EDIT

<?php

/*

 * Definition of privacy levels

 */

define('TAXONPRIVACY_PRIVATE', 'Private');

define('TAXONPRIVACY_PUBLIC', 'Public');

/**

 * Implementation of hook_perm()

 *

 * Valid permissions for this module

 * @return array An array of valid permissions for the taxon_experts module

 */

function cdm_taxontree_perm() {

    return array(

        'view private taxoninterests',

    //TODO which else permission are required?

    );

}

/**

 * Implementation of hook_field()

 *

 */

function cdm_taxontree_field($op, &$node, $field, &$items, $teaser, $page) {

    switch ($op) {

        case 'view':

            $context = $teaser ? 'teaser' : 'full';

            $formatter = isset($field['display_settings'][$context]['format']) ? $field['display_settings'][$context]['format'] : 'default';

            foreach ($items as $delta => $item) {

                $items[$delta]['view'] = content_format($field, $item, $formatter, $node);

            }

            return theme('field', $node, $field, $items, $teaser, $page);

    }

}

/**

 * Implementation of hook_field_settings().

 */

function cdm_taxontree_field_settings($op, $field) {

    switch ($op) {

        case 'form':

            $form = array(

        '#theme' => 'cdm_taxontree_field_settings',

            );

            return $form;

        case 'save':

            break;

        case 'database columns':

            return array(

        'tid' => array('type' => 'int', 'length' => 10, 'unsigned' => TRUE, 'not null' => TRUE, 'default' => 0),

            );

            break;

        case 'filters':

            return array(

             'default' => array(

       'operator' => 'views_handler_operator_like',

       'handler' => 'cdm_taxontree_views_filter_handler',

            ),

            );

            break;

        case 'callbacks': //pairs up with cck_fullname_field::view

            return array(

        'view' => CONTENT_CALLBACK_CUSTOM,

            );

            break;

    }

}

/**

 * implementation of hook_widget_info()

 *

 */

function cdm_taxontree_widget_info(){

    $vocabularies = taxonomy_get_vocabularies();

    $vocabs = array();

    foreach ($vocabularies as $vid => $vocab) {

        $vocabs['cdm_taxontree_' .$vocab->vid] = array(

        'label' => $vocab->name,

        'field types' => array('cdm_taxontree'),

        );

    }

    return $vocabs;

}

/**

 * implementation of hook_widget()

 *

 */

function cdm_taxontree_widget($op, &$node, $field, &$node_field){

    switch($op){

        case 'prepare form values':

            // get posted values in both node edit and profile edit mode

            if ($_POST[$field['field_name']] || $_POST[$field['type_name'].'_node_form'][$field['field_name']]) {

                $node_field = ($_POST['form_id'] == 'user_edit') ?  $_POST[$field['type_name'].'_node_form'][$field['field_name']] : $_POST[$field['field_name']];

            }else{

                $node_field_transposed = content_transpose_array_rows_cols($node_field);

                $node_field = array();

                $node_field[0]['cdm_taxontree_select'] = $node_field_transposed['tid'];

            }

            return;

        case 'form':

            $form = array();

            $form[$field['field_name']] = array(

        '#tree' => TRUE,

        '#theme' => NULL,

        '#type' => 'markup',

        '#title' => t($field['widget']['label']),

        '#description' => t($field['widget']['description']),

        '#weight' => $field['widget']['weight'],

            );

            // add the form

            $delta = 0;

            _cdm_taxontree_widget_form($form[$field['field_name']][$delta], $field, $node_field);

            return $form;

        case 'validate':

            if($field['required'] && count($node_field[0]['cdm_taxontree_select']) < 1){

                form_set_error('cdm_taxontree_select', t('Please select at least one item from %type.', array('%type' => $field['widget']['label'])));

            }

         return;

      }

    }

function _cdm_taxontree_widget_form(&$form_item, $field = array(), $node_field = array(), $delta = 0) {

  // get vocabulary id

  $vid = substr($field['widget']['type'], strlen($field['type'])+1);

  // build the tree

  $tree = cdm_taxontree_build_tree(NULL, NULL, $vid);

