Index: TODO
===================================================================
diff -u -rc81b840c71a9f0de9d0a502e3e4ddfde57b81fdd -rec9e525c887a0ae430bdb35bef01f499b25d617f
--- TODO	(.../TODO)	(revision c81b840c71a9f0de9d0a502e3e4ddfde57b81fdd)
+++ TODO	(.../TODO)	(revision ec9e525c887a0ae430bdb35bef01f499b25d617f)
@@ -2585,6 +2585,8 @@
 - Let "info slot" return the slot object
 - nx::mongo: Initial commit of the experimental mongoDB interface for nx
 
+- nx.tcl: fix handling of arg in converter
+
 TODO:
 - how to delete attributes?
 
Index: library/mongodb/README
===================================================================
diff -u -r433066d5cd921df865e2b34685caf7a2b8e0035a -rec9e525c887a0ae430bdb35bef01f499b25d617f
--- library/mongodb/README	(.../README)	(revision 433066d5cd921df865e2b34685caf7a2b8e0035a)
+++ library/mongodb/README	(.../README)	(revision ec9e525c887a0ae430bdb35bef01f499b25d617f)
@@ -37,8 +37,15 @@
     This example script is using the higher level object oriented
     interface for nx (nx::mongo).
 
-After running the scripts, you should see output like the following
+After running the scripts, you should see output like the one below.
 
+   % /usr/local/bin/mongo
+   MongoDB shell version: 1.9.0-pre-
+   connecting to: test
+   > use tutorial
+   switched to db tutorial
+   > db.persons.find();
+
 -gustaf neumann
 
 ===============================================================
Index: library/mongodb/example-nx-bi.tcl
===================================================================
diff -u
--- library/mongodb/example-nx-bi.tcl	(revision 0)
+++ library/mongodb/example-nx-bi.tcl	(revision ec9e525c887a0ae430bdb35bef01f499b25d617f)
@@ -0,0 +1,74 @@
+#
+# The Business Insider Data Model
+#
+# { title: 'Too Big to Fail', 
+#   author: 'John S.',
+#   ts: Date('05-Nov-09 10:33'),
+#   [ comments: [ {author: 'Ian White',
+#                  comment: 'Great Article!' },
+#                 {author: 'Joe Smith',
+#                  comment: 'But how fast is it?',
+#                  replies: [ {author: Jane Smith',
+#                              comment: 'scalable?' }]
+#                 }
+#   ],
+#   tags: ['finance', 'economy']
+# }
+
+#
+# This is an example how to use the nx mongo mapping.
+#
+# Gustaf Neumann              fecit, April 2011
+#
+package require nx::mongo
+package require nx::serializer
+
+# Establish connection to the database
+::nx::mongo::db connect
+
+# Make sure, we start always from scratch
+nx::mongo::db remove tutorial.bi {}
+
+#
+# Create the application classes
+#
+
+# TODO: 
+#   - make embedded spec nicer
+#   - handle delete of mebedded obj
+#   - 
+
+
+nx::mongo::Class create Comment {
+  #:document "tutorial.bi"
+
+  :attribute author:required
+  :attribute comment:required 
+  :attribute replies:embedded,arg=::Comment,0..n {set :incremental 1}
+}
+
+nx::mongo::Class create Posting {
+  :document "tutorial.bi"
+  :index ts
+  :attribute title:required
+  :attribute author:required
+  :attribute ts:required
+  :attribute comments:embedded,arg=::Comment,0..n {
+    #set :incremental 1
+  }
+  :attribute tags:0..n
+}
+#puts stderr [Posting serialize]
+
+set p [Posting new -title "Too Big to Fail" -author "John S." -ts "05-Nov-09 10:33" -tags {finance economy} \
+	   -comments [list \
+			  [Comment new -author "Ian White" -comment "Great Article!"] \
+			  [Comment new -author "Joe Smith" -comment "But how fast is it?" \
+			       -replies [list [Comment new -author "Jane Smith" -comment "scalable?"]]] \
+			 ]]
+
+#puts [$p serialize]
+
+puts stderr ====
+$p save
+puts stderr ====EXIT
\ No newline at end of file
Index: library/mongodb/example-nx-mongo.tcl
===================================================================
diff -u -ra978b09df089800818fb317d67286d9082164f91 -rec9e525c887a0ae430bdb35bef01f499b25d617f
--- library/mongodb/example-nx-mongo.tcl	(.../example-nx-mongo.tcl)	(revision a978b09df089800818fb317d67286d9082164f91)
+++ library/mongodb/example-nx-mongo.tcl	(.../example-nx-mongo.tcl)	(revision ec9e525c887a0ae430bdb35bef01f499b25d617f)
@@ -6,10 +6,10 @@
 package require nx::mongo
 
