modules/multireference/multireference.module

<?php
// $Id: multireference.module,v 1.1 2008/03/31 21:12:52 stevem Exp $

/**
 * @file
 * multireference module
 *
 * This CCK module allows you to create a field containing a list
 * of items comprising 1) a description field, 2) a user or node
 * reference, and 3) an optional 2nd description field
 *
 */

/*---- Drupal core API ---- */

/**
 * Implementation of hook_help
 */
function multireference_help($section = '') {
  $output = '';
  switch ($section) {
    case "admin/help#multireference":
      $output = '<p>'. t("Allows creation of multiple node or user reference fields with descriptions."). '</p>';
      break;
  }
  return $output;
}

/**
 *  Implementation of hook_menu
 */
function multireference_menu($may_cache) {
  // register our autocomplete callback
  $items = array();
  $items[] = array(
    'path' => 'multireference/autocomplete_nodereference',
    'title' => '',
    'callback' => 'multireference_autocomplete_node',
    'type' => MENU_CALLBACK,
    'access' => user_access('access content'),
  );
  $items[] = array(
    'path' => 'multireference/autocomplete_userreference',
    'title' => '',
    'callback' => 'multireference_autocomplete_user',
    'type' => MENU_CALLBACK,
    'access' => user_access('access content'),
  );
  return $items;
}

/**
 *   Implementation of hook_nodeapi
 */
function multireference_nodeapi(&$node, $op, $teaser = NULL, $page = NULL) {
  switch ($op) {
    case 'update' :
      $sql = "UPDATE {node_field_multireference_data} SET r_text='%s' WHERE r_id=%d AND reference='nodereference';";
      db_query($sql, $node->title, $node->nid);
      break;

    case 'delete' :
      $sql = "UPDATE {node_field_multireference_data} SET r_id=0 WHERE r_id=%d AND reference='nodereference';";
      db_query($sql, $node->nid);
      break;
  }
}


/**
 *   Implementation of hook_user
 */
function multireference_user($op, &$edit, &$account, $category = NULL) {
  switch ($op) {
    case 'after_update' :
      $sql = "UPDATE {node_field_multireference_data} SET r_text='%s' WHERE r_id=%d AND reference='userreference';";
      db_query($sql, $account->name, $account->uid);
      break;

    case 'delete' :
      $sql = "UPDATE {node_field_multireference_data} SET r_id=0 WHERE r_id=%d AND reference='userreference';";
      db_query($sql, $account->uid);
      break;
  }
}


/*------ CCK field API ------*/


/**
 * Implementation of hook_field_info().
 */
function multireference_field_info() {
  return array(
    'multireference' => array('label' => 'Multi-Reference Field'),
  );
}

/**
 * Implementation of hook_field_settings().
 */
function multireference_field_settings($op, $field) {

  $reference = _multireference_filter_reference_type($field['r_type']);

  switch ($op) {
    case 'form':
      $form = array();

      // type of reference
      $options = array(
        'nodereference' => 'Node',
        'userreference' => 'User',
      );
      $form['r_type']  = array(
        '#type'          => 'radios',
        '#title'         => t('Type of reference'),
        '#description'   => t('This field can hold either node or user references. Please choose one, and configure the appropriate settings below.'),
        '#options'       => $options,
        '#default_value' => isset($field['r_type']) ? $field['r_type'] : '',
        '#required'      => TRUE,
        );

      // max number of line items
      $form['r_num'] = array(
        '#type'          => 'textfield',
        '#size'          => 4,
        '#title'         => t('What is the maximum number of lines that this field should provide?'),
        '#default_value' => isset($field['r_num']) ? $field['r_num'] : 20,
      );

      // autocomplete or select list?
      $options = array(
        'select' => 'Select list',
        'autocomplete' => 'Auto-complete field',
      );
      $form['r_field_type']  = array(
        '#type'          => 'radios',
        '#title'         => t('Type of form element'),
        '#options'       => $options,
        '#default_value' => isset($field['r_field_type']) ? $field['r_field_type'] : 'select',
        '#required'      => TRUE,
        );

      // alternates to select list/autocomplete?
      $options = array(
        'nothing' => 'Nothing',
        'text'    => 'Text input box',
        //'addnode' => 'AddNode form (node references only)',
      );
      $form['r_action']  = array(
        '#type'          => 'radios',
        '#title'         => t('Reference options'),
        '#description'   => t('What option do you want available in addition to choosing a reference?'),
        '#options'       => $options,
        '#default_value' => isset($field['r_action']) ? $field['r_action'] : 'nothing',
        '#required'      => TRUE,
        );

      // field titles
      $form['field_titles'] = array(
        '#type' => 'fieldset',
        '#title' => t('Field titles'),
        '#collapsible' => TRUE,
        '#collapsed' => TRUE,
      );
      $form['field_titles']['t_desc'] = array(
        '#type'          => 'textfield',
        '#title'         => t('Description'),
        '#default_value' => isset($field['t_desc']) ? $field['t_desc'] : '',
      );
      $form['field_titles']['t_ref'] = array(
        '#type'          => 'textfield',
        '#title'         => t('Reference'),
        '#default_value' => isset($field['t_ref']) ? $field['t_ref'] : '',
      );
      $form['field_titles']['t_desc2'] = array(
        '#type'          => 'textfield',
        '#title'         => t('Additional description'),
        '#default_value' => isset($field['t_desc2']) ? $field['t_desc2'] : '',
      );

