<?php
// $Id: content.module,v 1.90.2.25 2007-01-09 14:54:10 karens Exp $

/**
 * @file
 * Allows administrators to associate custom fields to content types.
 */

define('CONTENT_DB_STORAGE_PER_FIELD', 0);
define('CONTENT_DB_STORAGE_PER_CONTENT_TYPE', 1);

/**
 * Implementation of hook_init().
 */
function content_init() {
  // ensure we are not serving a cached page
  if (function_exists('drupal_set_content')) {
    // we don't do this in hook_menu to ensure the files are already included when
    // views_menu is executed
    if (module_exists('views')) {
      include_once('./'. drupal_get_path('module', 'content') .'/content_views.inc');
    }
    // according to http://drupal.org/node/60526, this should not go in hook_menu
    if (module_exists('pathauto')) {
      include_once('./'. drupal_get_path('module', 'content') .'/content_pathauto.inc');
    }
  }
}

/**
 * Implementation of hook_menu().
 */
function content_menu($may_cache) {
  if (!$may_cache) {
    // Only include administrative callbacks if we are viewing an admin page.
    if (arg(0) == 'admin') {
      include_once('./'. drupal_get_path('module', 'content') .'/content_admin.inc');
    }
    // Unconditionally include css exactly once per page.
    drupal_add_css(drupal_get_path('module', 'content') .'/content.css');
  }

  $items = array();
  $access = user_access('administer content types');

  if ($may_cache) {
      $items[] = array(
        'path' => 'admin/content/types/fields',
        'title' => t('Fields'),
        'callback' => '_content_admin_type_fields',
        'access' => $access,
        'type' => MENU_LOCAL_TASK,
      );
  }
  else {
    if (arg(0) == 'admin' && arg(1) == 'content' && arg(2) == 'types') {

      $content_type = content_types(arg(3));
      $type = node_get_types('types', $content_type['type']);


      if (!empty($type) && arg(3) && arg(3) == $content_type['url_str']) {
        $items[] = array(
          'path' => 'admin/content/types/'. $content_type['url_str'] .'/edit',
          'title' => t('Edit'),
          'callback' => 'drupal_get_form',
          'callback arguments' => array('node_type_form', $type),
          'type' => MENU_DEFAULT_LOCAL_TASK,
        );
        $items[] = array(
          'path' => 'admin/content/types/'. $content_type['url_str'] .'/fields',
          'title' => t('Manage fields'),
          'callback' => 'drupal_get_form',
          'access' => $access,
          'callback arguments' => array('content_admin_field_overview_form', $content_type['type']),
          'type' => MENU_LOCAL_TASK,
          'weight' => 1,
        );
        $items[] = array(
          'path' => 'admin/content/types/'. $content_type['url_str'] .'/add_field',
          'title' => t('Add field'),
          'callback' => '_content_admin_field_add',
          'access' => $access,
          'callback arguments' => array($content_type['type']),
          'type' => MENU_LOCAL_TASK,
          'weight' => 2,
        );

        if (arg(4) == 'fields' && arg(5) && isset($content_type['fields'][arg(5)])) {
          $items[] = array(
            'path' => 'admin/content/types/'. $content_type['url_str'] .'/fields/'. arg(5),
            'title' => t($content_type['fields'][arg(5)]['widget']['label']),
            'callback' => 'drupal_get_form',
            'access' => $access,
            'callback arguments' => array('_content_admin_field', $content_type['type'], arg(5)),
            'type' => MENU_CALLBACK,
          );
          $items[] = array(
            'path' => 'admin/content/types/'. $content_type['url_str'] .'/fields/'. arg(5) .'/remove',
            'title' => t('Remove field'),
            'callback' => 'drupal_get_form',
            'access' => $access,
            'callback arguments' => array('_content_admin_field_remove', $content_type['type'], arg(5)),
            'type' => MENU_CALLBACK,
          );
        }

