how to get category name of current product (on product detail page) in magento

Question

I used following codes but didn't work for this case:

$_category_detail=Mage::registry('current_category');
echo $_category_detail->getName();

got Fatal error: Call to a member function getName() on a non-object in /app/design/frontend/base/default/template/catalog/product/view.phtml

we make some filters and use below mention code in head.phtml:

$is_product = Mage::registry('product');

if($is_product){ 

  if(is_object(Mage::registry('current_category'))){ 
    $category_name = Mage::registry('current_category')->getName(); 
  }
  else{ $category_name = ""; }

}

But this only works if you go from a category to a product. If you visit the product page directly nothing is being displayed

Answer 1

It's because products can be attached to multiple categories. In your situation, when you visit a product page referred from a category page, your session has category information. But if you visit directly product page, Magento can not know which category you came from, so it can not show you a specific category, because your product can have multiple categories.

But in your situation, if your products are attached only one category, you can use this code, it shows first category name of product;

        $categoryIds = $_product->getCategoryIds();

        if(count($categoryIds) ){
            $firstCategoryId = $categoryIds[0];
            $_category = Mage::getModel('catalog/category')->load($firstCategoryId);

            echo $_category->getName();
        }