file.module

Same filename in other branches
  1. 7.x modules/file/file.module
  2. 9 core/modules/file/file.module
  3. 10 core/modules/file/file.module
  4. 11.x core/modules/file/file.module

Defines a "managed_file" Form API field and a "file" field for Field module.

File

core/modules/file/file.module

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<?php


/**
 * @file
 * Defines a "managed_file" Form API field and a "file" field for Field module.
 */
use Drupal\Component\Utility\Environment;
use Drupal\Core\Datetime\Entity\DateFormat;
use Drupal\Core\Field\FieldDefinitionInterface;
use Drupal\Core\File\Exception\FileException;
use Drupal\Core\File\FileSystemInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Messenger\MessengerInterface;
use Drupal\Core\Render\BubbleableMetadata;
use Drupal\Core\Render\Element;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\Link;
use Drupal\Core\Url;
use Drupal\file\Entity\File;
use Drupal\file\FileInterface;
use Drupal\Component\Utility\NestedArray;
use Drupal\Component\Utility\Unicode;
use Drupal\Core\Entity\EntityStorageInterface;
use Drupal\Core\Template\Attribute;

/**
 * The regex pattern used when checking for insecure file types.
 */
define('FILE_INSECURE_EXTENSION_REGEX', '/\\.(phar|php|pl|py|cgi|asp|js)(\\.|$)/i');
// Load all Field module hooks for File.
require_once __DIR__ . '/file.field.inc';

/**
 * Implements hook_help().
 */
function file_help($route_name, RouteMatchInterface $route_match) {
    switch ($route_name) {
        case 'help.page.file':
            $output = '';
            $output .= '<h3>' . t('About') . '</h3>';
            $output .= '<p>' . t('The File module allows you to create fields that contain files. See the <a href=":field">Field module help</a> and the <a href=":field_ui">Field UI help</a> pages for general information on fields and how to create and manage them. For more information, see the <a href=":file_documentation">online documentation for the File module</a>.', [
                ':field' => Url::fromRoute('help.page', [
                    'name' => 'field',
                ])->toString(),
                ':field_ui' => \Drupal::moduleHandler()->moduleExists('field_ui') ? Url::fromRoute('help.page', [
                    'name' => 'field_ui',
                ])->toString() : '#',
                ':file_documentation' => 'https://www.drupal.org/documentation/modules/file',
            ]) . '</p>';
            $output .= '<h3>' . t('Uses') . '</h3>';
            $output .= '<dl>';
            $output .= '<dt>' . t('Managing and displaying file fields') . '</dt>';
            $output .= '<dd>' . t('The <em>settings</em> and the <em>display</em> of the file field can be configured separately. See the <a href=":field_ui">Field UI help</a> for more information on how to manage fields and their display.', [
                ':field_ui' => \Drupal::moduleHandler()->moduleExists('field_ui') ? Url::fromRoute('help.page', [
                    'name' => 'field_ui',
                ])->toString() : '#',
            ]) . '</dd>';
            $output .= '<dt>' . t('Allowing file extensions') . '</dt>';
            $output .= '<dd>' . t('In the field settings, you can define the allowed file extensions (for example <em>pdf docx psd</em>) for the files that will be uploaded with the file field.') . '</dd>';
            $output .= '<dt>' . t('Storing files') . '</dt>';
            $output .= '<dd>' . t('Uploaded files can either be stored as <em>public</em> or <em>private</em>, depending on the <a href=":file-system">File system settings</a>. For more information, see the <a href=":system-help">System module help page</a>.', [
                ':file-system' => Url::fromRoute('system.file_system_settings')->toString(),
                ':system-help' => Url::fromRoute('help.page', [
                    'name' => 'system',
                ])->toString(),
            ]) . '</dd>';
            $output .= '<dt>' . t('Restricting the maximum file size') . '</dt>';
            $output .= '<dd>' . t('The maximum file size that users can upload is limited by PHP settings of the server, but you can restrict by entering the desired value as the <em>Maximum upload size</em> setting. The maximum file size is automatically displayed to users in the help text of the file field.') . '</dd>';
            $output .= '<dt>' . t('Displaying files and descriptions') . '<dt>';
            $output .= '<dd>' . t('In the field settings, you can allow users to toggle whether individual files are displayed. In the display settings, you can then choose one of the following formats: <ul><li><em>Generic file</em> displays links to the files and adds icons that symbolize the file extensions. If <em>descriptions</em> are enabled and have been submitted, then the description is displayed instead of the file name.</li><li><em>URL to file</em> displays the full path to the file as plain text.</li><li><em>Table of files</em> lists links to the files and the file sizes in a table.</li><li><em>RSS enclosure</em> only displays the first file, and only in a RSS feed, formatted according to the RSS 2.0 syntax for enclosures.</li></ul> A file can still be linked to directly by its URI even if it is not displayed.') . '</dd>';
            $output .= '</dl>';
            return $output;
    }
}

/**
 * Implements hook_field_widget_info_alter().
 */
function file_field_widget_info_alter(array &$info) {
    // Allows using the 'uri' widget for the 'file_uri' field type, which uses it
    // as the default widget.
    // @see \Drupal\file\Plugin\Field\FieldType\FileUriItem
    $info['uri']['field_types'][] = 'file_uri';
}

/**
 * Loads file entities from the database.
 *
 * @param array|null $fids
 *   (optional) An array of entity IDs. If omitted or NULL, all entities are
 *   loaded.
 * @param bool $reset
 *   (optional) Whether to reset the internal file_load_multiple() cache.
 *   Defaults to FALSE.
 *
 * @return array
 *   An array of file entities, indexed by fid.
 *
 * @deprecated in drupal:8.0.0 and is removed from drupal:9.0.0. Use
 *   \Drupal\file\Entity\File::loadMultiple().
 *
 * @see https://www.drupal.org/node/2266845
 */
function file_load_multiple(array $fids = NULL, $reset = FALSE) {
    @trigger_error('file_load_multiple() is deprecated in Drupal 8.0.0 and will be removed before Drupal 9.0.0. Use \\Drupal\\file\\Entity\\File::loadMultiple(). See https://www.drupal.org/node/2266845', E_USER_DEPRECATED);
    if ($reset) {
        \Drupal::entityTypeManager()->getStorage('file')
            ->resetCache($fids);
    }
    return File::loadMultiple($fids);
}

/**
 * Loads a single file entity from the database.
 *
 * @param int $fid
 *   A file ID.
 * @param bool $reset
 *   (optional) Whether to reset the internal file_load_multiple() cache.
 *   Defaults to FALSE.
 *
 * @return \Drupal\file\FileInterface|null
 *   A file entity or NULL if the file was not found.
 *
 * @deprecated in drupal:8.0.0 and is removed from drupal:9.0.0. Use
 *   \Drupal\file\Entity\File::load().
 *
 * @see https://www.drupal.org/node/2266845
 */
function file_load($fid, $reset = FALSE) {
    @trigger_error('file_load() is deprecated in Drupal 8.0.0 and will be removed before Drupal 9.0.0. Use \\Drupal\\file\\Entity\\File::load(). See https://www.drupal.org/node/2266845', E_USER_DEPRECATED);
    if ($reset) {
        \Drupal::entityTypeManager()->getStorage('file')
            ->resetCache([
            $fid,
        ]);
    }
    return File::load($fid);
}

/**
 * Copies a file to a new location and adds a file record to the database.
 *
 * This function should be used when manipulating files that have records
 * stored in the database. This is a powerful function that in many ways
 * performs like an advanced version of copy().
 * - Checks if $source and $destination are valid and readable/writable.
 * - If file already exists in $destination either the call will error out,
 *   replace the file or rename the file based on the $replace parameter.
 * - If the $source and $destination are equal, the behavior depends on the
 *   $replace parameter. FileSystemInterface::EXISTS_REPLACE will error out.
 *   FileSystemInterface::EXISTS_RENAME will rename the file until the
 *   $destination is unique.
 * - Adds the new file to the files database. If the source file is a
 *   temporary file, the resulting file will also be a temporary file. See
 *   file_save_upload() for details on temporary files.
 *
 * @param \Drupal\file\FileInterface $source
 *   A file entity.
 * @param string $destination
 *   A string containing the destination that $source should be
 *   copied to. This must be a stream wrapper URI.
 * @param int $replace
 *   (optional) Replace behavior when the destination file already exists.
 *   Possible values include:
 *   - FileSystemInterface::EXISTS_REPLACE: Replace the existing file. If a
 *     managed file with the destination name exists, then its database entry
 *     will be updated. If no database entry is found, then a new one will be
 *     created.
 *   - FileSystemInterface::EXISTS_RENAME: (default) Append
 *     _{incrementing number} until the filename is unique.
 *   - FileSystemInterface::EXISTS_ERROR: Do nothing and return FALSE.
 *
 * @return \Drupal\file\FileInterface|false
 *   File entity if the copy is successful, or FALSE in the event of an error.
 *
 * @see \Drupal\Core\File\FileSystemInterface::copy()
 * @see hook_file_copy()
 */
function file_copy(FileInterface $source, $destination = NULL, $replace = FileSystemInterface::EXISTS_RENAME) {
    
    /** @var \Drupal\Core\File\FileSystemInterface $file_system */
    $file_system = \Drupal::service('file_system');
    
