Index: TODO
===================================================================
diff -u -rd40717ac3710f2123cb9359e3d0442ad4ff3da73 -r2837e8ce08344ee3f82a7451109f14a4b7cb3395
--- TODO	(.../TODO)	(revision d40717ac3710f2123cb9359e3d0442ad4ff3da73)
+++ TODO	(.../TODO)	(revision 2837e8ce08344ee3f82a7451109f14a4b7cb3395)
@@ -2593,6 +2593,16 @@
 - nsf:c: fix dispatch of setter without current method
 - extended regression tests
 
+- nsf.c: added nsf::var::unset (provided so far just var::set)
+- nx::mongo: 
+  * added mongo::count
+  * obtain _id from mongo::insert
+  * added mongo::Object.delete method for embedded and
+    non-embedded objects
+  * handling of mongo-embedded objects when destroying objects
+  * simple bson pretty print function
+  * extended examples
+
 TODO:
 - how to delete attributes?
 
Index: library/mongodb/README
===================================================================
diff -u -rec9e525c887a0ae430bdb35bef01f499b25d617f -r2837e8ce08344ee3f82a7451109f14a4b7cb3395
--- library/mongodb/README	(.../README)	(revision ec9e525c887a0ae430bdb35bef01f499b25d617f)
+++ library/mongodb/README	(.../README)	(revision 2837e8ce08344ee3f82a7451109f14a4b7cb3395)
@@ -8,7 +8,7 @@
 Compile or obtain mongodb (the database).
 Compile or obtain the mongo-c-driver (client interface)
 
-Assume, tcl is under /usr/local/ns/lib and the mongo-c-driver is under
+Assume, Tcl is under /usr/local/ns/lib and the mongo-c-driver is under
 /usr/local/src/mongo-c-driver/, then configre the nsf interface via 
 
    ./configure --with-tcl=/usr/local/ns/lib --with-nsf=../../ \
Index: library/mongodb/example-nsf-mongo.tcl
===================================================================
diff -u -rc81b840c71a9f0de9d0a502e3e4ddfde57b81fdd -r2837e8ce08344ee3f82a7451109f14a4b7cb3395
--- library/mongodb/example-nsf-mongo.tcl	(.../example-nsf-mongo.tcl)	(revision c81b840c71a9f0de9d0a502e3e4ddfde57b81fdd)
+++ library/mongodb/example-nsf-mongo.tcl	(.../example-nsf-mongo.tcl)	(revision 2837e8ce08344ee3f82a7451109f14a4b7cb3395)
@@ -35,6 +35,9 @@
 puts stderr "\nAge > 30"
 puts  [join [::mongo::query $mongoConn tutorial.persons [list \$query object {age object {$gt int 30}}]] \n]
 
+puts stderr "\nCount Age > 30"
+puts  [::mongo::count $mongoConn tutorial.persons {age object {$gt int 30}}]
+
 puts stderr "\nArray 'a' contains 'x'"
 puts  [join [::mongo::query $mongoConn tutorial.persons [list \$query object {a string "x"}]] \n]
 
Index: library/mongodb/example-nx-bi.tcl
===================================================================
diff -u -rec9e525c887a0ae430bdb35bef01f499b25d617f -r2837e8ce08344ee3f82a7451109f14a4b7cb3395
--- library/mongodb/example-nx-bi.tcl	(.../example-nx-bi.tcl)	(revision ec9e525c887a0ae430bdb35bef01f499b25d617f)
+++ library/mongodb/example-nx-bi.tcl	(.../example-nx-bi.tcl)	(revision 2837e8ce08344ee3f82a7451109f14a4b7cb3395)
@@ -1,5 +1,5 @@
 #
-# The Business Insider Data Model
+# The "Business Insider" Data Model
 #
 # { title: 'Too Big to Fail', 
 #   author: 'John S.',
@@ -22,7 +22,15 @@
 #
 package require nx::mongo
 package require nx::serializer
+package require nx::test
 
+
+# TODO: 
+#   - make embedded spec nicer
+#   - handle fetch of embedded
+#   - handle count() like find()
+
+
 # Establish connection to the database
 ::nx::mongo::db connect
 
