Club Drupal

<?php

/**

 * @file

 * Defines the iCal Fields row style plugin, which lets users map view fields

 * to the components of the VEVENTs in the iCal feed.

 */

/**

 * A Views plugin which builds an iCal VEVENT from a views row with Fields.

 */

class date_ical_plugin_row_ical_fields extends views_plugin_row {

  /**

   * Set up the options for the row plugin.

   */

  public function option_definition() {

    $options = parent::option_definition();

    $options['date_field'] = array('default' => '');

    $options['title_field'] = array('default' => '');

    $options['description_field'] = array('default' => '');

    $options['location_field'] = array('default' => '');

    $options['additional_settings']['skip_blank_dates'] = array('default' => FALSE);

    return $options;

  }

  /**

   * Build the form for setting the row plugin's options.

   */

  public function options_form(&$form, &$form_state) {

    parent::options_form($form, $form_state);

    $all_field_labels = $this->display->handler->get_field_labels();

    $date_field_labels = $this->get_date_field_candidates($all_field_labels);

    $date_field_label_options = array_merge(array('first_available' => t('First populated Date field')), $date_field_labels);

    $text_field_label_options = array_merge(array('' => t('- None -')), $all_field_labels);

    $form['instructions'] = array(

      // The surrounding <div> ensures that the settings dialog expands.

      '#prefix' => '<div style="font-size: 90%">',

      '#suffix' => '</div>',

      '#markup' => t("Once you've finished setting up the fields for this View, you may want to return to this dialog to set the Date field."),

    );

    $form['date_field'] = array(

      '#type' => 'select',

      '#title' => t('Date field'),

      '#description' => t('The views field to use as the start (and possibly end) time for each event (DTSTART/DTEND).

        If you retain the default ("First populated Date field"), Date iCal will use the first non-empty Date field in the row.'),

      '#options' => $date_field_label_options,

      '#default_value' => $this->options['date_field'],

      '#required' => TRUE,

    );

    $form['title_field'] = array(

      '#type' => 'select',

      '#title' => t('Title field'),

      '#description' => t('The views field to use as the title for each event (SUMMARY).'),

      '#options' => $text_field_label_options,

      '#default_value' => $this->options['title_field'],

      '#required' => FALSE,

    );

    $form['description_field'] = array(

      '#type' => 'select',

      '#title' => t('Description field'),

      '#description' => t("The views field to use as the body text for each event (DESCRIPTION).<br>

          If you wish to include more than one entity field in the event body, you may want to use the 'Content: Rendered Node' views field,

          and set it to the 'iCal' view mode. Then configure the iCal view mode on your event nodes to include the text you want."),

      '#options' => $text_field_label_options,

      '#default_value' => $this->options['description_field'],

      '#required' => FALSE,

    );

    $form['location_field'] = array(

      '#type' => 'select',

      '#title' => t('Location field'),

      '#description' => t('(optional) The views field to use as the location for each event (LOCATION).'),

      '#options' => $text_field_label_options,

      '#default_value' => $this->options['location_field'],

      '#required' => FALSE,

    );

    $form['additional_settings'] = array(

      '#type' => 'fieldset',

      '#title' => t('Additional settings'),

      '#collapsible' => FALSE,

      '#collapsed' => FALSE,

    );

    $form['additional_settings']['skip_blank_dates'] = array(

      '#type' => 'checkbox',

      '#title' => t('Skip blank dates'),

      '#description' => t('Normally, if a view result has a blank date field, the feed will display an error,

        because it is impossible to create an iCal event with no date. This option makes Views silently skip those results, instead.'),

      '#default_value' => $this->options['additional_settings']['skip_blank_dates'],

    );

  }

  /**

   * Set up the environment for the render() function.

   */

  public function pre_render($result) {

    // Get the language for this view.

    $this->language = $this->display->handler->get_option('field_language');

    $substitutions = views_views_query_substitutions($this->view);

    if (array_key_exists($this->language, $substitutions)) {

      $this->language = $substitutions[$this->language];

    }

    $this->repeated_dates = array();

  }

  /**

   * Returns an Event array row in the query with index: $row->index.

   */

  public function render($row) {

    $date_field_name = $this->options['date_field'];

    // If this view is set to use the first populated date field, check each

    // field in the row to find the first non-NULL Date field.

    if ($date_field_name == 'first_available') {

      foreach (get_object_vars($row) as $name => $value) {

        if (strpos($name, 'field_field') === 0) {

          // This property's name starts with "field_field", which means it's

          // the actual field data for a field in this view.

          if (!empty($value[0]['raw']['date_type'])) {

            // Cut off the first "field_" from $name to get the field name.