    /** @var \Drupal\Core\StreamWrapper\StreamWrapperManagerInterface $stream_wrapper_manager */
    $stream_wrapper_manager = \Drupal::service('stream_wrapper_manager');
    if (!$stream_wrapper_manager->isValidUri($destination)) {
        if (($realpath = $file_system->realpath($source->getFileUri())) !== FALSE) {
            \Drupal::logger('file')->notice('File %file (%realpath) could not be copied because the destination %destination is invalid. This is often caused by improper use of file_copy() or a missing stream wrapper.', [
                '%file' => $source->getFileUri(),
                '%realpath' => $realpath,
                '%destination' => $destination,
            ]);
        }
        else {
            \Drupal::logger('file')->notice('File %file could not be copied because the destination %destination is invalid. This is often caused by improper use of file_copy() or a missing stream wrapper.', [
                '%file' => $source->getFileUri(),
                '%destination' => $destination,
            ]);
        }
        \Drupal::messenger()->addError(t('The specified file %file could not be copied because the destination is invalid. More information is available in the system log.', [
            '%file' => $source->getFileUri(),
        ]));
        return FALSE;
    }
    try {
        $uri = $file_system->copy($source->getFileUri(), $destination, $replace);
        $file = $source->createDuplicate();
        $file->setFileUri($uri);
        $file->setFilename($file_system->basename($uri));
        // If we are replacing an existing file re-use its database record.
        // @todo Do not create a new entity in order to update it. See
        //   https://www.drupal.org/node/2241865.
        if ($replace == FileSystemInterface::EXISTS_REPLACE) {
            $existing_files = \Drupal::entityTypeManager()->getStorage('file')
                ->loadByProperties([
                'uri' => $uri,
            ]);
            if (count($existing_files)) {
                $existing = reset($existing_files);
                $file->fid = $existing->id();
                $file->setOriginalId($existing->id());
                $file->setFilename($existing->getFilename());
            }
        }
        elseif ($replace == FileSystemInterface::EXISTS_RENAME && is_file($destination)) {
            $file->setFilename($file_system->basename($destination));
        }
        $file->save();
        // Inform modules that the file has been copied.
        \Drupal::moduleHandler()->invokeAll('file_copy', [
            $file,
            $source,
        ]);
        return $file;
    } catch (FileException $e) {
        return FALSE;
    }
}

/**
 * Moves a file to a new location and update the file's database entry.
 *
 * - Checks if $source and $destination are valid and readable/writable.
 * - Performs a file move if $source is not equal to $destination.
 * - If file already exists in $destination either the call will error out,
 *   replace the file or rename the file based on the $replace parameter.
 * - Adds the new file to the files database.
 *
 * @param \Drupal\file\FileInterface $source
 *   A file entity.
 * @param string $destination
 *   A string containing the destination that $source should be moved
 *   to. This must be a stream wrapper URI.
 * @param int $replace
 *   (optional) The replace behavior when the destination file already exists.
 *   Possible values include:
 *   - FileSystemInterface::EXISTS_REPLACE: Replace the existing file. If a
 *     managed file with the destination name exists then its database entry
 *     will be updated and $source->delete() called after invoking
 *     hook_file_move(). If no database entry is found, then the source files
 *     record will be updated.
 *   - FileSystemInterface::EXISTS_RENAME: (default) Append
 *     _{incrementing number} until the filename is unique.
 *   - FileSystemInterface::EXISTS_ERROR: Do nothing and return FALSE.
 *
 * @return \Drupal\file\FileInterface|false
 *   Resulting file entity for success, or FALSE in the event of an error.
 *
 * @see \Drupal\Core\File\FileSystemInterface::move()
 * @see hook_file_move()
 */
function file_move(FileInterface $source, $destination = NULL, $replace = FileSystemInterface::EXISTS_RENAME) {
    
    /** @var \Drupal\Core\File\FileSystemInterface $file_system */
    $file_system = \Drupal::service('file_system');
    
    /** @var \Drupal\Core\StreamWrapper\StreamWrapperManagerInterface $stream_wrapper_manager */
    $stream_wrapper_manager = \Drupal::service('stream_wrapper_manager');
    if (!$stream_wrapper_manager->isValidUri($destination)) {
        if (($realpath = $file_system->realpath($source->getFileUri())) !== FALSE) {
            \Drupal::logger('file')->notice('File %file (%realpath) could not be moved because the destination %destination is invalid. This may be caused by improper use of file_move() or a missing stream wrapper.', [
                '%file' => $source->getFileUri(),
                '%realpath' => $realpath,
                '%destination' => $destination,
            ]);
        }
        else {
            \Drupal::logger('file')->notice('File %file could not be moved because the destination %destination is invalid. This may be caused by improper use of file_move() or a missing stream wrapper.', [
                '%file' => $source->getFileUri(),
                '%destination' => $destination,
            ]);
        }
        \Drupal::messenger()->addError(t('The specified file %file could not be moved because the destination is invalid. More information is available in the system log.', [
            '%file' => $source->getFileUri(),
        ]));
        return FALSE;
    }
    try {
        $uri = $file_system->move($source->getFileUri(), $destination, $replace);
        $delete_source = FALSE;
        $file = clone $source;
        $file->setFileUri($uri);
        // If we are replacing an existing file re-use its database record.
        if ($replace == FileSystemInterface::EXISTS_REPLACE) {
            $existing_files = \Drupal::entityTypeManager()->getStorage('file')
                ->loadByProperties([
                'uri' => $uri,
            ]);
            if (count($existing_files)) {
                $existing = reset($existing_files);
                $delete_source = TRUE;
                $file->fid = $existing->id();
                $file->uuid = $existing->uuid();
            }
        }
        elseif ($replace == FileSystemInterface::EXISTS_RENAME && is_file($destination)) {
            $file->setFilename(\Drupal::service('file_system')->basename($destination));
        }
        $file->save();
        // Inform modules that the file has been moved.
        \Drupal::moduleHandler()->invokeAll('file_move', [
            $file,
            $source,
        ]);
        // Delete the original if it's not in use elsewhere.
        if ($delete_source && !\Drupal::service('file.usage')->listUsage($source)) {
            $source->delete();
        }
        return $file;
    } catch (FileException $e) {
        return FALSE;
    }
}

/**
 * Checks that a file meets the criteria specified by the validators.
 *
 * After executing the validator callbacks specified hook_file_validate() will
 * also be called to allow other modules to report errors about the file.
 *
 * @param \Drupal\file\FileInterface $file
 *   A file entity.
 * @param array $validators
 *   (optional) An associative array of callback functions used to validate
 *   the file. The keys are function names and the values arrays of callback
 *   parameters which will be passed in after the file entity. The functions
 *   should return an array of error messages; an empty array indicates that
 *   the file passed validation. The callback functions will be called in the
 *   order specified in the array, then the hook hook_file_validate()
 *   will be invoked so other modules can validate the new file.
 *
 * @return array
 *   An array containing validation error messages.
 *
 * @see hook_file_validate()
 */
function file_validate(FileInterface $file, $validators = []) {
    // Call the validation functions specified by this function's caller.
    $errors = [];
    foreach ($validators as $function => $args) {
        if (function_exists($function)) {
            array_unshift($args, $file);
            $errors = array_merge($errors, call_user_func_array($function, $args));
        }
    }
    // Let other modules perform validation on the new file.
    $errors = array_merge($errors, \Drupal::moduleHandler()->invokeAll('file_validate', [
        $file,
    ]));
    // Ensure the file does not contain a malicious extension. At this point
    // _file_save_upload_single() will have munged the file so it does not contain
    // a malicious extension. Contributed and custom code that calls this method
    // needs to take similar steps if they need to permit files with malicious
    // extensions to be uploaded.
    if (empty($errors) && !\Drupal::config('system.file')->get('allow_insecure_uploads') && preg_match(FILE_INSECURE_EXTENSION_REGEX, $file->getFilename())) {
        $errors[] = t('For security reasons, your upload has been rejected.');
    }
    return $errors;
}

/**
 * Checks for files with names longer than can be stored in the database.
 *
 * @param \Drupal\file\FileInterface $file
 *   A file entity.
 *
 * @return array
 *   An empty array if the file name length is smaller than the limit or an
 *   array containing an error message if it's not or is empty.
 */
function file_validate_name_length(FileInterface $file) {
    $errors = [];
    if (!$file->getFilename()) {
        $errors[] = t("The file's name is empty. Please give a name to the file.");
    }
    if (strlen($file->getFilename()) > 240) {
        $errors[] = t("The file's name exceeds the 240 characters limit. Please rename the file and try again.");
    }
    return $errors;
}

/**
 * Checks that the filename ends with an allowed extension.
 *
 * @param \Drupal\file\FileInterface $file
 *   A file entity.
 * @param string $extensions
 *   A string with a space separated list of allowed extensions.
 *
 * @return array
 *   An empty array if the file extension is allowed or an array containing an
 *   error message if it's not.
 *
 * @see hook_file_validate()
 */
function file_validate_extensions(FileInterface $file, $extensions) {
    $errors = [];
    $regex = '/\\.(' . preg_replace('/ +/', '|', preg_quote($extensions)) . ')$/i';
    if (!preg_match($regex, $file->getFilename())) {
        $errors[] = t('Only files with the following extensions are allowed: %files-allowed.', [
            '%files-allowed' => $extensions,
        ]);
    }
    return $errors;
}