      }
    }
  }

  return $items;
}

/**
 * Load data for a node type's fields.
 *
 * When loading one of the content.module nodes, we need to let each field handle
 * its own loading. This can make for a number of queries in some cases, so we
 * cache the loaded object structure and invalidate it during the update process.
 */
function content_load($node) {
  $cid = 'content:'. $node->nid .':'. $node->vid;
  if ($cached = cache_get($cid, 'cache')) {
    return unserialize($cached->data);
  }
  else {
    $default_additions = _content_field_invoke_default('load', $node);
    if ($default_additions) {
      foreach ($default_additions as $key => $value) {
        $node->$key = $value;
      }
    }
    $additions = _content_field_invoke('load', $node);
    if ($additions) {
      foreach ($additions as $key => $value) {
        $default_additions[$key] = $value;
      }
    }
    cache_set($cid, 'cache', serialize($default_additions), CACHE_PERMANENT);
    return $default_additions;
  }
}

/**
 * Create fields' form for a content type.
 *
 * Each field defines its own component of the content entry form, via its
 * chosen widget.
 */
function content_form(&$node) {
  $form = array();
  $type = content_types($node->type);

  // Set form parameters so we can accept file uploads.
  if (count($type['fields'])) {
    $form['#attributes'] = array("enctype" => "multipart/form-data");
  }

  _content_widget_invoke('prepare form values', $node);
  $form = array_merge($form, _content_widget_invoke('form', $node));
  return $form;
}

/**
 * Validate form callback to handle node type fields.
 *
 * Both widgets and fields have a chance to raise error flags when a node is
 * being validated.
 */
function content_validate(&$node) {
  _content_widget_invoke('validate', $node);
  _content_widget_invoke('process form values', $node);
  _content_field_invoke('validate', $node);
  _content_field_invoke_default('validate', $node);
}

/**
 * Submit form callback for node type fields.
 *
 * At submit time, the widget does whatever data massaging is necessary so that
 * the field has the content in the expected format and can commit the changes
 * to the database.
 */
function content_submit(&$node) {
  _content_widget_invoke('submit', $node);
  _content_widget_invoke('process form values', $node);
  _content_field_invoke('submit', $node);
  _content_field_invoke_default('submit', $node);
}

/**
 * Insert node type fields.
 */
function content_insert(&$node) {
  _content_field_invoke('insert', $node);
  _content_field_invoke_default('insert', $node);
}

/**
 * Update node type fields.
 */
function content_update(&$node) {
  _content_field_invoke('update', $node);
  _content_field_invoke_default('update', $node);
  cache_clear_all('content:'. $node->nid .':'. $node->vid, 'cache');
}

/**
 * Delete node type fields.
 */
function content_delete(&$node) {
  $type = content_types($node->type);
  if (!empty($type['fields'])) {
    _content_field_invoke('delete', $node);
    _content_field_invoke_default('delete', $node);
  }
  if (!empty($type['table']) && db_table_exists($type['table'])) {
    db_query('DELETE FROM {'. $type['table'] .'} WHERE nid = %d', $node->nid);
  }
  cache_clear_all('content:'. $node->nid, 'cache', TRUE);
}

/**
 * delete node type fields for a revision.
 */
function content_delete_revision(&$node) {
  $type = content_types($node->type);
  if (!empty($type['fields'])) {
    _content_field_invoke('delete revision', $node);
    _content_field_invoke_default('delete revision', $node);
  }
  if (!empty($type['table']) && db_table_exists($type['table'])) {
    db_query('DELETE FROM {'. $type['table'] .'} WHERE vid = %d', $node->vid);
  }
  cache_clear_all('content:'. $node->nid .':'. $node->vid, 'cache');
}

/**
 * Generate field render arrays.
 */
function content_view(&$node, $teaser = FALSE, $page = FALSE) {
  if ($node->in_preview) {
    _content_widget_invoke('process form values', $node);
  }
  $content = _content_field_invoke('view', $node, $teaser, $page);
  $node->content = array_merge((array) $node->content, $content);
}

/**
 * Implementation of hook_nodeapi().
 *
 * When a revision is deleted, make sure the appropriate cache item is cleared.
 * @todo: deprecate op==validate & op==submit in favor of form callbacks.
 */
function content_nodeapi(&$node, $op, $teaser, $page) {
  switch ($op) {
    case 'load':
      return content_load($node);

    case 'validate':
      content_validate($node);
      break;

    case 'submit':
      content_submit($node);
      break;

    case 'insert':
      content_insert($node);
      break;

    case 'update':
      content_update($node);
      break;

    case 'delete':
      content_delete($node);
      break;

    case 'delete revision':
      content_delete_revision($node);
      break;

    case 'view':
      content_view($node, $teaser, $page);
      break;
  }
}

/**
 *  Implementation of hook_form_alter().
 */
function content_form_alter($form_id, &$form) {
  if (isset($form['type'])) {
    $node = $form['#node'];
    if ($form['type']['#value'] .'_node_form' == $form_id) {
      $form = array_merge($form, content_form($node));
    }
  }
  if ($form_id == 'system_modules') {
    $form['#submit']['content_system_modules_submit'] = array();
  }
}

