attachment_links.module in Attachment Links 7

File

attachment_links.module

<?php

/**
 * @file
 * The Attachment Links module provides permanent links to files attached to a
 * node. A single, easy-to-remember URL can be used to retrieve the preferred
 * (canonical) or newest version of a file regardless of how many versions of
 * that file have been attached to a node.
 */
include 'attachment_links.field-formatters.inc';

/**
 * Implements hook_menu().
 */
function attachment_links_menu() {
  $items['node/%node/attachment'] = array(
    'title' => 'Authoritative Attachment',
    'description' => 'The canonical or "lightest" attached file.',
    'type' => MENU_CALLBACK,
    'page callback' => 'attachment_links_retrieve',
    'page arguments' => array(
      1,
      'authoritative',
    ),
    'access callback' => 'node_access',
    'access arguments' => array(
      'view',
      1,
    ),
  );
  $items['node/%node/attachment/newest'] = array(
    'title' => 'Latest Attachment',
    'description' => 'The most recently attached file.',
    'type' => MENU_CALLBACK,
    'page callback' => 'attachment_links_retrieve',
    'page arguments' => array(
      1,
      'newest',
    ),
    'access callback' => 'node_access',
    'access arguments' => array(
      'view',
      1,
    ),
  );
  return $items;
}

/**
 * Implements hook_node_view().
 */
function attachment_links_node_view($node, $view_mode, $langcode) {
  $file_field_name = variable_get('attachment_links_selection_' . $node->type, 0);

  // Add the links to the node display, for easy access.
  if ($file_field_name) {

    // Grab the files from the current node for the selected field.
    $files = field_get_items('node', $node, $file_field_name);
    if ($files) {
      $node->content['attachment_links'] = array(
        '#markup' => theme('attachment_links', array(
          'node' => $node,
        )),
        '#weight' => 3,
      );
    }
  }
}

/**
 * Implements hook_node_insert().
 */
function attachment_links_node_insert($node) {
  if (variable_get('attachment_links_create_alias_' . $node->type, FALSE)) {
    path_delete(array(
      'source' => 'node/' . $node->nid . '/attachment',
    ));
    attachment_links_save_alias($node);
  }
}

/**
 * Implements hook_node_update().
 */
function attachment_links_node_update($node) {
  path_delete(array(
    'source' => 'node/' . $node->nid . '/attachment',
  ));
  attachment_links_save_alias($node);
}

/**
 * Implements hook_node_delete().
 */
function attachment_links_node_delete($node) {

  // Delete all aliases associated with this node attachment.
  path_delete(array(
    'source' => 'node/' . $node->nid . '/attachment',
  ));
}

/**
 * Save the convenience alias.
 */
function attachment_links_save_alias($node) {
  $create_alias = variable_get('attachment_links_create_alias_' . $node->type, FALSE);
  if ($create_alias) {

    // Make sure that attachment links are enabled for a field on this node type.
    $file_field_name = variable_get('attachment_links_selection_' . $node->type, 0);
    if ($file_field_name) {

      // Grab the files from the current node for the selected field.
      $files = field_get_items('node', $node, $file_field_name);
      if (!empty($files)) {

        // Retreive the 'authorative' file.
        $file = reset($files);
        $file = file_load($file['fid']);
        if (!empty($node->path['alias'])) {
          $node_alias = $node->path['alias'];
          $alias_parts = explode('/', $node_alias);
          if (count($alias_parts) > 1) {
            array_pop($alias_parts);
            $node_alias = implode('/', $alias_parts);
          }
          $alias = $node_alias . '/' . $file->filename;
          $source = 'node/' . $node->nid . '/attachment';
          $new_alias = array(
            'source' => $source,
            'alias' => $alias,
            'language' => $node->language,
          );
          path_save($new_alias);
          return TRUE;
        }
      }
    }
  }
  return FALSE;
}

/**
 * Implements hook_theme().
 */
function attachment_links_theme($existing, $type, $theme, $path) {
  $hooks['attachment_links'] = array(
    'template' => 'attachment-links',
    'variables' => array(
      'node' => NULL,
    ),
  );
  $hooks['attachment_links_formatter_attachment_links_preferred'] = array(
    'arguments' => array(
      'element' => NULL,
    ),
  );
  $hooks['attachment_links_formatter_attachment_links_newest'] = array(
    'arguments' => array(
      'element' => NULL,
    ),
  );
  return $hooks;
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function attachment_links_form_node_type_form_alter(&$form, &$form_state) {

