class views_oai_pmh_plugin_display in Views OAI-PMH 6

We are based on a feed display for compatibility.

Hierarchy

• class \views_oai_pmh_plugin_display extends \views_plugin_display_page

1 string reference to 'views_oai_pmh_plugin_display'

views_oai_pmh_views_plugins in ./views_oai_pmh.views.inc

Implementation of hook_views_plugins().

File

plugins/views_oai_pmh_plugin_display.inc, line 15

Contains the OAI-PMH display plugin.

class views_oai_pmh_plugin_display extends views_plugin_display_page {
  public $oai_args;
  public $oai_errors = array();
  protected $oai_compression = TRUE;
  function init(&$view, &$display, $options = NULL) {
    parent::init($view, $display, $options);

    // Set the default row style. Ideally this would be part of the option
    // definition, but in this case it's dependent on the view's base table,
    // which we don't know until init().
    //  $row_plugins = views_fetch_plugin_names('row', $this->get_style_type(), array($view->base_table));
    //  $default_row_plugin = key($row_plugins);
    if ($this->options['row_plugin'] == '') {
      $this->options['row_plugin'] = $default_row_plugin;
    }
  }

  /**
   * Return the type of styles we require.
   */
  function get_style_type() {
    return 'oai-pmh';
  }
  function &get_oai_args() {
    return $this->oai_args;
  }
  function get_oai_errors() {
    return $this->oai_errors;
  }

  /**
   * Return the sections that can be defaultable.
   */
  function defaultable_sections($section = NULL) {
    if (in_array($section, array(
      'style_plugin',
      'items_per_page',
      'offset',
      'use_pager',
      'pager_element',
    ))) {
      return FALSE;
    }
    return parent::defaultable_sections($section);
  }

  /**
   * Define the option for this view.
   */
  function option_definition() {
    $options = parent::option_definition();
    if (!isset($this->oai_args)) {
      $this->oai_args = $this
        ->parse_oai_request();
    }
    $metadataPrefix = isset($this->oai_args['metadataPrefix']) ? $this->oai_args['metadataPrefix'] : 'oai_dc';
    switch ($metadataPrefix) {
      case 'etdms':
        $options['style_plugin']['default'] = 'views_oai_pmh_etdms';
        $options['row_plugin']['default'] = 'etdms';
        break;
      case 'oai_dc':
      default:
        $options['style_plugin']['default'] = 'views_oai_pmh_dc';
        $options['row_plugin']['default'] = 'dc';
        break;
    }
    $options['items_per_page'] = array(
      'default' => '0',
    );

    //  $options['style_plugin']['default'] = 'views_oai_pmh_dc';
    //  $options['row_plugin']['default'] = 'dc';
    if (isset($options['defaults']['default']['items_per_page'])) {
      $options['defaults']['default']['items_per_page'] = FALSE;
    }
    $options['displays'] = array(
      'default' => array(),
    );
    $options['defaults']['fields']['hide_empty'] = array(
      'default' => TRUE,
    );
    $options['defaults']['hide_empty'] = array(
      'default' => TRUE,
    );

    // Overrides for standard stuff:
    $options['defaults']['default']['style_plugin'] = FALSE;
    $options['defaults']['default']['style_options'] = FALSE;
    $options['defaults']['default']['row_plugin'] = FALSE;
    $options['defaults']['default']['row_options'] = FALSE;
    return $options;
  }

  /**
   * Provide the summary for page options in the views UI.
   *
   * This output is returned as an array.
   */
  function options_summary(&$categories, &$options) {

    // It is very important to call the parent function here:
    parent::options_summary($categories, $options);
    $categories['page']['title'] = t('OAI PMH settings');
  }

  /**
   * Provide the default form for setting options.
   */
  function options_form(&$form, &$form_state) {

    // It is very important to call the parent function here:
    parent::options_form($form, $form_state);
  }

  /**
   * Save the options from the options form.
   */

  /**
   * Execute this display handler.
   *
   */
  function execute() {
    if ($this->oai_compression) {
      ob_start('ob_gzhandler');
    }
    drupal_set_header('Content-Type: application/xml');
    print $this->view
      ->render();
    if ($this->oai_compression) {
      ob_end_flush();
    }
  }