/**
 *  Make sure that CCK content type info is synched with node type data
 *  any time the content module is submitted on the module installation page.
 */
function content_system_modules_submit($form_id, $form_values) {
  $content_status = $form_values['validation_modules']['content'];
  if ($content_status->status == 1) {
    include_once('./'. drupal_get_path('module', 'content') .'/content_admin.inc');
    include_once('./'. drupal_get_path('module', 'content') .'/content_crud.inc');
    content_types_rebuild();
  }
}

/**
 * Implementation of hook_field(). Handles common field housekeeping.
 *
 * This implementation is special, as content.module does not define any field
 * types. Instead, this function gets called after the type-specific hook, and
 * takes care of the database interface for field types that do not choose to
 * do their own storage.
 */
function content_field($op, &$node, $field, &$node_field, $teaser, $page) {
  $db_info = content_database_info($field);

  switch ($op) {
    case 'load':
      $column_names = array();
      foreach ($db_info['columns'] as $column => $attributes) {
        $column_names[] = $attributes['column'] .' AS '. $column;
      }
      if ($field['multiple']) {
        $result = db_query('SELECT '. implode(', ', $column_names) .' FROM {'. $db_info['table'] .'} WHERE vid = %d ORDER BY delta', $node->vid);
        $values = array();
        while ($value = db_fetch_array($result)) {
          $values[] = $value;
        }
        $additions = array($field['field_name'] => $values);
      }
      else {
        $result = db_query('SELECT '. implode(', ', $column_names) .' FROM {'. $db_info['table'] .'} WHERE vid = %d', $node->vid);
        $additions = array($field['field_name'] => array(db_fetch_array($result)));
      }
      return $additions;

    case 'insert':
      foreach ($node_field as $delta => $item) {
        $data = array();
        $column_names = array();
        $column_placeholders = array();
        $column_assignments = array();
        foreach ($db_info['columns'] as $column => $attributes) {
          $column_names[] = $attributes['column'];
          if ($item[$column] == '' && !$attributes['not null'] && !$field['required']) {
            $column_placeholders[] = '%s';
            $column_assignments[] = $attributes['column'] .' = %s';
            $item[$column] = 'NULL';
          }
          else {
            switch ($attributes['type']) {
            case 'int':
            case 'mediumint':
            case 'tinyint':
            case 'bigint':
              $column_placeholders[] = '%d';
              $column_assignments[] = $attributes['column'] .' = %d';
              break;
            case 'float':
              $column_placeholders[] = '%f';
              $column_assignments[] = $attributes['column'] .' = %f';
              break;
            default:
              $column_placeholders[] = "'%s'";
              $column_assignments[] = $attributes['column'] ." = '%s'";
            }
          }
          $data[] = $item[$column];
        }
        $data[] = $node->vid;
        $data[] = $node->nid;
        if ($field['multiple']) {
          $data[] = $delta;
        }

        if ($field['multiple']) {
          db_query('INSERT INTO {'. $db_info['table'] .'} ('. implode(', ', $column_names) .', vid, nid, delta) VALUES ('. implode(', ', $column_placeholders) .', %d, %d, %d)', $data);
        }
        else {
          if (db_result(db_query('SELECT COUNT(*) FROM {'. $db_info['table'] .'} WHERE vid = %d AND nid = %d', $node->vid, $node->nid))) {
            db_query('UPDATE {'. $db_info['table'] .'} SET '. implode(', ', $column_assignments) .' WHERE vid = %d AND nid = %d', $data);
          }
          else {
            db_query('INSERT INTO {'. $db_info['table'] .'} ('. implode(', ', $column_names) .', vid, nid) VALUES ('. implode(', ', $column_placeholders) .', %d, %d)', $data);
          }
        }
      }
      return;