            $date_field_name = substr($name, 6);

            break;

          }

        }

      }

    }

    // Fetch the event's date information.

    try {

      if ($date_field_name == 'first_available') {

        // If $date_field_name is still 'first_available' at this point, we

        // couldn't find an available Date value. Processing cannot proceed.

        $title = strip_tags($this->view->style_plugin->get_field($row->index, $this->options['title_field']));

        if (empty($title)) {

          $title = "Undetermined title";

        }

        throw new BlankDateFieldException(t("The row titled %title has no available Date value. An iCal entry cannot be created for it.", array('%title' => $title)));

      }

      $date = $this->get_row_date($row, $date_field_name);

    }

    catch (BlankDateFieldException $e) {

      // Unless the user has specifically said that they want to skip rows

      // with blank dates, let this exception percolate.

      if ($this->options['additional_settings']['skip_blank_dates']) {

        return NULL;

      }

      else {

        throw $e;

      }

    }

    // Create the event by starting with the date array from this row.

    $event = $date;

    $entity = $row->_field_data[$this->view->base_field]['entity'];

    $entity_type = $row->_field_data[$this->view->base_field]['entity_type'];

    // Add the CREATED, LAST-MODIFIED, and URL components based on the entity.

    // According to the iCal standard, CREATED and LAST-MODIFIED must be UTC.

    // Fortunately, Drupal stores timestamps in the DB as UTC, so we just need

    // to specify that UTC be used rather than the server's local timezone.

    if (isset($entity->created)) {

      $event['created'] = new DateObject($entity->created, 'UTC');

    }

    if (isset($entity->changed)) {

      $event['last-modified'] = new DateObject($entity->changed, 'UTC');

    }

    elseif (isset($entity->created)) {

      // If changed is unset, but created is, use that for last-modified.

      $event['last-modified'] = new DateObject($entity->created, 'UTC');

    }

    $uri = entity_uri($entity_type, $entity);

    $uri['options']['absolute'] = TRUE;

    $event['url'] = url($uri['path'], $uri['options']);

    // Generate a unique ID for this event by emulating the way the Date module

    // creates a Date ID.

    if (isset($row->{"field_data_{$date_field_name}_delta"})) {

      $date_field_delta = $row->{"field_data_{$date_field_name}_delta"};

    }

    else {

      // I'm not sure why the "field_data_{field_name}_delta" field is part of

      // the $row, so it's possible that it will sometimes be missing. If it

      // is, make an educated guess about the delta by comparing this row's

      // start date to each of the entity's dates.

      $date_field_delta = 0;

      foreach ($entity->{$date_field_name}['und'] as $ndx => $date_array) {

        if ($date['start']->originalTime == $date_array['value']) {

          $date_field_delta = $ndx;

          break;

        }

      }

    }

    $entity_id = $row->{$this->view->base_field};

    global $base_url;

    $domain = preg_replace('#^https?://#', '', $base_url);

    $event['uid'] = "calendar.$entity_id.$date_field_name.$date_field_delta@$domain";

    // Because of the way that Date implements repeating dates, we're going to

    // be given a separate view result for each repeat. We only want to

    // render a VEVENT (with an RRULE) for the first instance of that date, so

    // we need to record the entity ID and field name for each result that has

    // an RRULE, then skip any that we've already seen.

    if (!empty($date['rrule'])) {

      $repeat_id = "$entity_id.$date_field_name";

      if (!isset($this->repeated_dates[$repeat_id])) {

        $this->repeated_dates[$repeat_id] = $repeat_id;

      }

      else {

        return FALSE;

      }

    }

    // Retrieve the rendered text fields.

    $text_fields['summary'] = $this->get_field($row->index, $this->options['title_field']);

    $text_fields['description'] = $this->get_field($row->index, $this->options['description_field']);

    $text_fields['location'] = $this->get_field($row->index, $this->options['location_field']);

    // Allow other modules to alter the rendered text fields before they get

    // sanitized for iCal-compliance. This is most useful for fields of type

    // "Content: Rendered Node", which are likely to have complex HTML.

    $context = array(

      'row' => $row,

      'row_index' => $row->index,

      'language' => $this->language,

      'options' => $this->options,

    );

    drupal_alter('date_ical_export_html', $text_fields, $this->view, $context);

    // Sanitize the text fields for iCal compliance, and add them to the event.