  /**
   * Render the display.
   */
  function render() {
    return $this->view->style_plugin
      ->render();
  }
  function query() {
    if (count($this->oai_args['errors'])) {
      $this->view->executed = TRUE;
      return parent::query();
    }
    if (isset($this->oai_args['resumptionToken']) && isset($this->oai_args['query'])) {
      $this->view->query = $this->oai_args['query'];
      $this->view->query->pager
        ->set_current_page($this->oai_args['current_page'] + 1);
    }
    elseif (count($this->oai_args['errors'])) {
      $this->view->executed = TRUE;
    }
    else {
      $verb = $this->oai_args['verb'];
      $this->view->query
        ->add_field('node', 'nid');
      $this->view->query
        ->add_field('node', 'changed');
      $this->view->query
        ->add_orderby('node', 'nid', 'asc');
      if ($verb == 'GetRecord' && isset($this->oai_args['nid'])) {
        $this->view->query
          ->add_where(0, 'node.nid = %d', $this->oai_args['nid']);
      }
      if ($verb == 'ListIdentifiers' || $verb == 'ListRecords') {
        if (isset($this->oai_args['from'])) {
          $from = strtotime($this->oai_args['from']);
          $this->view->query
            ->add_where(0, 'node.changed >= %d', $from);
        }
        if (isset($this->oai_args['until'])) {
          $until = strtotime($this->oai_args['until']);
          $this->view->query
            ->add_where(0, 'node.changed <= %d', $until);
        }
      }
    }
    return parent::query();
  }
  function preview() {
    if (!isset($this->oai_args['verb']) || empty($this->oai_args['verb'])) {
      $this->oai_args['verb'] = 'ListRecords';
    }
    $this->oai_args['response_date'] = gmstrftime('%Y-%m-%dT%H:%M:%SZ', time());
    $this->oai_args['errors'] = array();
    if (!empty($this->view->live_preview)) {
      return '<pre>' . check_plain($this->view
        ->render()) . '</pre>';
    }
    return $this->view
      ->render();
  }
  function parse_oai_request() {
    $args = array();
    if (!empty($_GET)) {
      $args = $_GET;
    }
    if (!empty($_POST)) {
      $args = $_POST;
    }
    if (isset($args['q'])) {
      unset($args['q']);
    }

    // get rid of the Drupal q
    if (!count($args)) {
      $this
        ->oai_error('badRequestMethod', $_SERVER['REQUEST_METHOD']);
    }
    if (isset($args['verb']) && !count($this->oai_errors)) {
      switch ($args['verb']) {
        case 'GetRecord':
          $this
            ->oai_check_args($args, array(
            'identifier',
            'metadataPrefix',
          ));
          $this
            ->oai_check_metadata_prefix($args);
          if (count($this->oai_errors)) {
            return;
          }
          $args['nid'] = substr(strrchr($args['identifier'], ":"), 1);
          break;
        case 'ListIdentifiers':
        case 'ListRecords':
          $args += $this
            ->oai_check_args($args, array(
            'metadataPrefix',
          ), array(
            'from',
            'until',
            'set',
          ));
          $this
            ->oai_check_metadata_prefix($args);
          break;
        case 'Identify':
          $this
            ->oai_check_args($args);
          $this->oai_compression = FALSE;
          break;
        case 'ListMetadataFormats':
          $this
            ->oai_check_args($args, array(), array(
            'identifier',
          ));
          if (count($this->oai_errors)) {
            return;
          }
          if (isset($args['identifier'])) {
            $args['nid'] = substr(strrchr($args['identifier'], ":"), 1);
          }
          break;
        case 'ListSets':
          $this
            ->oai_error('noSetHierarchy');

          //  $this->oai_resumption_token();
          break;
        default:

