Refactor embedsMany - auto-save parent

With this change, saving an embedded model now correctly updates the
parent model.

Before, a separate `save()` call on the parent was required, contrary
to other relation types.

lib/relation-definition.js

@@ -1607,11 +1607,48 @@ RelationDefinition.embedsMany = function embedsMany(modelFrom, modelTo, params)
   scopeDefinition.related = scopeMethods.related;
 };
 
+EmbedsMany.prototype.prepareEmbeddedInstance = function(inst) {
+  if (inst && inst.triggerParent !== 'function') {
+    var relationName = this.definition.name;
+    var modelInstance = this.modelInstance;
+    inst.triggerParent = function(actionName, callback) {
+      if (actionName === 'save' || actionName === 'destroy') {
+        var embeddedList = modelInstance[relationName] || [];
+        modelInstance.updateAttribute(relationName,
+          embeddedList, function(err, modelInst) {
+          callback(err, err ? null : modelInst);
+        });
+      } else {
+        process.nextTick(callback);
+      }
+    };
+    var originalTrigger = inst.trigger;
+    inst.trigger = function(actionName, work, data, callback) {
+      if (typeof work === 'function') {
+        var originalWork = work;
+        work = function(next) {
+          originalWork.call(this, function(done) {
+            inst.triggerParent(actionName, function(err, inst) {
+              next(done); // TODO [fabien] - error handling?
+            });
+          });
+        };
+      }
+      originalTrigger.call(this, actionName, work, data, callback);
+    };
+  }
+};
+
+EmbedsMany.prototype.embeddedList = function(modelInstance) {
+  modelInstance = modelInstance || this.modelInstance;
+  var embeddedList = modelInstance[this.definition.name] || [];
+  embeddedList.forEach(this.prepareEmbeddedInstance.bind(this));
+  return embeddedList;
+};
+
 EmbedsMany.prototype.related = function(receiver, scopeParams, condOrRefresh, cb) {
   var modelTo = this.definition.modelTo;
-  var relationName = this.definition.name;
   var modelInstance = this.modelInstance;
-  var self = receiver;
   
   var actualCond = {};
   var actualRefresh = false;
@@ -1628,9 +1665,9 @@ EmbedsMany.prototype.related = function(receiver, scopeParams, condOrRefresh, cb
     throw new Error('Method can be only called with one or two arguments');
   }
   
-  var embeddedList = self[relationName] || [];
+  var embeddedList = this.embeddedList(receiver);
   
-  this.definition.applyScope(modelInstance, actualCond);
+  this.definition.applyScope(receiver, actualCond);
   
   var params = mergeQuery(actualCond, scopeParams);
   
@@ -1652,10 +1689,9 @@ EmbedsMany.prototype.related = function(receiver, scopeParams, condOrRefresh, cb
 EmbedsMany.prototype.findById = function (fkId, cb) {
   var pk = this.definition.keyFrom;
   var modelTo = this.definition.modelTo;
-  var relationName = this.definition.name;
   var modelInstance = this.modelInstance;
   
-  var embeddedList = modelInstance[relationName] || [];
+  var embeddedList = this.embeddedList();
   
   var find = function(id) {
     for (var i = 0; i < embeddedList.length; i++) {
@@ -1695,7 +1731,7 @@ EmbedsMany.prototype.updateById = function (fkId, data, cb) {
   var relationName = this.definition.name;
   var modelInstance = this.modelInstance;
   
-  var embeddedList = modelInstance[relationName] || [];
+  var embeddedList = this.embeddedList();
   
   var inst = this.findById(fkId);
   
@@ -1729,7 +1765,7 @@ EmbedsMany.prototype.destroyById = function (fkId, cb) {
   var relationName = this.definition.name;
   var modelInstance = this.modelInstance;
   
-  var embeddedList = modelInstance[relationName] || [];
+  var embeddedList = this.embeddedList();
   
   var inst = (fkId instanceof modelTo) ? fkId : this.findById(fkId);
   
@@ -1754,10 +1790,9 @@ EmbedsMany.prototype.unset = EmbedsMany.prototype.destroyById;
 
 EmbedsMany.prototype.at = function (index, cb) {
   var modelTo = this.definition.modelTo;
-  var relationName = this.definition.name;
   var modelInstance = this.modelInstance;
   
-  var embeddedList = modelInstance[relationName] || [];
+  var embeddedList = this.embeddedList();
   
   var item = embeddedList[parseInt(index)];
   item = (item instanceof modelTo) ? item : null;
@@ -1784,7 +1819,7 @@ EmbedsMany.prototype.create = function (targetModelData, cb) {
   }
   targetModelData = targetModelData || {};
   
-  var embeddedList = modelInstance[relationName] || [];
+  var embeddedList = this.embeddedList();
   
   var inst = this.build(targetModelData);
   
@@ -1805,11 +1840,10 @@ EmbedsMany.prototype.create = function (targetModelData, cb) {
 EmbedsMany.prototype.build = function(targetModelData) {
   var pk = this.definition.keyFrom;
   var modelTo = this.definition.modelTo;
-  var relationName = this.definition.name;
   var modelInstance = this.modelInstance;
   var autoId = this.definition.options.autoId !== false;
   
-  var embeddedList = modelInstance[relationName] || [];
+  var embeddedList = this.embeddedList();
   
   targetModelData = targetModelData || {};
   
@@ -1834,6 +1868,8 @@ EmbedsMany.prototype.build = function(targetModelData) {
     embeddedList.push(inst);
   }
   
+  this.prepareEmbeddedInstance(inst);
+  
   return inst;
 };
 

test/relations.test.js

@@ -1758,14 +1758,12 @@ describe('relations', function () {
         category = cat;
         var link = cat.items.build({ notes: 'Some notes...' });
         link.product.create({ name: 'Product 1' }, function(err, p) {
-          cat.save(function(err, cat) { // save parent object!
+          cat.links[0].id.should.eql(p.id);
-            cat.links[0].id.should.eql(p.id);
+          cat.links[0].name.should.equal('Product 1'); // denormalized
-            cat.links[0].name.should.equal('Product 1'); // denormalized
+          cat.links[0].notes.should.equal('Some notes...');
-            cat.links[0].notes.should.equal('Some notes...');
+          cat.items.at(0).should.equal(cat.links[0]);
-            cat.items.at(0).should.equal(cat.links[0]);
+          done();
-            done();
+        });
-          });
-        })
       });
     });
     
@@ -1787,6 +1785,26 @@ describe('relations', function () {
       });
     });
     
+    it('should update items on scope - and save parent', function(done) {
+      Category.findById(category.id, function(err, cat) {
+        var link = cat.items.at(0);
+        link.updateAttributes({notes: 'Updated notes...'}, function(err, link) {
+          link.notes.should.equal('Updated notes...');
+          done();
+        });
+      });
+    });
+    
+    it('should find items on scope - verify update', function(done) {
+      Category.findById(category.id, function(err, cat) {
+        cat.name.should.equal('Category B');
+        cat.links.toObject().should.eql([
+          {id: 5, name: 'Product 1', notes: 'Updated notes...'}
+        ]);
+        done();
+      });
+    });
+    
   });
   
   describe('embedsMany - polymorphic relations', function () {