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class views_oai_pmh_request in Views OAI-PMH 7.3

Class views_oai_pmh_request.

This class parses and performs error checks against the parameters of the requested URL. The view plugin delegates those tasks to an object of this class, and accesses its public members when needed instead of directly checking the $_REQUEST.

Hierarchy

Expanded class hierarchy of views_oai_pmh_request

File

includes/request.inc, line 16
Represents an OAI-PMH request.

View source 
class views_oai_pmh_request {

  /**
   * The base URL of this OAI-PMH request.
   *
   * @var string
   */
  public $base_url = '';

  /**
   * The request verb.
   *
   * @var string
   */
  public $verb = '';

  /**
   * Name of the style plugin callback corresponding to $verb.
   *
   * @var string
   */
  public $callback = '';

  /**
   * The metadata prefix.
   *
   * @var string
   */
  public $metadata_prefix = '';

  /**
   * A views_oai_pmh_metadata_format object.
   *
   * @var string
   */
  public $metadata_format;

  /**
   * The base URL of this OAI-PMH request.
   *
   * @var string
   */
  public $resumption_token = '';

  /**
   * The node id.
   *
   * @var int
   */
  public $nid = 0;

  /**
   * Unknow.
   *
   * @var int
   */
  public $from = 0;

  /**
   * Unknow.
   *
   * @var int
   */
  public $until = 0;

  /**
   * TODO: Add $set if we decide to support sets.
   */

  /**
   * The response date.
   *
   * @var int
   */
  public $response_date = '';

  /**
   * The response time.
   *
   * @var int
   */
  public $response_timestamp = 0;

  /**
   * Errors.
   *
   * @var array
   */
  public $errors = array();

  /**
   * Of the responses.
   *
   * Arguments as given by the user. Do NOT use those
   * unvalidated arguments during request execution. These are only needed for
   * the 'request' element.
   *
   * @var array
   */
  public $original_args = array();

  /**
   * Constructs the object based on $_REQUEST data.
   */
  public function __construct($base_url, $allowed_metadata_prefixes, $live_preview = FALSE) {
    $this->base_url = $base_url;
    if ($live_preview) {
      $args['verb'] = 'ListRecords';
      $args['metadataPrefix'] = 'oai_dc';
    }
    else {
      $args = $_REQUEST;
    }
    if (isset($args['q'])) {

      // Ignore the Drupal 'q' argument.
      unset($args['q']);
    }
    $this->response_timestamp = time();
    $this->response_date = gmstrftime('%Y-%m-%dT%H:%M:%SZ', $this->response_timestamp);
    if (!isset($args['verb'])) {
      $this->errors[] = new views_oai_pmh_error_missing_verb();
    }
    elseif (!in_array($args['verb'], array(
      'GetRecord',
      'ListIdentifiers',
      'ListRecords',
      'Identify',
      'ListMetadataFormats',
      'ListSets',
    ))) {
      $this->errors[] = new views_oai_pmh_error_bad_verb();
    }
    else {
      $this->verb = $args['verb'];

      // Remove this one before further parsing.
      unset($args['verb']);
      switch ($this->verb) {
        case 'Identify':
          $this->callback = 'identify';
          $this
            ->parse_arguments($args);
          break;
        case 'ListMetadataFormats':
          $this->callback = 'list_metadata_formats';
          $this
            ->parse_arguments($args, array(), array(
            'identifier',
          ));
          break;
        case 'ListIdentifiers':
          $this->callback = 'list_identifiers';
          $this
            ->parse_arguments($args, array(
            'metadataPrefix',
          ), array(
            'resumptionToken',
            'from',
            'until',
            'set',
          ));
          $this
            ->parse_metadata_prefix($args, $allowed_metadata_prefixes);
          break;
        case 'GetRecord':
          $this->callback = 'get_record';
          $this
            ->parse_arguments($args, array(
            'identifier',
            'metadataPrefix',
          ));
          $this
            ->parse_metadata_prefix($args, $allowed_metadata_prefixes);
          break;
        case 'ListRecords':
          $this->callback = 'list_records';
          $this
            ->parse_arguments($args, array(
            'metadataPrefix',
          ), array(
            'resumptionToken',
            'from',
            'until',
            'set',
          ));
          $this
            ->parse_metadata_prefix($args, $allowed_metadata_prefixes);
          break;
        case 'ListSets':
          $this
            ->parse_arguments($args);
          $this->errors[] = new views_oai_pmh_error_no_set_hierarchy();
          break;
      }
    }
  }

  /**
   *
   */
  public function get_host() {
    $parts = parse_url($this->base_url);
    return $parts['host'];
  }

  /**
   *
   */
  public function make_record_identifier_prefix() {
    return 'oai:' . $this
      ->get_host() . ':';
  }

  /**
   * Returns TRUE if either a 'badVerb' or a 'badArgument' error has occurred.
   */
  public function is_bad() {
    foreach ($this->errors as $error) {
      if ($error->code == 'badVerb' || $error->code == 'badArgument') {
        return TRUE;
      }
    }
    return FALSE;
  }

  /**
   * Parse the given arguments, initializing each argument's corresponding
   * member variable if the argument is valid, or appending an error when it is
   * not.
   */
  protected function parse_arguments($args, $required = array(), $optional = array()) {
    $possible = array_merge($required, $optional);