          // we never use compression with errors
          $this->oai_compression = FALSE;
          $this
            ->oai_error('badVerb', $args['verb']);
          $args['verb'] = '';
      }
    }
    elseif (!count($this->oai_errors)) {
      $args['verb'] = '';
      $this
        ->oai_error('noVerb');
    }
    $args['response_date'] = gmstrftime('%Y-%m-%dT%H:%M:%SZ', time());
    $args['errors'] = $this->oai_errors;
    return $args;
  }
  function oai_check_identifier($identifier) {
    return db_result(db_query("SELECT nid FROM {node} WHERE nid = %d", $identifier));
  }
  function oai_check_args($args, $required = array(), $optional = array()) {
    unset($args['verb']);
    if (isset($args['resumptionToken']) && count($args) > 1) {
      $this
        ->oai_error('exclusiveArgument');
      return array();
    }
    elseif (isset($args['resumptionToken']) && count($args) == 1) {
      return $this
        ->get_oai_resumption_token($args['resumptionToken']);
    }
    if (count($args) < count($required)) {
      foreach ($required as $arg) {
        if (!isset($args[$arg])) {
          $this
            ->oai_error('missingArgument', $arg);
          return array();
        }
      }
    }
    $possible = array_merge($required, $optional);
    $supplied = array_keys($args);
    if (count($bad_args = array_diff($supplied, $possible))) {
      foreach ($bad_args as $arg) {
        $this
          ->oai_error('badArgument', $arg, $args[$arg]);
      }
      return array();
    }
    if (isset($args['from'])) {
      if (!($fromgran = $this
        ->check_date_format($args['from']))) {
        $this
          ->oai_error('badGranularity', 'from', $args['from']);
      }
    }
    if (isset($args['until'])) {
      if (!($untilgran = $this
        ->check_date_format($args['until']))) {
        $this
          ->oai_error('badGranularity', 'until', $args['until']);
      }
    }
    if (isset($fromgran) && isset($untilgran) && $fromgran != $untilgran) {
      $this
        ->oai_error('badGranularity', 'mismatched Granularity', $until);
    }
    if (isset($args['identifier'])) {
      $id = substr(strrchr($args['identifier'], ":"), 1);
      if (!$this
        ->oai_check_identifier($id)) {
        $this
          ->oai_error('idDoesNotExist', 'badArgument', $id);
      }
    }
    return array();
  }
  function oai_check_metadata_prefix($args) {
    if (!isset($args['metadataPrefix'])) {
      $this
        ->oai_error('missingArgument', 'metadataPrefix');
    }
    elseif (array_search($args['metadataPrefix'], array(
      'oai_dc',
      'etdms',
    )) === FALSE) {
      $this
        ->oai_error('cannotDisseminateFormat', 'metadataPrefix', $args['metadataPrefix']);
    }
  }
  function oai_error($code, $argument = '', $value = '') {
    $this->oai_compression = FALSE;
    $error = array(
      'key' => 'error',
      'attributes' => array(
        'code' => $code,
      ),
    );
    switch ($code) {
      case 'badArgument':
        $error += array(
          'value' => t("The argument @argument (value=@value) included in the request is not valid.", array(
            '@value' => $value,
            '@argument' => $argument,
          )),
        );
        break;
      case 'badGranularity':
        $error = array(
          'key' => 'error',
          'attributes' => array(
            'code' => 'badArgument',
          ),
          'value' => t("The value @value of the argument '@argument' is not valid.", array(
            '@value' => $value,
            '@argument' => $argument,
          )),
        );
        break;
      case 'badResumptionToken':
        $error += array(
          'value' => t("The resumptionToken @value does not exist or has already expired.", array(
            '@value' => $value,
          )),
        );
        break;
      case 'badRequestMethod':
        $error = array(
          'key' => 'error',
          'attributes' => array(
            'code' => 'badVerb',
          ),
          'value' => t("The request method @argument is unknown.", array(
            '@argument' => $argument,
          )),
        );
        break;
      case 'badVerb':
        $error += array(
          'value' => t("The verb @argument provided in the request is illegal.", array(
            '@argument' => $argument,
          )),
        );
        break;
      case 'cannotDisseminateFormat':
        $error += array(
          'value' => t("The metadata format @value given by @argument is not supported by this repository.", array(
            '@value' => $value,
            '@argument' => $argument,
          )),
        );
        break;
      case 'exclusiveArgument':
        $error = array(
          'key' => 'error',
          'attributes' => array(
            'code' => 'badArgument',
          ),
          'value' => t('The usage of resumptionToken as an argument allows no other arguments.'),
        );
        break;
      case 'idDoesNotExist':
        $error += array(
          'value' => t("The value @value of the identifier is illegal for this repository.", array(
            '@value' => $value,
          )),
        );
        break;
      case 'missingArgument':
        $error = array(
          'key' => 'error',
          'attributes' => array(
            'code' => 'badArgument',
          ),
          'value' => t("The required argument @argument is missing in the request.", array(
            '@argument' => $argument,
          )),
        );
        break;
      case 'noRecordsMatch':
        $error += array(
          'value' => t('The combination of the given values results in an empty list.'),
        );
        break;
      case 'noMetadataFormats':
        $error += array(
          'value' => t('There are no metadata formats available for the specified item.'),
        );
        break;
      case 'noVerb':
        $error = array(
          'key' => 'error',
          'attributes' => array(
            'code' => 'badVerb',
          ),
          'value' => t('The request does not provide any verb.'),
        );
        break;
      case 'noSetHierarchy':
        $error += array(
          'value' => t('This repository does not support sets.'),
        );
        break;
      case 'sameArgument':
        $error = array(
          'key' => 'error',
          'attributes' => array(
            'code' => 'badArgument',
          ),
          'value' => t('Do not use them same argument more than once.'),
        );
        break;
      case 'sameVerb':
        $error = array(
          'key' => 'error',
          'attributes' => array(
            'code' => 'badVerb',
          ),
          'value' => t('Do not use verb more than once.'),
        );
        break;
      default:
        $error = array(
          'key' => 'error',
          'attributes' => array(
            'code' => 'badArgument',
          ),
          'value' => t("Unknown error: code: @code, argument: @argument, value: @value", array(
            '@value' => $value,
            '@argument' => $argument,
            '@code' => $code,
          )),
        );
    }
    $this->oai_errors[] = $error;
    return $this->oai_errors;
  }
  function build_oai_resumption_token() {
    if (count($this->oai_errors)) {
      return;
    }
    $items_per_page = $this->view->query->pager
      ->get_items_per_page();
    $current_page = $this->view->query->pager
      ->get_current_page();
    $total_items = $this->view->query->pager
      ->get_total_items();
    $total_pages = $this->view->query->pager
      ->get_pager_total();
    $cursor = $items_per_page * $current_page;
    $token = $current_page == $total_pages - 1 ? NULL : md5(uniqid());
    $token_expire_time = gmstrftime('%Y-%m-%dT%H:%M:%SZ', time() + 24 * 3600);
    $token_attrs = array(
      'completeListSize' => $total_items,
      'cursor' => $cursor,
    );
    if ($token) {
      $token_attrs['expirationDate'] = $token_expire_time;
      $data = array(
        'cursor' => $cursor,
        'total_items' => $total_items,
        'current_page' => $current_page,
        'metadataPrefix' => $this->oai_args['metadataPrefix'],
        'query' => $this->view->query,
      );
      $fields = array(
        'serialized' => 1,
        'created' => REQUEST_TIME,
        'expire' => time() + OAI_TOKEN_LIFETIME,
        'data' => serialize($data),
        'cid' => $token,
      );

