[PBXFileReference] Removes all items related to an external project.

Test case thanks to @jpsim.

CHANGELOG.md

@@ -2,6 +2,16 @@
 
 ## master
 
+###### Enhancements
+
+* [PBXFileReference] If a file reference represents an external Xcode project
+  and is removed from the project then all items related to the external
+  project will also be removed.
+  [JP Simard](https://github.com/jpsim)
+  [Eloy Durán](https://github.com/alloy)
+  [Xcodeproj#158](https://github.com/CocoaPods/Xcodeproj/issues/158)
+  [Xcodeproj#161](https://github.com/CocoaPods/Xcodeproj/pull/161)
+
 ###### Bug fixes
 
 * [Workspace] Fixed adding a project to a workspace.

lib/xcodeproj/project.rb

@@ -371,7 +371,7 @@ def new(klass)
     # @note   Implementation detail: as objects usually are created serially
     #         this method creates a batch of UUID and stores the not colliding
     #         ones, so the search for collisions with known UUIDS (a
-    #         performance bottleneck) is performed is performed less often.
+    #         performance bottleneck) is performed less often.
     #
     # @return [String] A UUID unique to the project.
     #

lib/xcodeproj/project/object.rb

@@ -199,8 +199,8 @@ def add_referrer(referrer)
         end
 
         # Informs the object that another object stopped referencing it. If the
-        # object has no other references it is removed form project UUIDs hash
-        # because it is unreachable.
+        # object has no other references it is removed from the project UUIDs
+        # hash because it is unreachable.
         #
         # @return [void]
         #

lib/xcodeproj/project/object/container_item_proxy.rb

@@ -38,6 +38,7 @@ class PBXContainerItemProxy < AbstractObject
         #         If this assumption is incorrect, there could be loss of
         #         information opening and saving an existing project.
         #
+        # TODO this is the external reference that 'contains' other proxy items
         attribute :container_portal, String
 
         # @return [String] the type of the proxy.

lib/xcodeproj/project/object/file_reference.rb

@@ -225,6 +225,8 @@ def set_explicit_file_type(type = nil)
           end
         end
 
+        #---------------------------------------------------------------------#
+
         # Checks whether the reference is a proxy.
         #
         # @return [Bool] always false for this ISA.
@@ -233,6 +235,90 @@ def proxy?
           false
         end
 
+        # If this file reference represents an external Xcode project reference
+        # then this will return metadata about it which includes the reference
+        # to the 'Products' group that's created in this project (the project
+        # that includes the external project).
+        #
+        # @return [ObjectDictionary, nil] The external project metadata for
+        #         this file reference or `nil` if it's not an external project.
+        #
+        def project_reference_metadata
+          project.root_object.project_references.find do |project_reference|
+            project_reference['ProjectRef'] == self
+          end
+        end
+
+        # If this file reference represents an external Xcode project reference
+        # then this will return the objects that are 'containers' for items
+        # contained in the external Xcode project.
+        #
+        # @return [Array<PBXContainerItemProxy>] The containers for items in
+        #         the external Xcode project.
+        #
+        def proxy_containers
+          project.objects.select do |object|
+            object.isa == 'PBXContainerItemProxy' &&
+              object.container_portal == self.uuid
+          end
+        end
+
+        # If this file reference represents an external Xcode project reference
+        # then this will return proxies for file references contained in the
+        # external Xcode project.
+        #
+        # @return [Array<PBXReferenceProxy>] The file reference proxies for
+        #         items located in the external Xcode project.
+        #
+        def file_reference_proxies
+          containers = proxy_containers
+          if containers.empty?
+            []
+          else
+            project.objects.select do |object|
+              object.isa == 'PBXReferenceProxy' &&
+                containers.include?(object.remote_ref)
+            end
+          end
+        end
+
+        # If this file reference represents an external Xcode project reference
+        # then this will return dependencies on targets contained in the
+        # external Xcode project.
+        #
+        # @return [Array<PBXTargetDependency>] The dependencies on targets
+        #         located in the external Xcode project.
+        #
+        def target_dependency_proxies
+          containers = proxy_containers
+          if containers.empty?
+            []
+          else
+            project.objects.select do |object|
+              object.isa == 'PBXTargetDependency' &&
+                containers.include?(object.target_proxy)
+            end
+          end
+        end
+
+        # In addition to removing the file reference, this will also remove any
+        # items related to this reference in case it represents an external
+        # Xcode project.
+        #
+        # @see AbstractObject#remove_from_project
+        #
+        # @return [void]
+        #
+        def remove_from_project
+          if project_reference = project_reference_metadata
+            file_reference_proxies.each(&:remove_from_project)
+            target_dependency_proxies.each(&:remove_from_project)
+            project_reference['ProductGroup'].remove_from_project
+            project.root_object.project_references.delete(project_reference)
+          end
+          super
+        end
+
         #---------------------------------------------------------------------#
 
       end

lib/xcodeproj/project/object_attributes.rb

@@ -44,9 +44,9 @@ class AbstractObjectAttribute
         #         the class that owns the attribute.
         #
         def initialize(type, name, owner)
-          @type  =  type
-          @name  =  name
-          @owner =  owner
+          @type  = type
+          @name  = name
+          @owner = owner
         end
 
         # @return[String] The name of the attribute in camel case.
@@ -65,7 +65,7 @@ def plist_name
           end
         end
 
-        # @return [Hash] a shared store which cahces the plist name of the
+        # @return [Hash] a shared store which caches the plist name of the
         #         attributes.
         #
         def self.plist_name_store

lib/xcodeproj/project/object_dictionary.rb

@@ -110,7 +110,7 @@ def delete(key)
       #
       def to_hash
         result = {}
-        each { |key, obj| result[key] = obj.uuid }
+        each { |key, obj| result[key] = obj.uuid if obj }
         result
       end
 

spec/project/object/file_reference_spec.rb

@@ -67,13 +67,67 @@ module ProjectSpecs
       @file.last_known_file_type.should.be.nil
     end
 
