filter can now be used as a replacement to Model#toJSON()

lib/filtered.js

@@ -1,3 +1,7 @@
+'use strict';
+
+var clone = require('./utils/clone');
+
 module.exports = function(Model) {
   var filteredAttrs = [];
 
@@ -9,7 +13,7 @@ module.exports = function(Model) {
   });
 
   Model.prototype.filter = function(filterList) {
-    if(typeof filterList == 'string') {
+    if(typeof filterList === 'string') {
       filterList = [filterList];
     }
 
@@ -19,10 +23,16 @@ module.exports = function(Model) {
 
     filterList = filterList.concat(filteredAttrs);
 
-    var attrs = this.toJSON();
+    var attrs = {};
+    var self = this;
+
+    Object.keys(this.attrs).forEach(function (key) {
+        var val = self.attrs[key];
+        attrs[key] = (val && val.toJSON) ? val.toJSON() : clone(val);
+    });
 
     for(var i = 0; i < filterList.length; ++i) {
-      delete attrs[filterList[i]];
+        delete attrs[filterList[i]];
     }
 
     return attrs;

lib/utils/clone.js

@@ -0,0 +1,59 @@
+/**
+ * TODO: cleanup. This is a pretty big hack. inlined `clone` because
+ * it cannot handle objectid instances
+ */
+
+/**
+ * Module dependencies
+ */
+
+var type = require('./type');
+
+/**
+ * Expose `clone`
+ */
+
+module.exports = clone;
+
+/**
+ * Clone values.
+ *
+ * @param {Mixed} val
+ * @return {Mixed}
+ * @api public
+ */
+
+function clone(obj) {
+  switch (type(obj)) {
+    case 'object':
+      // Hack for BSON IDs
+      if(obj.toHexString)
+        return obj;
+      var copy = {};
+      for (var key in obj) {
+        copy[key] = clone(obj[key]);
+      }
+      return copy;
+
+    case 'array':
+      var copy = new Array(obj.length);
+      for (var i = 0, l = obj.length; i < l; i++) {
+        copy[i] = clone(obj[i]);
+      }
+      return copy;
+
+    case 'regexp':
+      // from millermedeiros/amd-utils - MIT
+      var flags = '';
+      flags += obj.multiline ? 'm' : '';
+      flags += obj.global ? 'g' : '';
+      flags += obj.ignoreCase ? 'i' : '';
+      return new RegExp(obj.source, flags);
+
+    case 'date':
+      return new Date(obj.getTime());
+
+    default: // string, number, boolean, …
+      return obj;
+  }
+}

lib/utils/type.js

@@ -0,0 +1,35 @@
+/**
+ * https://github.com/component/type
+ *
+ * TODO: un-bundle, once we have a way to use component and node together
+ */
+
+/**
+ * toString ref.
+ */
+
+var toString = Object.prototype.toString;
+
+/**
+ * Return the type of `val`.
+ *
+ * @param {Mixed} val
+ * @return {String}
+ * @api public
+ */
+
+module.exports = function(val){
+  switch (toString.call(val)) {
+    case '[object Function]': return 'function';
+    case '[object Date]': return 'date';
+    case '[object RegExp]': return 'regexp';
+    case '[object Arguments]': return 'arguments';
+    case '[object Array]': return 'array';
+  }
+
+  if (val === null) return 'null';
+  if (val === undefined) return 'undefined';
+  if (val === Object(val)) return 'object';
+
+  return typeof val;
+};

test/filtered.js

@@ -32,4 +32,20 @@ describe("Filtered", function() {
   it("auto-filters properties defined with filter flag", function() {
     expect(user.filter()).to.not.have.key('hashedPassword');
   });
+
+  it("can be used inside model#toJSON()", function() {
+      User.prototype.toJSON = function() {
+          return this.filter;
+      };
+      var user = new User({
+          username: 'thisisauser',
+          hashedPassword: '129408158932dsjkaklfjsad',
+          socialSecurityNumber: '123-456-7890'
+      });
+      var result = user.filter('socialSecurityNumber');
+
+      expect(result).to.not.have.key('socialSecurityNumber');
+      expect(result).to.have.key('username');
+
+  });
 });