  // Add a section to the node type edit form that allows the user to select
  // which file field will be used by Attachment links, as there may be multiple.
  if (isset($form['type'])) {
    $node_type = $form['#node_type']->type;
    if (isset($node_type)) {

      // Get all file fields on this node type for select options:
      $options = array(
        0 => 'Disabled',
      );
      $instances = field_info_instances('node', $node_type);
      foreach ($instances as $field_name => $instance) {
        $field_info = field_info_field($field_name);
        if ($field_info['type'] == 'file') {
          $options[$field_name] = $instances[$field_name]['label'] . " ({$field_name})";
        }
      }
      $form['attachment_links'] = array(
        '#type' => 'fieldset',
        '#title' => t('Attachment links'),
        '#group' => 'additional_settings',
      );
      $form['attachment_links']['attachment_links_selection'] = array(
        '#type' => 'select',
        '#title' => t('Select file field'),
        '#description' => t('When hitting attachment links URLs, it will deliver files from this file field.'),
        '#default_value' => variable_get('attachment_links_selection_' . $node_type, 0),
        '#options' => $options,
        '#weight' => 5,
      );
      $form['attachment_links']['attachment_links_create_alias'] = array(
        '#type' => 'checkbox',
        '#title' => t('Generate convenience aliases'),
        '#description' => t('Uses the file extension and node alias to create a file alias, see README.txt for more info.'),
        '#default_value' => variable_get('attachment_links_create_alias_' . $node_type, FALSE),
        '#weight' => 6,
      );
    }

    // Add a submit handler so that we can clear the fields info cache when this
    // form is submitted.
    $form['#submit'][] = 'attachment_links_node_type_form_submit';
  }
}

/**
 * Submit handler for the node type form.
 */
function attachment_links_node_type_form_submit($form, &$form_state) {

  // Clear the fields info cache. This is only so that the pseudo-field that
  // appears in 'Display fields' will show for the correct content types only.
  // Otherwise, we'd have to show the pseudo field for all content types.
  field_info_cache_clear();
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function attachment_links_form_node_form_alter(&$form, &$form_state) {
  $node = $form['#node'];

  // Provide some help and info on the node edit form.
  if (isset($form['type']) && isset($node)) {
    $file_field_name = variable_get('attachment_links_selection_' . $node->type, 0);
    if ($file_field_name) {
      $instances = field_info_instances('node', $node->type);
      $label = $instances[$file_field_name]['label'];
      $form['attachment_links'] = array(
        '#type' => 'fieldset',
        '#collapsible' => TRUE,
        '#collapsed' => TRUE,
        '#title' => t('Attachment links'),
        '#group' => 'additional_settings',
        '#weight' => 50,
      );
      $help_blurb = t('Attachment links provides permanent links for files in the field %field. The "preferred" version is the first file listed on the field %field above. Click and drag the handles to the left of each file to reorder them. You can choose a different field in the content type settings.', array(
        '%field' => $label,
      ));

      // Display different help text for node creation and node editing forms.
      if ($form['nid']['#value']) {
        $help_blurb .= theme('attachment_links', array(
          'node' => $node,
        ));
      }
      else {
        $help_blurb .= '<div><strong>' . t('Attachment links will be shown here after you save the node.') . '</strong></div>';
      }
      $form['attachment_links']['current'] = array(
        '#type' => 'item',
        '#title' => t('Attachment links on %field', array(
          '%field' => $label . ' (' . $file_field_name . ')',
        )),
        '#markup' => $help_blurb,
      );
    }
  }
}

/**
 * Menu callback to fetch the reqested file for the given node.
 */
function attachment_links_retrieve($node, $type) {

  // Make sure that attachment links are enabled for a field on this node type.
  $file_field_name = variable_get('attachment_links_selection_' . $node->type, 0);
  if (!$file_field_name) {
    return MENU_NOT_FOUND;
  }

  // Grab the files from the current node for the selected field.
  $files = field_get_items('node', $node, $file_field_name);

  // If we have files, continue, else return 404.
  if (!empty($files)) {
    switch ($type) {
      case 'authoritative':