-    it "returns whether it is a proxy" do
-      @file.proxy?.should == false
-    end
-
     it "can have associated comments, but these are no longer used by Xcode" do
       @file.comments = 'This file was automatically generated.'
       @file.comments.should == 'This file was automatically generated.'
     end
+
+    describe "concerning proxies" do
+      it "returns that it is not a proxy" do
+        @file.should.not.be.a.proxy
+      end
+
+      it "returns no proxies" do
+        @file.file_reference_proxies.should.be.empty
+      end
+
+      before do
+        @file_container = @project.new(PBXContainerItemProxy)
+        @file_container.container_portal = @file.uuid
+        @file_proxy = @project.new(PBXReferenceProxy)
+        @project.main_group.children << @file_proxy
+        @file_proxy.remote_ref = @file_container
+
+        @target_container = @project.new(PBXContainerItemProxy)
+        @target_container.container_portal = @file.uuid
+        @target_dependency = @project.new(PBXTargetDependency)
+        @target = @project.new_target(:static_library, 'Pods', :ios)
+        @target.dependencies << @target_dependency
+        @target_dependency.target_proxy = @target_container
+
+        @group = @project.main_group.new_group('Products')
+        @project_reference = Xcodeproj::Project::ObjectDictionary.new(@project.root_object.references_by_keys_attributes.first, @project.root_object)
+        @project_reference['ProjectRef'] = @file
+        @project_reference['ProductGroup'] = @group
+        @project.root_object.project_references << @project_reference
+      end
+
+      it "returns the project reference metadata" do
+        @file.project_reference_metadata.should == @project_reference
+      end
+
+      it "returns the proxy containers that are contained in this external project" do
+        @file.proxy_containers.should == [@file_container, @target_container]
+      end
+
+      it "returns the file reference proxies" do
+        @file.file_reference_proxies.should == [@file_proxy]
+      end
+
+      it "returns the target dependencies that depend on targets in this Xcode project file reference" do
+        @file.target_dependency_proxies.should == [@target_dependency]
+      end
+
+      it "removes the proxy related objects when removing the file reference" do
+        @file.remove_from_project
+        @project.objects_by_uuid[@file_proxy.uuid].should == nil
+        @project.objects_by_uuid[@file_container.uuid].should == nil
+        @project.objects_by_uuid[@target_container.uuid].should == nil
+        @project.objects_by_uuid[@target_dependency.uuid].should == nil
+        @project.objects_by_uuid[@group.uuid].should == nil
+        @project.root_object.project_references.should.not.include @project_reference
+        @target.dependencies.should.be.empty
+      end
+    end
   end
 end

spec/project_spec.rb

@@ -165,6 +165,41 @@ module ProjectSpecs
         new_instance.should == @project
       end
 
+      it "can save a project after removing a subproject" do
+        project = Xcodeproj::Project.open(fixture_path("Sample Project/Cocoa Application.xcodeproj"))
+
+        # UUID's related to ReferencedProject.xcodeproj (subproject)
+        # FIXME: these UUID's should all be deleted automatically when calling 
+        #        remove_from_project on the subproject PBXFileReference
+        #        See https://github.com/CocoaPods/Xcodeproj/issues/158
+        uuids_to_remove = [
+          "E5FBB3451635ED35009E96B0", # The Xcode subproject file reference that should trigger the removal.
+
+          "5138059B16499F4C001D82AD", # PBXContainerItemProxy links to E5FBB3451635ED35009E96B0
+          "5138059C16499F4C001D82AD", # PBXTargetDependency links to 5138059B16499F4C001D82AD
+          "E5FBB3461635ED35009E96B0", # PBXGroup for products links to E5FBB34C1635ED36009E96B0, E5FBB34E1635ED36009E96B0, E5FBB3501635ED36009E96B0
+
+          "E5FBB34B1635ED36009E96B0", # PBXContainerItemProxy links to E5FBB3451635ED35009E96B0
+          "E5FBB34C1635ED36009E96B0", # PBXReferenceProxy links to E5FBB34B1635ED36009E96B0
+
+          "E5FBB34D1635ED36009E96B0", # PBXContainerItemProxy links to E5FBB3451635ED35009E96B0
+          "E5FBB34E1635ED36009E96B0", # PBXReferenceProxy links to E5FBB34D1635ED36009E96B0
+
+          "E5FBB34F1635ED36009E96B0", # PBXContainerItemProxy links to E5FBB3451635ED35009E96B0
+          "E5FBB3501635ED36009E96B0", # PBXReferenceProxy links to E5FBB34F1635ED36009E96B0
+        ]
+
+        subproject_file_reference = project.objects_by_uuid['E5FBB3451635ED35009E96B0']
+        subproject_file_reference.remove_from_project
+        project.save(@path)
+
+        new_instance = Xcodeproj::Project.open(@path)
+        new_instance.objects.count.should > 0 # make sure we still have a valid project
+        new_instance.root_object.project_references.should.be.empty # this contains the Products group of the external project
+        removed_objects = new_instance.objects.select { |o| uuids_to_remove.include?(o.uuid) }
+        removed_objects.count.should == 0
+      end
+
       it "can open a project and save it without altering any information" do
         project = Xcodeproj::Project.open(fixture_path("Sample Project/Cocoa Application.xcodeproj"))
         plist = Xcodeproj.read_plist(fixture_path("Sample Project/Cocoa Application.xcodeproj/project.pbxproj"))