EDIT

/**

 * Crates an array which can be used in render arrays to be passed to the theme_table() and theme_list().

 * @param array $fieldunit_dtos

 *     list of FieldUnitDTOs

 */

function specimen_render_array_items(array $fieldunit_dtos){

  $render_array_items = array();

  $items = array();

  //we need one more item to contain the items of one level (fieldunit, derivate data etc.)

  foreach ($fieldunit_dtos as &$fieldunit_dto) {

    $items['data'] = $fieldunit_dto->listLabel ;

    $specimen = compose_cdm_specimen_or_observation_tree_entry($fieldunit_dto);

    $children = array();

    $child = array();

    $child['data'] =$specimen;

    // $children[] = create_specimen_array($specimenOrObservation->derivates);

    if (isset($fieldunit_dto->derivates) && sizeof($fieldunit_dto->derivates) > 0){

      $child['children']= specimen_render_array_items($fieldunit_dto->derivates);

    }

    $children[]=$child;

    $items['children'] = $children;

    $render_array_items[] = $items;

  }

  return $render_array_items;

}

/**

 * Creates the drupal render array for the table showing all derivatives which

 * stem from a common gathering event.

 *

 * @param $field_unit_uuids array

 *  An array of uuids for cdm FieldUnit entities.

 *

 * @return array

 *  A drupal render array for a table

 *

 * @ingroup compose

 */

function compose_compressed_specimen_derivate_table($field_unit_uuids) {

  // prepare font icons

  $expand_icon = font_awesome_icon_markup(

    'fa-plus-square-o',

    array(

      'alt' => 'Show details',

      'class' => array('expand_icon')

    )

  );

  $collapse_icon = font_awesome_icon_markup(

    'fa-minus-square-o',

    array(

      'alt' => 'Show details',

      'class' => array('collapse_icon')

    )

  );

  $detail_image_icon = '<img title="Detail Image" src="' . base_path() . drupal_get_path('module', 'cdm_dataportal') . '/images/detail_image_derivate-16x16-32.png' . '"/>';

  $checked_box_icon = '<img src="' . base_path() . drupal_get_path('module', 'cdm_dataportal') . '/images/step_done.gif' . '"/>';

  $sequence_icon = '<img title="Molecular Data" src="' . base_path() . drupal_get_path('module', 'cdm_dataportal') . '/images/sequence_derivate-16x16-32.png' . '"/>';

  $character_data_icon = '<img title="Character Data" src="' . base_path() . drupal_get_path('module', 'cdm_dataportal') . '/images/character_data_derivate-16x16-32.png' . '"/>';

  $rowcount = 0;

  $rows = array();

  foreach ($field_unit_uuids as $field_unit_uuid) {

    //get derivate hierarchy for the FieldUnit

    $derivateHierarchy = cdm_ws_get(CDM_WS_PORTAL_OCCURRENCE, array($field_unit_uuid, 'derivateHierarchy'));

    if ($derivateHierarchy) {

      //summary row

      $rows[] = array(

        'data' => array(

          array(

            'data' => $expand_icon . $collapse_icon,

            'class' => array('summary_row_cell', 'summary_row_icon', 'expand_column')

          ),

          array(

            'data' => $derivateHierarchy->country,

            'class' => array('summary_row_cell')

          ),

          array(

            'data' => $derivateHierarchy->date,

            'class' => array('summary_row_cell')

          ),

          array(

            'data' => $derivateHierarchy->collectingString,

            'class' => array('summary_row_cell')

          ),

          @array(

            'data' => $derivateHierarchy->collection,

            'class' => array('summary_row_cell')

          ),

          array(

            'data' => $derivateHierarchy->hasType ? $checked_box_icon : "",

            'class' => array('summary_row_cell', 'summary_row_icon')

          ),

          array(

            'data' => $derivateHierarchy->hasSpecimenScan ? $checked_box_icon : "",

            'class' => array('summary_row_cell', 'summary_row_icon')

          ),

          array(

            'data' => ($derivateHierarchy->hasDna ? $sequence_icon : "") . " "

              . ($derivateHierarchy->hasDetailImage ? $detail_image_icon : "") . " "

              . ($derivateHierarchy->hasCharacterData ? $character_data_icon : ""),

            'class' => array('summary_row_cell', 'summary_row_icon')

          )

        ),

        'id' => 'derivate_summary' . $rowcount, // summary row id

        'class' => array('summary_row'),

      );

      //assemble field unit details

      $detail_html = "";

      // - citation

      if ($derivateHierarchy->citation) {

        $detail_html .= create_label("Citation") . $derivateHierarchy->citation . "<br>";