        // Return the first element of the array, which is the 'highest' one.
        $file = reset($files);
        $uri = $file['uri'];
        break;
      case 'newest':

        // Get the newest item by timestamp. In the case of multiple timestamps
        // being equal, the 'highest' one will be selected. The handy part is
        // that the array returned by field_get_items is already in weight order,
        // with key 0 being the lightest.
        $max_timestamp = 0;
        foreach ($files as $key => $file) {
          if ($file['timestamp'] > $max_timestamp) {
            $max_timestamp = $file['timestamp'];
            $max_key = $key;
          }
        }
        $uri = $files[$max_key]['uri'];
        break;
    }

    // We check for public, and redirect to the file path in that case. In the
    // case of private, we start serving the file in the current request instead
    // of redirecting, this saves resources and is useful when we have an alias
    // for the file path.
    $scheme = file_uri_scheme($uri);
    if ($scheme == 'public') {
      $file_url = file_create_url($uri);
      drupal_goto($file_url);
    }
    else {
      if ($scheme == 'private') {

        // Serve the file from private files.
        if ($wrapper = file_stream_wrapper_get_instance_by_uri($uri)) {

          // Unfortunately we have to do this str_replace nonsense because the
          // function that we want to call (getTarget) is protected in the stream
          // wrapper.
          $file_url = $wrapper
            ->getExternalUrl();
          $file_url = str_replace(url('system/files/', array(
            'absolute' => TRUE,
          )), '', $file_url);

          // The file_url will have URL entities encoded, but file_download()
          // expects a real filename. Decode first (i.e. turn "%20" into " ")
          $file_url = urldecode($file_url);
          $args = explode('/', $file_url);
          array_unshift($args, 'private');

          // Need to send the filename since we aren't redirecting to a file
          // but sending the stream directly. file_download() will handle sending
          // the MIME type and other necessaryt headers.
          header('Content-Disposition: attachment; filename="' . end($args) . '"');

          // This calls the menu callback for private files directly, ensuring that
          // all access permissions are taken care of.
          call_user_func_array('file_download', $args);
        }
      }
      else {
        return MENU_NOT_FOUND;
      }
    }
  }
  else {
    return MENU_NOT_FOUND;
  }
}

/**
 * Process variables for attachment-links.tpl.php.
 */
function template_preprocess_attachment_links(&$vars) {
  $node = $vars['node'];
  $options = array(
    'absolute' => TRUE,
  );
  $vars['items'] = array(
    t('Preferred version: !link', array(
      '!link' => l(url("node/{$node->nid}/attachment", $options), "node/{$node->nid}/attachment"),
    )),
    t('Newest version: !link', array(
      '!link' => l(url("node/{$node->nid}/attachment/newest", $options), "node/{$node->nid}/attachment/newest"),
    )),
  );
}

/**
 * Implements hook_field_extra_fields().
 */
function attachment_links_field_extra_fields() {
  $types = node_type_get_types();
  foreach ($types as $key => $type) {
    if (variable_get('attachment_links_selection_' . $key, 0)) {
      $extra['node'][$key] = array(
        'display' => array(
          'attachment_links' => array(
            'label' => t('Attachment links'),
            'description' => t('Links to the canonical or preferred version of the attached files.'),
            'weight' => 3,
          ),
        ),
      );
    }
  }
  if (isset($extra)) {
    return $extra;
  }
}

Functions

Name	Description
attachment_links_field_extra_fields	Implements hook_field_extra_fields().
attachment_links_form_node_form_alter	Implements hook_form_FORM_ID_alter().
attachment_links_form_node_type_form_alter	Implements hook_form_FORM_ID_alter().
attachment_links_menu	Implements hook_menu().
attachment_links_node_delete	Implements hook_node_delete().
attachment_links_node_insert	Implements hook_node_insert().
attachment_links_node_type_form_submit	Submit handler for the node type form.
attachment_links_node_update	Implements hook_node_update().
attachment_links_node_view	Implements hook_node_view().
attachment_links_retrieve	Menu callback to fetch the reqested file for the given node.
attachment_links_save_alias	Save the convenience alias.
attachment_links_theme	Implements hook_theme().
template_preprocess_attachment_links	Process variables for attachment-links.tpl.php.