 # Establish connection to the database
-set mongoConn [::mongo::connect]
+::nx::mongo::db connect
 
 # Make sure, we start always from scratch
-::mongo::remove $mongoConn tutorial.persons {}
+nx::mongo::db remove tutorial.persons {}
 
 #
 # Create the application class "Person"
Index: library/mongodb/nx-mongo.tcl
===================================================================
diff -u -rc81b840c71a9f0de9d0a502e3e4ddfde57b81fdd -rec9e525c887a0ae430bdb35bef01f499b25d617f
--- library/mongodb/nx-mongo.tcl	(.../nx-mongo.tcl)	(revision c81b840c71a9f0de9d0a502e3e4ddfde57b81fdd)
+++ library/mongodb/nx-mongo.tcl	(.../nx-mongo.tcl)	(revision ec9e525c887a0ae430bdb35bef01f499b25d617f)
@@ -11,251 +11,326 @@
 # todo: handle embedded bson objects
 # todo: handle named nx objects (e.g. attribute _oid?}
 
-#
-# nx::mongo::Attribute is a specialized attribute slot
-#
-::nx::MetaSlot create ::nx::mongo::Attribute -superclass ::nx::Attribute {
-  :attribute mongotype
+namespace eval ::nx::mongo {
 
-  :protected method init {} {
+  ::nx::Object create ::nx::mongo::db {
+    :public method connect {args} {set :mongoConn [::mongo::connect {*}$args]}
+    :public method index   {args} {::mongo::index  ${:mongoConn} {*}$args}
+    :public method insert  {args} {::mongo::insert ${:mongoConn} {*}$args}
+    :public method remove  {args} {::mongo::remove ${:mongoConn} {*}$args}
+    :public method query   {args} {::mongo::query  ${:mongoConn} {*}$args}
+    :public method update  {args} {::mongo::update ${:mongoConn} {*}$args}
+  }
+  
+  #
+  # nx::mongo::Attribute is a specialized attribute slot
+  #
+  ::nx::MetaSlot create ::nx::mongo::Attribute -superclass ::nx::Attribute {
+    :attribute mongotype
+    
+    :protected method init {} {
+      #
+      # If the mongotype was not provided, set it to a value derived
+      # from "type". Not all types are mappable easily to mongo types.
+      #
+      if {![info exists :mongotype]} {
+	set :mongotype string
+	if {[info exists :type]} {
+	  puts stderr "type of ${:name} is ${:type}"
+	  switch -glob ${:type} {
+	    "boolean" -
+	    "integer" {set :mongotype ${:type}}
+	    "embedded" {set :mongotype object}
+	  }
+	  #"::*" {set :mongotype object}
+	}
+      }
+      puts stderr "mongo type of ${:name} is ${:mongotype} [info exists :type]"
+      next
+    }
+    
     #
-    # If the mongotype was not provided, set it to a value derived
-    # from "type". Not all types are mappable easily to mongo types.
+    # The methods "bson encode|decode" perform the low level type
+    # mapping. For now, this handles just the array notation.
     #
-    if {![info exists :mongotype]} {
-      set :mongotype string
-      if {[info exists :type]} {
-	switch ${:type} {
-	  "boolean" -
-	  "integer" {set :mongotype ${:type}}
+    :method "bson decode" {bsontype value} {
+      #puts stderr "bson decode of ${:name} /$bsontype/ '$value'"
+      if {$bsontype eq "array"} {
+	if {![:isMultivalued]} {
+	  # We got an array, but the slot is not multivalued. Maybe
+	  # generating an error is too harsh, but for the mapping back,
+	  # we check for multivalued as well.
+	  error "Attribute ${:name} should be multivalued, but it is not"
 	}
+	set result [list]
+	foreach {pos type v} $value {lappend result $v}
+	return $result
       }
+      return $value
     }
-    next
-  }
+    
+    :method "bson encodeValue" {value} {
+      if {${:mongotype} eq "object"} {
+	return [list ${:mongotype} [$value bson encode]]
+      } else {
+	return [list ${:mongotype} $value]
+      }
+    }
 