  $options = array();

  if (!empty($node_field[$delta]['cdm_taxontree_select'])){

    $options = _cdm_taxontree_recreate_options($node_field[$delta]['cdm_taxontree_select']);

  }

  // prefix and suffix: render the taxon tree div structure around the select field

  $prefix .= '<div class="cdm_taxontree_widget">';

  // hide labels in filter view

  if(substr($field['field_name'],-7,7) !== '_filter'){

    $prefix .= '<div class="taxontree_header">';

    $prefix .= '<div class="field-label column-left">' . t($field['widget']['label']) . ':' . ($field['required'] == 1 ? ' <span class="form-required" title="' .t('This field is required.'). '">*</span>' : '') . '</div>';

    $prefix .= '<div class="field-label column-right">' . t('Your Selection') . ':</div>';

    $prefix .= '</div>';

  }

  $prefix .= '<div class="taxontree">';

  $prefix .= '<div class="cdm_taxontree_scroller_x">';

  $prefix .= '<div class="cdm_taxontree_container">';

  $prefix .= '<div class="cdm_taxontree_scroller_y">';

  // inject the taxon tree

  $prefix .= theme('cdm_taxontree',$tree, NULL, FALSE, 'cdm_taxontree_node_reference_widget', $field['field_name']);

  $prefix .= '</div></div></div></div>';

  $prefix .= '<div class="taxontree_devider"><span class="hidden">&gt;&gt;</span></div>';

  // this is the place where to put the select box without disturbing the scrollers

  $suffix = '</div>';

  // pull in the default value

  $default_value = (!empty($field['widget']['default_value'][$delta]['cdm_taxontree_select'])) ? $field['widget']['default_value'][$delta]['cdm_taxontree_select'] : array();

  // $default_show_childnodes = ($field['widget']['default_value']['include_childnodes']['include_childnodes'] === 'include_childnodes') ? 'checked="checked"' : '';

  $default_show_childnodes = 'checked="checked"';

  // add the select box and set to multiple, if appropriate

  $form_item['cdm_taxontree_select'] = array(

        '#tree' => TRUE,

        '#type' => 'select',

        '#default_value' => !empty($node_field[$delta]['cdm_taxontree_select']) ? $node_field[$delta]['cdm_taxontree_select'] : $default_value ,

        '#multiple' => $field['multiple'] ? TRUE : FALSE,

        '#options' => $options,

        '#size' => $field['multiple'] ? 12 : 2,

        '#prefix' => $prefix,

        '#suffix' => $suffix,

        '#attributes' => array('class' => 'taxontree_select'),

  );

  // add the scripts for multiple widgets, if not already present

  theme('cdm_taxontree_add_scripts');

  global $taxontree_script_present;

  if(!$taxontree_script_present[$field['field_name']]){

    drupal_add_js('$(document).ready(function() {$(\'ul.cdm_taxontree.' . $field['field_name'] . '\').cdm_taxontree(

      {

        widget:                 true,

        element_name:           \''.$field['field_name'] .'\',  //

        multiselect:            '.($field['multiple']?'true':'false').'         //

      }

      );});', 'inline');

    $taxontree_script_present[$field['field_name']] = TRUE;

  }

  // add flag for including child nodes if selected in settings

  // this is only tirggered in filter mode

  if($field['show_include_childnodes']){

    $default_value = (count($_GET)==1) ? $default_show_childnodes : ($field['include_childnodes_flag']) ? 'checked="checked"' : '';

    $include_label = 'Include Childnodes';

    $include_childnode_message = 'Include childnodes and parent node';

    // HACK! Replace the text to display as 'include childnodes text'

    if(substr($field['field_name'],-7,7) == '_filter'){

      $vocabulary = substr($field['widget']['type'],strlen($field['type'])+1);

      switch($vocabulary){

        case 8:

          $include_label = 'Include Childtaxa';

          $include_childnode_message = 'Check, if all child taxa of the selected taxa shall be included';

          break;

        case 3:

          $include_label = 'Include Subregions';

          $include_childnode_message = 'Check, if all subregions of the selected region should be included';

          break;

