Add support for adding subprojects

CHANGELOG.md

@@ -2,10 +2,16 @@
 
 ## Master
 
-* [PlistHelper] Now the `plutil` tool is used to save the files if available to
+* `PlistHelper`: Now the `plutil` tool is used to save the files if available to
   produce output consistent with Xcode.  
   [Fabio Pelosin](https://github.com/irrationalfab)
 
+* `PBXGroup`: Now file references to Xcode projects are properly handled and
+  setup. Also the `ObjectDictionary` class has been improved and now can be
+  used to edit the attributes using it.
+  [Fabio Pelosin](https://github.com/irrationalfab)
+  [Xcodeproj#172](https://github.com/CocoaPods/Xcodeproj/pull/172)
+
 ## 0.18.0
 
 ###### Enhancements

lib/xcodeproj/constants.rb

@@ -71,21 +71,24 @@ module Constants
     FILE_TYPES_BY_EXTENSION = {
       'a'           => 'archive.ar',
       'app'         => 'wrapper.application',
+      'bundle'      => 'wrapper.plug-in',
       'dylib'       => 'compiled.mach-o.dylib',
       'framework'   => 'wrapper.framework',
-      'bundle'      => 'wrapper.plug-in',
       'h'           => 'sourcecode.c.h',
       'm'           => 'sourcecode.c.objc',
+      'markdown'    => 'text',
+      'mdimporter'  => 'wrapper.cfbundle',
+      'octest'      => 'wrapper.cfbundle',
       'pch'         => 'sourcecode.c.h',
-      'xcconfig'    => 'text.xcconfig',
-      'xcdatamodel' => 'wrapper.xcdatamodel',
-      'xib'         => 'file.xib',
+      'plist'       => 'text.plist.xml',
       'sh'          => 'text.script.sh',
       'swift'       => 'sourcecode.swift',
-      'plist'       => 'text.plist.xml',
-      'markdown'    => 'text',
       'xcassets'    => 'folder.assetcatalog',
-      'xctest'      => 'wrapper.cfbundle'
+      'xcconfig'    => 'text.xcconfig',
+      'xcdatamodel' => 'wrapper.xcdatamodel',
+      'xcodeproj'   => 'wrapper.pb-project',
+      'xctest'      => 'wrapper.cfbundle',
+      'xib'         => 'file.xib',
     }.freeze
 
     # @return [Hash] The uniform type identifier of various product types.

lib/xcodeproj/project/name_helper.rb

@@ -0,0 +1,59 @@
+module Xcodeproj
+  class Project
+    module Object
+      # Converts between camel case names used in the xcodeproj plist files
+      # and the ruby symbols used to represent them.
+      #
+      module NameHelper
+        # @return [String] The plist equivalent of the given Ruby name.
+        #
+        # @param  [Symbol, String] name
+        #         The name to convert
+        #
+        # @param  [Symbol, Nil] type
+        #         The type of conversion. Pass `nil` for normal camel case and
+        #         `:lower` for camel case starting with a lower case letter.
+        #
+        # @example
+        #   NameHelper.convert_to_plist(:project_ref) #=> ProjectRef
+        #
+        def self.convert_to_plist(name, type = nil)
+          case name
+          when :remote_global_id_string
+            'remoteGlobalIDString'
+          else
+            if type == :lower
+              cache = self.plist_cache[:lower] ||= {}
+              cache[name] ||= name.to_s.camelize(:lower)
+            else
+              cache = self.plist_cache[:normal] ||= {}
+              cache[name] ||= name.to_s.camelize()
+            end
+          end
+        end
+
+        # @return [Symbol] The Ruby equivalent of the given plist name.
+        #
+        # @param  [String] name
+        #         The name to convert
+        #
+        # @example
+        #   NameHelper.convert_to_ruby('ProjectRef') #=> :project_ref
+        #
+        def self.convert_to_ruby(name)
+          name.to_s.underscore.to_sym
+        end
+
+        # @return [Hash] A cache for the conversion to the Plist format.
+        #
+        # @note   A cache is used because this operation is performed for each
+        #         attribute of the project when it is saved and caching it has
+        #         an important performance benefit.
+        #
+        def self.plist_cache
+          @plist_cache ||= {}
+        end
+      end
+    end
+  end
+end

lib/xcodeproj/project/object.rb

@@ -65,7 +65,9 @@ def initialize(project, uuid)
           @project, @uuid = project, uuid
           @isa = self.class.isa
           @referrers = []
-          raise "[Xcodeproj] Attempt to initialize an abstract class." unless @isa.match(/^(PBX|XC)/)
+          unless @isa.match(/^(PBX|XC)/)
+            raise "[Xcodeproj] Attempt to initialize an abstract class."
+          end
         end
 
         # Initializes the object with the default values of simple attributes.
@@ -261,7 +263,10 @@ def remove_reference(object)
         def configure_with_plist(objects_by_uuid_plist)
           object_plist = objects_by_uuid_plist[uuid].dup
 