      }

      //assemble specimen details

      if ($derivateHierarchy->derivates) {

        foreach ($derivateHierarchy->derivates as $preservedSpecimenDTO) {

          $detail_html .= "<br>";

          $detail_html .= render_cdm_specimenDTO_page($preservedSpecimenDTO);

        }

      }

      $detail_html .= "<br>";

      //detail row resp. one BIG detail cell

      $rows[] = array(

        'data' => array(

          array(

            'data' => "", //empty first column

            'class' => array('expand_column')

          ),

          array(

            'data' => $detail_html,

            'colspan' => 7,

          ),

        ),

        'id' => 'derivate_details' . $rowcount,//details row ID

        'class' => array('detail_row'),

      );

      $rowcount++;

    }

  }

  $tableId = "derivate_hierarchy_table";

  $derivateHierarchyTable = array(

    "#theme" => "table",

    "#weight" => 2,

    "#header" => array(

      array(

        'data' => "",

        'class' => array('expand_column')

      ),

      "Country", "Date", "Collector + collecting number", "Herbaria", "Type", "Scan", "Derivatives"),

    "#rows" => $rows,

    "#attributes" => array(

      "id" => $tableId,

      "border" => 2

    )

  );

  //add toggle functionality to derivate hierarchy table

  drupal_add_js_rowToggle("#" . $tableId);

  return $derivateHierarchyTable;

}

function compose_specimen_table_top_down(array $fieldunit_dtos){

  $specimen_render_array_items = specimen_render_array_items($fieldunit_dtos);

    // add icons

  $expand_icon = font_awesome_icon_markup(

    'fa-plus-square-o',

    array(

      'alt' => 'Show details',

      'class' => array('expand_icon')

    )

  );

  $collapse_icon = font_awesome_icon_markup(

    'fa-minus-square-o',

    array(

      'alt' => 'Show details',

      'class' => array('collapse_icon')

    )

  );

  $tableId = "specimen_tree_table";

  $specimen_table = array(

    '#theme' => 'table',

    '#weight' => 2,

    // prefix attributes and rows with '#' to let it pass toF the theme function,

    // otherwise it is handled as child render array

    '#attributes' => array(

      'class' => 'specimens',

      'id' => $tableId

    ),

    '#rows' => array(),

  );

  $rowcount = 0;

  foreach($specimen_render_array_items as $value){

    $renderArray = array(

      '#theme' => 'item_list',

      '#items' => $value['children'],

      '#type' => 'ul');

    $output = drupal_render($renderArray);

    $specimen_table['#rows'][] = array(

      'data' =>array(

        array(

          'data' => $expand_icon . $collapse_icon,

          'class' => array('summary_row_cell', 'summary_row_icon', 'expand_column')

        ),

        $value['data']

      ),

      'id' => 'label' . $rowcount, // summary row id

      'class' => array('summary_row'),

    );

    $specimen_table['#rows'][] = array(

      'data' =>  array(

        array(

          'data' => "", //empty first column

          'class' => array('expand_column')

        ),

        array(

          'data' => $output

        )

      ),

      'class' =>  array('detail_row')

//                'class' =>  array(

//                    'descriptionElement',

//                    'descriptionElement_IndividualsAssociation'

      //               ),

    );

    $rowcount++;

  }

  drupal_add_js_rowToggle("#".$tableId);

  return $specimen_table;

/**

 * Orders occurrences by date but types should be on top of the list.

 *

 * @param $specimensOrObservations_or_fieldUnitDTO

 *

 * @return array

 */

function order_specimens_or_observations_by_date_and_type($specimensOrObservations)

{

// order occurrences by date but types should be on top of the list

  $type_specimens = array();

  $other_occurrences = array();

  foreach ($specimensOrObservations as &$occurrence) {

    $typeDesignationsPager = cdm_ws_get(CDM_WS_OCCURRENCE . '/$0/specimenTypeDesignations', $occurrence->uuid);

    if (isset($typeDesignationsPager->count) && $typeDesignationsPager->count > 0) {

      $type_specimens[] = $occurrence;

    } else {

      $other_occurrences[] = $occurrence;

    }

  }

  $specimensOrObservations = array_merge($type_specimens, $other_occurrences);

  return $specimensOrObservations;

}

/**

 * Orders FieldUnitDTOs by date but types should be on top of the list.

 *

 * Delegates internally to order_specimens_or_observations_by_date_and_type()

 *

 * @param $fieldUnitDTOs

 *

 * @return array

 */

function order_fieldUnitDtos_by_date_and_type($fieldUnitDTOs)

{

  return order_specimens_or_observations_by_date_and_type($fieldUnitDTOs);

}