Adding ability to find by array of ids

lib/mongoid/criteria.rb

@@ -210,8 +210,9 @@ def in(attributes = {})
     # <tt>criteria.id("4ab2bc4b8ad548971900005c")</tt>
     #
     # Returns: <tt>self</tt>
-    def id(object_id)
-      @selector[:_id] = object_id; self
+    def id(*args)
+      (args.flatten.size > 1) ? self.in(:_id => args.flatten) : (@selector[:_id] = *args)
+      self
     end
 
     # Create the new +Criteria+ object. This will initialize the selector
@@ -410,12 +411,8 @@ def skip(value = 0)
     def self.translate(*args)
       klass = args[0]
       params = args[1] || {}
-      if params.is_a?(String)
-        document = new(klass).id(params).one
-        if Mongoid.raise_not_found_error
-          raise Errors::DocumentNotFound.new(klass, params) unless document
-        end
-        return document
+      unless params.is_a?(Hash)
+        return id_criteria(klass, params)
       end
       return new(klass).where(params.delete(:conditions) || {}).extras(params)
     end
@@ -472,5 +469,16 @@ def update_selector(attributes, operator)
       attributes.each { |key, value| @selector[key] = { operator => value } }; self
     end
 
+    class << self
+      # Return a criteria or single document based on an id search.
+      def id_criteria(klass, params)
+        criteria = new(klass).id(params)
+        result = params.is_a?(String) ? criteria.one : criteria.entries
+        if Mongoid.raise_not_found_error
+          raise Errors::DocumentNotFound.new(klass, params) if result.blank?
+        end
+        return result
+      end
+    end
   end
 end

lib/mongoid/errors.rb

@@ -5,11 +5,11 @@ module Errors #:nodoc
     # Raised when querying the database for a document by a specific id which
     # does not exist.
     class DocumentNotFound < RuntimeError
-      def initialize(klass, identifier)
-        @klass, @identifier = klass, identifier
+      def initialize(klass, ids)
+        @klass, @identifier = klass, ids.is_a?(Array) ? ids.join(", ") : ids
       end
       def message
-        "Document not found for class #{@klass} and id #{@identifier}"
+        "Document not found for class #{@klass} and id(s) #{@identifier}"
       end
     end
 

spec/integration/mongoid/finders_spec.rb

@@ -5,7 +5,11 @@
   describe "#find" do
 
     before do
+      @documents = []
       @document = Person.create(:title => "Mrs.", :ssn => "another")
+      3.times do |n|
+        @documents << Person.create(:title => "Mr.", :ssn => "#{n}22")
+      end
     end
 
     after do
@@ -32,6 +36,27 @@
 
     end
 
+    context "with an array of ids as args" do
+
+      context "when the documents are found" do
+
+        it "returns an array of the documents" do
+          @people = Person.find(@documents.map(&:id))
+          @people.should == @documents
+        end
+
+      end
+
+      context "when no documents found" do
+
+        it "raises an error" do
+          lambda { Person.find(["11", "21", "31"]) }.should raise_error
+        end
+
+      end
+
+    end
+
   end
 
 end

spec/unit/mongoid/criteria_spec.rb

@@ -1112,6 +1112,7 @@
 
       it "creates a criteria for a string" do
         @criteria.expects(:one).returns(@document)
+        @document.expects(:blank? => false)
         Mongoid::Criteria.translate(Person, @id)
       end
 
@@ -1128,6 +1129,33 @@
 
     context "multiple arguments" do
 
+      context "when an array of ids" do
+
+        before do
+          @ids = []
+          @documents = []
+          3.times do
+            @ids << Mongo::ObjectID.new.to_s
+            @documents << stub
+          end
+          @collection = stub
+          Person.expects(:collection).returns(@collection)
+        end
+
+        it "returns an ids criteria" do
+          @collection.expects(:find).with(
+            { :_type =>
+              { "$in" =>
+                ["Doctor", "Person"]
+              },
+              :_id =>
+              { "$in" => @ids }
+          }, {}).returns([{ "_id" => "4", "title" => "Sir", "_type" => "Person" }])
+          @criteria = Mongoid::Criteria.translate(Person, @ids)
+        end
+
+      end
+
       context "when Person, :conditions => {}" do
 
         before do
@@ -1200,7 +1228,8 @@
 
         it "adds the clause to the selector" do
           @criteria.where(:title => "Title", :text => "Text")
-          @criteria.selector.should == { :_type => { "$in" => ["Doctor", "Person"] }, :title => "Title", :text => "Text" }
+          @criteria.selector.should ==
+            { :_type => { "$in" => ["Doctor", "Person"] }, :title => "Title", :text => "Text" }
         end
 
       end
@@ -1211,7 +1240,8 @@
 
           it "returns those matching an all clause" do
             @criteria.where(:title.all => ["Sir"])
-            @criteria.selector.should == { :_type => { "$in" => ["Doctor", "Person"] }, :title => { "$all" => ["Sir"] } }
+            @criteria.selector.should ==
+              { :_type => { "$in" => ["Doctor", "Person"] }, :title => { "$all" => ["Sir"] } }
           end
 