      }

    }

    $form_item['include_childnodes'] = array(

      '#tree' => TRUE,

      '#type' => 'markup',

      '#prefix' => '<div class="include-options">',

      '#value' => '<label class="field-label" for="' . $field['field_name'] . $delta . '-include">' . t($include_label) . '</label><div class="field-description">' . t($include_childnode_message) . '<input type="checkbox" name="'  .$field['field_name'] . $delta . '_include" id="' . $field['field_name'] . $delta . '-include" value="include_childnodes" ' . $default_value . '/></div>',

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

    );

  }

}

/**

 * implementation of hook_filters_alter(), a *views modification*

 * to enable injection of more filter values

 *

 * @param object $view, needed to find cdm_taxontree filters by $delta

 * @param array $filters, incoming filter values

 * @return array $filters extended filter values

 */

function cdm_taxontree_views_filters_alter($view, $filters){

    if($view->name == 'search_interest'){

        // find the cdm_taxontree_filter

        foreach($view->exposed_filter as $delta => $filter){

            if(preg_match('@^cdm_taxontree@',$filter['field'])){

                // include child terms and parent term

                if($_GET['cdm_taxontree_filter' . $delta . '_include'] == TRUE && is_array($filters[$delta]['filter'])){

                    foreach($filters[$delta]['filter'] as $key => $val){

                        if(is_numeric($val)){

                            $child_terms[] = $val;

                        }

                    }

                    $term_collection = array();

                    // get child terms from cache

                    foreach($child_terms as $key => $term){

                        if(!$children = cdm_taxontree_cache_get($term,'cache_cdm_taxontree')){

                            // no data in cache? add some!

                            $child_terms = _cdm_taxontree_get_all_children($child_terms,TRUE);

                            // add parent term

                            $parent_terms = taxonomy_get_parents($term);

                            foreach($parent_terms as $key => $term_obj){

                                $child_terms[$key] = $key;

                            }

                            cdm_taxontree_cache_set($term,'cache_cdm_taxontree',serialize($child_terms));

                            $children = $child_terms;

                        }

                        else{

                            $children = unserialize($children->data);

                        }

                        $term_collection = array_merge($term_collection, $children);

                    }

                    // re-add filter values

                    $filters[$delta]['filter'] = $term_collection;

                }

            }

        }

    }

    /*

     * React on taxonprivacy settings

     * Remove taxon_privacy from taxonomy / filters, if user is allowed to view private taxon interests

     */

    global $user;

    // show information only to roles with access to private interests

    if($user->uid && user_access('view private taxoninterests',$user)){

            foreach($view->filter as $delta => $filter){

                if(preg_match('@^term_node_@',$filter['field'])){

                    $tid = intval(str_replace('.tid','',str_replace('term_node_','',$filter['field'])));

                    if($tid == 9){

                        unset($view->filter[$delta]);

                    }

                }

            }

    }

    return $filters;

}

/*

 * implementation of hook_form_alter()

 *

 * used to replace the standard taxonomy selectbox

 * with our nice cdm_taxontree_widget form.

 *

 */

function cdm_taxontree_form_alter($form_id, &$form){

    if($form_id == 'views_filters')

    {

        global $user;

        $view = $form['view']['#value'];

        // find the cdm_taxontree_filter

        foreach($view->exposed_filter as $delta => $filter){

            if(preg_match('@^cdm_taxontree@',$filter['field'])){

                // simulate field settings to invoke the widget form correctly

                $field = array(

                    'field_name' => 'cdm_taxontree_filter',

                    'type' => 'cdm_taxontree',

                  'multiple' => $form['filter'.$delta]['#multiple'],

                    'show_include_childnodes' => 1,

                    'include_childnodes_flag' => $_GET['cdm_taxontree_filter' . $delta . '_include'] ? 1 : 0,

                    'widget' => array(

                        'type' => 'cdm_taxontree_' . $form['filter'.$delta]['#vocab'],

                        'label' => $filter['label'],

                ),

                );

                // simulate the node_field data from filter form values

                $filter_field = array();

                $filter_values = $form['filter'.$delta]['#default_value'];

