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<?php
/**
* @file
* Examples demonstrating the Drupal File API (and Stream Wrappers).
*/
/**
* @defgroup file_example Example: Files
* @ingroup examples
* @{
* Examples demonstrating the Drupal File API (and Stream Wrappers).
*
* The File Example module is a part of the Examples for Developers Project
* and provides various Drupal File API Examples. You can download and
* experiment with this code at the
* @link http://drupal.org/project/examples Examples for Developers project page. @endlink
*
* See @link http://drupal.org/node/555118 Drupal File API @endlink for handbook
* documentation on the File API and
* @link file File summary on api.drupal.org @endlink for the function summary.
*/
/**
* Implements hook_menu().
*
* Set up the URLs (menu entries) for the file examples.
*/
function file_example_menu() {
$items = array();
$items['examples/file_example'] = array(
'title' => 'File Example',
'page callback' => 'file_example_intro',
'access callback' => TRUE,
'expanded' => TRUE,
);
$items['examples/file_example/fileapi'] = array(
'title' => 'Use File API to read/write a file',
'page callback' => 'drupal_get_form',
'access arguments' => array('use file example'),
'page arguments' => array('file_example_readwrite'),
);
$items['examples/file_example/access_session'] = array(
'page callback' => 'file_example_session_contents',
'access arguments' => array('use file example'),
'type' => MENU_CALLBACK,
);
return $items;
}
/**
* Implements hook_permission().
*/
function file_example_permission() {
return array(
'use file example' => array(
'title' => t('Use the examples in the File Example module'),
),
);
}
/**
* A simple introduction to the workings of this module.
*/
function file_example_intro() {
$markup = t('The file example module provides a form and code to demonstrate the Drupal 7 file api. Experiment with the form, and then look at the submit handlers in the code to understand the file api.');
return array('#markup' => $markup);
}
/**
* Form builder function.
*
* A simple form that allows creation of a file, managed or unmanaged. It
* also allows reading/deleting a file and creation of a directory.
*/
function file_example_readwrite($form, &$form_state) {
if (empty($_SESSION['file_example_default_file'])) {
$_SESSION['file_example_default_file'] = 'session://drupal.txt';
}
$default_file = $_SESSION['file_example_default_file'];
if (empty($_SESSION['file_example_default_directory'])) {
$_SESSION['file_example_default_directory'] = 'session://directory1';
}
$default_directory = $_SESSION['file_example_default_directory'];
$form['write_file'] = array(
'#type' => 'fieldset',
'#title' => t('Write to a file'),
);
$form['write_file']['write_contents'] = array(
'#type' => 'textfield',
'#title' => t('Enter something you would like to write to a file') . ' ' . date('m'),
'#default_value' => t('Put some text here or just use this text'),
);
$form['write_file']['destination'] = array(
'#type' => 'textfield',
'#default_value' => $default_file,
'#title' => t('Optional: Enter the streamwrapper saying where it should be written'),
'#description' => t('This may be public://some_dir/test_file.txt or private://another_dir/some_file.txt, for example. If you include a directory, it must already exist. The default is "public://". Since this example supports session://, you can also use something like session://somefile.txt.'),
);
$form['write_file']['managed_submit'] = array(
'#type' => 'submit',
'#value' => t('Write managed file'),
'#submit' => array('file_example_managed_write_submit'),
);
$form['write_file']['unmanaged_submit'] = array(
'#type' => 'submit',
'#value' => t('Write unmanaged file'),
'#submit' => array('file_example_unmanaged_write_submit'),
);
$form['write_file']['unmanaged_php'] = array(
'#type' => 'submit',
'#value' => t('Unmanaged using PHP'),
'#submit' => array('file_example_unmanaged_php_submit'),
);
$form['fileops'] = array(
'#type' => 'fieldset',
'#title' => t('Read from a file'),
);
$form['fileops']['fileops_file'] = array(
'#type' => 'textfield',
'#default_value' => $default_file,
'#title' => t('Enter the URI of a file'),
'#description' => t('This must be a stream-type description like public://some_file.txt or http://drupal.org or private://another_file.txt or (for this example) session://yet_another_file.txt.'),
);
$form['fileops']['read_submit'] = array(
'#type' => 'submit',
'#value' => t('Read the file and store it locally'),
'#submit' => array('file_example_read_submit'),
);
$form['fileops']['delete_submit'] = array(
'#type' => 'submit',
'#value' => t('Delete file'),
'#submit' => array('file_example_delete_submit'),
);
$form['fileops']['check_submit'] = array(
'#type' => 'submit',
'#value' => t('Check to see if file exists'),
'#submit' => array('file_example_file_check_exists_submit'),
);
$form['directory'] = array(
'#type' => 'fieldset',
'#title' => t('Create or prepare a directory'),
);
$form['directory']['directory_name'] = array(
'#type' => 'textfield',
'#title' => t('Directory to create/prepare/delete'),
'#default_value' => $default_directory,
'#description' => t('This is a directory as in public://some/directory or private://another/dir.'),
);
$form['directory']['create_directory'] = array(
'#type' => 'submit',
'#value' => t('Create directory'),
'#submit' => array('file_example_create_directory_submit'),
);
$form['directory']['delete_directory'] = array(
'#type' => 'submit',
'#value' => t('Delete directory'),
'#submit' => array('file_example_delete_directory_submit'),
);
$form['directory']['check_directory'] = array(
'#type' => 'submit',
'#value' => t('Check to see if directory exists'),
'#submit' => array('file_example_check_directory_submit'),
);
$form['debug'] = array(
'#type' => 'fieldset',
'#title' => t('Debugging'),
);
$form['debug']['show_raw_session'] = array(
'#type' => 'submit',
'#value' => t('Show raw $_SESSION contents'),
'#submit' => array('file_example_show_session_contents_submit'),
);
return $form;
}
/**
* Submit handler to write a managed file.