    case 'update':
      if ($field['multiple']) {
        // Delete and insert, rather than update, in case a field was added.
        db_query('DELETE FROM {'. $db_info['table'] .'} WHERE vid = %d', $node->vid);
      }

      foreach ($node_field as $delta => $item) {
        $data = array();
        $column_names = array();
        $column_placeholders = array();
        $column_assignments = array();
        foreach ($db_info['columns'] as $column => $attributes) {
          $column_names[] = $attributes['column'];
          if ($item[$column] == '' && !$attributes['not null'] && !$field['required']) {
            $column_placeholders[] = '%s';
            $column_assignments[] = $attributes['column'] .' = %s';
            $item[$column] = 'NULL';
          }
          else {
            switch ($attributes['type']) {
            case 'int':
            case 'mediumint':
            case 'tinyint':
            case 'bigint':
              $column_placeholders[] = '%d';
              $column_assignments[] = $attributes['column'] .' = %d';
              break;
            case 'float':
              $column_placeholders[] = '%f';
              $column_assignments[] = $attributes['column'] .' = %f';
              break;
            default:
              $column_placeholders[] = "'%s'";
              $column_assignments[] = $attributes['column'] ." = '%s'";
            }
          }
          $data[] = $item[$column];
        }
        $data[] = $node->vid;
        $data[] = $node->nid;
        if ($field['multiple']) {
          $data[] = $delta;
        }

        if ($field['multiple']) {
          db_query('INSERT INTO {'. $db_info['table'] .'} ('. implode(', ', $column_names) .', vid, nid, delta) VALUES ('. implode(', ', $column_placeholders) .', %d, %d, %d)', $data);
        }
        else {
          if (db_result(db_query('SELECT COUNT(*) FROM {'. $db_info['table'] .'} WHERE vid = %d AND nid = %d', $node->vid, $node->nid))) {
            db_query('UPDATE {'. $db_info['table'] .'} SET '. implode(', ', $column_assignments) .' WHERE vid = %d AND nid = %d', $data);
          }
          else {
            db_query('INSERT INTO {'. $db_info['table'] .'} ('. implode(', ', $column_names) .', vid, nid) VALUES ('. implode(', ', $column_placeholders) .', %d, %d)', $data);
          }
        }
      }
      return;

    case 'delete':
      // Delete using nid rather than vid to purge all revisions.
      db_query('DELETE FROM {'. $db_info['table'] .'} WHERE nid = %d', $node->nid);
      return;

    case 'delete revision':
      db_query('DELETE FROM {'. $db_info['table'] .'} WHERE vid = %d', $node->vid);
      return;
  }
}


/**
 * Invoke a field hook.
 *
 * For each operation, both this function and _content_field_invoke_default() are
 * called so that the default database handling can occur.
 */
function _content_field_invoke($op, &$node, $teaser = NULL, $page = NULL) {
  $type_name = is_string($node) ? $node : (is_array($node) ? $node['type'] : $node->type);
  $type = content_types($type_name);
  $field_types = _content_field_types();

  $return = array();
  if (count($type['fields'])) {
    foreach ($type['fields'] as $field) {
      $node_field = isset($node->$field['field_name']) ? $node->$field['field_name'] : array();

      $module = $field_types[$field['type']]['module'];
      $function = $module .'_field';
      if (function_exists($function)) {
        $result = $function($op, $node, $field, $node_field, $teaser, $page);
        if ($op == 'view') {
          if (!is_array($result)) $result = array($result);
          $return[$field['field_name']] = array('#weight' => $field['widget']['weight']);
          foreach ($result as $delta => $value) {
            $return[$field['field_name']][$delta] = array('#value' => $value);
          }
        }
        elseif (is_array($result)) {
          $return = array_merge($return, $result);
        }
        else if (isset($result)) {
          $return[] = $result;
        }
      }
      // test for values in $node_field in case modules added items on insert
      if (isset($node->$field['field_name']) || count($node_field)) {
        $node->$field['field_name'] = $node_field;
      }
    }
  }
  return $return;
}

/**
 * Invoke content.module's version of a field hook.
 */
function _content_field_invoke_default($op, &$node, $teaser = NULL, $page = NULL) {
  $type_name = is_string($node) ? $node : (is_array($node) ? $node['type'] : $node->type);
  $type = content_types($type_name);
  $field_types = _content_field_types();