                // transpose the filter values to a form understood by the widget

                if(is_array($filter_values)){

                    foreach($filter_values as $key => $val){

                        $filter_field[$delta]['cdm_taxontree_select'][] = $val;

                    }

                }else if(is_numeric($key)){

                    $filter_field[$delta]['cdm_taxontree_select'][] = $filter_values;

                }

                // create the widget

                $subform = array();

                _cdm_taxontree_widget_form($subform['cdm_taxontree_filter'], $field, $filter_field, $delta);

                // add some important attributes

                $subform['cdm_taxontree_filter']['cdm_taxontree_select']['#name'] = 'filter'.$delta;

                $subform['cdm_taxontree_filter']['cdm_taxontree_select']['#id'] = 'edit-filter'.$delta;

                // replace original form element with widget

                $form['filter'.$delta] = $subform['cdm_taxontree_filter'];

            }

        }

    }

}

/**

 * Implematation of hook_views_tables()

 *

 *

 * @return onject views related db table data

 */

function cdm_taxontree_views_tables() {

    $tables = array();

    // field_name, type_name, widget_type

    $result = db_query("SELECT nfi.*, nf.db_storage FROM {node_field_instance} nfi INNER JOIN {node_field} nf ON nfi.field_name = nf.field_name WHERE widget_type LIKE 'cdm_taxontree_%'");

    while ($row = db_fetch_object($result)) {

        // Build the list of options

        $vid = substr($row->widget_type, 14); // 14 = strlen('cdm_taxontree)!

        $options = array();

        $tree = taxonomy_form($vid);

        foreach ($tree['#options'] as $index => $option) {

            if (is_object($option)) {

                foreach($option->option as $key => $value) {

                    $options[$key] = $value;

                }

            }

        }

        // Rely on CCK to provide us with the correct table name.

        if ($row->db_storage == CONTENT_DB_STORAGE_PER_FIELD) {

            $table_name = _content_tablename($row->field_name, CONTENT_DB_STORAGE_PER_FIELD);

        }

        else {

            $table_name = _content_tablename($row->type_name, CONTENT_DB_STORAGE_PER_CONTENT_TYPE);

        }

        # Get the taxonomy multi select property

        $vocab = taxonomy_get_vocabulary($vid);

        $multiple = $vocab->multiple;

        $table = array(

      'name' => $table_name,

      'provider' => 'cdm_taxontree',

      'join' => array(

        'left' => array('table' => 'node', 'field' => 'vid',),

        'right' => array('field' => 'vid'),

        ),

      'filters' => array(

        $row->field_name .'_tid' => array(

          'name' => t('CDM Taxontree: @field_name', array('@field_name' => $row->field_name)),

          'help' => t('Filter on @field_name terms.', array('@field_name' => $row->field_name)),

          'operator' => 'views_handler_operator_or',

                    'handler' => 'cdm_taxontree_views_handler_filter_default',

          'value' => array(

            '#type' => 'select',

        // pass the vocabulary id

                        '#vocab' => $vid,

            '#options' => $options,

            '#multiple' => $multiple,

        ),

        ),

        ),

        );

        $tables['cdm_taxontree'. $row->field_name] = $table;

    }

    return $tables;

}

function cdm_taxontree_views_handler_filter_default($op, $filter, $filterinfo, &$query) {

    $table = $filterinfo['table'];

    $field = $filterinfo['field'];

    if (is_array($filter['value']) && count($filter['value'])) {

        if ($filter['operator'] == 'OR' || $filter['operator'] == 'NOR') {

            $query->ensure_table($table);

            $where_args = array_merge(array($query->use_alias_prefix . $table, $field), $filter['value']);

            $placeholder = array_fill(0, count($filter['value']), '%s');

            if ($filter['operator'] == 'OR') {

                $query->add_where("%s.%s IN (". implode(", ", $placeholder) .")", $where_args);

            }

            else {

                $where_args[] = $where_args[0];

                $where_args[] = $where_args[1];

                $query->add_where("(%s.%s NOT IN (". implode(", ", $placeholder) .") OR %s.%s IS NULL)", $where_args);

            }

        }

        else {

            $howmany = count($filter['value']);

