fe_do.rb in openwferu-0.9.8

- old
+ new
@@ -37,64 +37,134 @@
 # "made in Japan"
 #
 # John Mettraux at openwfe.org
 #
 
+require 'openwfe/utils'
 require 'openwfe/expressions/flowexpression'
 
 
 #
-# do / redo / undo
+# redo / undo (cancel)
 #
 
 module OpenWFE
 
     #
-    # in preparation.
+    # Every expression in OpenWFEru accepts a 'tag' attribute. This tag
+    # can later be referenced by an 'undo' or 'redo' expression.
+    # Tags are active as soon as an expression is applied and they vanish
+    # when the expression replies to its parent expression or is cancelled.
     #
-    class DoExpression < FlowExpression
+    # Calling for the undo of a non-existent tag throws no error, the flow 
+    # simply resumes.
+    #
+    #     concurrence do
+    #         sequence :tag => "side_job" do
+    #             participant "alice"
+    #             participant "bob"
+    #         end
+    #         sequence do
+    #             participant "charly"
+    #             undo :ref => "side_job"
+    #         end
+    #     end
+    #
+    # In this example, as soon as the participant charly is over, the sequence
+    # 'side_job' gets undone (cancelled). If the sequence 'side_job' was
+    # already over, the "undo" will have no effect.
+    #
+    class UndoExpression < FlowExpression
 
-        attr_accessor \
-            :name
+        names :undo
 
-        #
-        # apply / reply
-
         def apply (workitem)
-        end
 
-        def reply (workitem)
-        end
-    end
+            tag = lookup_tag(workitem)
 
-    #
-    # in preparation.
-    #
-    class UndoExpression < FlowExpression
+            undo_self = false
 
+            if tag
+                #OpenWFE::call_in_thread(fei.expression_name, self) do
+                process_tag(tag)
+                #end
+
+                undo_self = tag.fei.ancestor_of?(@fei)
+            end
+
+            reply_to_parent(workitem) unless undo_self
+        end
+
         #
-        # apply / reply
+        # Calls the expression pool cancel() method upon the tagged
+        # expression.
+        #
+        def process_tag (tag)
 
-        def apply (workitem)
+            ldebug do
+                "process_tag() #{fei.to_debug_s} to undo #{tag.fei.to_debug_s}"
+            end
+
+            #get_expression_pool.cancel_and_reply_to_parent(
+            #    tag.raw_expression.fei, tag.workitem)
+
+            exp = get_expression_pool.fetch_expression(tag.raw_expression.fei)
+
+            get_expression_pool.cancel(tag.raw_expression.fei)
+
+            get_expression_pool.reply_to_parent(exp, tag.workitem, false)
+                #
+                # 'remove' is set to false, cancel already removed the
+                # expression
         end
 
         #def reply (workitem)
         #end
+
+        protected
+
+            def lookup_tag (workitem)
+
+                tagname = lookup_attribute(:ref, workitem)
+
+                tag = lookup_variable(tagname)
+
+                lwarn { "lookup_tag() no tag named '#{tagname}' found" } \
+                    unless tag
+
+                tag
+            end
     end
 
     #
-    # in preparation.
+    # Every expression in OpenWFEru accepts a 'tag' attribute. This tag
+    # can later be referenced by an 'undo' or 'redo' expression.
     #
-    class RedoExpression < FlowExpression
+    # Calling for the undo of a non-existent tag throws no error, the flow 
+    # simply resumes.
+    #
+    class RedoExpression < UndoExpression
 
-        #
-        # apply / reply
+        names :redo
 
-        def apply (workitem)
-        end
+        def process_tag (tag)
 
-        #def reply (workitem)
-        #end
+            ldebug do
+                "process_tag() #{fei.to_debug_s} to redo #{tag.fei.to_debug_s}"
+            end
+
+            #
+            # cancel
+
+            get_expression_pool.cancel(tag.fei)
+
+            #
+            # [re]apply
+
+            tag.raw_expression.application_context = @application_context
+
+            get_expression_pool.apply(tag.raw_expression, tag.workitem)
+        end
     end
 
 end
 