/**
 * Checks that the file's size is below certain limits.
 *
 * @param \Drupal\file\FileInterface $file
 *   A file entity.
 * @param int $file_limit
 *   (optional) The maximum file size in bytes. Zero (the default) indicates
 *   that no limit should be enforced.
 * @param int $user_limit
 *   (optional) The maximum number of bytes the user is allowed. Zero (the
 *   default) indicates that no limit should be enforced.
 *
 * @return array
 *   An empty array if the file size is below limits or an array containing an
 *   error message if it's not.
 *
 * @see hook_file_validate()
 */
function file_validate_size(FileInterface $file, $file_limit = 0, $user_limit = 0) {
    $user = \Drupal::currentUser();
    $errors = [];
    if ($file_limit && $file->getSize() > $file_limit) {
        $errors[] = t('The file is %filesize exceeding the maximum file size of %maxsize.', [
            '%filesize' => format_size($file->getSize()),
            '%maxsize' => format_size($file_limit),
        ]);
    }
    // Save a query by only calling spaceUsed() when a limit is provided.
    if ($user_limit && \Drupal::entityTypeManager()->getStorage('file')
        ->spaceUsed($user->id()) + $file->getSize() > $user_limit) {
        $errors[] = t('The file is %filesize which would exceed your disk quota of %quota.', [
            '%filesize' => format_size($file->getSize()),
            '%quota' => format_size($user_limit),
        ]);
    }
    return $errors;
}

/**
 * Checks that the file is recognized as a valid image.
 *
 * @param \Drupal\file\FileInterface $file
 *   A file entity.
 *
 * @return array
 *   An empty array if the file is a valid image or an array containing an error
 *   message if it's not.
 *
 * @see hook_file_validate()
 */
function file_validate_is_image(FileInterface $file) {
    $errors = [];
    $image_factory = \Drupal::service('image.factory');
    $image = $image_factory->get($file->getFileUri());
    if (!$image->isValid()) {
        $supported_extensions = $image_factory->getSupportedExtensions();
        $errors[] = t('The image file is invalid or the image type is not allowed. Allowed types: %types', [
            '%types' => implode(', ', $supported_extensions),
        ]);
    }
    return $errors;
}

/**
 * Verifies that image dimensions are within the specified maximum and minimum.
 *
 * Non-image files will be ignored. If an image toolkit is available the image
 * will be scaled to fit within the desired maximum dimensions.
 *
 * @param \Drupal\file\FileInterface $file
 *   A file entity. This function may resize the file affecting its size.
 * @param string|int $maximum_dimensions
 *   (optional) A string in the form WIDTHxHEIGHT; for example, '640x480' or
 *   '85x85'. If an image toolkit is installed, the image will be resized down
 *   to these dimensions. A value of zero (the default) indicates no restriction
 *   on size, so no resizing will be attempted.
 * @param string|int $minimum_dimensions
 *   (optional) A string in the form WIDTHxHEIGHT. This will check that the
 *   image meets a minimum size. A value of zero (the default) indicates that
 *   there is no restriction on size.
 *
 * @return array
 *   An empty array if the file meets the specified dimensions, was resized
 *   successfully to meet those requirements or is not an image. If the image
 *   does not meet the requirements or an attempt to resize it fails, an array
 *   containing the error message will be returned.
 *
 * @see hook_file_validate()
 */
function file_validate_image_resolution(FileInterface $file, $maximum_dimensions = 0, $minimum_dimensions = 0) {
    $errors = [];
    // Check first that the file is an image.
    $image_factory = \Drupal::service('image.factory');
    $image = $image_factory->get($file->getFileUri());
    if ($image->isValid()) {
        $scaling = FALSE;
        if ($maximum_dimensions) {
            // Check that it is smaller than the given dimensions.
            list($width, $height) = explode('x', $maximum_dimensions);
            if ($image->getWidth() > $width || $image->getHeight() > $height) {
                // Try to resize the image to fit the dimensions.
                if ($image->scale($width, $height)) {
                    $scaling = TRUE;
                    $image->save();
                    if (!empty($width) && !empty($height)) {
                        $message = t('The image was resized to fit within the maximum allowed dimensions of %dimensions pixels. The new dimensions of the resized image are %new_widthx%new_height pixels.', [
                            '%dimensions' => $maximum_dimensions,
                            '%new_width' => $image->getWidth(),
                            '%new_height' => $image->getHeight(),
                        ]);
                    }
                    elseif (empty($width)) {
                        $message = t('The image was resized to fit within the maximum allowed height of %height pixels. The new dimensions of the resized image are %new_widthx%new_height pixels.', [
                            '%height' => $height,
                            '%new_width' => $image->getWidth(),
                            '%new_height' => $image->getHeight(),
                        ]);
                    }
                    elseif (empty($height)) {
                        $message = t('The image was resized to fit within the maximum allowed width of %width pixels. The new dimensions of the resized image are %new_widthx%new_height pixels.', [
                            '%width' => $width,
                            '%new_width' => $image->getWidth(),
                            '%new_height' => $image->getHeight(),
                        ]);
                    }
                    \Drupal::messenger()->addStatus($message);
                }
                else {
                    $errors[] = t('The image exceeds the maximum allowed dimensions and an attempt to resize it failed.');
                }
            }
        }
        if ($minimum_dimensions) {
            // Check that it is larger than the given dimensions.
            list($width, $height) = explode('x', $minimum_dimensions);
            if ($image->getWidth() < $width || $image->getHeight() < $height) {
                if ($scaling) {
                    $errors[] = t('The resized image is too small. The minimum dimensions are %dimensions pixels and after resizing, the image size will be %widthx%height pixels.', [
                        '%dimensions' => $minimum_dimensions,
                        '%width' => $image->getWidth(),
                        '%height' => $image->getHeight(),
                    ]);
                }
                else {
                    $errors[] = t('The image is too small. The minimum dimensions are %dimensions pixels and the image size is %widthx%height pixels.', [
                        '%dimensions' => $minimum_dimensions,
                        '%width' => $image->getWidth(),
                        '%height' => $image->getHeight(),
                    ]);
                }
            }
        }
    }
    return $errors;
}

/**
 * Saves a file to the specified destination and creates a database entry.
 *
 * @param string $data
 *   A string containing the contents of the file.
 * @param string|null $destination
 *   (optional) A string containing the destination URI. This must be a stream
 *   wrapper URI. If no value or NULL is provided, a randomized name will be
 *   generated and the file will be saved using Drupal's default files scheme,
 *   usually "public://".
 * @param int $replace
 *   (optional) The replace behavior when the destination file already exists.
 *   Possible values include:
 *   - FileSystemInterface::EXISTS_REPLACE: Replace the existing file. If a
 *     managed file with the destination name exists, then its database entry
 *     will be updated. If no database entry is found, then a new one will be
 *     created.
 *   - FileSystemInterface::EXISTS_RENAME: (default) Append
 *     _{incrementing number} until the filename is unique.
 *   - FileSystemInterface::EXISTS_ERROR: Do nothing and return FALSE.
 *
 * @return \Drupal\file\FileInterface|false
 *   A file entity, or FALSE on error.
 *
 * @see \Drupal\Core\File\FileSystemInterface::saveData()
 */
function file_save_data($data, $destination = NULL, $replace = FileSystemInterface::EXISTS_RENAME) {
    $user = \Drupal::currentUser();
    if (empty($destination)) {
        $destination = \Drupal::config('system.file')->get('default_scheme') . '://';
    }
    
    /** @var \Drupal\Core\StreamWrapper\StreamWrapperManagerInterface $stream_wrapper_manager */
    $stream_wrapper_manager = \Drupal::service('stream_wrapper_manager');
    if (!$stream_wrapper_manager->isValidUri($destination)) {
        \Drupal::logger('file')->notice('The data could not be saved because the destination %destination is invalid. This may be caused by improper use of file_save_data() or a missing stream wrapper.', [
            '%destination' => $destination,
        ]);
        \Drupal::messenger()->addError(t('The data could not be saved because the destination is invalid. More information is available in the system log.'));
        return FALSE;
    }
    try {
        $uri = \Drupal::service('file_system')->saveData($data, $destination, $replace);
        // Create a file entity.
        $file = File::create([
            'uri' => $uri,
            'uid' => $user->id(),
            'status' => FILE_STATUS_PERMANENT,
        ]);
        // If we are replacing an existing file re-use its database record.
        // @todo Do not create a new entity in order to update it. See
        //   https://www.drupal.org/node/2241865.
        if ($replace == FileSystemInterface::EXISTS_REPLACE) {
            $existing_files = \Drupal::entityTypeManager()->getStorage('file')
                ->loadByProperties([
                'uri' => $uri,
            ]);
            if (count($existing_files)) {
                $existing = reset($existing_files);
                $file->fid = $existing->id();
                $file->setOriginalId($existing->id());
                $file->setFilename($existing->getFilename());
            }
        }
        elseif ($replace == FileSystemInterface::EXISTS_RENAME && is_file($destination)) {
            $file->setFilename(\Drupal::service('file_system')->basename($destination));
        }
        $file->save();
        return $file;
    } catch (FileException $e) {
        return FALSE;
    }
}

/**
 * Examines a file entity and returns appropriate content headers for download.
 *
 * @param \Drupal\file\FileInterface $file
 *   A file entity.
 *
 * @return array
 *   An associative array of headers, as expected by
 *   \Symfony\Component\HttpFoundation\StreamedResponse.
 */
function file_get_content_headers(FileInterface $file) {
    $type = Unicode::mimeHeaderEncode($file->getMimeType());
    return [
        'Content-Type' => $type,
        'Content-Length' => $file->getSize(),
        'Cache-Control' => 'private',
    ];
}

/**
 * Implements hook_theme().
 */
function file_theme() {
    return [
        // From file.module.
'file_link' => [
            'variables' => [
                'file' => NULL,
                'description' => NULL,
                'attributes' => [],
            ],
        ],
        'file_managed_file' => [
            'render element' => 'element',
        ],
        'file_audio' => [
            'variables' => [
                'files' => [],
                'attributes' => NULL,
            ],
        ],
        'file_video' => [
            'variables' => [
                'files' => [],
                'attributes' => NULL,
            ],
        ],
        // From file.field.inc.
'file_widget_multiple' => [
            'render element' => 'element',
            'file' => 'file.field.inc',
        ],
        'file_upload_help' => [
            'variables' => [
                'description' => NULL,
                'upload_validators' => NULL,
                'cardinality' => NULL,
            ],
            'file' => 'file.field.inc',
        ],
    ];
}

/**
 * Implements hook_file_download().
 */
function file_file_download($uri) {
    // Get the file record based on the URI. If not in the database just return.
    