            $high_table = $query->add_table($table, true, $howmany);

            if (!$high_table) { // couldn't add the table

                return;

            }

            $table_num = $high_table - $howmany;

            foreach ($filter['value'] as $item) {

                $table_num++;

                $tn = $query->get_table_name($table, $table_num);

                $query->add_where("%s.%s = '%s'", $tn, $field, $item);

            }

        }

    }

    else {

        $query->ensure_table("$table");

        $query->add_where("%s.%s %s '%s'", $query->use_alias_prefix . $table, $field, $filter['operator'], $filter['value']);

    }

}

/**

 * implematation of hook_token_list()

 *

 */

function cdm_taxontree_token_list($type = 'all') {

    if ($type == 'field' || $type == 'all') {

        $tokens = array();

        $tokens['cdm_taxontree']['tid'] = t("Term ID - first item only.");

        $tokens['cdm_taxontree']['tid-all'] = t("Term ID - all items comma separated");

        $tokens['cdm_taxontree']['tid-n'] = t("Term ID - where n = the value to select if more than one value in the field.");

        $tokens['cdm_taxontree']['raw'] = t("Raw, unfiltered term - first item only");

        $tokens['cdm_taxontree']['raw-all'] = t("Raw, unfiltered terms - all items comma separated");

        $tokens['cdm_taxontree']['raw-n'] = t('Raw, unfiltered terms - where n = the value to select if more than one value in the field');

        $tokens['cdm_taxontree']['formatted'] = t("Formatted and filtered terms - first item only");

        $tokens['cdm_taxontree']['formatted-all'] = t("Formatted and filtered terms - all items with line break separated");

        $tokens['cdm_taxontree']['formatted-n'] = t('Formatted and filtered terms - where n = the value to select if more than one value in the field');

        return $tokens;

    }

}

/**

 * implementation of hook_token_values()

 *

 */

function cdm_taxontree_token_values($type, $object = NULL) {

    if ($type == 'field') {

        $i = 0;

        foreach ($object as $value) {

            $term = taxonomy_get_term($value['tid']);

            $values[] = $term->name;

            $views[] = $value['view'];

            $tokens['raw-' . $i] = $term->name;

            $tokens['formatted-' . $i] = $value['view'];

            $i++;

        }

        //for backwards compat

        $tokens['raw-all']  = implode(', ' , $values);

        $tokens['formatted-all'] = implode("\n", $views);

        return $tokens;

    }

}

/**

 * Helper function to transpose a list of term ids into an

 * array with key = tid and value = term name;

 * used to recreate cdm_taxontree_widgets select list options.

 *

 * @param array $options

 * @return array transposed options

 */

function _cdm_taxontree_recreate_options($options = array()){

    $transposed = array();

    foreach($options as $key => $tid){

        if(is_numeric($tid)){

            $parents = taxonomy_get_parents_all($tid);

            $path = theme('cdm_taxontree_taxon_fullpath',array_reverse($parents),3);

            $transposed[$tid] = $path;

        }

    }

    return $transposed;

}

/**

 * Theme function that returns a <span> element containing the secundum of a given TreeNode> element

 *

 * @param array $node The <TreeNode> element as returned by the webservice

 *

 * @return String html formatted title of the secundum

 * @deprecated replace by according taxonomictree function

 */

function theme_cdm_taxontree_node_reference(&$node){

  $secRefTitle = cdm_taxontree_secRefTitle_for($node->secUuid);

  // encode any special characters

  $secRefTitle = check_plain($secRefTitle);

  $out = ' <span class="sec_ref widget_select" title="'.$secRefTitle.'" style="background-color:#'._uuid_to_rgbhex($node->secUuid).'" alt="'.$node->secUuid.'">'

      .$secRefTitle.'</span>';

  return $out;

}

/**

 * theme function to display terms in the cd,_taxontree_widget with additional data.

