Symfony2 - Set related category to post dynamically - symfony

Question

I'm new to Sf2/Doctrine2. I have a doctrine query that is retrieving related posts in the same category and excluding the current post that's being shown.
I need to figure out how to pass in category dynamically so I don't have to set this in the controller.
The show route is showing posts from different categories, and I'd like to only show posts related to that specific category without hardcoding it in the controller.
Can I get some help on how to fix this doctrine query?
Doctrine query
public function getRelatedPosts($exceptPost, $limit, $category) // Using Doctrine to exclude the shown post
{
return $this
->createQueryBuilder('post')
->leftJoin('post.category','category')
->where('post != :exceptPost')
->andWhere('category.title = :category')
->setParameter('category', $category)
->setMaxResults($limit)
->orderBy('post.createdAt', 'DESC')
->setParameter('exceptPost', $exceptPost)
->getQuery()
->execute();
}
Controller (setting category in controller -- How do I set this dynamically?)
/**
* Show action for post
*
* #param string $slug
* #throws \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
* #return array
*
* #Route("/{catslug}/{slug}", name="acme_demo_page_show")
* #Template("AcmeDemoBundle:Page:show.html.twig")
*/
public function showAction($slug)
{
$post = $this->getDoctrine()->getRepository('AcmeDemoBundle:Post')
->findOneBy(array(
'slug' => $slug
));
if (null === $post) {
throw $this->createNotFoundException('Post was not found');
}
$posts = $this->getDoctrine()->getRepository('AcmeDemoBundle:Post')
->getRelatedPosts($post, 4, 'articles');
return array(
'post' => $post,
'posts' => $posts
);
}
Category entity
class Category
{
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="title", type="string", length=255)
*/
private $title;
/**
* #ORM\OneToMany(targetEntity="Post", mappedBy="category")
*/
protected $posts;
/**
* #var string
*
* #Gedmo\Slug(fields={"title"}, unique=false)
* #ORM\Column(length=255)
*/
private $catslug;
public function __construct()
{
$this->posts = new ArrayCollection();
}
public function __toString()
{
return $this->getTitle() ? $this->getTitle() : "";
}
/**
* Get id
*
* #return integer
*/
public function getId()
{
return $this->id;
}
/**
* Set title
*
* #param string $title
* #return Category
*/
public function setTitle($title)
{
$this->title = $title;
return $this;
}
/**
* Get title
*
* #return string
*/
public function getTitle()
{
return $this->title;
}
/**
* Add posts
*
* #param \Acme\DemoBundle\Entity\Post $posts
* #return Category
*/
public function addPost(\Acme\DemoBundle\Entity\Post $posts)
{
$this->posts[] = $posts;
return $this;
}
/**
* Remove posts
*
* #param \Acme\DemoBundle\Entity\Post $posts
*/
public function removePost(\Acme\DemoBundle\Entity\Post $posts)
{
$this->posts->removeElement($posts);
}
/**
* Get posts
*
* #return \Doctrine\Common\Collections\Collection
*/
public function getPosts()
{
return $this->posts;
}
/**
* Set catslug
*
* #param string $catslug
* #return Category
*/
public function setCatSlug($catslug)
{
$this->slug = $catslug;
return $this;
}
/**
* Get slug
*
* #return string
*/
public function getCatSlug()
{
return $this->catslug;
}
}
Post entity
/**
* #ORM\ManyToOne(targetEntity="Category", inversedBy="posts")
* #ORM\JoinColumn(name="category_id", referencedColumnName="id")
*/
protected $category;
/**
* Set category
*
* #param \Acme\AcmeDemoBundle\Entity\Category $category
* #return Post
*/
public function setCategory(\Acme\AcmeDemoBundle\Entity\Category $category = null)
{
$this->category = $category;
return $this;
}
/**
* Get category
*
* #return \Acme\AcmeDemoBundle\Entity\Category
*/
public function getCategory()
{
return $this->category;
}

Answer 1

from you controller use $post->getCategory() to retrieve the post Category.
In you'r query, all you have to do is ->setParameter('category', $category)