*
* The key functions used here are:
* - file_save_data(), which takes a buffer and saves it to a named file and
* also creates a tracking record in the database and returns a file object.
* In this function we use FILE_EXISTS_RENAME (the default) as the argument,
* which means that if there's an existing file, create a new non-colliding
* filename and use it.
* - file_create_url(), which converts a URI in the form public://junk.txt or
* private://something/test.txt into a URL like
* http://example.com/sites/default/files/junk.txt.
*/
function file_example_managed_write_submit($form, &$form_state) {
$data = $form_state['values']['write_contents'];
$uri = !empty($form_state['values']['destination']) ? $form_state['values']['destination'] : NULL;
// Managed operations work with a file object.
$file_object = file_save_data($data, $uri, FILE_EXISTS_RENAME);
if (!empty($file_object)) {
$url = file_create_url($file_object->uri);
$_SESSION['file_example_default_file'] = $file_object->uri;
drupal_set_message(
t('Saved managed file: %file to destination %destination (accessible via !url, actual uri=<span id="uri">@uri</span>)',
array(
'%file' => print_r($file_object, TRUE),
'%destination' => $uri, '@uri' => $file_object->uri,
'!url' => l(t('this URL'), $url),
)
)
);
}
else {
drupal_set_message(t('Failed to save the managed file'), 'error');
}
}
/**
* Submit handler to write an unmanaged file.
*
* The key functions used here are:
* - file_unmanaged_save_data(), which takes a buffer and saves it to a named
* file, but does not create any kind of tracking record in the database.
* This example uses FILE_EXISTS_REPLACE for the third argument, meaning
* that if there's an existing file at this location, it should be replaced.
* - file_create_url(), which converts a URI in the form public://junk.txt or
* private://something/test.txt into a URL like
* http://example.com/sites/default/files/junk.txt.
*/
function file_example_unmanaged_write_submit($form, &$form_state) {
$data = $form_state['values']['write_contents'];
$destination = !empty($form_state['values']['destination']) ? $form_state['values']['destination'] : NULL;
// With the unmanaged file we just get a filename back.
$filename = file_unmanaged_save_data($data, $destination, FILE_EXISTS_REPLACE);
if ($filename) {
$url = file_create_url($filename);
$_SESSION['file_example_default_file'] = $filename;
drupal_set_message(
t('Saved file as %filename (accessible via !url, uri=<span id="uri">@uri</span>)',
array(
'%filename' => $filename,
'@uri' => $filename,
'!url' => l(t('this URL'), $url),
)
)
);
}
else {
drupal_set_message(t('Failed to save the file'), 'error');
}
}
/**
* Submit handler to write an unmanaged file using plain PHP functions.
*
* The key functions used here are:
* - file_unmanaged_save_data(), which takes a buffer and saves it to a named
* file, but does not create any kind of tracking record in the database.
* - file_create_url(), which converts a URI in the form public://junk.txt or
* private://something/test.txt into a URL like
* http://example.com/sites/default/files/junk.txt.
* - drupal_tempnam() generates a temporary filename for use.
*/
function file_example_unmanaged_php_submit($form, &$form_state) {
$data = $form_state['values']['write_contents'];
$destination = !empty($form_state['values']['destination']) ? $form_state['values']['destination'] : NULL;
if (empty($destination)) {
// If no destination has been provided, use a generated name.
$destination = drupal_tempnam('public://', 'file');
}
// With all traditional PHP functions we can use the stream wrapper notation
// for a file as well.