@@ -32,13 +40,6 @@
 #
 # Create the application classes
 #
-
-# TODO: 
-#   - make embedded spec nicer
-#   - handle delete of mebedded obj
-#   - 
-
-
 nx::mongo::Class create Comment {
   #:document "tutorial.bi"
 
@@ -53,10 +54,8 @@
   :attribute title:required
   :attribute author:required
   :attribute ts:required
-  :attribute comments:embedded,arg=::Comment,0..n {
-    #set :incremental 1
-  }
-  :attribute tags:0..n
+  :attribute comments:embedded,arg=::Comment,0..n {set :incremental 1}
+  :attribute tags:0..n {set :incremental 1}
 }
 #puts stderr [Posting serialize]
 
@@ -66,9 +65,46 @@
 			  [Comment new -author "Joe Smith" -comment "But how fast is it?" \
 			       -replies [list [Comment new -author "Jane Smith" -comment "scalable?"]]] \
 			 ]]
+#
+# When we save the item, the embedded objects (the comments and
+# replies) are saved together with the entry.
+#
+puts stderr ====
+$p save
+puts stderr ====
 
-#puts [$p serialize]
+# After saving the item, the main object contains an _id, such that a
+# subsequent save operation does not create an additional item. For
+# our little experiment here, we like to save multiple copies to see
+# the results of our changes, and we remove the _id manually
+$p eval {unset :_id}
 
-puts stderr ====
+# Now we want to remove e.g. the second comment (with the embedded
+# replies). First get the corresponding object $c ...
+set c [lindex [$p comments] 1]
+# ... and delete it
+$c delete
+
+# The delete operation on an embedded object removes it from the
+# object lists, but the change is not automatically persisted, since
+# there might be multiple changes in a complex document. Therefore we
+# have to perform an save operation of the containing document.
 $p save
+
+# Now, we have two postings in the database, the first with the two
+# comments, the second one with just a single comment.  
+? {nx::mongo::db count tutorial.bi {}} 2
+
+# Again, we want to continue with our test and remove the fresh _id as
+# well.
+$p eval {unset :_id}
+
+# Add an additional comment at the end of the list of the comments....
+$p comments add [Comment new -author "Gustaf N" -comment "This sounds pretty cool"] end
+# ... and add another tag ...
+$p tags add nx
+# ... and save it
+$p save
+? {nx::mongo::db count tutorial.bi {}} 3
+
 puts stderr ====EXIT
\ No newline at end of file
Index: library/mongodb/mongoAPI.decls
===================================================================
diff -u -rc81b840c71a9f0de9d0a502e3e4ddfde57b81fdd -r2837e8ce08344ee3f82a7451109f14a4b7cb3395
--- library/mongodb/mongoAPI.decls	(.../mongoAPI.decls)	(revision c81b840c71a9f0de9d0a502e3e4ddfde57b81fdd)
+++ library/mongodb/mongoAPI.decls	(.../mongoAPI.decls)	(revision 2837e8ce08344ee3f82a7451109f14a4b7cb3395)
@@ -17,6 +17,12 @@
   {-argName "-port" -required 0 -nrargs 1 -type int}
 }
 
+cmd count NsfMongoCount {
+  {-argName "conn" -required 1 -type tclobj}
+  {-argName "namespace" -required 1}
+  {-argName "query" -required 1 -type tclobj}
+}
+
 cmd index NsfMongoIndex {
   {-argName "conn" -required 1 -type tclobj}
   {-argName "namespace" -required 1}
Index: library/mongodb/mongoAPI.h
===================================================================
diff -u -rc81b840c71a9f0de9d0a502e3e4ddfde57b81fdd -r2837e8ce08344ee3f82a7451109f14a4b7cb3395
--- library/mongodb/mongoAPI.h	(.../mongoAPI.h)	(revision c81b840c71a9f0de9d0a502e3e4ddfde57b81fdd)
+++ library/mongodb/mongoAPI.h	(.../mongoAPI.h)	(revision 2837e8ce08344ee3f82a7451109f14a4b7cb3395)
@@ -13,6 +13,7 @@
 };
 static int NsfMongoCloseStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
 static int NsfMongoConnectStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
+static int NsfMongoCountStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
 static int NsfMongoIndexStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
 static int NsfMongoInsertStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
 static int NsfMongoQueryStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv []);
@@ -21,6 +22,7 @@
 