         end
@@ -1220,7 +1250,8 @@
 
           it "returns those matching an exists clause" do
             @criteria.where(:title.exists => true)
-            @criteria.selector.should == { :_type => { "$in" => ["Doctor", "Person"] }, :title => { "$exists" => true } }
+            @criteria.selector.should ==
+              { :_type => { "$in" => ["Doctor", "Person"] }, :title => { "$exists" => true } }
           end
 
         end
@@ -1229,7 +1260,8 @@
 
           it "returns those matching a gt clause" do
             @criteria.where(:age.gt => 30)
-            @criteria.selector.should == { :_type => { "$in" => ["Doctor", "Person"] }, :age => { "$gt" => 30 } }
+            @criteria.selector.should ==
+              { :_type => { "$in" => ["Doctor", "Person"] }, :age => { "$gt" => 30 } }
           end
 
         end
@@ -1238,7 +1270,8 @@
 
           it "returns those matching a gte clause" do
             @criteria.where(:age.gte => 33)
-            @criteria.selector.should == { :_type => { "$in" => ["Doctor", "Person"] }, :age => { "$gte" => 33 } }
+            @criteria.selector.should ==
+              { :_type => { "$in" => ["Doctor", "Person"] }, :age => { "$gte" => 33 } }
           end
 
         end
@@ -1247,7 +1280,8 @@
 
           it "returns those matching an in clause" do
             @criteria.where(:title.in => ["Sir", "Madam"])
-            @criteria.selector.should == { :_type => { "$in" => ["Doctor", "Person"] }, :title => { "$in" => ["Sir", "Madam"] } }
+            @criteria.selector.should ==
+              { :_type => { "$in" => ["Doctor", "Person"] }, :title => { "$in" => ["Sir", "Madam"] } }
           end
 
         end
@@ -1256,7 +1290,8 @@
 
           it "returns those matching a lt clause" do
             @criteria.where(:age.lt => 34)
-            @criteria.selector.should == { :_type => { "$in" => ["Doctor", "Person"] }, :age => { "$lt" => 34 } }
+            @criteria.selector.should ==
+              { :_type => { "$in" => ["Doctor", "Person"] }, :age => { "$lt" => 34 } }
           end
 
         end
@@ -1265,7 +1300,8 @@
 
           it "returns those matching a lte clause" do
             @criteria.where(:age.lte => 33)
-            @criteria.selector.should == { :_type => { "$in" => ["Doctor", "Person"] }, :age => { "$lte" => 33 } }
+            @criteria.selector.should ==
+              { :_type => { "$in" => ["Doctor", "Person"] }, :age => { "$lte" => 33 } }
           end
 
         end
@@ -1274,7 +1310,8 @@
 
           it "returns those matching a ne clause" do
             @criteria.where(:age.ne => 50)
-            @criteria.selector.should == { :_type => { "$in" => ["Doctor", "Person"] }, :age => { "$ne" => 50 } }
+            @criteria.selector.should ==
+              { :_type => { "$in" => ["Doctor", "Person"] }, :age => { "$ne" => 50 } }
           end
 
         end
@@ -1283,7 +1320,8 @@
 
           it "returns those matching a nin clause" do
             @criteria.where(:title.nin => ["Esquire", "Congressman"])
-            @criteria.selector.should == { :_type => { "$in" => ["Doctor", "Person"] }, :title => { "$nin" => ["Esquire", "Congressman"] } }
+            @criteria.selector.should ==
+              { :_type => { "$in" => ["Doctor", "Person"] }, :title => { "$nin" => ["Esquire", "Congressman"] } }
           end
 
         end
@@ -1292,7 +1330,8 @@
 
           it "returns those matching a size clause" do
             @criteria.where(:aliases.size => 2)
-            @criteria.selector.should == { :_type => { "$in" => ["Doctor", "Person"] }, :aliases => { "$size" => 2 } }
+            @criteria.selector.should ==
+              { :_type => { "$in" => ["Doctor", "Person"] }, :aliases => { "$size" => 2 } }
           end
 
         end
@@ -1305,7 +1344,8 @@
 
       it "adds the $where clause to the selector" do
         @criteria.where("this.date < new Date()")
-        @criteria.selector.should == { :_type => { "$in" => ["Doctor", "Person"] }, "$where" => "this.date < new Date()" }
+        @criteria.selector.should ==
+          { :_type => { "$in" => ["Doctor", "Person"] }, "$where" => "this.date < new Date()" }
       end
 
     end

spec/unit/mongoid/finders_spec.rb

@@ -95,6 +95,19 @@
 
     end
 
+    context "when an array of ids is passed in" do
+
+      before do
+        @ids = []
+        3.times { @ids << Mongo::ObjectID.new.to_s }
+      end
+
+      it "delegates to the criteria" do
+
+      end
+
+    end
+
     context "when nil passed in" do
 
       it "raises an error" do