$fp = fopen($destination, 'w');
// To demonstrate the fact that everything is based on streams, we'll do
// multiple 5-character writes to put this to the file. We could easily
// (and far more conveniently) write it in a single statement with
// fwrite($fp, $data).
$length = strlen($data);
$write_size = 5;
for ($i = 0; $i < $length; $i += $write_size) {
$result = fwrite($fp, substr($data, $i, $write_size));
if ($result === FALSE) {
drupal_set_message(t('Failed writing to the file %file', array('%file' => $destination)), 'error');
fclose($fp);
return;
}
}
$url = file_create_url($destination);
$_SESSION['file_example_default_file'] = $destination;
drupal_set_message(
t('Saved file as %filename (accessible via !url, uri=<span id="uri">@uri</span>)',
array(
'%filename' => $destination,
'@uri' => $destination,
'!url' => l(t('this URL'), $url),
)
)
);
}
/**
* Submit handler for reading a stream wrapper.
*
* Drupal now has full support for PHP's stream wrappers, which means that
* instead of the traditional use of all the file functions
* ($fp = fopen("/tmp/some_file.txt");) far more sophisticated and generalized
* (and extensible) things can be opened as if they were files. Drupal itself
* provides the public:// and private:// schemes for handling public and
* private files. PHP provides file:// (the default) and http://, so that a
* URL can be read or written (as in a POST) as if it were a file. In addition,
* new schemes can be provided for custom applications, as will be demonstrated
* below.
*
* Here we take the stream wrapper provided in the form. We grab the
* contents with file_get_contents(). Notice that's it's as simple as that:
* file_get_contents("http://example.com") or
* file_get_contents("public://somefile.txt") just works. Although it's
* not necessary, we use file_unmanaged_save_data() to save this file locally
* and then find a local URL for it by using file_create_url().
*/
function file_example_read_submit($form, &$form_state) {
$uri = $form_state['values']['fileops_file'];
if (!is_file($uri)) {
drupal_set_message(t('The file %uri does not exist', array('%uri' => $uri)), 'error');
return;
}
// Make a working filename to save this by stripping off the (possible)
// file portion of the streamwrapper. If it's an evil file extension,
// file_munge_filename() will neuter it.
$filename = file_munge_filename(preg_replace('@^.*/@', '', $uri), '', TRUE);
$buffer = file_get_contents($uri);
if ($buffer) {
$sourcename = file_unmanaged_save_data($buffer, 'public://' . $filename);
if ($sourcename) {
$url = file_create_url($sourcename);
$_SESSION['file_example_default_file'] = $sourcename;
drupal_set_message(
t('The file was read and copied to %filename which is accessible at !url',
array(
'%filename' => $sourcename,
'!url' => l($url, $url),
)
)
);
}
else {
drupal_set_message(t('Failed to save the file'));
}
}
else {
// We failed to get the contents of the requested file.
drupal_set_message(t('Failed to retrieve the file %file', array('%file' => $uri)));
}
}
/**
* Submit handler to delete a file.
*/
function file_example_delete_submit($form, &$form_state) {
$uri = $form_state['values']['fileops_file'];
// Since we don't know if the file is managed or not, look in the database
// to see. Normally, code would be working with either managed or unmanaged
// files, so this is not a typical situation.
$file_object = file_example_get_managed_file($uri);
// If a managed file, use file_delete().
if (!empty($file_object)) {
$result = file_delete($file_object);
if ($result !== TRUE) {
drupal_set_message(t('Failed deleting managed file %uri. Result was %result',
array(
'%uri' => $uri,
'%result' => print_r($result, TRUE),
)
), 'error');
}
else {
drupal_set_message(t('Successfully deleted managed file %uri', array('%uri' => $uri)));
$_SESSION['file_example_default_file'] = $uri;
}
}
// Else use file_unmanaged_delete().
else {
$result = file_unmanaged_delete($uri);
if ($result !== TRUE) {
drupal_set_message(t('Failed deleting unmanaged file %uri', array('%uri' => $uri, 'error')));
}
else {
drupal_set_message(t('Successfully deleted unmanaged file %uri', array('%uri' => $uri)));
$_SESSION['file_example_default_file'] = $uri;
}
}
}
/**
* Submit handler to check existence of a file.
*/
function file_example_file_check_exists_submit($form, &$form_state) {
$uri = $form_state['values']['fileops_file'];
if (is_file($uri)) {
drupal_set_message(t('The file %uri exists.', array('%uri' => $uri)));
}
else {
drupal_set_message(t('The file %uri does not exist.', array('%uri' => $uri)));
}
}
/**
* Submit handler for directory creation.
*
* Here we create a directory and set proper permissions on it using
* file_prepare_directory().
