EDIT

      $block_content_is_empty = TRUE;

        $block_content_is_empty = FALSE;

          $elements_render_array = compose_cdm_descriptionElements($node->descriptionElements, $node->feature, $taxon_uuid);

          $block_content_is_empty = empty($elements_render_array);

          $block->content[] = $elements_render_array;

          $block_content_is_empty = $block_content_is_empty && empty($text);

          $block_content_is_empty = $block_content_is_empty && empty($media_list);

      } // END all other features

      if(!$block_content_is_empty){ // skip empty block content

        $out .= theme('block',

          array(

            'elements' => array(

              '#block' => $block,

              '#children' => drupal_render($block->content),

            ),

          )

        );

      } // END: skip empty block content

        $text_data_render_array = compose_cdm_descriptionElementTextData($text_data_element, $asListElement, $text_data_element->feature->uuid);

        $repr = drupal_render($text_data_render_array);

        if (!array_search($repr, $text_data_out_array)) { // de-duplication !!

          // and what is about cases like the bibliography where

          // any content can be prefixed with some foot-note anchors?

 * Textdata elements and not for all text data description elements.

 * @param $element

 *    The CDM TextData description element which contains the textual  information.

 * @param $asListElement

 *    A boolean which determines whether the citations should

 *    TODO remove and replace $asListElement by $feature_block_settings['as_list']

 *  @param $feature_uuid

 * @return array

 *   A drupal render array with the following elements being used:

 *    - #tag: either 'div', 'li', ...

 *    ⁻ #attributes: class attributes

 *    - #value_prefix: (optionally) contains footnote anchors

 *    - #value: contains the textual content

 *    - #value_suffix: (optionally) contains footnote keys

 *

 * @ingroup compose

function compose_cdm_descriptionElementTextData($element, $asListElement, $feature_uuid) {

  $render_array = array(

    '#type' => 'html_tag',

    '#tag' => $asListElement ? 'li' : 'span',

    '#attributes' => array(

      'class' => 'DescriptionElement DescriptionElement-' . $element->class . '

      ' .  html_class_attribute_ref($element)

    ),

    '#value' => '',

    '#value_suffix' => NULL

  );

  // TODO this should be configurable

      // compare with theme_cdm_reference() where it is only appended

      // FIXME the CDM_WS_NOMENCLATURAL_REFERENCE_CITATION service should onyl be used for nomenclatural references

      // needs however further discussion with the users!!!

    $render_array['#value-suffix'] = theme('cdm_annotations_as_footnotekeys',

    $render_array['#value-suffix'] = cdm_create_description_element_footnotes($element, ',', $footnote_list_key_suggestion);

  // FIXME the only distinction between $asListElement = TRUE and FLASE is the different display of the

  // nameInSource which is prepended with "name in source:" in case of the 'not as list' case:

  if ($asListElement) {

        $render_array['#value'] = $name_used_in_source . ': ';

        $render_array['#value'] .= $name_used_in_source . ' ';

    $render_array['#value'] .= $description . $sourceRefs;

    $render_array['#value'] = $description . $sourceRefs . $name_used_in_source;

  return $render_array;

    $text_data_render_array = compose_cdm_descriptionElementTextData($text_data_element, TRUE, $text_data_element->feature->uuid);

    $text_data_out[] = drupal_render($text_data_render_array);

 *

 * @param  $feature_uuid

 *

 * @return

 *    A drupal render array for the $descriptionElements, may be an empty array if the textual content was empty.

 *    Footnote key or anchors are not considered to be textual content.

  $render_array = array();

  $elements_out_array = array();

  /*

   * $feature_block_has_content will be set true if at least one of the

   * $descriptionElements contains some text which makes up some content

   * for the feature block. Footnote keys are not considered

   * to be content in this sense.

   */

  $feature_block_has_content = false;

              $text_data_render_array = compose_cdm_descriptionElementTextData($descriptionElement, $asListElement, $descriptionElement->feature->uuid);

              $feature_block_has_content = $feature_block_has_content || !empty($text_data_render_array['#value']);

              $elements_out_array[] = drupal_render($text_data_render_array);

            $feature_block_has_content = true;

            $elements_out_array[] = theme('cdm_descriptionElement_CategoricalData', array('element' => $descriptionElement));

            $feature_block_has_content = true;

            $elements_out_array[] = theme('cdm_descriptionElement_QuantitativeData', array('element' => $descriptionElement));

            $feature_block_has_content = true;

            $elements_out_array[] = theme('cdm_descriptionElement_IndividualsAssociation', array('element' => $descriptionElement));

            $feature_block_has_content = true;

            $elements_out_array[] = theme('cdm_descriptionElement_TaxonInteraction', array('element' => $descriptionElement));

          $feature_block_has_content = true;

          $elements_out_array[] = '<li>No method for rendering unknown description class: ' . $descriptionElement->class . '</li>';

      sort($elements_out_array);

      $elements_out_array[] = theme('cdm_description_element_image_source', array('image_sources' => $image_sources, 'asListElement' => TRUE));

  if($feature_block_has_content){

    $render_array = compose_cdm_feature_block_elements(

      $elements_out_array,

      $feature

    );

  }