partial saves fully implemented, handles complex structures, casting,…

… nested objects.

lib/model.js

@@ -13,11 +13,14 @@ Model = this.Model = Class({
     this.__doc._id = new ObjectID();
     this.isNew = true;
     this._dirty = {};
+    this._partials = {};
     if (hydrate){
       this._hydrate(doc);
     } else if(doc){
       this.merge(doc);
-    } 
+    }
+    this._diff();
+    return this;
   },
 
   _hydrate: function(doc){
@@ -26,6 +29,20 @@ Model = this.Model = Class({
     return this;
   },
 
+  _diff: function(){
+    var keys = Object.keys(this.__doc),
+        casters = Object.keys(this._casters),
+        exclude = {};
+
+    for(var i = 0, l = casters.length; i < l; i++){
+      this._partials[casters[i]] = JSON.stringify(this._get(casters[i]));
+    }
+
+    for(var i = 0, l = keys.length; i < l; i++){
+        this._partials[keys[i]] = JSON.stringify(this.__doc[keys[i]]);
+    }
+  },
+
   _error: function(err){
     this.emit('error', err);
   },
@@ -114,9 +131,31 @@ Model = this.Model = Class({
   },
 
   _getDirty: function(){
+
     var _doc = this._normalize(),
-        dirty = {}, dirt;
-    for(dirt in this._dirty) dirty[dirt] = this._get(dirt);
+        dirty = {}, dirt, exclude = {};
+    for(dirt in this._dirty){
+      var data = this._get(dirt), comp, part;
+      if(this._partials[dirt]){
+        if(this._partials[dirt] != (comp = JSON.stringify(data))){
+          dirty[dirt] = data; this._partials[dirt] = comp;
+        }
+      } else { dirty[dirt] = this._partials[dirt] = data; }
+      parts = dirt.split('.');
+      while(parts.pop() && parts.length)
+        exclude[parts.join('.')] = true;
+    }
+
+    var keys = Object.keys(this._partials);
+    for(var i = 0, l = keys.length; i < l; i++){
+      if(!exclude[keys[i]]){
+        var obj = this._get(keys[i]), comp = JSON.stringify(obj);
+        if(comp != this._partials[keys[i]]){
+          dirty[keys[i]] = obj;
+          this._partials[keys[i]] = comp;
+        }
+      }
+    }
     return dirty;
   },