How to handle exception in magento 2

Question

I have prepared one module in which I have used Image upload button. And My button is working fine unless I am not entering any "Disallowed file type". When I enter any disallowed file type it gives me exception.

I have written the below function to upload file of my required file-type and to handle exception. I have also prepared required block and model file for image upload. I have followed this post

public function uploadFileAndGetName($input, $destinationFolder, $data)
{
    try {
        if (isset($data[$input]['delete'])) {
            return '';
        } else {
            $uploader = $this->uploaderFactory->create(['fileId' => $input]);
            $uploader->setAllowedExtensions(['jpg', 'jpeg', 'gif', 'png']);
            $uploader->setAllowRenameFiles(true);
            $uploader->setFilesDispersion(true);
            $uploader->setAllowCreateFolders(true);
            $result = $uploader->save($destinationFolder);
            return $result['file'];
        }
    } catch (\Exception $e) {
        if ($e->getCode() != \Magento\Framework\File\Uploader::TMP_NAME_EMPTY) {
            throw new FrameworkException($e->getMessage());
        } else {
            if (isset($data[$input]['value'])) {
                return $data[$input]['value'];
            }
        }
    }
    return '';
}

When I enter any disallowed file-type, it gives me blank page and gives error "Disallowed file type".

If anyone faced this issue, please help me.

Answer 1

In my case it was due to the Exception class in the throw block. I'm using magento 2.17, the Uploader class throws Exception class. Please check framework/file/Uploader.php:: _validateFile(). Makesure the Exception class in the Uploader throw block and your Exception reference in your code is identical. My case it is worked: framework/file/Uploader.php:

  protected function _validateFile()
{
    if ($this->_fileExists === false) {
        return;
    }

    //is file extension allowed
    if (!$this->checkAllowedExtension($this->getFileExtension())) {

        throw new \Exception('Disallowed file type.');
    }
    //run validate callbacks
    foreach ($this->_validateCallbacks as $params) {
        if (is_object($params['object'])
            && method_exists($params['object'], $params['method'])
            && is_callable([$params['object'], $params['method']])
        ) {
            $params['object']->{$params['method']}($this->_file['tmp_name']);
        }
    }
}

And in my code it was like:

try {
                $this->_fileUploaderFactory = $this->_objectManager->get('Magento\MediaStorage\Model\File\UploaderFactory');
                $uploader = $this->_fileUploaderFactory->create(['fileId' => 'banner']);

                $uploader->setAllowedExtensions(['jpg', 'jpeg','png']);

                $uploader->setAllowRenameFiles(false);
                $uploader->setFilesDispersion(false);
                $mediaDirectory = $this->_objectManager->get('Magento\Framework\Filesystem')
                    ->getDirectoryRead(DirectoryList::MEDIA);
                $path           = $mediaDirectory->getAbsolutePath('bannerslider/images/');


                $result = $uploader->save($path);


                $data['banner'] = isset($result['file']) ? $result['file'] : null;
            } catch (\Exception $e) {

                $data['banner'] = $_FILES['banner']['name'];
                $this->messageManager->addError($e->getMessage());

                $resultRedirect = $this->resultFactory->create(ResultFactory::TYPE_REDIRECT);

                // Your code

                $resultRedirect->setUrl($this->_redirect->getRefererUrl());
                return $resultRedirect;

            }