Magento 2 After plugin with parameter

Question

I am trying to implement after plugin to the following method.

public function getCategoryUrl($category)
{
    if ($category instanceof ModelCategory) {
        return $category->getUrl();
    }
    return $this->_categoryFactory->create()->setData($category->getData())->getUrl();
}

Please note the $category parameter passed to the above method.

As the resolution, I have implemented below code.

public function afterGetCategoryUrl(\Magento\Catalog\Helper\Category $subject, $result)
{
    return $result;
} 

Now, my question is: How do I get the $category parameter passed in parent method to my plugin? I just want to modify result based on the certain value in $category object.

Answer 1

If you need input parameters and you also need to change output, you should use an around plugin, not an after plugin:

public function aroundGetCategoryUrl(
    \Magento\Catalog\Helper\Category $subject,
    \Closure $proceed,
    $category
) {
   ...
   // Do your stuffs here, now you have $category
   // If you need you can call the original method with:
   // $proceed($category);
   ...
   return $something;
} 

I your case it could be something like this:

public function aroundGetCategoryUrl(
    \Magento\Catalog\Helper\Category $subject,
    \Closure $proceed,
    $category
) {
   $originalResult = $proceed($category);

   if (...) {
      ...
      return $otherResult;
   }

   return $originalResult;
} 

Just a note:

Please notice that if you are going to change an internal behaviour, a preference could be a better option that a plugin. It depends on what you are going to do.

Answer 2

Since Magento 2.2 it is possible to have input parameters in after plugin

namespace My\Module\Plugin;

class AuthLogger
{
    private $logger;

    public function __construct(\Psr\Log\LoggerInterface $logger)
    {
        $this->logger = $logger;
    }

    /**
     * @param \Magento\Backend\Model\Auth $authModel
     * @param null $result
     * @param string $username
     * @return void
     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
     */
    public function afterLogin(\Magento\Backend\Model\Auth $authModel, $result, $username)
    {
        $this->logger->debug('User ' . $username . ' signed in.');
    }
}

See Magento documentation for details https://devdocs.magento.com/guides/v2.2/extension-dev-guide/plugins.html#after-methods