    /** @var \Drupal\file\FileInterface[] $files */
    $files = \Drupal::entityTypeManager()->getStorage('file')
        ->loadByProperties([
        'uri' => $uri,
    ]);
    if (count($files)) {
        foreach ($files as $item) {
            // Since some database servers sometimes use a case-insensitive comparison
            // by default, double check that the filename is an exact match.
            if ($item->getFileUri() === $uri) {
                $file = $item;
                break;
            }
        }
    }
    if (!isset($file)) {
        return;
    }
    // Find out if a temporary file is still used in the system.
    if ($file->isTemporary()) {
        $usage = \Drupal::service('file.usage')->listUsage($file);
        if (empty($usage) && $file->getOwnerId() != \Drupal::currentUser()->id()) {
            // Deny access to temporary files without usage that are not owned by the
            // same user. This prevents the security issue that a private file that
            // was protected by field permissions becomes available after its usage
            // was removed and before it is actually deleted from the file system.
            // Modules that depend on this behavior should make the file permanent
            // instead.
            return -1;
        }
    }
    // Find out which (if any) fields of this type contain the file.
    $references = file_get_file_references($file, NULL, EntityStorageInterface::FIELD_LOAD_CURRENT, NULL);
    // Stop processing if there are no references in order to avoid returning
    // headers for files controlled by other modules. Make an exception for
    // temporary files where the host entity has not yet been saved (for example,
    // an image preview on a node/add form) in which case, allow download by the
    // file's owner.
    if (empty($references) && ($file->isPermanent() || $file->getOwnerId() != \Drupal::currentUser()->id())) {
        return;
    }
    if (!$file->access('download')) {
        return -1;
    }
    // Access is granted.
    $headers = file_get_content_headers($file);
    return $headers;
}

/**
 * Implements hook_cron().
 */
function file_cron() {
    $age = \Drupal::config('system.file')->get('temporary_maximum_age');
    $file_storage = \Drupal::entityTypeManager()->getStorage('file');
    
    /** @var \Drupal\Core\StreamWrapper\StreamWrapperManagerInterface $stream_wrapper_manager */
    $stream_wrapper_manager = \Drupal::service('stream_wrapper_manager');
    // Only delete temporary files if older than $age. Note that automatic cleanup
    // is disabled if $age set to 0.
    if ($age) {
        $fids = Drupal::entityQuery('file')->accessCheck(FALSE)
            ->condition('status', FILE_STATUS_PERMANENT, '<>')
            ->condition('changed', REQUEST_TIME - $age, '<')
            ->range(0, 100)
            ->execute();
        $files = $file_storage->loadMultiple($fids);
        foreach ($files as $file) {
            $references = \Drupal::service('file.usage')->listUsage($file);
            if (empty($references)) {
                if (!file_exists($file->getFileUri())) {
                    if (!$stream_wrapper_manager->isValidUri($file->getFileUri())) {
                        \Drupal::logger('file system')->warning('Temporary file "%path" that was deleted during garbage collection did not exist on the filesystem. This could be caused by a missing stream wrapper.', [
                            '%path' => $file->getFileUri(),
                        ]);
                    }
                    else {
                        \Drupal::logger('file system')->warning('Temporary file "%path" that was deleted during garbage collection did not exist on the filesystem.', [
                            '%path' => $file->getFileUri(),
                        ]);
                    }
                }
                // Delete the file entity. If the file does not exist, this will
                // generate a second notice in the watchdog.
                $file->delete();
            }
            else {
                \Drupal::logger('file system')->info('Did not delete temporary file "%path" during garbage collection because it is in use by the following modules: %modules.', [
                    '%path' => $file->getFileUri(),
                    '%modules' => implode(', ', array_keys($references)),
                ]);
            }
        }
    }
}

/**
 * Saves form file uploads.
 *
 * The files will be added to the {file_managed} table as temporary files.
 * Temporary files are periodically cleaned. Use the 'file.usage' service to
 * register the usage of the file which will automatically mark it as permanent.
 *
 * @param array $element
 *   The FAPI element whose values are being saved.
 * @param \Drupal\Core\Form\FormStateInterface $form_state
 *   The current state of the form.
 * @param null|int $delta
 *   (optional) The delta of the file to return the file entity.
 *   Defaults to NULL.
 * @param int $replace
 *   (optional) The replace behavior when the destination file already exists.
 *   Possible values include:
 *   - FileSystemInterface::EXISTS_REPLACE: Replace the existing file.
 *   - FileSystemInterface::EXISTS_RENAME: (default) Append
 *     _{incrementing number} until the filename is unique.
 *   - FileSystemInterface::EXISTS_ERROR: Do nothing and return FALSE.
 *
 * @return array|\Drupal\file\FileInterface|null|false
 *   An array of file entities or a single file entity if $delta != NULL. Each
 *   array element contains the file entity if the upload succeeded or FALSE if
 *   there was an error. Function returns NULL if no file was uploaded.
 *
 * @internal
 *   This function is internal, and may be removed in a minor version release.
 *   It wraps file_save_upload() to allow correct error handling in forms.
 *   Contrib and custom code should not call this function, they should use the
 *   managed file upload widgets in core.
 *
 * @see https://www.drupal.org/project/drupal/issues/3069020
 * @see https://www.drupal.org/project/drupal/issues/2482783
 */
function _file_save_upload_from_form(array $element, FormStateInterface $form_state, $delta = NULL, $replace = FileSystemInterface::EXISTS_RENAME) {
    // Get all errors set before calling this method. This will also clear them
    // from $_SESSION.
    $errors_before = \Drupal::messenger()->deleteByType(MessengerInterface::TYPE_ERROR);
    $upload_location = isset($element['#upload_location']) ? $element['#upload_location'] : FALSE;
    $upload_name = implode('_', $element['#parents']);
    $upload_validators = isset($element['#upload_validators']) ? $element['#upload_validators'] : [];
    $result = file_save_upload($upload_name, $upload_validators, $upload_location, $delta, $replace);
    // Get new errors that are generated while trying to save the upload. This
    // will also clear them from $_SESSION.
    $errors_new = \Drupal::messenger()->deleteByType(MessengerInterface::TYPE_ERROR);
    if (!empty($errors_new)) {
        if (count($errors_new) > 1) {
            // Render multiple errors into a single message.
            // This is needed because only one error per element is supported.
            $render_array = [
                'error' => [
                    '#markup' => t('One or more files could not be uploaded.'),
                ],
                'item_list' => [
                    '#theme' => 'item_list',
                    '#items' => $errors_new,
                ],
            ];
            $error_message = \Drupal::service('renderer')->renderPlain($render_array);
        }
        else {
            $error_message = reset($errors_new);
        }
        $form_state->setError($element, $error_message);
    }
    // Ensure that errors set prior to calling this method are still shown to the
    // user.
    if (!empty($errors_before)) {
        foreach ($errors_before as $error) {
            \Drupal::messenger()->addError($error);
        }
    }
    return $result;
}