 static int NsfMongoClose(Tcl_Interp *interp, Tcl_Obj *conn);
 static int NsfMongoConnect(Tcl_Interp *interp, CONST char *withHost, int withPort);
+static int NsfMongoCount(Tcl_Interp *interp, Tcl_Obj *conn, CONST char *namespace, Tcl_Obj *query);
 static int NsfMongoIndex(Tcl_Interp *interp, Tcl_Obj *conn, CONST char *namespace, Tcl_Obj *attributes, int withDropdups, int withUnique);
 static int NsfMongoInsert(Tcl_Interp *interp, Tcl_Obj *conn, CONST char *namespace, Tcl_Obj *values);
 static int NsfMongoQuery(Tcl_Interp *interp, Tcl_Obj *conn, CONST char *namespace, Tcl_Obj *query, int withLimit, int withSkip);
@@ -30,6 +32,7 @@
 enum {
  NsfMongoCloseIdx,
  NsfMongoConnectIdx,
+ NsfMongoCountIdx,
  NsfMongoIndexIdx,
  NsfMongoInsertIdx,
  NsfMongoQueryIdx,
@@ -75,6 +78,27 @@
 }
 
 static int
+NsfMongoCountStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]) {
+  ParseContext pc;
+  (void)clientData;
+
+  if (ArgumentParse(interp, objc, objv, NULL, objv[0], 
+                     method_definitions[NsfMongoCountIdx].paramDefs, 
+                     method_definitions[NsfMongoCountIdx].nrParameters, 1,
+                     &pc) != TCL_OK) {
+    return TCL_ERROR;
+  } else {
+    Tcl_Obj *conn = (Tcl_Obj *)pc.clientData[0];
+    CONST char *namespace = (CONST char *)pc.clientData[1];
+    Tcl_Obj *query = (Tcl_Obj *)pc.clientData[2];
+
+    assert(pc.status == 0);
+    return NsfMongoCount(interp, conn, namespace, query);
+
+  }
+}
+
+static int
 NsfMongoIndexStub(ClientData clientData, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]) {
   ParseContext pc;
   (void)clientData;
@@ -194,6 +218,11 @@
   {"-host", 0, 1, Nsf_ConvertToString, NULL,NULL,NULL,NULL,NULL,NULL,NULL},
   {"-port", 0, 1, Nsf_ConvertToInteger, NULL,NULL,NULL,NULL,NULL,NULL,NULL}}
 },
+{"::mongo::count", NsfMongoCountStub, 3, {
+  {"conn", NSF_ARG_REQUIRED, 0, Nsf_ConvertToTclobj, NULL,NULL,NULL,NULL,NULL,NULL,NULL},
+  {"namespace", NSF_ARG_REQUIRED, 0, Nsf_ConvertToString, NULL,NULL,NULL,NULL,NULL,NULL,NULL},
+  {"query", NSF_ARG_REQUIRED, 0, Nsf_ConvertToTclobj, NULL,NULL,NULL,NULL,NULL,NULL,NULL}}
+},
 {"::mongo::index", NsfMongoIndexStub, 5, {
   {"conn", NSF_ARG_REQUIRED, 0, Nsf_ConvertToTclobj, NULL,NULL,NULL,NULL,NULL,NULL,NULL},
   {"namespace", NSF_ARG_REQUIRED, 0, Nsf_ConvertToString, NULL,NULL,NULL,NULL,NULL,NULL,NULL},
Index: library/mongodb/nsfmongo.c
===================================================================
diff -u -rc81b840c71a9f0de9d0a502e3e4ddfde57b81fdd -r2837e8ce08344ee3f82a7451109f14a4b7cb3395
--- library/mongodb/nsfmongo.c	(.../nsfmongo.c)	(revision c81b840c71a9f0de9d0a502e3e4ddfde57b81fdd)
+++ library/mongodb/nsfmongo.c	(.../nsfmongo.c)	(revision 2837e8ce08344ee3f82a7451109f14a4b7cb3395)
@@ -482,6 +482,56 @@
 }
 
