media_update.module in Media Update 7.2

Defines the module media_update.

File

media_update.module

<?php

/**
 * @file
 * Defines the module media_update.
 */
define('MEDIA_UPDATE_REPLACE_SAME', 'media_update_replace_same');
define('MEDIA_UPDATE_REPLACE_DIFFERENT', 'media_update_replace_different');
require_once dirname(__FILE__) . '/media_update.admin.inc';

/**
 * Implements hook_media_update_params().
 *
 * Base implementation of hook_media_update_params to return values for
 * media_internet module and allow for updates of existing media.
 */
function media_update_media_update_params($schema) {

  // Handle standard media_internet functionality
  if (function_exists('media_internet_get_providers')) {
    $internet_provider = media_internet_get_providers();
    foreach ($internet_provider as $provider) {

      // TODO: Seriously, can this be the only way? Seems SO fragile.
      if ($provider['title'] == $schema) {
        return array(
          'form' => 'media_internet_add',
          'field' => 'embed_code',
          'type' => 'field',
        );
      }
    }
  }

  // Default to standard file upload.
  return array();
}

/**
 * Given a schema, return the relevant fields for updating a particular media
 * item.
 *
 * @param string $schema
 *  The stream type for determining the appropriate update params.
 */
function media_update_get_update_params($schema = 'public') {
  $handlers = module_invoke_all('media_update_params', $schema);

  // Standard types (public/private) are handled here as the default.
  if (!isset($handlers['form'])) {
    $handlers = array(
      'form' => 'media_add_upload',
      'field' => 'upload',
      'type' => 'file',
    );
  }
  return $handlers;
}

/**
 * Implements hook_form_FORM_ID_alter().
 *
 *  Adds the original "add" fields for the appropriate media allowing files to
 *  be replaced during update.
 */
function media_update_form_media_edit_alter(&$form, &$form_state) {

  // Determine the existing schema, and use it to determine appropriate update
  // function and params.
  $schema = file_uri_scheme($form['preview']['#file']->uri);
  $handlers = media_update_get_update_params($schema);
  if (isset($handlers['form'])) {

    // Call the original add form so that we add the schema-specific fields.
    $form = $handlers['form']($form, $form_state);

    // If we don't have a defined validate function, add a default validate function.
    if (!isset($handlers['validate']) && function_exists($handlers['form'] . '_validate')) {
      $form_state['update_validate'] = $handlers['form'] . '_validate';
    }

    // If we don't have a defined submit function, add a default submit function.
    if (!isset($handlers['submit']) && function_exists($handlers['form'] . '_submit')) {
      $form_state['update_submit'] = $handlers['form'] . '_submit';
    }

    // Pull the relevant field and type for "update" recognition.
    $form_state['update_field'] = $handlers['field'];
    $form_state['update_type'] = $handlers['type'];
    unset($form['submit']);
  }

  // Using the previous function for upload
  // NOTE: This funciton saves the file permanently prematurely.
  // NOTE: Commenting this out for now, redoing the logic in media_update_submit.
  // $form['actions']['submit']['#submit'][] = 'media_add_upload_submit';
  $form['actions']['submit']['#validate'][] = 'media_update_validate';
  if (!isset($form['actions']['submit']['#submit'])) {
    $form['actions']['submit']['#submit'] = array(
      'media_edit_submit',
    );
  }
  array_unshift($form['actions']['submit']['#submit'], 'media_update_presubmit');
}

/**
 * Provides validation based on hook_media_update_params.
 *
 * Checks to ensure that an update is actually occurring, stores the existing
 * file, then performs a validation based on our validation params.
 */
function media_update_validate($form, &$form_state) {
  if (isset($form_state['update_field']) && _media_update_should_validate($form_state)) {
    _media_update_original_file($form_state['file']);
    $form_state['update_validate']($form, $form_state);
  }
}

/**
 * Implements hook_file_presave().
 *
 * Switches our media file's fid value so that all relevant hooks in file_save
 * are executed with the original (rather than the new) file fid.
 */
function media_update_file_presave($file) {
  $original_file = _media_update_original_file();