 *

 */

function theme_cdm_taxontree_node_reference_widget(&$node){

    $title = ($node->titleCache) ? check_plain($node->titleCache) : check_plain($node->name);

    $parents = taxonomy_get_parents_all($node->tid);

    $path = theme('cdm_taxontree_taxon_fullpath',array_reverse($parents),3);

    $out = ' <span class="sec_ref widget_select" title="' . (!empty($path) ? $path : $title) . '" alt="'.$node->tid.'">' . $title . '</span>';

    return $out;

}

/**

 * theme function to replace term names with full path to term name

 *

 * @param array $tids path->to->term

 * @param integer $max_levels, 0 is unlimited

 * @return text representation of path->to->term

 */

function theme_cdm_taxontree_taxon_fullpath($tids = array(), $max_levels = 3){

    $path = array();

    foreach ($tids as $tid){

        $path[] = $tid->name;

    }

    if(count($path) > $max_levels){

        $abbr_path = array_slice($path,0,$max_levels-1);

        array_push($abbr_path,'…');

        array_push($abbr_path,array_pop($path));

        $path = $abbr_path;

    }

    return implode(' » ',$path);

}

function cdm_taxontree_cache_get($term){

  if(variable_get('cdm_taxontree_cache', 0)){

    return cache_get($term,'cache_cdm_taxontree');

  }

}

function cdm_taxontree_cache_set($term, $child_terms){

  if(variable_get('cdm_taxontree_cache', 0)){

    return cache_set($term,'cache_cdm_taxontree', serialize($child_terms));

  }

}

/**

 * function to empty the cdm_taxontree cache table

 *

 */

function cdm_taxontree_cache_clear() {

    // clear core tables

    $alltables = array('cache_cdm_taxontree');

    foreach ($alltables as $table) {

        cache_clear_all('*', $table, TRUE);

    }

    drupal_set_message('CDM Taxontree Cache cleared.');

    drupal_goto('admin/settings/cdm_dataportal');

}

/**

 * Converts a UUID into a hexadecimal RGB colour code.

 *

 * @param UUID $uuid

 * @return Number hexadecimal

 */

function _uuid_to_rgbhex($uuid){

  $xfoot = _str_crossfoot($uuid);

  $h = $xfoot / 255;

  $h = $h - floor($h);

  $RGB = _hsv_2_rgb($h, 0.45, 1);

  return dechex($RGB['R']).dechex($RGB['G']).dechex($RGB['B']);

}

/**

 * Sums up ASCII values of the character in the given string.

 *

 * @param String $str

 * @return Number

 */

function _str_crossfoot($str){

  $xfoot = 0;

  for($i=0; $i<strlen($str); $i++){

    $xfoot = $xfoot + ord($str[$i]);

  }

  return $xfoot;

}

/**

 * Converts HSV colour codes into their RGB counterpart

 *

 * @param Number $H value 0-1

 * @param Number $S value 0-1

 * @param Number $V value 0-1

 * @return array three values  0-255

 */

function _hsv_2_rgb($H, $S, $V) // HSV Values:Number 0-1

{ //

  $RGB = array();

  if($S == 0){

    $R = $G = $B = $V * 255;

  } else {

    $var_H = $H * 6;

    $var_i = floor( $var_H );

    $var_1 = $V * ( 1 - $S );

    $var_2 = $V * ( 1 - $S * ( $var_H - $var_i ) );

    $var_3 = $V * ( 1 - $S * (1 - ( $var_H - $var_i ) ) );

    if ($var_i == 0) { $var_R = $V ; $var_G = $var_3 ; $var_B = $var_1 ; }

    else if ($var_i == 1) { $var_R = $var_2 ; $var_G = $V ; $var_B = $var_1 ; }

    else if ($var_i == 2) { $var_R = $var_1 ; $var_G = $V ; $var_B = $var_3 ; }

    else if ($var_i == 3) { $var_R = $var_1 ; $var_G = $var_2 ; $var_B = $V ; }

    else if ($var_i == 4) { $var_R = $var_3 ; $var_G = $var_1 ; $var_B = $V ; }

    else { $var_R = $V ; $var_G = $var_1 ; $var_B = $var_2 ; }

    $R = $var_R * 255;

    $G = $var_G * 255;

    $B = $var_B * 255;

  }

  $RGB['R'] = $R;

  $RGB['G'] = $G;

  $RGB['B'] = $B;

  return $RGB;

}