-  #
-  # The methods "bson encode|decode" perform the low level type
-  # mapping. For now, this handles just the array notation.
-  #
-  :method "bson decode" {bsontype value} {
-    #puts stderr "bson decode of ${:name} /$bsontype/ '$value'"
-    if {$bsontype eq "array"} {
-      if {![:isMultivalued]} {
-	# We got an array, but the slot is not multivalued. Maybe
-	# generating an error is too harsh, but for the mapping back,
-	# we check for multivalued as well.
-	error "Attribute ${:name} should be multivalued, but it is not"
+    :method "bson encode" {value} {
+      if {[:isMultivalued]} {
+	set c -1
+	set array [list]
+	foreach v $value {lappend array [incr c] {*}[:bson encodeValue $v]}
+	return [list array $array]
+      } else {
+	return [:bson encodeValue $value]
       }
-      set result [list]
-      foreach {pos type v} $value {lappend result $v}
-      return $result
     }
-    return $value
-  }
 
-  :method "bson encode" {value} {
-    if {[:isMultivalued]} {
-      set c -1
-      set array [list]
-      foreach v $value {lappend array [incr c] ${:mongotype} $v}
-      return [list array $array]
-    } else {
-      return [list ${:mongotype} $value]
+    #
+    #
+    #
+    :public method type=embedded {name value args} {
+      set s [:uplevel self]
+      puts stderr "assign $name '$value' args='$args' s=$s"
+      if {[::nsf::isobject $value] && [::nsf::is class $args] && [$value info has type $args]} {
+	::nsf::var::set $value _embedded_in [list $s $name]
+	puts stderr [list ::nsf::var::set $value _embedded_in [list $s $name]]
+      } else {
+	error "value '$value' for attribute $name is not of type $args"
+      }
     }
   }
-}
-
-nx::Class create nx::mongo::Class -superclass nx::Class {
   
