Index: TODO
===================================================================
diff -u -rc85ca5808548fc506bfc39600bafb8b11ecfac43 -r8f4ba2af8b01697a3aab727a2794cb3b456d6632
--- TODO	(.../TODO)	(revision c85ca5808548fc506bfc39600bafb8b11ecfac43)
+++ TODO	(.../TODO)	(revision 8f4ba2af8b01697a3aab727a2794cb3b456d6632)
@@ -2612,6 +2612,8 @@
   * new method "show" for mongo mapped classes
   * added two new example files example-nx-reference-many.tcl and
     example-nx-reference-one.tcl
+  * replaced "arg" by "type" in spec for mongo attributes to make
+    spec less stange
 
 TODO:
 
Index: library/mongodb/example-nx-bi.tcl
===================================================================
diff -u -rfe68b259d9a15328a04a9dc64394dc5ffe5ba5a4 -r8f4ba2af8b01697a3aab727a2794cb3b456d6632
--- library/mongodb/example-nx-bi.tcl	(.../example-nx-bi.tcl)	(revision fe68b259d9a15328a04a9dc64394dc5ffe5ba5a4)
+++ library/mongodb/example-nx-bi.tcl	(.../example-nx-bi.tcl)	(revision 8f4ba2af8b01697a3aab727a2794cb3b456d6632)
@@ -33,9 +33,9 @@
 
 # Make sure, we start always from scratch, so remove everything from
 # the collection.
-nx::mongo::db remove tutorial.comments {}
+nx::mongo::db remove tutorial.postings {}
 
-#
+######################################################################
 # Create the application classes based on the "Business Insider" data
 # model. Note that instances of the class "Comment" can be embedded in
 # a posting (attribute "comments") as well as in an comment itself
@@ -44,23 +44,21 @@
 # "... delete ..." to add values to the attributes).
 #
 nx::mongo::Class create Comment {
-  # This class does not have a :mongo_ns" spec, since it is embedded.
-
   :attribute author:required
   :attribute comment:required 
-  :attribute replies:embedded,arg=::Comment,0..n {set :incremental 1}
+  :attribute replies:embedded,type=::Comment,0..n {set :incremental 1}
 }
 
 nx::mongo::Class create Posting {
   :index tags
   :attribute title:required
   :attribute author:required
   :attribute ts:required
-  :attribute comments:embedded,arg=::Comment,0..n {set :incremental 1}
+  :attribute comments:embedded,type=::Comment,0..n {set :incremental 1}
   :attribute tags:0..n {set :incremental 1}
 }
 
-#
+######################################################################
 # Build a composite Posting instance based on the example above.
 #
 set p [Posting new -title "Too Big to Fail" -author "John S." \
@@ -137,6 +135,44 @@
 # We still have three entries in the database
 ? {Posting count} 3
 
-puts stderr [$q bson pp [$q eval {:bson encode}]]
+Posting show
 
-puts stderr ====EXIT
\ No newline at end of file
+puts stderr ====EXIT
+######################################################################
+# Output
+######################################################################
+# {
+#     _id: 4daaeb04727b2b1000000000, 
+#     title: {Too Big to Fail}, 
+#     comments: [ { 
+#       author: {Ian White}, 
+#       comment: {Great Article!} }, { 
+#       replies: [ { 
+#         author: {Jane Smith}, 
+#         comment: scalable? } ], 
+#       author: {Joe Smith}, 
+#       comment: {But how fast is it?} } ], 
+#     author: {John S.}, 
+#     ts: {05-Nov-09 10:33}, 
+#     tags: [ finance, economy ]
+# }, {
+#     _id: 4daaeb04727b2b1000000001, 
+#     title: {Too Big to Fail}, 
+#     comments: [ { 
+#       author: {Ian White}, 
+#       comment: {Great Article!} } ], 
+#     author: {John S.}, 
+#     ts: {05-Nov-09 10:33}, 
+#     tags: [ finance, economy ]
+# }, {
+#     _id: 4daaeb04727b2b1000000002, 
+#     title: {Too Big to Fail}, 
+#     comments: [ { 
+#       author: {Ian White}, 
+#       comment: {Great Article!} }, { 
+#       author: {Gustaf N}, 
+#       comment: {This sounds pretty cool} } ], 
+#     author: {John S.}, 
+#     ts: {05-Nov-09 10:33}, 
+#     tags: [ nsf, nx, finance, economy ]
+# }
\ No newline at end of file
Index: library/mongodb/example-nx-reference-many.tcl
===================================================================
diff -u -rc85ca5808548fc506bfc39600bafb8b11ecfac43 -r8f4ba2af8b01697a3aab727a2794cb3b456d6632
--- library/mongodb/example-nx-reference-many.tcl	(.../example-nx-reference-many.tcl)	(revision c85ca5808548fc506bfc39600bafb8b11ecfac43)
+++ library/mongodb/example-nx-reference-many.tcl	(.../example-nx-reference-many.tcl)	(revision 8f4ba2af8b01697a3aab727a2794cb3b456d6632)
@@ -70,7 +70,7 @@
 }
 nx::mongo::Class create Group {
   :attribute name
-  :attribute members:embedded,arg=::Member,0..n
+  :attribute members:embedded,type=::Member,0..n
 }
 
