Added feature to manipulate easily the chain of filters.

library/server/wsf/router/filter/wsf_filter.e

@@ -1,6 +1,5 @@
 note
 	description: "Objects than can pre-process incoming data and post-process outgoing data."
-	author: "Olivier Ligot"
 	date: "$Date$"
 	revision: "$Revision$"
 
@@ -9,9 +8,23 @@ deferred class
 
 feature -- Access
 
-	next: detachable WSF_FILTER
+	next: detachable WSF_FILTER assign set_next
 			-- Next filter
 
+	last: WSF_FILTER
+			-- Last filter in the chain following `next'.
+		do
+			from
+				Result := Current
+			until
+				not attached Result.next as l_next
+			loop
+				Result := l_next
+			end
+		ensure
+			is_closing: Result /= Void and then Result.next = Void
+		end			
+
 feature -- Element change
 
 	set_next (a_next: like next)
@@ -22,6 +35,24 @@ feature -- Element change
 			next_set: next = a_next
 		end
 
+	append (a_filter: attached like next)
+			-- Append `a_filter' to the `last' filter.
+		do
+			last.set_next (a_filter)
+		end
+
+	insert_after (a_filter: attached like next)
+			-- Append `a_filter' to the `last' filter.
+		local
+			f: like next
+		do
+			f := next
+			set_next (a_filter)
+			if f /= Void then
+				a_filter.append (f)
+			end
+		end
+
 feature -- Basic operations
 
 	execute (req: WSF_REQUEST; res: WSF_RESPONSE)

library/server/wsf/router/filter/wsf_filtered.e

@@ -29,22 +29,19 @@ feature {NONE} -- Initialization
 		deferred
 		end
 
+	append_filter (a_filter: WSF_FILTER)
+			-- Append `a_filter' to the end of the `filter' chain.
+		do
+			filter.append (a_filter)
+		end
+
 	append_filters (a_filters: ITERABLE [WSF_FILTER])
 			-- Append collection `a_filters' of filters to the end of the `filter' chain.
 		local
 			f: like filter
 			l_next_filter: detachable like filter
 		do
-			from
-				f := filter
-				l_next_filter := f.next
-			until
-				l_next_filter = Void
-			loop
-				f := l_next_filter
-				l_next_filter := f.next
-			end
-			check f_attached_without_next: f /= Void and then f.next = Void end
+			f := filter.last
 			across
 				a_filters as ic
 			loop
@@ -59,5 +56,4 @@ feature -- Access
 	filter: WSF_FILTER
 			-- Filter
 
-
 end