    $event['summary'] = date_ical_sanitize_text($text_fields['summary']);

    $event['location'] = date_ical_sanitize_text($text_fields['location']);

    $event['description'] = date_ical_sanitize_text($text_fields['description']);

    // Allow other modules to alter the event object before it gets passed to

    // the style plugin to be converted into an iCal VEVENT.

    drupal_alter('date_ical_export_raw_event', $event, $this->view, $context);

    return $event;

  }

  /**

   * Returns an normalized array for the current row's datefield/timestamp.

   *

   * @param object $row

   *   The current row object.

   * @param string $date_field_name

   *   The name of the date field.

   *

   * @return array

   *   The normalized array.

   */

  protected function get_row_date($row, $date_field_name) {

    $start = NULL;

    $end   = NULL;

    $rrule = NULL;

    $delta = 0;

    $is_date_field = FALSE;

    // Fetch the date field value.

    $date_field_value = $this->view->style_plugin->get_field_value($row->index, $date_field_name);

    // Handle date fields.

    if (isset($date_field_value[$delta]) && is_array($date_field_value[$delta])) {

      $is_date_field = TRUE;

      $date_field = $date_field_value[$delta];

      $start = new DateObject($date_field['value'], $date_field['timezone_db']);

      if (!empty($date_field['value2'])) {

        $end = new DateObject($date_field['value2'], $date_field['timezone_db']);

      }

      else {

        $end = clone $start;

      }

      if (isset($date_field['rrule'])) {

        $rrule = $date_field['rrule'];

      }

    }

    elseif (is_numeric($date_field_value)) {

      // Handle timestamps, which are always in UTC.

      $start = new DateObject($date_field_value, 'UTC');

      $end   = new DateObject($date_field_value, 'UTC');

    }

    else {

      // Processing cannot proceed with a blank date value.

      $title = strip_tags($this->view->style_plugin->get_field($row->index, $this->options['title_field']));

      throw new BlankDateFieldException(t("The row %title has a blank date. An iCal entry cannot be created for it.", array('%title' => $title)));

    }

    // Set the display timezone to whichever tz is stored for this field.

    // If there isn't a stored TZ, use the site default.

    $timezone = isset($date_field['timezone']) ? $date_field['timezone'] : date_default_timezone(FALSE);

    $dtz = new DateTimeZone($timezone);

    $start->setTimezone($dtz);

    $end->setTimezone($dtz);

    $granularity = 'second';

    if ($is_date_field) {

      $granularity_settings = $this->view->field[$date_field_name]->field_info['settings']['granularity'];

      $granularity = date_granularity_precision($granularity_settings);

    }

    // Check if the start and end dates indicate that this is an All Day event.

    $all_day = date_is_all_day(

      date_format($start, DATE_FORMAT_DATETIME),

      date_format($end, DATE_FORMAT_DATETIME),

      $granularity

    );

    if ($all_day) {

      // According to RFC 2445 (clarified in RFC 5545) the DTEND value is

      // non-inclusive. When dealing with All Day values, they are DATEs rather

      // than DATETIMEs, so we need to add a day to conform to RFC.

      $end->modify("+1 day");

    }

    $date = array(

      'start' => $start,

      'end' => $end,

      'all_day' => $all_day,

      'rrule' => $rrule,

    );

    return $date;

  }

  /**

   * Filter the list of views fields down to only supported date-type fields.

   *

   * The supported date-type fields are timestamps and the three Date fields.

   *

   * @param array $view_fields

   *   An associative array like views_plugin_display::get_field_labels().

   *

   * @return array

   *   An associative array (alias => label) of date fields.

   */

  protected function get_date_field_candidates($view_fields) {

    $handlers = $this->display->handler->get_handlers('field');

    $field_candidates = array();

    // These are Date, Date (ISO format), and Date (Unix timestamp).

    $date_fields = array('datetime', 'date', 'datestamp');

    foreach ($view_fields as $alias => $label) {

      $handler_class = get_class($handlers[$alias]);

      if ($handler_class == 'views_handler_field_date'

          || ($handler_class == 'views_handler_field_field'

            && in_array($handlers[$alias]->field_info['type'], $date_fields))) {

        $field_candidates[$alias] = $label;

      }

    }

    return $field_candidates;

  }

  /**

   * Retrieves a field value from the style plugin.

   *

   * @param int $index

   *   The index count of the row

   * @param string $field_id

   *   The ID assigned to the required field in the display.

   *

   * @see views_plugin_style::get_field()

   */

  protected function get_field($index, $field_id) {

    if (empty($this->view->style_plugin) || !is_object($this->view->style_plugin) || empty($field_id)) {

      return '';

    }

    return $this->view->style_plugin->get_field($index, $field_id);

  }

}