-  #
-  # Every mongo class can be configured with a document, from which
-  # its instance data is queried.
-  #
-  :attribute document
-
-  #
-  # Provide helper methods to access from an external specifier
-  # (attribute name or operator name) internal representations
-  # (eg. mongo type, or mongo operator).
-  #
-
-  :method "get slot" {att} {
-    set classes [concat [self] [:info mixin classes] [:info heritage]]
-    foreach cls $classes {
-      set slot [$cls info slot $att]
-      if {$slot ne ""} {
-	return $slot
+  ::nx::Class create ::nx::mongo::Class -superclass nx::Class {
+    
+    #
+    # Every mongo class can be configured with a document, from which
+    # its instance data is queried.
+    #
+    :attribute document
+    
+    #
+    # Provide helper methods to access from an external specifier
+    # (attribute name or operator name) internal representations
+    # (eg. mongo type, or mongo operator).
+    #
+    
+    :method "get slot" {att} {
+      set classes [concat [self] [:info mixin classes] [:info heritage]]
+      foreach cls $classes {
+	set slot [$cls info slot $att]
+	if {$slot ne ""} {
+	  return $slot
+	}
       }
     }
-  }
-
-  :public method "get relop" {op} {
-    array set "" {< $lt > $gt <= $lte >= $gte != $ne}
-    return $($op)
-  }
-
-  #
-  # For interaction with bson structures, we provide on the class
-  # level "bson query" (a small dsl for a more convenient syntax in
-  # bson queries) and "bson parameter" which translates from a bson
-  # structure (tuple) into a dashed parameter list used in object
-  # creation.
-  #
-
-  :method "bson query" {{-cond ""} {-orderby ""}} {
-    set bson [list]
-    foreach {att op value} $cond {
-      set slot [:get slot $att]
+    
+    :public method "get relop" {op} {
+      array set "" {< $lt > $gt <= $lte >= $gte != $ne}
+      return $($op)
+    }
+    
+    #
+    # For interaction with bson structures, we provide on the class
+    # level "bson query" (a small dsl for a more convenient syntax in
+    # bson queries) and "bson parameter" which translates from a bson
+    # structure (tuple) into a dashed parameter list used in object
+    # creation.
+    #
+    
+    :method "bson query" {{-cond ""} {-orderby ""}} {
+      set bson [list]
+      foreach {att op value} $cond {
+	set slot [:get slot $att]
       switch $op {
 	"=" {lappend bson $att [$slot mongotype] $value}
 	">" - "<" - "<=" - ">=" - "!="  {
 	  lappend bson $att object [list [:get relop $op] [$slot mongotype] $value]
 	}
 	default {error "unknown operator $op"}
       }
+      }
+      set result [list \$query object $bson]
+      if {[llength $orderby] > 0} {
+	set bson [list]
+	foreach attspec $orderby {
+	  lassign $attspec att direction
+	  lappend bson $att int [expr {$direction eq "desc" ? -1 : 1}]
+	}
+	lappend result \$orderby object $bson
+      }
+      puts "Query: $result"
+      return $result
     }
-    set result [list \$query object $bson]
-    if {[llength $orderby] > 0} {
-      set bson [list]
-      foreach attspec $orderby {
-	lassign $attspec att direction
-	lappend bson $att int [expr {$direction eq "desc" ? -1 : 1}]
+    
+    :method "bson parameter" {tuple} {
+      set objParams [list]
+      foreach {att type value} $tuple {
+	set slot [:get slot $att]
+	lappend objParams -$att [$slot bson decode $type $value]
       }
-      lappend result \$orderby object $bson
+      return $objParams
     }
-    puts "Query: $result"
-    return $result
-  }
-
-  :method "bson parameter" {tuple} {
-    set objParams [list]
-    foreach {att type value} $tuple {
-      set slot [:get slot $att]
-      lappend objParams -$att [$slot bson decode $type $value]
+    
+    #
+    # Overload method attribute to provide "::nx::mongo::Attribute" as a
+    # default slot class
+    #
+    :public method attribute {spec {-class ::nx::mongo::Attribute} {initblock ""}} {
+      next [list $spec -class $class $initblock]
     }
-    return $objParams
-  }
-
-  #
-  # Overload method attribute to provide "::nx::mongo::Attribute" as a
-  # default slot class
-  #
-  :public method attribute {spec {-class ::nx::mongo::Attribute} {initblock ""}} {
-    next [list $spec -class $class $initblock]
-  }
-
-  #
-  # index method
-  #
-  :public method index {att {-type 1}} {
-    # todo: 2d index will need a different type
-    ::mongo::index $::mongoConn ${:document} [list $att int $type]
-  }
-
-  #
-  # A convenience method for inserting a fresh tuple
-  #
-  :public method insert {args} {
-    set p [:new {*}$args]
-    $p save
-    $p destroy
-  }
-
-  #
-  # The query interface consists currently of "find first" (returning
-  # a single instance) and "find all" (returning a list of instances).
-  #
-  :public method "find first" {
-     -instance 
-     {-cond ""}
-     {-orderby ""} 
-   } {
-    set fetched [::mongo::query $::mongoConn ${:document} \
-		     [:bson query -cond $cond -orderby $orderby] \
-		     -limit 1]
-    puts "[join $fetched \n]"
-    foreach tuple $fetched {
-      if {[info exists instance]} {
-	set o [:uplevel [list [self] create $instance {*}[:bson parameter $tuple]]]
-	return $o
-      } else {
-	return [:uplevel [list [self] new {*}[:bson parameter $tuple]]]
+    
+    #
+    # index method
+    #
+    :public method index {att {-type 1}} {
+      # todo: 2d index will need a different type
+      #::mongo::index $::mongoConn ${:document} [list $att int $type]
+      db index ${:document} [list $att int $type]
+    }
+    
+    #
+    # A convenience method for inserting a fresh tuple
+    #
+    :public method insert {args} {
+      set p [:new {*}$args]
+      $p save
+      $p destroy
+    }
+    
+    #
+    # The query interface consists currently of "find first" (returning
+    # a single instance) and "find all" (returning a list of instances).
+    #
+    :public method "find first" {
+				 -instance 
+				 {-cond ""}
+				 {-orderby ""} 
+			       } {
+      set fetched [::nx::mongo::db query ${:document} \
+		       [:bson query -cond $cond -orderby $orderby] \
+		       -limit 1]
+      puts "[join $fetched \n]"
+      foreach tuple $fetched {
+	if {[info exists instance]} {
+	  set o [:uplevel [list [self] create $instance {*}[:bson parameter $tuple]]]
+	  return $o
+	} else {
+	  return [:uplevel [list [self] new {*}[:bson parameter $tuple]]]
+	}
       }
     }
-  }
-
-  :public method "find all" {
-     {-cond ""} 
-     {-orderby ""} 
-     {-limit} 
-     {-skip} 
-   } {
-    set result [list]
-    set opts [list]
-    if {[info exists limit]} {lappend opts -limit $limit}
-    if {[info exists skip]} {lappend opts -skip $skip}
-    set fetched [::mongo::query $::mongoConn ${:document} \
-		     [:bson query -cond $cond -orderby $orderby] \
-		     {*}$opts]
-    puts "[join $fetched \n]"
-    foreach tuple $fetched {
-      lappend result [:uplevel [list [self] new {*}[:bson parameter $tuple]]]
+    
+    :public method "find all" {
+			       {-cond ""} 
+			       {-orderby ""} 
+			       {-limit} 
+			       {-skip} 
+			     } {
+      set result [list]
+      set opts [list]
+      if {[info exists limit]} {lappend opts -limit $limit}
+      if {[info exists skip]} {lappend opts -skip $skip}
+      set fetched [::nx::mongo::db query ${:document} \
+		       [:bson query -cond $cond -orderby $orderby] \
+		       {*}$opts]
+      puts "[join $fetched \n]"
+      foreach tuple $fetched {
+	lappend result [:uplevel [list [self] new {*}[:bson parameter $tuple]]]
+      }
+      return $result
     }
-    return $result
+    
+    #
+    # When a mongo::Class is created, mixin the mongo::Object to make
+    # "save" etc. available
+    #
+    
+    :method init {} {
+      :mixin add ::nx::mongo::Object
+    }
+    
+    # :public method create args {
+    #   puts stderr CREATE-[self]-$args
+    #   set o [next]
+    #   $o mixin add ::nx::mongo::Object
+    #   puts stderr CREATED-$o-[$o info mixin]
+    #   return $o
+    # }
+    
   }
-
+  
   #
-  # When a mongo::Class is created, mixin the mongo::Object to make
-  # "save" etc. available
+  # The class mongo::Object provides methods for mongo objects (such as
+  # "save")
   #
-  
-  :method init {} {
-    :mixin add ::nx::mongo::Object
-  }
+  ::nx::Class create ::nx::mongo::Object {
+    
+    #
+    # _id is the special attribute maintained by mongoDB
+    #
+    :attribute _id -class ::nx::mongo::Attribute {
+      set :mongotype oid
+    }
 