 Group insert -name "grp3" \
@@ -96,7 +96,7 @@
 }
 nx::mongo::Class create Group {
   :attribute name
-  :attribute members:reference,arg=::Member,0..n
+  :attribute members:reference,type=::Member,0..n
 }
 
 Group insert -name "grp4" \
@@ -114,6 +114,9 @@
 puts stderr "Content of collection groups:"
 Group show
 
+######################################################################
+# Output
+######################################################################
 # Content of collection groups:
 # {
 #     _id: 4daae3e492b5570e00000000, 
Index: library/mongodb/example-nx-reference-one.tcl
===================================================================
diff -u -rc85ca5808548fc506bfc39600bafb8b11ecfac43 -r8f4ba2af8b01697a3aab727a2794cb3b456d6632
--- library/mongodb/example-nx-reference-one.tcl	(.../example-nx-reference-one.tcl)	(revision c85ca5808548fc506bfc39600bafb8b11ecfac43)
+++ library/mongodb/example-nx-reference-one.tcl	(.../example-nx-reference-one.tcl)	(revision 8f4ba2af8b01697a3aab727a2794cb3b456d6632)
@@ -67,7 +67,7 @@
 }
 nx::mongo::Class create Post {
   :attribute title
-  :attribute user:embedded,arg=::User
+  :attribute user:embedded,type=::User
 }
 
 Post insert -title "Hello embedded World" -user [User new -name Smith]
@@ -86,7 +86,7 @@
 }
 nx::mongo::Class create Post {
   :attribute title
-  :attribute user:reference,arg=::User
+  :attribute user:reference,type=::User
 }
 
 Post insert -title "Hello referenced World" -user [User new -name Smith]
@@ -98,6 +98,10 @@
 puts stderr "Content of the collection groups:"
 Post show
 
+######################################################################
+# Output
+######################################################################
+
 # Content of the collection groups:
 # {
 #     _id: 4daae48056b77f0e00000000, 
Index: library/mongodb/nx-mongo.tcl
===================================================================
diff -u -rc85ca5808548fc506bfc39600bafb8b11ecfac43 -r8f4ba2af8b01697a3aab727a2794cb3b456d6632
--- library/mongodb/nx-mongo.tcl	(.../nx-mongo.tcl)	(revision c85ca5808548fc506bfc39600bafb8b11ecfac43)
+++ library/mongodb/nx-mongo.tcl	(.../nx-mongo.tcl)	(revision 8f4ba2af8b01697a3aab727a2794cb3b456d6632)
@@ -8,11 +8,14 @@
 package provide nx::mongo 0.2
 
 # todo: how to handle multiple connections; currently we have a single, global connection
-# todo: make embedded, reference spec nicer
 # todo: all references are currently auto-fetched. make this optional
+# todo: If "emebds" or "references" are used, the object must be of 
+#       the specified classes, no subclasses allowed
+# todo: extend the query language syntax, e.g. regexp, ...
 # todo: handle remove for non-multivalued embedded objects
 # idea: handle names of nx objects (e.g. attribute like __name)
 # idea: handle classes von nx objects (e.g. attribute like __class)
+# todo: make "embedded", "reference" spec even nicer?
 
 namespace eval ::nx::mongo {
 
@@ -307,6 +310,7 @@
     # default slot class
     #
     :public method attribute {spec {-class ::nx::mongo::Attribute} {initblock ""}} {
+      regsub -all {,type=} $spec {,arg=} spec
       next [list $spec -class $class $initblock]
     }