 +199,21 @@ class MyRandomclass
     end      
 
 
+    it "should not merge attributes that are included in the ignore_attributes array" do
+      @A.array_hashes = [{test1: "test1"}]
+      @B.array_hashes = [{test2: "test2"}]
+      @A.merge!(@B, {}, ['array_hashes'])
+
+      @A.array_hashes.size.should == 1
+    end
+
+    it "should merge attributes that are not included in the ignore_attributes array" do
+      @A.array_hashes = [{test1: "test1"}]
+      @B.array_hashes = [{test2: "test2"}]
+      @A.merge!(@B, {}, ['not_array_hashes'])
+
+      @A.array_hashes.size.should == 2
+    end
+
   end
 end