My Custom Module API Data not saving in magento 2

Question

I have created a custom module (Blog) which contains a save() method, it is executed but values are not saved and it returns an empty object.

<?php
namespace Learning\Blog\Model\Resource;
use Learning\Blog\Api\Data\BlogInterface;
class BlogRepository implements BlogRepositoryInterface
{
 protected $blogFactory;
public function __construct
 (
 \Learning\Blog\Model\BlogFactory $blogFactory
 ){
 $this->blogFactory = $blogFactory;
 }
public function save(BlogInterface $blog){
 $blog_Data = $this->blogFactory->create();
 $blog_Data->save();
 return $blog_Data;
 }
}

Did I miss anything?

Answer 1

Finally I have achieved to update.

class BlogRepository implements BlogRepositoryInterface
{
 protected $blogFactory;
 protected $blogBuilder;
 protected $extensibleDataObjectConverter;
public function __construct
 (
 \Magento\Framework\Api\ExtensibleDataObjectConverter $extensibleDataObjectConverter,
 \Learning\Blog\Model\BlogFactory $blogFactory
 ){
 $this->extensibleDataObjectConverter = $extensibleDataObjectConverter;
 $this->blogBuilder = $blogDataBuilder;
 $this->blogFactory = $blogFactory;
 }
public function save(BlogInterface $blog){
 $customerData = $this->extensibleDataObjectConverter->toNestedArray(
 $blog,
 [],
 '\Learning\Blog\Api\Data\BlogInterface'
 );
 $blog_Data = $this->blogFactory->create();
 $blog_Data->setData($customerData);
 $item = $blog_Data->save();
 return $item;
 }
}

• Juliano Vargas: I was not able to do this I've got error : Fatal Error: 'Uncaught TypeError: Argument 1 passed to Magento\\Framework\\Api\\ExtensibleDataObjectConverter::toNestedArray() must implement interface Magento\\Framework\\Api\\ExtensibleDataInterface, instance of Vendor\\Module\\Model\\CustomModel given Did you manage to get this working?