  $return = array();
  if (count($type['fields'])) {
    foreach ($type['fields'] as $field) {
      $node_field = isset($node->$field['field_name']) ? $node->$field['field_name'] : array();

      $db_info = content_database_info($field);
      if (count($db_info['columns'])) {
        $result = content_field($op, $node, $field, $node_field, $teaser, $page);
        if ($op == 'view') {
          // do nothing, handled by field view hook
          return;
        }
        elseif (is_array($result)) {
          $return = array_merge($return, $result);
        }
        else if (isset($result)) {
          $return[] = $result;
        }
      }
      if (isset($node->$field['field_name'])) {
        $node->$field['field_name'] = $node_field;
      }
    }
  }

  return $return;
}

/**
 * Invoke a widget hook.
 */
function _content_widget_invoke($op, &$node) {
  $type_name = is_string($node) ? $node : (is_array($node) ? $node['type'] : $node->type);
  $type = content_types($type_name);
  $widget_types = _content_widget_types();

  $return = array();
  if (count($type['fields'])) {
    foreach ($type['fields'] as $field) {
      $node_field = isset($node->$field['field_name']) ? $node->$field['field_name'] : array();

      $module = $widget_types[$field['widget']['type']]['module'];
      $function = $module .'_widget';
      if (function_exists($function)) {
        $result = $function($op, $node, $field, $node_field);
        if (is_array($result) && $op == 'form') {
          $result[$field['field_name']]['#weight'] = $field['widget']['weight'];
        }
        if (is_array($result)) {
          $return = array_merge($return, $result);
        }
        else if (isset($result)) {
          $return[] = $result;
        }
      }
      // test for values in $node_field in case modules added items on insert
      if (is_object($node) && (isset($node->$field['field_name']) || count($node_field))) {
        $node->$field['field_name'] = $node_field;
      }
    }
  }
  return $return;
}

/**
 * Return a list of all content types.
 *
 * @param $content_type_name
 *   If set, return information on just this type.
 */
function content_types($type_name = NULL) {
  // handle type name with either an underscore or a dash
  $type_name = !empty($type_name) ? str_replace('-', '_', $type_name) : NULL;

  $info = _content_type_info();
  if (isset($type_name)) {
    if (isset($info['content types'][$type_name])) {
      return $info['content types'][$type_name];
    }
    else {
      return NULL;
    }
  }
  return $info['content types'];
}

/**
 * Return a list of all fields.
 *
 * @param $field_name
 *   If set, return information on just this field.
 * @param $content_type_name
 *   If set, return information of the field within the context of this content
 *   type.
 */
function content_fields($field_name = NULL, $content_type_name = NULL) {
  $info = _content_type_info();
  if (isset($field_name)) {
    if (isset($info['fields'][$field_name])) {
      if (isset($content_type_name)) {
        if (isset($info['content types'][$content_type_name]['fields'][$field_name])) {
          return $info['content types'][$content_type_name]['fields'][$field_name];
        }
        else {
          return NULL;
        }
      }
      else {
        return $info['fields'][$field_name];
      }
    }
    else {
      return NULL;
    }
  }
  return $info['fields'];
}

/**
 * Return a list of field types.
 */
function _content_field_types() {
  $info = _content_type_info();
  return $info['field types'];
}

/**
 * Return a list of widget types.
 */
function _content_widget_types() {
  $info = _content_type_info();
  return $info['widget types'];
}

/**
 * Collate all information on content types, fields, and related structures.
 *
 * @param $reset
 *   If TRUE, clear the cache and fetch the information from the database again.
 */
function _content_type_info($reset = FALSE) {
  static $info;

  if ($reset || !isset($info)) {
    if ($cached = cache_get('content_type_info', 'cache')) {
      $info = unserialize($cached->data);
    }
    else {
      $info = array(
        'field types' => array(),
        'widget types' => array(),
        'fields' => array(),
        'content types' => array(),
      );

      foreach (module_list() as $module) {
        $module_field_types = module_invoke($module, 'field_info');
        if ($module_field_types) {
          foreach ($module_field_types as $name => $field_info) {
            $info['field types'][$name] = $field_info;
            $info['field types'][$name]['module'] = $module;
            $info['field types'][$name]['formatters'] = array();
          }
        }