 /*
+cmd query NsfMongoCount {
+  {-argName "conn" -required 1 -type tclobj}
+  {-argName "namespace" -required 1}
+  {-argName "query" -required 1 -type tclobj}
+}
+*/
+static int 
+NsfMongoCount(Tcl_Interp *interp, Tcl_Obj *connObj, CONST char *namespace, Tcl_Obj *queryObj) {
+  int objc, result;
+  Tcl_Obj **objv;
+  mongo_connection *connPtr = MongoGetConn(connObj);
+  char *db, *collection;
+  int count, length;
+  bson query[1];
+
+  if (connPtr == NULL)  {
+    return NsfObjErrType(interp, "", connObj, "connection", NULL);
+  }
+
+  result = Tcl_ListObjGetElements(interp, queryObj, &objc, &objv);
+  if (result != TCL_OK || (objc % 3 != 0)) {
+    return NsfPrintError(interp, "%s: must contain a multiple of 3 elements", ObjStr(queryObj));
+  }
+  
+  BsonAppendObjv(interp, query, objc, objv);
+  
+  length = strlen(namespace)+1;
+  db = ckalloc(length);
+  memcpy(db, namespace, length);
+  collection = strchr(db, '.');
+
+  if (collection != NULL) {
+    /* successful */
+    *collection = '\0';
+    collection ++;
+    count = mongo_count(connPtr, db, collection, query);
+  } else {
+    count = 0;
+  }
+       
+  bson_destroy( query );
+  ckfree(db);
+
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(count));
+
+  return TCL_OK;
+}
+
+
+/*
 cmd index NsfMongoIndex {
   {-argName "conn" -required 1 -type tclobj}
   {-argName "namespace" -required 1}
@@ -531,7 +581,7 @@
 static int NsfMongoInsert(Tcl_Interp *interp, Tcl_Obj *connObj, CONST char *namespace, Tcl_Obj *valuesObj) {
   mongo_connection *connPtr = MongoGetConn(connObj);
   int i, objc, result;
-  Tcl_Obj **objv;
+  Tcl_Obj **objv, *resultObj;
   bson_buffer buf[1];
   bson b[1];
 
@@ -557,6 +607,10 @@
 
   bson_from_buffer( b, buf );
   mongo_insert(connPtr, namespace, b);
+  
+  resultObj = BsonToList(interp, b->data, 0);
+  Tcl_SetObjResult(interp, resultObj);
+
   bson_destroy(b);
 
   return TCL_OK;
@@ -595,7 +649,7 @@
   resultObj = Tcl_NewListObj(0, NULL);
 
   /* 
-   *  The la񓩌st field of mongo_find is options, semantics are described here
+   *  The last field of mongo_find is options, semantics are described here
    *  http://www.mongodb.org/display/DOCS/Mongo+Wire+Protocol#MongoWireProtocol-OPQUERY
    */
   cursor = mongo_find( connPtr, namespace, query, NULL, withLimit, withSkip, 0 );
Index: library/mongodb/nx-mongo.tcl
===================================================================
diff -u -rec9e525c887a0ae430bdb35bef01f499b25d617f -r2837e8ce08344ee3f82a7451109f14a4b7cb3395
--- library/mongodb/nx-mongo.tcl	(.../nx-mongo.tcl)	(revision ec9e525c887a0ae430bdb35bef01f499b25d617f)
+++ library/mongodb/nx-mongo.tcl	(.../nx-mongo.tcl)	(revision 2837e8ce08344ee3f82a7451109f14a4b7cb3395)
@@ -15,6 +15,7 @@
 