/**
 * Saves file uploads to a new location.
 *
 * The files will be added to the {file_managed} table as temporary files.
 * Temporary files are periodically cleaned. Use the 'file.usage' service to
 * register the usage of the file which will automatically mark it as permanent.
 *
 * Note that this function does not support correct form error handling. The
 * file upload widgets in core do support this. It is advised to use these in
 * any custom form, instead of calling this function.
 *
 * @param string $form_field_name
 *   A string that is the associative array key of the upload form element in
 *   the form array.
 * @param array $validators
 *   (optional) An associative array of callback functions used to validate the
 *   file. See file_validate() for a full discussion of the array format.
 *   If the array is empty, it will be set up to call file_validate_extensions()
 *   with a safe list of extensions, as follows: "jpg jpeg gif png txt doc
 *   xls pdf ppt pps odt ods odp". To allow all extensions, you must explicitly
 *   set this array to ['file_validate_extensions' => '']. (Beware: this is not
 *   safe and should only be allowed for trusted users, if at all.)
 * @param string|false $destination
 *   (optional) A string containing the URI that the file should be copied to.
 *   This must be a stream wrapper URI. If this value is omitted or set to
 *   FALSE, Drupal's temporary files scheme will be used ("temporary://").
 * @param null|int $delta
 *   (optional) The delta of the file to return the file entity.
 *   Defaults to NULL.
 * @param int $replace
 *   (optional) The replace behavior when the destination file already exists.
 *   Possible values include:
 *   - FileSystemInterface::EXISTS_REPLACE: Replace the existing file.
 *   - FileSystemInterface::EXISTS_RENAME: (default) Append
 *     _{incrementing number} until the filename is unique.
 *   - FileSystemInterface::EXISTS_ERROR: Do nothing and return FALSE.
 *
 * @return array|\Drupal\file\FileInterface|null|false
 *   An array of file entities or a single file entity if $delta != NULL. Each
 *   array element contains the file entity if the upload succeeded or FALSE if
 *   there was an error. Function returns NULL if no file was uploaded.
 *
 * @see _file_save_upload_from_form()
 *
 * @todo: move this logic to a service in https://www.drupal.org/node/2244513.
 */
function file_save_upload($form_field_name, $validators = [], $destination = FALSE, $delta = NULL, $replace = FileSystemInterface::EXISTS_RENAME) {
    static $upload_cache;
    $all_files = \Drupal::request()->files
        ->get('files', []);
    // Make sure there's an upload to process.
    if (empty($all_files[$form_field_name])) {
        return NULL;
    }
    $file_upload = $all_files[$form_field_name];
    // Return cached objects without processing since the file will have
    // already been processed and the paths in $_FILES will be invalid.
    if (isset($upload_cache[$form_field_name])) {
        if (isset($delta)) {
            return $upload_cache[$form_field_name][$delta];
        }
        return $upload_cache[$form_field_name];
    }
    // Prepare uploaded files info. Representation is slightly different
    // for multiple uploads and we fix that here.
    $uploaded_files = $file_upload;
    if (!is_array($file_upload)) {
        $uploaded_files = [
            $file_upload,
        ];
    }
    $files = [];
    foreach ($uploaded_files as $i => $file_info) {
        $files[$i] = _file_save_upload_single($file_info, $form_field_name, $validators, $destination, $replace);
    }
    // Add files to the cache.
    $upload_cache[$form_field_name] = $files;
    return isset($delta) ? $files[$delta] : $files;
}

/**
 * Saves a file upload to a new location.
 *
 * @param \SplFileInfo $file_info
 *   The file upload to save.
 * @param string $form_field_name
 *   A string that is the associative array key of the upload form element in
 *   the form array.
 * @param array $validators
 *   (optional) An associative array of callback functions used to validate the
 *   file.
 * @param bool $destination
 *   (optional) A string containing the URI that the file should be copied to.
 * @param int $replace
 *   (optional) The replace behavior when the destination file already exists.
 *
 * @return \Drupal\file\FileInterface|false
 *   The created file entity or FALSE if the uploaded file not saved.
 *
 * @throws \Drupal\Core\Entity\EntityStorageException
 *
 * @internal
 *   This method should only be called from file_save_upload(). Use that method
 *   instead.
 *
 * @see file_save_upload()
 */
function _file_save_upload_single(\SplFileInfo $file_info, $form_field_name, $validators = [], $destination = FALSE, $replace = FileSystemInterface::EXISTS_REPLACE) {
    $user = \Drupal::currentUser();
    $original_file_name = trim($file_info->getClientOriginalName(), '.');
    // Check for file upload errors and return FALSE for this file if a lower
    // level system error occurred. For a complete list of errors:
    // See http://php.net/manual/features.file-upload.errors.php.
    switch ($file_info->getError()) {
        case UPLOAD_ERR_INI_SIZE:
        case UPLOAD_ERR_FORM_SIZE:
            \Drupal::messenger()->addError(t('The file %file could not be saved because it exceeds %maxsize, the maximum allowed size for uploads.', [
                '%file' => $original_file_name,
                '%maxsize' => format_size(Environment::getUploadMaxSize()),
            ]));
            return FALSE;
        case UPLOAD_ERR_PARTIAL:
        case UPLOAD_ERR_NO_FILE:
            \Drupal::messenger()->addError(t('The file %file could not be saved because the upload did not complete.', [
                '%file' => $original_file_name,
            ]));
            return FALSE;
        case UPLOAD_ERR_OK:
            // Final check that this is a valid upload, if it isn't, use the
            // default error handler.
            if (is_uploaded_file($file_info->getRealPath())) {
                break;
            }
        default:
            // Unknown error
            \Drupal::messenger()->addError(t('The file %file could not be saved. An unknown error has occurred.', [
                '%file' => $original_file_name,
            ]));
            return FALSE;
    }
    // Begin building file entity.
    $values = [
        'uid' => $user->id(),
        'status' => 0,
        'filename' => $original_file_name,
        'uri' => $file_info->getRealPath(),
        'filesize' => $file_info->getSize(),
    ];
    $values['filemime'] = \Drupal::service('file.mime_type.guesser')->guess($values['filename']);
    $file = File::create($values);
    $extensions = '';
    if (isset($validators['file_validate_extensions'])) {
        if (isset($validators['file_validate_extensions'][0])) {
            // Build the list of non-munged extensions if the caller provided them.
            $extensions = $validators['file_validate_extensions'][0];
        }
        else {
            // If 'file_validate_extensions' is set and the list is empty then the
            // caller wants to allow any extension. In this case we have to remove the
            // validator or else it will reject all extensions.
            unset($validators['file_validate_extensions']);
        }
    }
    else {
        // No validator was provided, so add one using the default list.
        // Build a default non-munged safe list for file_munge_filename().
        $extensions = 'jpg jpeg gif png txt doc xls pdf ppt pps odt ods odp';
        $validators['file_validate_extensions'] = [];
        $validators['file_validate_extensions'][0] = $extensions;
    }
    //  Don't rename if 'allow_insecure_uploads' evaluates to TRUE.
    if (!\Drupal::config('system.file')->get('allow_insecure_uploads')) {
        if (!empty($extensions)) {
            // Munge the filename to protect against possible malicious extension
            // hiding within an unknown file type (ie: filename.html.foo).
            $file->setFilename(file_munge_filename($file->getFilename(), $extensions));
        }
        // Rename potentially executable files, to help prevent exploits (i.e. will
        // rename filename.php.foo and filename.php to filename.php_.foo_.txt and
        // filename.php_.txt, respectively).
        if (preg_match(FILE_INSECURE_EXTENSION_REGEX, $file->getFilename())) {
            // If the file will be rejected anyway due to a disallowed extension, it
            // should not be renamed; rather, we'll let file_validate_extensions()
            // reject it below.
            if (!isset($validators['file_validate_extensions']) || empty(file_validate_extensions($file, $extensions))) {
                $file->setMimeType('text/plain');
                $filename = $file->getFilename();
                if (substr($filename, -4) != '.txt') {
                    // The destination filename will also later be used to create the URI.
                    $filename .= '.txt';
                }
                $file->setFilename(file_munge_filename($filename, $extensions));
                \Drupal::messenger()->addStatus(t('For security reasons, your upload has been renamed to %filename.', [
                    '%filename' => $file->getFilename(),
                ]));
                // The .txt extension may not be in the allowed list of extensions. We
                // have to add it here or else the file upload will fail.
                if (!empty($validators['file_validate_extensions'][0])) {
                    $validators['file_validate_extensions'][0] .= ' txt';
                }
            }
        }
    }
    // If the destination is not provided, use the temporary directory.
    if (empty($destination)) {
        $destination = 'temporary://';
    }
    
    /** @var \Drupal\Core\StreamWrapper\StreamWrapperManagerInterface $stream_wrapper_manager */
    $stream_wrapper_manager = \Drupal::service('stream_wrapper_manager');
    // Assert that the destination contains a valid stream.
    $destination_scheme = $stream_wrapper_manager::getScheme($destination);
    if (!$stream_wrapper_manager->isValidScheme($destination_scheme)) {
        \Drupal::messenger()->addError(t('The file could not be uploaded because the destination %destination is invalid.', [
            '%destination' => $destination,
        ]));
        return FALSE;
    }
    $file->source = $form_field_name;
    // A file URI may already have a trailing slash or look like "public://".
    if (substr($destination, -1) != '/') {
        $destination .= '/';
    }
    