        $module_widgets = module_invoke($module, 'widget_info');
        if ($module_widgets) {
          foreach ($module_widgets as $name => $widget_info) {
            $info['widget types'][$name] = $widget_info;
            $info['widget types'][$name]['module'] = $module;
          }
        }
      }
      foreach (module_list() as $module) {
        $module_formatters = module_invoke($module, 'field_formatter_info');
        if ($module_formatters) {
          foreach ($module_formatters as $name => $formatter_info) {
            foreach ($formatter_info['field types'] as $field_type) {
              $info['field types'][$field_type]['formatters'][$name] = $formatter_info;
              $info['field types'][$field_type]['formatters'][$name]['module'] = $module;
            }
          }
        }
      }

      $field_result = db_query('SELECT * FROM {node_field} nf');
      while ($field = db_fetch_array($field_result)) {
        $global_settings = $field['global_settings'] ? unserialize($field['global_settings']) : array();
        unset($field['global_settings']);
        // Preventative error handling for PHP5 if field nodule hasn't created an arrray.
        if (is_array($global_settings)) {
          $field = array_merge($field, $global_settings);
        }
        $instance_info = db_fetch_array(db_query("SELECT type_name, label FROM {node_field_instance} WHERE field_name = '%s'", $field['field_name']));
        $field['widget']['label'] = $instance_info['label'];
        $field['type_name'] = $instance_info['type_name'];
        $info['fields'][$field['field_name']] = $field;
      }

      $type_result = db_query('SELECT * FROM {node_type} nt ORDER BY nt.type ASC');
      while ($type = db_fetch_array($type_result)) {
        $type['url_str'] = str_replace('_', '-', $type['type']);
        $type['fields'] = array();
        $type['table'] = _content_tablename($type['type']);
        $field_result = db_query("SELECT nfi.field_name, nfi.weight, nfi.label, nfi.widget_type, nfi.widget_settings, nfi.description FROM {node_field_instance} nfi WHERE nfi.type_name = '%s' ORDER BY nfi.weight ASC, nfi.label ASC", $type['type']);
        while ($field = db_fetch_array($field_result)) {
          // Overwrite global field information with specific information
          $field = array_merge($info['fields'][$field['field_name']], $field);

          $widget_settings = $field['widget_settings'] ? unserialize($field['widget_settings']) : array();
          unset($field['widget_settings']);
          $field['widget'] = $widget_settings;
          $field['widget']['type'] = $field['widget_type'];
          unset($field['widget_type']);
          $field['widget']['weight'] = $field['weight'];
          unset($field['weight']);
          $field['widget']['label'] = $field['label'];
          unset($field['label']);
          $field['widget']['description'] = $field['description'];
          unset($field['description']);
          $field['type_name'] = $type['type'];
          $type['fields'][$field['field_name']] = $field;
        }
        $info['content types'][$type['type']] = $type;
      }

      cache_set('content_type_info', 'cache', serialize($info), CACHE_PERMANENT);
    }
  }
  return $info;
}

/**
 *  Implementation of hook_node_type()
 *  React to change in node types
 */
function content_node_type($op, $info) {
  switch ($op) {
    case 'insert':
      include_once('./'. drupal_get_path('module', 'content') .'/content_crud.inc');
      content_type_create($info);
      break;
    case 'update':
      include_once('./'. drupal_get_path('module', 'content') .'/content_crud.inc');
      content_type_update($info);
      break;
    case 'delete':
      include_once('./'. drupal_get_path('module', 'content') .'/content_crud.inc');
      content_type_delete($info);
      break;
  }
}

/**
 * Clear the cache of content_types; called in several places when content
 * information is changed.
 */
function content_clear_type_cache() {
  cache_clear_all('content_type_info', 'cache');

  _content_type_info(TRUE);

  if (module_exists('views')) {
    views_invalidate_cache();
  }
}

/**
 * Retrieve the database storage location(s) for a field.
 *
 * @param $field
 *   The field whose database information is requested.
 * @return
 *   An array with the keys:
 *     "table": The name of the database table where the field data is stored.
 *     "columns": An array of columns stored for this field. Each is a collection
 *       of information returned from hook_field_settings('database columns'),
 *       with the addition of a "column" attribute which holds the name of the
 *       database column that stores the data.
 */
function content_database_info($field) {
  $field_types = _content_field_types();
  $module = $field_types[$field['type']]['module'];
  $columns = module_invoke($module, 'field_settings', 'database columns', $field);

