another aproach to call a method given by a string....maybe less optimal

app/config/storage.yml

@@ -58,7 +58,7 @@
       - 'organizationalRole'
       - 'MailAlias'
 
-    :dnPat: "cn=#{:user},o=#{:mail|sub(/.*@/, '')}"
+    :dnPat: "cn=#{:user},o=#{:mail|:sub, /.*@/, ''}"
 
     :map:
       :cn: :user
@@ -72,7 +72,7 @@
       - 'person'
       - 'MailAlias'
 
-    :dnPat: "mail=#{:mail},o=#{:mail|sub(/.*@/, '')}"
+    :dnPat: "mail=#{:mail},o=#{:mail|:sub, /.*@/, ''}"
 
     :map:
       :sn: :surname
@@ -87,7 +87,7 @@
       - 'person'
       - 'MailAccount'
 
-    :dnPat: "mail=#{:mail},o=#{:mail|sub(/.*@/, '')}"
+    :dnPat: "mail=#{:mail},o=#{:mail|:sub, /.*@/, ''}"
 
     :map:
       :homedirectory: :home

app/storage/config.rb

@@ -20,16 +20,29 @@ class DsAdmin::Storage::Config
   ##
   # replace special patterns within config strings with data
   # given by the data hash param. These patterns also allow to send
-  # a message to the replaces data e.g. for some kind of subtitution.
+  # a message to the actual substituted data to do any kind of
+  # conversion to it.
+  #
+  # actually this is used within the handling of the ldap specific
+  # :dnPat config parameter to generate the dn entry for a given model
+  # Data (create or replace)
+  #
+  # TODO: I would like to get rid of the eval statements but i don't know
+  # a better way to build the correct objects from the config strings
   #
   def eval_pattern(pattern, data = {})
     scan_exp = /([^#]*)(#\{(:[^}|]+)(\|([^}]*))?\})?/
 
     result = String.new
     pattern.scan(scan_exp) do |m|
-      key = m[2][1..m[2].length].to_sym if m[2]
+      key = (eval m[2]) if m[2]
       val = data[key] if data[key]
-      val = eval('"' + val + '".send ' + m[4]) if val && m[4]
+
+      args = m[4].split(',').map do |arg|
+        eval arg.strip
+      end if m[4]
+
+      val = val.send *args if args
 
       result += m[0] + (val || "")
     end

app/tester.rb

@@ -148,5 +148,10 @@ user.name = 'brad'
 puts 'returns: ' + user.save
 puts 'base: ' + user.inspect
 
+puts
+alias_person.mail = 'noop@steffers.org'
+puts 'returns: ' + alias_person.save
+puts 'base: ' + alias_person.inspect
+
 puts
 puts 'Memory useage: ' + `ps -o rss= -p #{Process.pid}`