-  # :public method create args {
-  #   puts stderr CREATE-[self]-$args
-  #   set o [next]
-  #   $o mixin add ::nx::mongo::Object
-  #   puts stderr CREATED-$o-[$o info mixin]
-  #   return $o
-  # }
+    #
+    # Encode all object data in bson notation
+    #
+    :method "bson encode" {} {
+      set bson [list]
+      set cls [:info class]
+      foreach var [:info vars] {
+	set slot [$cls get slot $var]
+	if {$slot ne ""} {
+	  lappend bson $var {*}[$slot bson encode [set :$var]]
+	}
+      }
+      return $bson
+    }
 
-}
+    #
+    # embedded_in denotes that the object is embedded in another
+    # object with a reference to the attribute
+    #
+    # :public method embedded_in {object attribute} {
+    #   set :_embedded_in [list $object $attribute]
+    #   $object $attribute add [self] end
+    # }
 
-#
-# The class mongo::Object provides methods for mongo objects (such as
-# "save")
-#
-nx::Class create nx::mongo::Object {
-
-  #
-  # _id is the special attribute maintained by mongoDB
-  #
-  :attribute _id -class ::nx::mongo::Attribute {
-    set :mongotype oid
-  }
-
-  #
-  # Save the current object. When we have an _id, perform an update,
-  # otherwise perform an insert
-  #
-  :public method save {} {
-    set bson [list]
-    set cls [:info class]
-    foreach var [:info vars] {
-      set slot [$cls get slot $var]
-      lappend bson $var {*}[$slot bson encode [set :$var]]
+    #
+    # delete the current object from the db
+    #
+    :public method delete {} {
+      set document [[:info class] document]
+      if {$document eq ""} {
+	set embeddedIn [...]
+      } else {
+      }
     }
-    if {[info exists :_id]} {
-      #puts stderr "we have to update $bson"
-      ::mongo::update $::mongoConn [$cls document] [list _id oid ${:_id}] $bson
-    } else {
-      #puts stderr "we have to insert $bson"
-      ::mongo::insert $::mongoConn [$cls document] $bson
+    
+    #
+    # Save the current object. When we have an _id, perform an update,
+    # otherwise perform an insert
+    #
+    :public method save {} {
+      set document [[:info class] document]
+      if {$document eq ""} {
+	# We could perform the delegation probably automatically, but
+	# for now we provide an error
+	error "No document specified for [:info class]. In case this is an embedded object, save the embedding one."
+      } else {
+	set bson [:bson encode]
+	if {[info exists :_id]} {
+	  #puts stderr "we have to update $bson"
+	  ::nx::mongo::db update $document [list _id oid ${:_id}] $bson
+	} else {
+	  puts stderr "we have to insert $bson"
+	  ::nx::mongo::db insert $document $bson
+	}
+      }
     }
   }
-
-}
-
+  
+}
\ No newline at end of file