-          raise "[Xcodeproj] Attempt to initialize `#{isa}` from plist with different isa `#{object_plist}`" unless object_plist['isa'] == isa
+          unless object_plist['isa'] == isa
+          raise "[Xcodeproj] Attempt to initialize `#{isa}` from plist with " \
+            "different isa `#{object_plist}`"
+          end
           object_plist.delete('isa')
 
           simple_attributes.each do |attrb|
@@ -303,9 +308,10 @@ def configure_with_plist(objects_by_uuid_plist)
           end
 
           unless object_plist.empty?
-            raise "[!] Xcodeproj doesn't know about the following attributes " \
-                  "#{object_plist.inspect} for the '#{isa}' isa.\n" \
-                  "Please file an issue: https://github.com/CocoaPods/Xcodeproj/issues/new"
+            raise "[!] Xcodeproj doesn't know about the following " \
+                  "attributes #{object_plist.inspect} for the '#{isa}' isa." \
+                  "\nPlease file an issue: " \
+                  "https://github.com/CocoaPods/Xcodeproj/issues/new"
           end
         end
 
@@ -333,15 +339,15 @@ def configure_with_plist(objects_by_uuid_plist)
         def object_with_uuid(uuid, objects_by_uuid_plist, attribute)
           unless object = project.objects_by_uuid[uuid] || project.new_from_plist(uuid, objects_by_uuid_plist)
             UI.warn "`#{inspect}` attempted to initialize an object with " \
-              "an unknown UUID. `#{uuid}` for attribute: `#{attribute.name}`."\
-              " This can be the result of a merge and the unknown UUID is "    \
-              "being discarded."
+              "an unknown UUID. `#{uuid}` for attribute: " \
+              "`#{attribute.name}`. This can be the result of a merge and  " \
+              "the unknown UUID is being discarded."
           end
           object
         rescue NameError
           attributes = objects_by_uuid_plist[uuid]
           raise "`#{isa}` attempted to initialize an object with unknown ISA "\
-                "`#{attributes['isa']}` from attributes: `#{attributes}`\n"   \
+                "`#{attributes['isa']}` from attributes: `#{attributes}`\n" \
                 "Please file an issue: https://github.com/CocoaPods/Xcodeproj/issues/new"
         end
 
@@ -460,9 +466,10 @@ def inspect
   end
 end
 
-require 'xcodeproj/project/object_list'
-require 'xcodeproj/project/object_dictionary'
+require 'xcodeproj/project/name_helper'
 require 'xcodeproj/project/object_attributes'
+require 'xcodeproj/project/object_dictionary'
+require 'xcodeproj/project/object_list'
 
 # Required because some classes have cyclical references to each other.
 #

lib/xcodeproj/project/object/file_reference.rb

@@ -245,7 +245,7 @@ def proxy?
         #
         def project_reference_metadata
           project.root_object.project_references.find do |project_reference|
-            project_reference['ProjectRef'] == self
+            project_reference[:project_ref] == self
           end
         end
 
@@ -313,7 +313,7 @@ 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_reference[:product_group].remove_from_project
             project.root_object.project_references.delete(project_reference)
           end
           super

lib/xcodeproj/project/object/helpers/file_references_factory.rb

@@ -23,8 +23,11 @@ class << self
           # @return [PBXFileReference, XCVersionGroup] The new reference.
           #
           def new_reference(group, path, source_tree)
-            if File.extname(path).downcase == '.xcdatamodeld'
+            ref = case File.extname(path).downcase
+            when '.xcdatamodeld'
               ref = new_xcdatamodeld(group, path, source_tree)
+            when '.xcodeproj'
+              ref = new_subproject(group, path, source_tree)
             else
               ref = new_file_reference(group, path, source_tree)
             end
@@ -154,6 +157,60 @@ def new_xcdatamodeld(group, path, source_tree)
             ref
           end
 
+          # Creates a file reference to another Xcode subproject and setups the
+          # proxies to the targets.
+          #
+          # @param  [PBXGroup] group
+          #         The group to which to add the reference.
+          #
+          # @param  [#to_s] path
+          #         The, preferably absolute, path of the reference.
+          #
+          # @param  [Symbol] source_tree
+          #         The source tree key to use to configure the path (@see
+          #         GroupableHelper::SOURCE_TREES_BY_KEY).
+          #
+          # @note   To analyze the targets the given project is read and thus
+          #         it should already exist in the disk.
+          #
+          # @return [PBXFileReference] The new file reference.
+          #
+          def new_subproject(group, path, source_tree)
+            ref = new_file_reference(group, path, source_tree)
+            ref.include_in_index = nil
+
+            product_group_ref = group.project.new(PBXGroup)
+            product_group_ref.name = 'Products'
+            product_group_ref.source_tree = '<group>'
+
+            subproj = Project.open(path)
+            subproj.products_group.files.each do |product_reference|
+              container_proxy = group.project.new(PBXContainerItemProxy)
+              container_proxy.container_portal = ref.uuid
+              container_proxy.proxy_type = '2'
+              container_proxy.remote_global_id_string = product_reference.uuid
+              container_proxy.remote_info = 'Subproject'
+
+
+              reference_proxy = group.project.new(PBXReferenceProxy)
+              extension = File.extname(product_reference.path)[1..-1]
+              reference_proxy.file_type = Constants::FILE_TYPES_BY_EXTENSION[extension]
+              reference_proxy.path = product_reference.path
+              reference_proxy.remote_ref = container_proxy
+              reference_proxy.source_tree = 'BUILT_PRODUCTS_DIR'
+
+              product_group_ref << reference_proxy
+            end
+
+            attribute = PBXProject.references_by_keys_attributes.find {|attribute| attribute.name == :project_references }
+            project_reference = ObjectDictionary.new(attribute, group.project.root_object)
+            project_reference[:project_ref] = ref
+            project_reference[:product_group] = product_group_ref
+            group.project.root_object.project_references << project_reference
+
+            ref
+          end
+
           # Configures a file reference according to the extension to math
           # Xcode behaviour.
           #