Initial Import: Database transaction handling.

Initial Import: Error handling using ewf error library.
Added a CMS_ERROR_FILTER as part of registered filters of CMS_SERVICE

persistence/implementation/common/database/error/database_error.e

@@ -0,0 +1,23 @@
+note
+	description: "Error from database"
+	date: "$Date: 2013-08-08 16:39:49 -0300 (ju. 08 de ago. de 2013) $"
+	revision: "$Revision: 195 $"
+
+class
+	DATABASE_ERROR
+
+inherit
+	ERROR_CUSTOM
+
+create
+	make_from_message
+
+feature {NONE} -- Init
+
+	make_from_message (a_m: like message; a_code: like code)
+			-- Create from `a_m'
+		do
+			make (a_code, once "Database Error", a_m)
+		end
+
+end

persistence/implementation/common/database/error/database_error_handler.e

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+note
+	description: "Database error handler"
+	date: "$Date: 2013-08-08 16:39:49 -0300 (ju. 08 de ago. de 2013) $"
+	revision: "$Revision: 195 $"
+
+class
+	DATABASE_ERROR_HANDLER
+
+inherit
+	ERROR_HANDLER
+
+create
+	make
+
+feature -- Error operation
+
+	add_database_error (a_message: READABLE_STRING_32; a_code: INTEGER)
+			-- Add a database error.
+		local
+			l_error: DATABASE_ERROR
+		do
+			create l_error.make_from_message (a_message, a_code)
+			add_error (l_error)
+		end
+
+	add_database_no_change_error (a_message: READABLE_STRING_32; a_code: INTEGER)
+			-- Add a database error.
+		local
+			l_error: DATABASE_NO_CHANGE_ERROR
+		do
+			create l_error.make_from_message (a_message, a_code)
+			add_error (l_error)
+		end
+
+end

persistence/implementation/common/database/error/shared_error_handler.e

@@ -0,0 +1,39 @@
+note
+	description: "Shared error handler for database"
+	date: "$Date: 2013-08-08 16:39:49 -0300 (ju. 08 de ago. de 2013) $"
+	revision: "$Revision: 195 $"
+
+class
+	SHARED_ERROR_HANDLER
+
+inherit
+
+	SHARED_LOGGER
+
+feature -- Access
+
+	database_error_handler: DATABASE_ERROR_HANDLER
+			-- Error handler.
+		once
+			create Result.make
+		end
+
+feature -- Status Report
+
+	has_error: BOOLEAN
+			-- Has error?
+		do
+			Result := database_error_handler.has_error
+		end
+
+feature -- Helper
+
+	exception_as_error (a_e: like {EXCEPTION_MANAGER}.last_exception)
+			-- Record exception as an error.
+		do
+			if attached a_e as l_e and then attached l_e.exception_trace as l_trace then
+				database_error_handler.add_error_details (l_e.code, once "Exception", l_trace.as_string_32)
+			end
+		end
+
+end