    // Preserve original value of every authorized tag.
    foreach ($possible as $arg) {
      if (isset($args[$arg])) {
        $this->original_args[$arg] = $args[$arg];
      }
    }

    // Parse resumption token.
    if (isset($args['resumptionToken']) && in_array('resumptionToken', $possible)) {
      if (count($args) > 1) {
        $this->errors[] = new views_oai_pmh_error_exclusive_argument('resumptionToken');
      }
      else {
        $this->resumption_token = $args['resumptionToken'];
      }

      // No more arguments to check since resumptionToken is exclusive.
      return;
    }

    // Check required arguments.
    foreach ($required as $arg) {
      if (!isset($args[$arg])) {
        $this->errors[] = new views_oai_pmh_error_missing_argument($arg);
      }
    }

    // Check for extraneous arguments.
    foreach (array_keys($args) as $arg) {
      if (!in_array($arg, $possible)) {
        $this->errors[] = new views_oai_pmh_error_bad_argument($arg);

        // Prevent further error reports about the same argument.
        unset($args[$arg]);
      }
    }

    // Check for the 'set' argument (unsupported).
    if (isset($args['set'])) {
      $this->errors[] = new views_oai_pmh_error_no_set_hierarchy();
    }

    // Check date arguments.
    $from_granularity = 0;
    $until_granularity = 0;
    if (isset($args['from'])) {
      if (!($from_granularity = $this
        ->check_date_format($args['from']))) {
        $this->errors[] = new views_oai_pmh_error_bad_value('from', $args['from']);
      }
    }
    if (isset($args['until'])) {
      if (!($until_granularity = $this
        ->check_date_format($args['until']))) {
        $this->errors[] = new views_oai_pmh_error_bad_value('until', $args['until']);
      }
    }
    if ($from_granularity && $until_granularity && $from_granularity != $until_granularity) {
      $this->errors[] = new views_oai_pmh_error_bad_value('until', $args['until']);
    }
    else {
      if ($from_granularity) {
        $this->from = $args['from'];
      }
      if ($until_granularity) {
        $this->until = $args['until'];
      }
    }

    // Check identifier argument.
    if (isset($args['identifier'])) {
      $matches = array();
      if (preg_match('/^' . preg_quote($this
        ->make_record_identifier_prefix()) . '([0-9]+)$/', $args['identifier'], $matches)) {
        $this->nid = $matches[1];
      }
      else {
        $this->errors[] = new views_oai_pmh_error_invalid_id($args['identifier']);
      }
    }
  }

  /**
   *
   */
  protected function check_date_format($date) {
    $matches = array();
    if (preg_match('/^([0-9]{4})-([0-9]{1,2})-([0-9]{1,2})T([0-9]{2}):([0-9]{2}):([0-9]{2})Z$/', $date, $matches)) {
      if (checkdate($matches[2], $matches[3], $matches[1])) {
        return 1;
      }
    }
    elseif (preg_match('/^([0-9]{4})-([0-9]{1,2})-([0-9]{1,2})$/', $date, $matches)) {
      if (checkdate($matches[2], $matches[3], $matches[1])) {
        return 2;
      }
    }
    return 0;
  }

  /**
   * Checks that the metadataPrefix argument matches a supported metadata
   * format.
   */
  protected function parse_metadata_prefix($args, $metadata_prefixes) {
    if (isset($args['metadataPrefix'])) {
      if (isset($metadata_prefixes[$args['metadataPrefix']]) && in_array($metadata_prefixes[$args['metadataPrefix']], views_oai_pmh_list_metadata_formats())) {
        $this->metadata_format = views_oai_pmh_get_metadata_format($metadata_prefixes[$args['metadataPrefix']]);
        $this->metadata_prefix = $args['metadataPrefix'];
        return;
      }
      $this->errors[] = new views_oai_pmh_error_cannot_disseminate_format($args['metadataPrefix']);
    }
  }

}

Members

Namesort descending Modifiers Type Description Overrides
views_oai_pmh_request::$base_url public property The base URL of this OAI-PMH request.
views_oai_pmh_request::$callback public property Name of the style plugin callback corresponding to $verb.
views_oai_pmh_request::$errors public property Errors.
views_oai_pmh_request::$from public property Unknow.
views_oai_pmh_request::$metadata_format public property A views_oai_pmh_metadata_format object.
views_oai_pmh_request::$metadata_prefix public property The metadata prefix.
views_oai_pmh_request::$nid public property The node id.
views_oai_pmh_request::$original_args public property Of the responses.
views_oai_pmh_request::$response_date public property The response date.
views_oai_pmh_request::$response_timestamp public property The response time.
views_oai_pmh_request::$resumption_token public property The base URL of this OAI-PMH request.
views_oai_pmh_request::$until public property Unknow.
views_oai_pmh_request::$verb public property The request verb.
views_oai_pmh_request::check_date_format protected function
views_oai_pmh_request::get_host public function
views_oai_pmh_request::is_bad public function Returns TRUE if either a 'badVerb' or a 'badArgument' error has occurred.
views_oai_pmh_request::make_record_identifier_prefix public function
views_oai_pmh_request::parse_arguments protected function Parse the given arguments, initializing each argument's corresponding member variable if the argument is valid, or appending an error when it is not.
views_oai_pmh_request::parse_metadata_prefix protected function Checks that the metadataPrefix argument matches a supported metadata format.
views_oai_pmh_request::__construct public function Constructs the object based on $_REQUEST data.