  // By checking if our original file exists, we ensure that we only swap the
  // fid when we're doing a file update.
  if (!empty($original_file) && (!isset($file->fid) || $original_file->fid != $file->fid)) {

    // Let's try just swapping the file fid and see what happens. :-)
    $file->fid = $original_file->fid;
  }
}

/**
 * Helper function to provide a static cache of our original file so that it
 * can be referenced outside of the form context (aka in file_presave).
 *
 * @param object $original_file
 *  A file object to store temporarily.
 */
function _media_update_original_file($original_file = NULL, $reset = FALSE) {
  static $file;
  if (!empty($original_file) || $reset) {
    $file = $original_file;
  }
  return $file;
}

/**
 * Helper function to determine if our validation function should or should not
 * be run.
 */
function _media_update_should_validate(&$form_state) {
  $field = $form_state['update_field'];
  $type = $form_state['update_type'];
  $form_state['file_updated'] = FALSE;

  // If our update is just a field update, check to ensure the field is populated.
  if ($type == 'field') {
    $form_state['file_updated'] = !empty($form_state['values'][$field]);
  }
  elseif ($type == 'file') {
    if (isset($_FILES['files']['name'][$field]) && UPLOAD_ERR_OK == $_FILES['files']['error'][$field]) {
      $form_state['file_updated'] = TRUE;
    }
  }
  return $form_state['file_updated'];
}

/**
 * Provides submit handling based on hook_media_update_params.
 *
 * Checks to ensure that an update is actually occurring then performs a
 * form submission based on our validation params.
 */
function media_update_presubmit($form, &$form_state) {
  if (isset($form_state['update_field']) && $form_state['file_updated']) {
    $field = $form_state['update_field'];
    if (isset($form_state['values'][$field])) {
      $original_file = $form_state['file'];

      // We have to update the fid of the file object for file-based uploads,
      // but this entity isn't an object in other scenarios.
      if (isset($form_state['values'][$field]) && is_object($form_state['values'][$field]) && $form_state['update_type'] == 'file') {
        $form_state['values'][$field]->fid = $original_file->fid;
        $file_name_changed = $original_file->filename == $form_state['values'][$field]->filename;

        // See if we need to remove the original file.
        $remove_original_file = !$file_name_changed && variable_get(MEDIA_UPDATE_REPLACE_SAME, 0) || $file_name_changed && variable_get(MEDIA_UPDATE_REPLACE_DIFFERENT, 0);
        if ($remove_original_file) {
          file_unmanaged_delete($original_file->uri);
        }
      }

      // @todo: Find a better way to handle this.
      // We're doing this because both the edit form and the add form pass an
      // argument. The edit form passes a file object while the add form needs
      // a params array. The array holds little of value to our submit, but
      // the incorrect object type causes chaos.
      $arg0 = $form_state['build_info']['args'][0];
      $form_state['build_info']['args'][0] = array();

      // Call the original add submit handler.
      $form_state['update_submit']($form, $form_state);
      _media_update_original_file(NULL, TRUE);

      // Potentially 2 file saves happen per file upload, but we want to ensure
      // that any upload logic occurs as well as any update logic.
      $form_state['file'] = file_load($original_file->fid);

      // We're done with our submit handler, so reset the args element.
      $form_state['build_info']['args'][0] = $arg0;

      // Raise an event so that other modules know that a file has been replaced.
      module_invoke_all('media_update_updated', $original_file);
    }
  }
}

Functions

Name	Description
media_update_file_presave	Implements hook_file_presave().
media_update_form_media_edit_alter	Implements hook_form_FORM_ID_alter().
media_update_get_update_params	Given a schema, return the relevant fields for updating a particular media item.
media_update_media_update_params	Implements hook_media_update_params().
media_update_presubmit	Provides submit handling based on hook_media_update_params.
media_update_validate	Provides validation based on hook_media_update_params.
_media_update_original_file	Helper function to provide a static cache of our original file so that it can be referenced outside of the form context (aka in file_presave).
_media_update_should_validate	Helper function to determine if our validation function should or should not be run.

Constants

Name	Description
MEDIA_UPDATE_REPLACE_DIFFERENT
MEDIA_UPDATE_REPLACE_SAME	@file Defines the module media_update.