<?php
// $Id: content_taxonomy_term_list.module,v 1.1 2010/11/15 16:18:19 njt1982 Exp $

/**
 * @file
 * Defines a read-only field type for embeding Taxonomy terms into the $content output of a node
 */


/**
 * Implementation of hook_theme().
 */
function content_taxonomy_term_list_theme() {
  $items = array();

  $items['content_taxonomy_term_list_formatter_default'] = array('arguments' => array('element' => NULL));

  foreach (array('text', 'link') as $type) {
    foreach (array('inline', 'block') as $style) {
      $items['content_taxonomy_term_list_formatter_'. $type .'__'. $style] = array(
        'arguments' => array('element' => NULL),
        'function' => 'theme_content_taxonomy_term_list_formatter_default',
      );
    }
  }

  return $items;
}


/**
 * Implementation of hook_field_info().
 */
function content_taxonomy_term_list_field_info() {
  return array(
    'content_taxonomy_term_list' => array(
      'label' => t('Content Taxonomy Term List'),
      'description' => t('Represents a read-only field for terms'),
      'callbacks' => array(
        'tables' => CONTENT_CALLBACK_DEFAULT,
        'arguments' => CONTENT_CALLBACK_DEFAULT,
      ),
    ),
  );
}


/**
 * Implementation of hook_field_settings().
 */
function content_taxonomy_term_list_field_settings($op, $field) {
  switch ($op) {
    case 'form':
      $form = array();
      $form['multiple'] = array('#type' => 'value', '#value' => 1);
      $form['required'] = array('#type' => 'value', '#value' => 0);
      return $form;

    case 'save' : return array();
    case 'database columns' :  return array();
    case 'views data' : return array();
  }
}


/**
 * Implementation of hook_field().
 */
function content_taxonomy_term_list_field($op, &$node, $field, &$items, $teaser, $page) {
  switch ($op) {
    case 'insert' :
      if (empty($items['0'])) {
        $items = array();
        $node->{$field['field_name']} = array();
      }
      break;

    case 'load':
      $vids = array_filter($field['widget']['vids']);

      $values = array();
      $args = array_merge(array($node->nid), $vids);
      $result = db_query('SELECT td.* FROM {term_node} tn INNER JOIN {term_data} td ON td.tid = tn.tid WHERE tn.nid = %d AND td.vid IN ('. db_placeholders($vids) .')', $args);
      while ($term = db_fetch_array($result)) {
        $values[] = $term;
      }
      return array($field['field_name'] => $values);
  }
}


/**
 * Implementation of hook_widget_info().
 */
function content_taxonomy_term_list_widget_info() {
  return array(
    'content_taxonomy_term_list_readonly' => array(
      'label' => t('Term List (read only)'),
      'field types' => array('content_taxonomy_term_list'),
      'multiple values' => CONTENT_HANDLE_MODULE,
      'callbacks' => array(
        'default value' => CONTENT_CALLBACK_DEFAULT,
      ),
    ),
  );
}


/**
 * Implementation of hook_widget_settings().
 */
function content_taxonomy_term_list_widget_settings($op, $widget) {
  switch ($op) {
    case 'form':
      $form = array();

      $options = array();
      $vocabs = taxonomy_get_vocabularies();
      foreach ($vocabs as $v) {
        $options[$v->vid] = $v->name;
      }

      $form['vids'] = array(
        '#title' => t('Which vocabularies should this field display?'),
        '#type' => 'checkboxes',
        '#options' => $options,
        '#default_value' => isset($widget['vids']) ? $widget['vids'] : array(),
      );

      return $form;

    case 'save' :
      return array('vids');
  }
}


/**
 * Implementation of hook_field_formatter_info().
 */
function content_taxonomy_term_list_field_formatter_info() {
  $items = array();

  foreach (array('text', 'link') as $type) {
    foreach (array('inline', 'block') as $style) {
      $items[$type .'__'. $style] = array(
        'label' => t('As !style !type', array('!style' => $style, '!type' => $type)),
        'field types' => array('content_taxonomy_term_list'),
        'multiple values' => CONTENT_HANDLE_MODULE,
      );
    }
  }

  return $items;
}


/**
 * Theme function for 'default' text field formatter.
 */
function theme_content_taxonomy_term_list_formatter_default($element) {
  list($type, $style) = explode('__', $element['#formatter']);

  // Define our wrapper HTML element depending on formatter style
  switch ($style) {
    case 'inline' : $wrapper = 'span'; break;
    case 'block' : $wrapper = 'div'; break;
  }

  // Generate the values
  $values = array();
  foreach (element_children($element) as $key) {
    // Grab the term and make an object
    $term = (object)$element[$key]['#item'];

    // Depending on type (text or link), create a value
    switch ($type) {
      case 'link' : $value = l($term->name, taxonomy_term_path($term)); break;
      case 'text' : $value = check_plain($term->name); break;
    }

    // Add it to our values, wrapper in the appropriate wrapper
    $values[] = "<{$wrapper}>{$value}</{$wrapper}>";
  }

  // Reset the value string - we need this now for the return value
  $value = '';

  // If the style is inline (not block), then we can make this a fancy "a, b and c" type list.
  if ($style == 'inline') {
    // Only need to do this if its greater than 1 item.
    if (count($values) > 1) {
      $last = array_pop($values);
      $value = t('!firsts, !last', array('!firsts' => implode(', ', $values), '!last' => $last));
    }
    else {
      $value = array_pop($values);
    }
  }
  else {
    $value = implode("\n", $values);
  }

  return $value;
}


/**
 * Implementation of hook_content_is_empty().
 */
function content_taxonomy_term_list_content_is_empty($item, $field) {
  return empty($item);
}


/**
 * Implementation of hook_taxonomy().
 */
function content_taxonomy_term_list_taxonomy($op, $type, $array = NULL) {
  switch ($op) {
    case 'delete' :
    case 'update' :
      cache_clear_all('content:', 'cache_content', TRUE);
      break;
  }
}