Implemented polymorphic hasMany through inverse

Added option invert: true to enable inverse polymorphic hasMany
relations.

Fixed missing fk1 in query of HasManyThrough.prototype.exists.

lib/relation-definition.js

@@ -371,8 +371,10 @@ RelationDefinition.hasMany = function hasMany(modelFrom, modelTo, params) {
   
   if (typeof params.polymorphic === 'string') {
     var polymorphic = params.polymorphic;
-    fk = i8n.camelize(polymorphic + '_id', true);
     typeTo = i8n.camelize(polymorphic + '_type', true);
+    if (!params.invert) {
+      fk = i8n.camelize(polymorphic + '_id', true);
+    }
     if (!params.through) {
       modelTo.dataSource.defineProperty(modelTo.modelName, typeTo, { type: 'string', index: true });
     }
@@ -445,7 +447,11 @@ RelationDefinition.hasMany = function hasMany(modelFrom, modelTo, params) {
     
     definition.applyScope(this, filter);
     
-    if (params.through) {
+    if (params.through && params.polymorphic && params.invert) {
+      filter.where[typeTo] = modelTo.modelName; // overwrite
+      filter.collect = params.polymorphic;
+      filter.include = filter.collect;
+    } else if (params.through) {
       filter.collect = i8n.camelize(modelTo.modelName, true);
       filter.include = filter.collect;
     }
@@ -758,7 +764,6 @@ HasManyThrough.prototype.exists = function (acInst, done) {
   var modelThrough = definition.modelThrough;
   var pk1 = definition.keyFrom;
 
-  var data = {};
   var query = {};
 
   // The primary key for the target model
@@ -768,12 +773,14 @@ HasManyThrough.prototype.exists = function (acInst, done) {
   var fk1 = keys[0];
   var fk2 = keys[1];
 
+  query[fk1] = this.modelInstance[pk1];
   query[fk2] = (acInst instanceof definition.modelTo) ? acInst[pk2] : acInst;
-
+  
-  data[fk1] = this.modelInstance[pk1];
+  var filter = { where: query };
-  data[fk2] = (acInst instanceof definition.modelTo) ? acInst[pk2] : acInst;
+  
-
+  definition.applyScope(this.modelInstance, filter);
-  modelThrough.count(query, function(err, ac) {
+  
+  modelThrough.count(filter.where, function(err, ac) {
     done(err, ac > 0);
   });
 };

test/relations.test.js

@@ -788,6 +788,8 @@ describe('relations', function () {
     it('can be declared', function (done) {
       Author.hasAndBelongsToMany(Picture, { through: PictureLink, polymorphic: 'imageable' });
       Reader.hasAndBelongsToMany(Picture, { through: PictureLink, polymorphic: 'imageable' });
+      Picture.hasMany(Author, { through: PictureLink, polymorphic: 'imageable', invert: true });
+      Picture.hasMany(Reader, { through: PictureLink, polymorphic: 'imageable', invert: true });
       db.automigrate(done);
     });
     
@@ -821,7 +823,11 @@ describe('relations', function () {
         link.pictureId.should.equal(1);
         link.imageableId.should.equal(4);
         link.imageableType.should.equal('Author');
-        done();
+        link.imageable(function(err, imageable) {
+          imageable.should.be.instanceof(Author);
+          imageable.id.should.equal(4);
+          done();
+        });
       });
     });
     
@@ -856,6 +862,7 @@ describe('relations', function () {
       Author.find({ include: 'pictures' }, function(err, authors) {
         authors.should.have.length(1);
         authors[0].pictures(function(err, pics) {
+          pics.should.have.length(2);
           pics[0].name.should.equal('Author Pic 1');
           pics[1].name.should.equal('Author Pic 2');
           done();
@@ -878,7 +885,7 @@ describe('relations', function () {
     });
     
     it('should create polymorphic through model', function (done) {
-      PictureLink.findOne({ where: { pictureId: 7 } }, function(err, link) {
+      PictureLink.findOne({ where: { pictureId: 7, imageableType: 'Author' } }, function(err, link) {
         should.not.exist(err);
         link.pictureId.should.equal(7);
         link.imageableId.should.equal(4);
@@ -887,6 +894,57 @@ describe('relations', function () {
       });
     });
     
+    it('should add to a polymorphic relation - author', function (done) {
+      Author.create({ id: 5, name: 'Author 2' }, function (err, author) {
+        author.pictures.add(7, function (err, p) {
+          should.not.exist(err);
+          done();
+        });
+      });
+    });
+    
+    it('should add to a polymorphic relation - author', function (done) {
+      Reader.create({ id: 5, name: 'Reader 2' }, function (err, reader) {
+        reader.pictures.add(7, function (err, p) {
+          should.not.exist(err);
+          done();
+        });
+      });
+    });
+    
+    it('should get the inverse polymorphic relation - author', function (done) {
+      Picture.findById(7, function(err, p) {
+        p.authors(function(err, authors) {
+          authors.should.have.length(2);
+          authors[0].name.should.equal('Author 1');
+          authors[1].name.should.equal('Author 2');
+          done();
+        });
+      });
+    });
+    
+    it('should get the inverse polymorphic relation - reader', function (done) {
+      Picture.findById(7, function(err, p) {
+        p.readers(function(err, readers) {
+          readers.should.have.length(1);
+          readers[0].name.should.equal('Reader 2');
+          done();
+        });
+      });
+    });
+    
+    it('should find polymorphic items - author', function (done) {
+      Author.findById(4, function(err, author) {
+        author.pictures(function(err, pics) {
+          pics.should.have.length(3);
+          pics[0].name.should.equal('Author Pic 1');
+          pics[1].name.should.equal('Author Pic 2');
+          pics[2].name.should.equal('Example');
+          done();
+        });
+      });
+    });
+    
     it('should check if polymorphic relation exists - author', function (done) {
       Author.findById(4, function(err, author) {
         author.pictures.exists(7, function(err, exists) {
@@ -905,6 +963,17 @@ describe('relations', function () {
       });
     });
     
+    it('should find polymorphic items - author', function (done) {
+      Author.findById(4, function(err, author) {
+        author.pictures(function(err, pics) {
+          pics.should.have.length(2);
+          pics[0].name.should.equal('Author Pic 1');
+          pics[1].name.should.equal('Author Pic 2');
+          done();
+        });
+      });
+    });
+    
     it('should check if polymorphic relation exists - author', function (done) {
       Author.findById(4, function(err, author) {
         author.pictures.exists(7, function(err, exists) {