*/
function file_example_create_directory_submit($form, &$form_state) {
$directory = $form_state['values']['directory_name'];
// The options passed to file_prepare_directory are a bitmask, so we can
// specify either FILE_MODIFY_PERMISSIONS (set permissions on the directory),
// FILE_CREATE_DIRECTORY, or both together:
// FILE_MODIFY_PERMISSIONS | FILE_CREATE_DIRECTORY.
// FILE_MODIFY_PERMISSIONS will set the permissions of the directory by
// by default to 0755, or to the value of the variable 'file_chmod_directory'.
if (!file_prepare_directory($directory, FILE_MODIFY_PERMISSIONS | FILE_CREATE_DIRECTORY)) {
drupal_set_message(t('Failed to create %directory.', array('%directory' => $directory)), 'error');
}
else {
drupal_set_message(t('Directory %directory is ready for use.', array('%directory' => $directory)));
$_SESSION['file_example_default_directory'] = $directory;
}
}
/**
* Submit handler for directory deletion.
*
* @see file_unmanaged_delete_recursive()
*/
function file_example_delete_directory_submit($form, &$form_state) {
$directory = $form_state['values']['directory_name'];
$result = file_unmanaged_delete_recursive($directory);
if (!$result) {
drupal_set_message(t('Failed to delete %directory.', array('%directory' => $directory)), 'error');
}
else {
drupal_set_message(t('Recursively deleted directory %directory.', array('%directory' => $directory)));
$_SESSION['file_example_default_directory'] = $directory;
}
}
/**
* Submit handler to test directory existence.
*
* This actually just checks to see if the directory is writable
*
* @param array $form
* FormAPI form.
* @param array $form_state
* FormAPI form state.
*/
function file_example_check_directory_submit($form, &$form_state) {
$directory = $form_state['values']['directory_name'];
$result = is_dir($directory);
if (!$result) {
drupal_set_message(t('Directory %directory does not exist.', array('%directory' => $directory)));
}
else {
drupal_set_message(t('Directory %directory exists.', array('%directory' => $directory)));
}
}
/**
* Utility submit function to show the contents of $_SESSION.
*/
function file_example_show_session_contents_submit($form, &$form_state) {
// If the devel module is installed, use it's nicer message format.
if (module_exists('devel')) {
dsm($_SESSION['file_example'], t('Entire $_SESSION["file_example"]'));
}
else {
drupal_set_message('<pre>' . print_r($_SESSION['file_example'], TRUE) . '</pre>');
}
}
/**
* Utility function to check for and return a managed file.
*
* In this demonstration code we don't necessarily know if a file is managed
* or not, so often need to check to do the correct behavior. Normal code
* would not have to do this, as it would be working with either managed or
* unmanaged files.
*
* @param string $uri
* The URI of the file, like public://test.txt.
*/
function file_example_get_managed_file($uri) {
$fid = db_query('SELECT fid FROM {file_managed} WHERE uri = :uri', array(':uri' => $uri))->fetchField();
if (!empty($fid)) {
$file_object = file_load($fid);
return $file_object;
}
return FALSE;
}
/**
* Implements hook_stream_wrappers().
*
* hook_stream_wrappers() is Drupal's way of exposing the class that PHP will
* use to provide a new stream wrapper class. In this case, we'll expose the
* 'session' scheme, so a file reference like "session://example/example.txt"
* is readable and writable as a location in the $_SESSION variable.
*
* @see FileExampleSessionStreamWrapper
*/
function file_example_stream_wrappers() {
$wrappers = array(
'session' => array(
'name' => t('Example: $_SESSION variable storage'),
'class' => 'FileExampleSessionStreamWrapper',
'description' => t('Store files in the $_SESSION variable as an example.'),
),
);
return $wrappers;
}
/**
* Show the contents of a session file.
*
* This page callback function is called by the Menu API for the path
* examples/file_example/access_session. Any extra path elements
* beyond this are considered to be the session path. E.g.:
* examples/file_example/access_session/foo/bar.txt would be the
* equivalent of session://foo/bar.txt, which will map into
* $_SESSION as keys: $_SESSION['foo']['bar.txt']
*
* Menu API will pass in additional path elements as function arguments. You
* can obtain these with func_get_args().
*
* @return string
* A message containing the contents of the session file.
*
* @see file_get_contents()
*/
function file_example_session_contents() {
$path_components = func_get_args();
$session_path = 'session://' . implode('/', $path_components);
$content = file_get_contents($session_path);
if ($content !== FALSE) {
return t('Contents of @path :',
array('@path' => check_plain($session_path))) . ' ' .
print_r($content, TRUE);
}
return t('Unable to load contents of: @path',
array('@path' => check_plain($session_path)));
}
/**
* @} End of "defgroup file_example".
*/