    /** @var \Drupal\Core\File\FileSystemInterface $file_system */
    $file_system = \Drupal::service('file_system');
    try {
        $file->destination = $file_system->getDestinationFilename($destination . $file->getFilename(), $replace);
    } catch (FileException $e) {
        \Drupal::messenger()->addError(t('The file %filename could not be uploaded because the name is invalid.', [
            '%filename' => $file->getFilename(),
        ]));
        return FALSE;
    }
    // If the destination is FALSE then there is an existing file and $replace is
    // set to return an error, so we need to exit.
    if ($file->destination === FALSE) {
        \Drupal::messenger()->addError(t('The file %source could not be uploaded because a file by that name already exists in the destination %directory.', [
            '%source' => $form_field_name,
            '%directory' => $destination,
        ]));
        return FALSE;
    }
    // Add in our check of the file name length.
    $validators['file_validate_name_length'] = [];
    // Call the validation functions specified by this function's caller.
    $errors = file_validate($file, $validators);
    // Check for errors.
    if (!empty($errors)) {
        $message = [
            'error' => [
                '#markup' => t('The specified file %name could not be uploaded.', [
                    '%name' => $file->getFilename(),
                ]),
            ],
            'item_list' => [
                '#theme' => 'item_list',
                '#items' => $errors,
            ],
        ];
        // @todo Add support for render arrays in
        // \Drupal\Core\Messenger\MessengerInterface::addMessage()?
        // @see https://www.drupal.org/node/2505497.
        \Drupal::messenger()->addError(\Drupal::service('renderer')->renderPlain($message));
        return FALSE;
    }
    $file->setFileUri($file->destination);
    if (!$file_system->moveUploadedFile($file_info->getRealPath(), $file->getFileUri())) {
        \Drupal::messenger()->addError(t('File upload error. Could not move uploaded file.'));
        \Drupal::logger('file')->notice('Upload error. Could not move uploaded file %file to destination %destination.', [
            '%file' => $file->getFilename(),
            '%destination' => $file->getFileUri(),
        ]);
        return FALSE;
    }
    // Set the permissions on the new file.
    $file_system->chmod($file->getFileUri());
    // If we are replacing an existing file re-use its database record.
    // @todo Do not create a new entity in order to update it. See
    //   https://www.drupal.org/node/2241865.
    if ($replace == FileSystemInterface::EXISTS_REPLACE) {
        $existing_files = \Drupal::entityTypeManager()->getStorage('file')
            ->loadByProperties([
            'uri' => $file->getFileUri(),
        ]);
        if (count($existing_files)) {
            $existing = reset($existing_files);
            $file->fid = $existing->id();
            $file->setOriginalId($existing->id());
        }
    }
    // Update the filename with any changes as a result of security or renaming
    // due to an existing file.
    $file->setFilename(\Drupal::service('file_system')->basename($file->destination));
    // We can now validate the file object itself before it's saved.
    $violations = $file->validate();
    foreach ($violations as $violation) {
        $errors[] = $violation->getMessage();
    }
    if (!empty($errors)) {
        $message = [
            'error' => [
                '#markup' => t('The specified file %name could not be uploaded.', [
                    '%name' => $file->getFilename(),
                ]),
            ],
            'item_list' => [
                '#theme' => 'item_list',
                '#items' => $errors,
            ],
        ];
        // @todo Add support for render arrays in
        // \Drupal\Core\Messenger\MessengerInterface::addMessage()?
        // @see https://www.drupal.org/node/2505497.
        \Drupal::messenger()->addError(\Drupal::service('renderer')->renderPlain($message));
        return FALSE;
    }
    // If we made it this far it's safe to record this file in the database.
    $file->save();
    // Allow an anonymous user who creates a non-public file to see it. See
    // \Drupal\file\FileAccessControlHandler::checkAccess().
    if ($user->isAnonymous() && $destination_scheme !== 'public') {
        $session = \Drupal::request()->getSession();
        $allowed_temp_files = $session->get('anonymous_allowed_file_ids', []);
        $allowed_temp_files[$file->id()] = $file->id();
        $session->set('anonymous_allowed_file_ids', $allowed_temp_files);
    }
    return $file;
}

/**
 * Determines the preferred upload progress implementation.
 *
 * @return string|false
 *   A string indicating which upload progress system is available. Either "apc"
 *   or "uploadprogress". If neither are available, returns FALSE.
 */
function file_progress_implementation() {
    static $implementation;
    if (!isset($implementation)) {
        $implementation = FALSE;
        // We prefer the PECL extension uploadprogress because it supports multiple
        // simultaneous uploads. APCu only supports one at a time.
        if (extension_loaded('uploadprogress')) {
            $implementation = 'uploadprogress';
        }
    }
    return $implementation;
}

/**
 * Implements hook_ENTITY_TYPE_predelete() for file entities.
 */
function file_file_predelete(File $file) {
    // @todo Remove references to a file that is in-use.
}

/**
 * Implements hook_tokens().
 */
function file_tokens($type, $tokens, array $data, array $options, BubbleableMetadata $bubbleable_metadata) {
    $token_service = \Drupal::token();
    $url_options = [
        'absolute' => TRUE,
    ];
    if (isset($options['langcode'])) {
        $url_options['language'] = \Drupal::languageManager()->getLanguage($options['langcode']);
        $langcode = $options['langcode'];
    }
    else {
        $langcode = NULL;
    }
    $replacements = [];
    if ($type == 'file' && !empty($data['file'])) {
        
        /** @var \Drupal\file\FileInterface $file */
        $file = $data['file'];
        foreach ($tokens as $name => $original) {
            switch ($name) {
                // Basic keys and values.
                case 'fid':
                    $replacements[$original] = $file->id();
                    break;
                // Essential file data
                case 'name':
                    $replacements[$original] = $file->getFilename();
                    break;
                case 'path':
                    $replacements[$original] = $file->getFileUri();
                    break;
                case 'mime':
                    $replacements[$original] = $file->getMimeType();
                    break;
                case 'size':
                    $replacements[$original] = format_size($file->getSize());
                    break;
                case 'url':
                    // Ideally, this would use file_url_transform_relative(), but because
                    // tokens are also often used in e-mails, it's better to keep absolute
                    // file URLs. The 'url.site' cache context is associated to ensure the
                    // correct absolute URL is used in case of a multisite setup.
                    $replacements[$original] = $file->createFileUrl(FALSE);
                    $bubbleable_metadata->addCacheContexts([
                        'url.site',
                    ]);
                    break;
                // These tokens are default variations on the chained tokens handled below.
                case 'created':
                    $date_format = DateFormat::load('medium');
                    $bubbleable_metadata->addCacheableDependency($date_format);
                    $replacements[$original] = \Drupal::service('date.formatter')->format($file->getCreatedTime(), 'medium', '', NULL, $langcode);
                    break;
                case 'changed':
                    $date_format = DateFormat::load('medium');
                    $bubbleable_metadata = $bubbleable_metadata->addCacheableDependency($date_format);
                    $replacements[$original] = \Drupal::service('date.formatter')->format($file->getChangedTime(), 'medium', '', NULL, $langcode);
                    break;
                case 'owner':
                    $owner = $file->getOwner();
                    $bubbleable_metadata->addCacheableDependency($owner);
                    $name = $owner->label();
                    $replacements[$original] = $name;
                    break;
            }
        }
        if ($date_tokens = $token_service->findWithPrefix($tokens, 'created')) {
            $replacements += $token_service->generate('date', $date_tokens, [
                'date' => $file->getCreatedTime(),
            ], $options, $bubbleable_metadata);
        }
        if ($date_tokens = $token_service->findWithPrefix($tokens, 'changed')) {
            $replacements += $token_service->generate('date', $date_tokens, [
                'date' => $file->getChangedTime(),
            ], $options, $bubbleable_metadata);
        }
        if (($owner_tokens = $token_service->findWithPrefix($tokens, 'owner')) && $file->getOwner()) {
            $replacements += $token_service->generate('user', $owner_tokens, [
                'user' => $file->getOwner(),
            ], $options, $bubbleable_metadata);
        }
    }
    return $replacements;
}

/**
 * Implements hook_token_info().
 */
function file_token_info() {
    $types['file'] = [
        'name' => t("Files"),
        'description' => t("Tokens related to uploaded files."),
        'needs-data' => 'file',
    ];
    // File related tokens.
    $file['fid'] = [
        'name' => t("File ID"),
        'description' => t("The unique ID of the uploaded file."),
    ];
    $file['name'] = [
        'name' => t("File name"),
        'description' => t("The name of the file on disk."),
    ];
    $file['path'] = [
        'name' => t("Path"),
        'description' => t("The location of the file relative to Drupal root."),
    ];
    $file['mime'] = [
        'name' => t("MIME type"),
        'description' => t("The MIME type of the file."),
    ];
    $file['size'] = [
        'name' => t("File size"),
        'description' => t("The size of the file."),
    ];
    $file['url'] = [
        'name' => t("URL"),
        'description' => t("The web-accessible URL for the file."),
    ];
    $file['created'] = [
        'name' => t("Created"),
        'description' => t("The date the file created."),
        'type' => 'date',
    ];
    $file['changed'] = [
        'name' => t("Changed"),
        'description' => t("The date the file was most recently changed."),
        'type' => 'date',
    ];
    $file['owner'] = [
        'name' => t("Owner"),
        'description' => t("The user who originally uploaded the file."),
        'type' => 'user',
    ];
    return [
        'types' => $types,
        'tokens' => [
            'file' => $file,
        ],
    ];
}