  $db_info = array();

  if ($field['db_storage'] == CONTENT_DB_STORAGE_PER_FIELD) {
    $db_info['table'] = _content_tablename($field['field_name'], 'field');
  }
  else {
    $type = content_types($field['type_name']);
    $db_info['table'] = $type['table'];
  }

  if (is_array($columns) && count($columns)) {
    $db_info['columns'] = $columns;
    foreach ($columns as $column_name => $attributes) {
      $db_info['columns'][$column_name]['column'] = $field['field_name'] .'_'. $column_name;
    }
  }
  else {
    $db_info['columns'] = array();
  }

  return $db_info;
}

/**
 * Manipulate a 2D array to reverse rows and columns.
 *
 * The default data storage for fields is delta first, column names second.
 * This is sometimes inconvenient for field modules, so this function can be
 * used to present the data in an alternate format.
 *
 * @param $array
 *   The array to be transposed. It must be at least two-dimensional, and
 *   the subarrays must all have the same keys or behavior is undefined.
 *
 * @return
 *   The transposed array.
 */
function content_transpose_array_rows_cols($array) {
  $result = array();
  if (is_array($array)) {
    foreach ($array as $key1 => $value1) {
      if (is_array($value1)) {
        foreach ($value1 as $key2 => $value2) {
          if (!isset($result[$key2])) {
            $result[$key2] = array();
          }
          $result[$key2][$key1] = $value2;
        }
      }
    }
  }
  return $result;
}

/**
 * Format a field item for display.
 *
 * @param $field
 *   Either a field array or the name of the field.
 * @param $item
 *   The field item to be formatted (such as $node->field_foo[0]).
 * @param $formatter
 *   The name of the formatter to use.
 * @param $node
 *   Optionally, the containing node object for context purposes.
 *
 * @return
 *   A string containing the contents of the field item sanitized for display.
 *   It will have been passed through the necessary check_plain() or check_markup()
 *   functions as necessary.
 */
function content_format($field, $item, $formatter = 'default', $node = NULL) {
  if (!is_array($field)) {
    $field = content_fields($field);
  }
  $field_types = _content_field_types();
  $formatters = $field_types[$field['type']]['formatters'];

  if (!isset($formatter, $formatters)) {
    $formatter = 'default';
  }
  return module_invoke($formatters[$formatter]['module'], 'field_formatter', $field, $item, $formatter, $node);
}

/**
 * Format an individual field for display.
 *
 * @param $node
 *   The node being displayed (provided for context).
 * @param $field
 *   The field that is to be displayed (for information about the label, field
 *   type, and so forth).
 * @param $items
 *   The actual items to theme. This will be a linear array, each element of
 *   which has a "view" property which contains the filtered, formatted contents
 *   of the item.
 * @param $teaser
 *   Whether the node is being displayed as a teaser or full version.
 * @param $page
 *   Whether the node is being displayed as a full web page.
 *
 * @return
 *   An HTML string containing the fully themed field.
 */
function theme_field(&$node, &$field, &$items, $teaser, $page) {
  $items_output = '';
  foreach ($items as $item) {
    if (!empty($item['view']) || $item['view'] === "0") {
      $items_output .= '<div class="field-item">'. $item['view'] .'</div>';
    }
  }
  $output = '';
  if (!empty($items_output)) {
    $output .= '<div class="field field-type-'. strtr($field['type'], '_', '-') .' field-'. strtr($field['field_name'], '_', '-') .'">';
    $output .= '<h3 class="field-label">'. $field['widget']['label'] .'</h3>';
    $output .= '<div class="field-items">'. $items_output .'</div>';
    $output .= '</div>';
  }
  return $output;
}

/**
 * Generate a table name for a field or a content type.
 *
 * @param $name
 *   The name of the content type or content field
 * @param $entity
 *   'field' or 'type'
 *
 * @return
 *   A string containing the generated name for the database table
 */
function _content_tablename($name, $entity = 'type') {
  switch ($entity) {
    case 'type' :
      return 'node_'.$name;
    case 'field' :
      return 'node_data_'.$name;
  }
}