   ::nx::Object create ::nx::mongo::db {
     :public method connect {args} {set :mongoConn [::mongo::connect {*}$args]}
+    :public method count   {args} {::mongo::count  ${:mongoConn} {*}$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}
@@ -88,15 +89,34 @@
       }
     }
 
+    :public method remove {object value} {
+      if {[:isMultivalued]} {
+	set values [::nsf::var::set $object ${:name}]
+	set p [lsearch $values $value]
+	if {$p < 0} {
+	  error "$value not included in $object.$value ($values)"
+	}
+	set newValues [lreplace $values $p $p]
+	::nsf::var::set $object ${:name} $newValues
+      } else {
+	error "remove just implemented for multivalued slots"
+      }
+    }
+
     #
+    # Type converter for handling embedded objects. Makes sure to
+    # track "embedded in" relationship
     #
-    #
     :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]]
+	::nsf::var::set $value __embedded_in [list $s $name]
+	::nsf::var::set $s __contains($value) 1
+	puts stderr "
+	::nsf::var::set $value __embedded_in [list $s $name]
+	::nsf::var::set $s __contains($value) 1
+"
       } else {
 	error "value '$value' for attribute $name is not of type $args"
       }
@@ -290,23 +310,80 @@
       return $bson
     }
 
+    :method "bson pp_array" {{-indent 0} list} {
+      set result [list]
+      foreach {name type value} $list {
+	switch $type {
+	  object { lappend result "\{ [:bson pp -indent $indent $value] \}" }
+	  array { lappend result "\[ [:bson pp_array -indent $indent $value] \]" }
+	  default { lappend result [list $value]}
+	}
+      }
+      return [join $result ", "]
+    }
+
+    :method "bson pp" {{-indent 0} list} {
+      set result [list]
+      set nextIndent [expr {$indent + 2}]
+      foreach {name type value} $list {
+	set prefix "\n[string repeat { } $indent]$name: "
+	switch $type {
+	  object { lappend result "$prefix\{ [:bson pp -indent $nextIndent $value] \}" }
+	  array { lappend result "$prefix\[ [:bson pp_array -indent $nextIndent $value] \]" }
+	  default { lappend result $prefix[list $value]}
+	}
+      }
+      return [join $result ", "]
+    }
+
     #
     # 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]
+    #   set :__embedded_in [list $object $attribute]
     #   $object $attribute add [self] end
     # }
 
     #
+    # destroy a mapped object from memory
+    #
+    :public method destroy {} {
+      if {[array exists :__contains]} {
+	# destroy embedded object
+	foreach o [array names :__contains] {
+	  puts "[self] contains $o -> destroy"
+	  $o destroy
+	}
+      }
+      if {[info exists :__embedded_in]} {
+	lassign ${:__embedded_in} parent att
+	::nsf::var::unset $parent __contains([self])
+      }
+      next
+    }
+
+    #
     # delete the current object from the db
     #
     :public method delete {} {
-      set document [[:info class] document]
-      if {$document eq ""} {
-	set embeddedIn [...]
+      puts stderr "deleting [:serialize]"
+      if {[info exists :__embedded_in]} {
+	puts "[self] is embedded in ${:__embedded_in}"
+	lassign ${:__embedded_in} parent att
+	set slot [[$parent info class] get slot $att]
+	$slot remove $parent [self]
+	puts stderr [:serialize]
+	puts stderr "We must save parent $parent in mongo db"
+	:destroy
       } else {
+	puts "delete a non-embedded entry"
+	if {[info exists :_id]} {
+	  set document [[:info class] document]
+	  ::nx::mongo::db remove $document [list _id oid ${:_id}]
+	} else {
+	  error "[self]: object does not contain an _id; it can't be delete from the mongo db."
+	}
       }
     }
     
@@ -327,7 +404,9 @@
 	  ::nx::mongo::db update $document [list _id oid ${:_id}] $bson
 	} else {
 	  puts stderr "we have to insert $bson"
-	  ::nx::mongo::db insert $document $bson
+	  puts stderr [:bson pp $bson]
+	  set r [::nx::mongo::db insert $document $bson]
+	  set :_id [lindex $r 2]
 	}
       }
     }