/**
 * Form submission handler for upload / remove buttons of managed_file elements.
 *
 * @see \Drupal\file\Element\ManagedFile::processManagedFile()
 */
function file_managed_file_submit($form, FormStateInterface $form_state) {
    // Determine whether it was the upload or the remove button that was clicked,
    // and set $element to the managed_file element that contains that button.
    $parents = $form_state->getTriggeringElement()['#array_parents'];
    $button_key = array_pop($parents);
    $element = NestedArray::getValue($form, $parents);
    // No action is needed here for the upload button, because all file uploads on
    // the form are processed by \Drupal\file\Element\ManagedFile::valueCallback()
    // regardless of which button was clicked. Action is needed here for the
    // remove button, because we only remove a file in response to its remove
    // button being clicked.
    if ($button_key == 'remove_button') {
        $fids = array_keys($element['#files']);
        // Get files that will be removed.
        if ($element['#multiple']) {
            $remove_fids = [];
            foreach (Element::children($element) as $name) {
                if (strpos($name, 'file_') === 0 && $element[$name]['selected']['#value']) {
                    $remove_fids[] = (int) substr($name, 5);
                }
            }
            $fids = array_diff($fids, $remove_fids);
        }
        else {
            // If we deal with single upload element remove the file and set
            // element's value to empty array (file could not be removed from
            // element if we don't do that).
            $remove_fids = $fids;
            $fids = [];
        }
        foreach ($remove_fids as $fid) {
            // If it's a temporary file we can safely remove it immediately, otherwise
            // it's up to the implementing module to remove usages of files to have them
            // removed.
            if ($element['#files'][$fid] && $element['#files'][$fid]->isTemporary()) {
                $element['#files'][$fid]->delete();
            }
        }
        // Update both $form_state->getValues() and FormState::$input to reflect
        // that the file has been removed, so that the form is rebuilt correctly.
        // $form_state->getValues() must be updated in case additional submit
        // handlers run, and for form building functions that run during the
        // rebuild, such as when the managed_file element is part of a field widget.
        // FormState::$input must be updated so that
        // \Drupal\file\Element\ManagedFile::valueCallback() has correct information
        // during the rebuild.
        $form_state->setValueForElement($element['fids'], implode(' ', $fids));
        NestedArray::setValue($form_state->getUserInput(), $element['fids']['#parents'], implode(' ', $fids));
    }
    // Set the form to rebuild so that $form is correctly updated in response to
    // processing the file removal. Since this function did not change $form_state
    // if the upload button was clicked, a rebuild isn't necessary in that
    // situation and calling $form_state->disableRedirect() would suffice.
    // However, we choose to always rebuild, to keep the form processing workflow
    // consistent between the two buttons.
    $form_state->setRebuild();
}

/**
 * Saves any files that have been uploaded into a managed_file element.
 *
 * @param array $element
 *   The FAPI element whose values are being saved.
 * @param \Drupal\Core\Form\FormStateInterface $form_state
 *   The current state of the form.
 *
 * @return array|false
 *   An array of file entities for each file that was saved, keyed by its file
 *   ID. Each array element contains a file entity. Function returns FALSE if
 *   upload directory could not be created or no files were uploaded.
 */
function file_managed_file_save_upload($element, FormStateInterface $form_state) {
    $upload_name = implode('_', $element['#parents']);
    $all_files = \Drupal::request()->files
        ->get('files', []);
    if (empty($all_files[$upload_name])) {
        return FALSE;
    }
    $file_upload = $all_files[$upload_name];
    $destination = isset($element['#upload_location']) ? $element['#upload_location'] : NULL;
    if (isset($destination) && !\Drupal::service('file_system')->prepareDirectory($destination, FileSystemInterface::CREATE_DIRECTORY)) {
        \Drupal::logger('file')->notice('The upload directory %directory for the file field %name could not be created or is not accessible. A newly uploaded file could not be saved in this directory as a consequence, and the upload was canceled.', [
            '%directory' => $destination,
            '%name' => $element['#field_name'],
        ]);
        $form_state->setError($element, t('The file could not be uploaded.'));
        return FALSE;
    }
    // Save attached files to the database.
    $files_uploaded = $element['#multiple'] && count(array_filter($file_upload)) > 0;
    $files_uploaded |= !$element['#multiple'] && !empty($file_upload);
    if ($files_uploaded) {
        if (!($files = _file_save_upload_from_form($element, $form_state))) {
            \Drupal::logger('file')->notice('The file upload failed. %upload', [
                '%upload' => $upload_name,
            ]);
            return [];
        }
        // Value callback expects FIDs to be keys.
        $files = array_filter($files);
        $fids = array_map(function ($file) {
            return $file->id();
        }, $files);
        return empty($files) ? [] : array_combine($fids, $files);
    }
    return [];
}

/**
 * Prepares variables for file form widget templates.
 *
 * Default template: file-managed-file.html.twig.
 *
 * @param array $variables
 *   An associative array containing:
 *   - element: A render element representing the file.
 */
function template_preprocess_file_managed_file(&$variables) {
    $element = $variables['element'];
    $variables['attributes'] = [];
    if (isset($element['#id'])) {
        $variables['attributes']['id'] = $element['#id'];
    }
    if (!empty($element['#attributes']['class'])) {
        $variables['attributes']['class'] = (array) $element['#attributes']['class'];
    }
}

/**
 * Prepares variables for file link templates.
 *
 * Default template: file-link.html.twig.
 *
 * @param array $variables
 *   An associative array containing:
 *   - file: A File entity to which the link will be created.
 *   - icon_directory: (optional) A path to a directory of icons to be used for
 *     files. Defaults to the value of the "icon.directory" variable.
 *   - description: A description to be displayed instead of the filename.
 *   - attributes: An associative array of attributes to be placed in the a tag.
 */
function template_preprocess_file_link(&$variables) {
    $file = $variables['file'];
    $options = [];
    // @todo Wrap in file_url_transform_relative(). This is currently
    // impossible. As a work-around, we currently add the 'url.site' cache context
    // to ensure different file URLs are generated for different sites in a
    // multisite setup, including HTTP and HTTPS versions of the same site.
    // Fix in https://www.drupal.org/node/2646744.
    $url = $file->createFileUrl(FALSE);
    $variables['#cache']['contexts'][] = 'url.site';
    $mime_type = $file->getMimeType();
    // Set options as per anchor format described at
    // http://microformats.org/wiki/file-format-examples
    $options['attributes']['type'] = $mime_type . '; length=' . $file->getSize();
    // Use the description as the link text if available.
    if (empty($variables['description'])) {
        $link_text = $file->getFilename();
    }
    else {
        $link_text = $variables['description'];
        $options['attributes']['title'] = $file->getFilename();
    }
    // Classes to add to the file field for icons.
    $classes = [
        'file',
        // Add a specific class for each and every mime type.
'file--mime-' . strtr($mime_type, [
            '/' => '-',
            '.' => '-',
        ]),
        // Add a more general class for groups of well known MIME types.
'file--' . file_icon_class($mime_type),
    ];
    // Set file classes to the options array.
    $variables['attributes'] = new Attribute($variables['attributes']);
    $variables['attributes']->addClass($classes);
    $variables['file_size'] = format_size($file->getSize());
    $variables['link'] = Link::fromTextAndUrl($link_text, Url::fromUri($url, $options))->toRenderable();
}

/**
 * Gets a class for the icon for a MIME type.
 *
 * @param string $mime_type
 *   A MIME type.
 *
 * @return string
 *   A class associated with the file.
 */
function file_icon_class($mime_type) {
    // Search for a group with the files MIME type.
    $generic_mime = (string) file_icon_map($mime_type);
    if (!empty($generic_mime)) {
        return $generic_mime;
    }
    // Use generic icons for each category that provides such icons.
    foreach ([
        'audio',
        'image',
        'text',
        'video',
    ] as $category) {
        if (strpos($mime_type, $category) === 0) {
            return $category;
        }
    }
    // If there's no generic icon for the type the general class.
    return 'general';
}

/**
 * Determines the generic icon MIME package based on a file's MIME type.
 *
 * @param string $mime_type
 *   A MIME type.
 *
 * @return string|false
 *   The generic icon MIME package expected for this file.
 */
function file_icon_map($mime_type) {
    switch ($mime_type) {
        // Word document types.
        case 'application/msword':
        case 'application/vnd.ms-word.document.macroEnabled.12':
        case 'application/vnd.oasis.opendocument.text':
        case 'application/vnd.oasis.opendocument.text-template':
        case 'application/vnd.oasis.opendocument.text-master':
        case 'application/vnd.oasis.opendocument.text-web':
        case 'application/vnd.openxmlformats-officedocument.wordprocessingml.document':
        case 'application/vnd.stardivision.writer':
        case 'application/vnd.sun.xml.writer':
        case 'application/vnd.sun.xml.writer.template':
        case 'application/vnd.sun.xml.writer.global':
        case 'application/vnd.wordperfect':
        case 'application/x-abiword':
        case 'application/x-applix-word':
        case 'application/x-kword':
        case 'application/x-kword-crypt':
            return 'x-office-document';
        // Spreadsheet document types.
        case 'application/vnd.ms-excel':
        case 'application/vnd.ms-excel.sheet.macroEnabled.12':
        case 'application/vnd.oasis.opendocument.spreadsheet':
        case 'application/vnd.oasis.opendocument.spreadsheet-template':
        case 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet':
        case 'application/vnd.stardivision.calc':
        case 'application/vnd.sun.xml.calc':
        case 'application/vnd.sun.xml.calc.template':
        case 'application/vnd.lotus-1-2-3':
        case 'application/x-applix-spreadsheet':
        case 'application/x-gnumeric':
        case 'application/x-kspread':
        case 'application/x-kspread-crypt':
            return 'x-office-spreadsheet';
        // Presentation document types.
        case 'application/vnd.ms-powerpoint':
        case 'application/vnd.ms-powerpoint.presentation.macroEnabled.12':
        case 'application/vnd.oasis.opendocument.presentation':
        case 'application/vnd.oasis.opendocument.presentation-template':
        case 'application/vnd.openxmlformats-officedocument.presentationml.presentation':
        case 'application/vnd.stardivision.impress':
        case 'application/vnd.sun.xml.impress':
        case 'application/vnd.sun.xml.impress.template':
        case 'application/x-kpresenter':
            return 'x-office-presentation';
        // Compressed archive types.
        case 'application/zip':
        case 'application/x-zip':
        case 'application/stuffit':
        case 'application/x-stuffit':
        case 'application/x-7z-compressed':
        case 'application/x-ace':
        case 'application/x-arj':
        case 'application/x-bzip':
        case 'application/x-bzip-compressed-tar':
        case 'application/x-compress':
        case 'application/x-compressed-tar':
        case 'application/x-cpio-compressed':
        case 'application/x-deb':
        case 'application/x-gzip':
        case 'application/x-java-archive':
        case 'application/x-lha':
        case 'application/x-lhz':
        case 'application/x-lzop':
        case 'application/x-rar':
        case 'application/x-rpm':
        case 'application/x-tzo':
        case 'application/x-tar':
        case 'application/x-tarz':
        case 'application/x-tgz':
            return 'package-x-generic';
        // Script file types.
        case 'application/ecmascript':
        case 'application/javascript':
        case 'application/mathematica':
        case 'application/vnd.mozilla.xul+xml':
        case 'application/x-asp':
        case 'application/x-awk':
        case 'application/x-cgi':
        case 'application/x-csh':
        case 'application/x-m4':
        case 'application/x-perl':
        case 'application/x-php':
        case 'application/x-ruby':
        case 'application/x-shellscript':
        case 'text/vnd.wap.wmlscript':
        case 'text/x-emacs-lisp':
        case 'text/x-haskell':
        case 'text/x-literate-haskell':
        case 'text/x-lua':
        case 'text/x-makefile':
        case 'text/x-matlab':
        case 'text/x-python':
        case 'text/x-sql':
        case 'text/x-tcl':
            return 'text-x-script';
        // HTML aliases.
        case 'application/xhtml+xml':
            return 'text-html';
        // Executable types.
        case 'application/x-macbinary':
        case 'application/x-ms-dos-executable':
        case 'application/x-pef-executable':
            return 'application-x-executable';
        // Acrobat types
        case 'application/pdf':
        case 'application/x-pdf':
        case 'applications/vnd.pdf':
        case 'text/pdf':
        case 'text/x-pdf':
            return 'application-pdf';
        default:
            return FALSE;
    }
}