      // doing my own insert here because cache_set was silently eating
      // max_allowed_packet errors and dropping cache inserts.  http://drupal.org/node/542874
      // changing the my.ini setting fixed the error, but I would like users to know about the error.
      //
      cache_set($token, $data, 'cache_views_oai_pmh', time() + OAI_TOKEN_LIFETIME);

      // db_insert('cache_views_oai_pmh')
      //   ->fields($fields)
      //  ->execute();
    }
    return format_xml_elements(array(
      array(
        'key' => 'resumptionToken',
        'attributes' => $token_attrs,
        'value' => $token,
      ),
    ));
  }
  function get_oai_resumption_token($token) {

    // need these includes so the query and pager classes un-serialize correclty
    module_load_include('inc', 'views', '/plugins/views_plugin_query');
    module_load_include('inc', 'views', '/plugins/views_plugin_query_default');
    module_load_include('inc', 'views', '/plugins/views_plugin_pager');
    module_load_include('inc', 'views', '/plugins/views_plugin_pager_full');
    $cache = cache_get($token, 'cache_views_oai_pmh');
    if (isset($cache->data) && is_array($cache->data)) {
      return $cache->data;
    }
    else {
      $this
        ->oai_error('badResumptionToken', '', $token);
      return array();
    }
  }
  function check_date_format($date) {
    $checkstr1 = '([0-9]{4})-([0-9]{1,2})-([0-9]{1,2})T([0-9]{2}):([0-9]{2}):([0-9]{2})Z$';
    $checkstr2 = '([0-9]{4})-([0-9]{1,2})-([0-9]{1,2}$)';
    if (ereg($checkstr1, $date, $regs)) {
      if (checkdate($regs[2], $regs[3], $regs[1])) {
        return 1;
      }
    }
    elseif (ereg($checkstr2, $date, $regs)) {
      if (checkdate($regs[2], $regs[3], $regs[1])) {
        return 2;
      }
    }
    return FALSE;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
views_oai_pmh_plugin_display::$oai_args	public	property
views_oai_pmh_plugin_display::$oai_compression	protected	property
views_oai_pmh_plugin_display::$oai_errors	public	property
views_oai_pmh_plugin_display::build_oai_resumption_token		function
views_oai_pmh_plugin_display::check_date_format		function
views_oai_pmh_plugin_display::defaultable_sections		function	Return the sections that can be defaultable.
views_oai_pmh_plugin_display::execute		function	Execute this display handler.
views_oai_pmh_plugin_display::get_oai_args		function
views_oai_pmh_plugin_display::get_oai_errors		function
views_oai_pmh_plugin_display::get_oai_resumption_token		function
views_oai_pmh_plugin_display::get_style_type		function	Return the type of styles we require.
views_oai_pmh_plugin_display::init		function
views_oai_pmh_plugin_display::oai_check_args		function
views_oai_pmh_plugin_display::oai_check_identifier		function
views_oai_pmh_plugin_display::oai_check_metadata_prefix		function
views_oai_pmh_plugin_display::oai_error		function
views_oai_pmh_plugin_display::options_form		function	Provide the default form for setting options.
views_oai_pmh_plugin_display::options_summary		function	Provide the summary for page options in the views UI.
views_oai_pmh_plugin_display::option_definition		function	Define the option for this view.
views_oai_pmh_plugin_display::parse_oai_request		function
views_oai_pmh_plugin_display::preview		function
views_oai_pmh_plugin_display::query		function
views_oai_pmh_plugin_display::render		function	Render the display.