WIP: Add scope in service #7

README.md

@@ -89,7 +89,7 @@ Another big drawback is that you have to instantiate as many objects as you have
 Our two classes stay untouched, the only thing you have to do is to add a configuration file.
 
 ```yaml
-# services.yml 
+# services.yml
 parameters:
   mailer.transporter: 'smtp'
 services:
@@ -176,6 +176,12 @@ And here's some more details about each keyword:
 
 * `alias`: A string containing the target service name.
 
+* `scope`: A string defining the service initialization scope:
+  * `container`: a service is initialized only one time accross the container life (default)
+  * `prototype`: a new service is initialized each time you call the container
+
+  Note that the usage of a `prototype` service inside a `container` service raise a `ScopeWideningInjectionError`
+
 __Please note:__
 * You can reference a variable in the configuration with the following syntax: `%variable%`.
 * You can reference declared services by prefixing it with an `@` sign.

lib/dependency_injection/container.rb

@@ -23,7 +23,7 @@ def get(name)
 
     def register(name, klass_name, lazy=false)
       definition = lazy ? LazyDefinition.new(klass_name, self) : Definition.new(klass_name, self)
-      @definitions[name] =definition
+      @definitions[name] = definition
     end
 
     def register_alias(name, alias_definition_name)

lib/dependency_injection/definition.rb

@@ -1,14 +1,16 @@
 require 'active_support/core_ext/string/inflections'
+require 'dependency_injection/scope_widening_injection_error'
 
 module DependencyInjection
   class Definition
-    attr_accessor :arguments, :configurator, :klass_name, :method_calls
+    attr_accessor :arguments, :configurator, :klass_name, :method_calls, :scope
 
     def initialize(klass_name, container)
       @container        = container
       self.arguments    = []
       self.klass_name   = klass_name
       self.method_calls = {}
+      self.scope        = :container
     end
 
     def add_argument(argument)
@@ -38,20 +40,30 @@ def klass
     end
 
     def object
-      return @object if @object
+      self.send("#{self.scope}_scoped_object")
+    end
+
+  private
+
+    def container_scoped_object
+      @object ||= initialize_object
+    end
 
-      @object = self.klass.new(*resolve(self.arguments))
+    def initialize_object
+      object = self.klass.new(*resolve(self.arguments))
       self.method_calls.each { |method_name, arguments| @object.send(method_name, *resolve(arguments)) }
       if self.configurator
         name, method_name   = self.configurator
         configurator_object = resolve([name]).first
-        configurator_object.send(method_name, @object)
+        configurator_object.send(method_name, object)
       end
 
-      @object
+      object
     end
 
-  private
+    def prototype_scoped_object
+      initialize_object
+    end
 
     def resolve(arguments)
       resolve_references(resolve_container_parameters(arguments))
@@ -70,7 +82,10 @@ def resolve_container_parameters(arguments)
     def resolve_references(arguments)
       arguments.map do |argument|
         if /^@(?<reference_name>.*)/ =~ argument
-          @container.get(reference_name)
+          reference = @container.get(reference_name)
+          raise ScopeWideningInjectionError if reference.scope == :prototype && scope == :container
+
+          reference
         else
           argument
         end

lib/dependency_injection/loaders/yaml.rb

@@ -38,6 +38,7 @@ def add_service(name, parameters)
       def add_standard_service(name, parameters)
         lazy_load  = parameters['lazy'] || false
         definition = @container.register(name, parameters['class'], lazy_load)
+        definition.scope = parameters['scope'] if parameters['scope']
         definition.add_arguments(*parameters['arguments']) if parameters['arguments']
         if (configurator = parameters['configurator'])
           definition.add_configurator(configurator[0], configurator[1])

lib/dependency_injection/scope_widening_injection_error.rb

@@ -0,0 +1,2 @@
+class ScopeWideningInjectionError < Error
+end