/**
 * Retrieves a list of references to a file.
 *
 * @param \Drupal\file\FileInterface $file
 *   A file entity.
 * @param \Drupal\Core\Field\FieldDefinitionInterface|null $field
 *   (optional) A field definition to be used for this check. If given,
 *   limits the reference check to the given field. Defaults to NULL.
 * @param int $age
 *   (optional) A constant that specifies which references to count. Use
 *   EntityStorageInterface::FIELD_LOAD_REVISION (the default) to retrieve all
 *   references within all revisions or
 *   EntityStorageInterface::FIELD_LOAD_CURRENT to retrieve references only in
 *   the current revisions of all entities that have references to this file.
 * @param string $field_type
 *   (optional) The name of a field type. If given, limits the reference check
 *   to fields of the given type. If both $field and $field_type are given but
 *   $field is not the same type as $field_type, an empty array will be
 *   returned. Defaults to 'file'.
 *
 * @return array
 *   A multidimensional array. The keys are field_name, entity_type,
 *   entity_id and the value is an entity referencing this file.
 *
 * @ingroup file
 */
function file_get_file_references(FileInterface $file, FieldDefinitionInterface $field = NULL, $age = EntityStorageInterface::FIELD_LOAD_REVISION, $field_type = 'file') {
    $references =& drupal_static(__FUNCTION__, []);
    $field_columns =& drupal_static(__FUNCTION__ . ':field_columns', []);
    // Fill the static cache, disregard $field and $field_type for now.
    if (!isset($references[$file->id()][$age])) {
        $references[$file->id()][$age] = [];
        $usage_list = \Drupal::service('file.usage')->listUsage($file);
        $file_usage_list = isset($usage_list['file']) ? $usage_list['file'] : [];
        foreach ($file_usage_list as $entity_type_id => $entity_ids) {
            $entities = \Drupal::entityTypeManager()->getStorage($entity_type_id)
                ->loadMultiple(array_keys($entity_ids));
            foreach ($entities as $entity) {
                $bundle = $entity->bundle();
                // We need to find file fields for this entity type and bundle.
                if (!isset($file_fields[$entity_type_id][$bundle])) {
                    $file_fields[$entity_type_id][$bundle] = [];
                    // This contains the possible field names.
                    foreach ($entity->getFieldDefinitions() as $field_name => $field_definition) {
                        // If this is the first time this field type is seen, check
                        // whether it references files.
                        if (!isset($field_columns[$field_definition->getType()])) {
                            $field_columns[$field_definition->getType()] = file_field_find_file_reference_column($field_definition);
                        }
                        // If the field type does reference files then record it.
                        if ($field_columns[$field_definition->getType()]) {
                            $file_fields[$entity_type_id][$bundle][$field_name] = $field_columns[$field_definition->getType()];
                        }
                    }
                }
                foreach ($file_fields[$entity_type_id][$bundle] as $field_name => $field_column) {
                    // Iterate over the field items to find the referenced file and field
                    // name. This will fail if the usage checked is in a non-current
                    // revision because field items are from the current
                    // revision.
                    // We also iterate over all translations because a file can be linked
                    // to a language other than the default.
                    foreach ($entity->getTranslationLanguages() as $langcode => $language) {
                        foreach ($entity->getTranslation($langcode)
                            ->get($field_name) as $item) {
                            if ($file->id() == $item->{$field_column}) {
                                $references[$file->id()][$age][$field_name][$entity_type_id][$entity->id()] = $entity;
                                break;
                            }
                        }
                    }
                }
            }
        }
    }
    $return = $references[$file->id()][$age];
    // Filter the static cache down to the requested entries. The usual static
    // cache is very small so this will be very fast.
    $entity_field_manager = \Drupal::service('entity_field.manager');
    if ($field || $field_type) {
        foreach ($return as $field_name => $data) {
            foreach (array_keys($data) as $entity_type_id) {
                $field_storage_definitions = $entity_field_manager->getFieldStorageDefinitions($entity_type_id);
                $current_field = $field_storage_definitions[$field_name];
                if ($field_type && $current_field->getType() != $field_type || $field && $field->uuid() != $current_field->uuid()) {
                    unset($return[$field_name][$entity_type_id]);
                }
            }
        }
    }
    return $return;
}

/**
 * Formats human-readable version of file status.
 *
 * @param int|null $choice
 *   (optional) An integer status code. If not set, all statuses are returned.
 *   Defaults to NULL.
 *
 * @return \Drupal\Core\StringTranslation\TranslatableMarkup|\Drupal\Core\StringTranslation\TranslatableMarkup[]
 *   An array of file statuses or a specified status if $choice is set.
 */
function _views_file_status($choice = NULL) {
    $status = [
        0 => t('Temporary'),
        FILE_STATUS_PERMANENT => t('Permanent'),
    ];
    if (isset($choice)) {
        return isset($status[$choice]) ? $status[$choice] : t('Unknown');
    }
    return $status;
}

Functions

Title Deprecated Summary
file_copy Copies a file to a new location and adds a file record to the database.
file_cron Implements hook_cron().
file_field_widget_info_alter Implements hook_field_widget_info_alter().
file_file_download Implements hook_file_download().
file_file_predelete Implements hook_ENTITY_TYPE_predelete() for file entities.
file_get_content_headers Examines a file entity and returns appropriate content headers for download.
file_get_file_references Retrieves a list of references to a file.
file_help Implements hook_help().
file_icon_class Gets a class for the icon for a MIME type.
file_icon_map Determines the generic icon MIME package based on a file's MIME type.
file_load

in drupal:8.0.0 and is removed from drupal:9.0.0. Use \Drupal\file\Entity\File::load().

Loads a single file entity from the database.
file_load_multiple

in drupal:8.0.0 and is removed from drupal:9.0.0. Use \Drupal\file\Entity\File::loadMultiple().

Loads file entities from the database.
file_managed_file_save_upload Saves any files that have been uploaded into a managed_file element.
file_managed_file_submit Form submission handler for upload / remove buttons of managed_file elements.
file_move Moves a file to a new location and update the file's database entry.
file_progress_implementation Determines the preferred upload progress implementation.
file_save_data Saves a file to the specified destination and creates a database entry.
file_save_upload Saves file uploads to a new location.
file_theme Implements hook_theme().
file_tokens Implements hook_tokens().
file_token_info Implements hook_token_info().
file_validate Checks that a file meets the criteria specified by the validators.
file_validate_extensions Checks that the filename ends with an allowed extension.
file_validate_image_resolution Verifies that image dimensions are within the specified maximum and minimum.
file_validate_is_image Checks that the file is recognized as a valid image.
file_validate_name_length Checks for files with names longer than can be stored in the database.
file_validate_size Checks that the file's size is below certain limits.
template_preprocess_file_link Prepares variables for file link templates.
template_preprocess_file_managed_file Prepares variables for file form widget templates.
_file_save_upload_from_form Saves form file uploads.
_file_save_upload_single Saves a file upload to a new location.
_views_file_status Formats human-readable version of file status.

Constants

Title Deprecated Summary
FILE_INSECURE_EXTENSION_REGEX The regex pattern used when checking for insecure file types.

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