      // description
      $form['description'] = array(
        '#type' => 'fieldset',
        '#title' => t('Description settings'),
        '#collapsible' => TRUE,
        '#collapsed' => TRUE,
      );
      $form['description']['desc_values'] = array(
        '#type'          => 'textarea',
        '#title'         => t('Allowed values for description (leave blank for free-form text entry)'),
        '#default_value' => isset($field['desc_values']) ? $field['desc_values'] : '',
      );
      $options = array(
        'false' => 'Optional',
        'true'  => 'Required',
      );
      $form['description']['desc_required']  = array(
        '#type'          => 'radios',
        '#title'         => t('Description required?'),
        '#description'   => t('Do you want the description to be mandatory?'),
        '#options'       => $options,
        '#default_value' => isset($field['desc_required']) ? $field['desc_required'] : 'false',
        '#required'      => TRUE,
        );

      // additional description field?
      $form['description2'] = array(
        '#type' => 'fieldset',
        '#title' => t('Additional description settings'),
        '#collapsible' => TRUE,
        '#collapsed' => TRUE,
      );
      $form['description2']['desc2_provide'] = array(
        '#type'          => 'checkbox',
        '#title'         => t('Provide a second description field'),
        '#default_value' => isset($field['desc2_provide']) ? $field['desc2_provide'] : 0,
      );
      $form['description2']['desc2_values'] = array(
        '#type'          => 'textarea',
        '#title'         => t('Allowed values for the additional description (leave blank for free-form text entry)'),
        '#default_value' => isset($field['desc2_values']) ? $field['des2c_values'] : '',
      );
      $options = array(
        'false' => 'Optional',
        'true'  => 'Required',
      );
      $form['description2']['desc2_required']  = array(
        '#type'          => 'radios',
        '#title'         => t('Additional description required?'),
        '#description'   => t('Do you want the additional description to be mandatory?'),
        '#options'       => $options,
        '#default_value' => isset($field['desc2_required']) ? $field['desc2_required'] : 'false',
        '#required'      => TRUE,
        );

      // node reference settings
      $form['node_ref'] = array(
        '#type' => 'fieldset',
        '#title' => t('Node reference settings'),
        '#collapsible' => TRUE,
        '#collapsed' => TRUE,
      );
      $subform = nodereference_field_settings($op, $field);
      foreach ($subform as $key => $array) {
        $form['node_ref'][$key] = $array;
      }

      // user reference settings
      $form['user_ref'] = array(
        '#type' => 'fieldset',
        '#title' => t('User reference settings'),
        '#collapsible' => TRUE,
        '#collapsed' => TRUE,
      );
      $subform = userreference_field_settings($op, $field);
      foreach ($subform as $key => $array) {
        $form['user_ref'][$key] = $array;
      }

      return $form;

    case 'validate' :
      // select the correct config field to test
      switch ($field['r_type']) {
        case 'nodereference' :
          $required_config = 'referenceable_types';
          break;
        case 'userreference' :
          $required_config = 'referenceable_roles';
          break;
        default : // this shouldn't happen ...
          form_set_error('r_type', t('Please select a reference type.'));
          return;
      }

       // make sure the config field has a value
      $has_values = FALSE;
      foreach ($field[$required_config] as $key => $val) {
        if (!empty($val)) {
          $has_values = TRUE;
          continue;
        }
      }
      if (!$has_values) {
        $err_name = substr($field['r_type'], 0, 4);
        form_set_error('', t("The '$err_name reference settings' section of the form must be filled out."));
      }

      // no ridiculous r_num values
      if (!is_numeric($field['r_num']) || $field['r_num'] < 1 || $field['r_num'] > 50) {
        form_set_error('r_num', t("Invalid entry for maximum # of items (the range is 1 to 50)."));
      }

      /*
      // cannot use addnode for userreference
      if ( $field['r_type'] == 'userreference' && $field['r_action'] == 'addnode' ) {
        form_set_error( 'r_type', t("You cannot provide addnode functionality for a user reference field.") );
      }
      */

      break;

    case 'save':
      global $form_values;
      if (!$reference) {
        // _content_admin_field_submit() doesn't call this op with any of
        // the form values included in the $field object (on initial creation)
        $reference = _multireference_filter_reference_type($form_values['r_type']);
        if (!$reference) {
          die('Bad reference.');
        }
      }
      $my_columns  = array(
        'r_type',
        'r_num',
        'r_action',
        'r_field_type',
        'desc_values',
        'desc_required',
        'desc2_provide',
        'desc2_values',
        'desc2_required',
        't_desc',
        't_ref',
        't_desc2',
        );
      eval('$ref_columns = '. $reference .'_field_settings(\'save\', $field);');
      $all_columns = array_merge($my_columns, $ref_columns);
      return $all_columns;

    /* Views support */
    case 'tables':
      $tables = _multireference_views_field_table($field);
      return $tables;
  }
}

/**
 * Implementation of hook_field().
 */
function multireference_field($op, &$node, $field, &$items, $teaser, $page) {
  switch ($op) {
    case 'load':
      $values = _multireference_load_values($node->nid, $field['field_name']);
      return array($field['field_name'] => $values);

    case 'update':
      db_query("DELETE FROM {node_field_multireference_data} WHERE vid = %d and field_name= '%s'", $node->vid, $field['field_name']);
      // fall through to insert updated values

    case 'insert':
      $weight = 0;
      foreach ($items as $delta => $data) {
        $desc  = empty($data['desc']) ? '' : $data['desc'];
        $desc2 = empty($data['desc2']) ? '' : $data['desc2'];
        $ref   = _multireference_get_reference_info($field, $data['r_data']);
        if (!empty($data['r_text'])) {   // new input from text entry field
          $ref['id'] = 0;
          $ref['text'] = $data['r_text'];
        }
        if (!empty($ref['text'])) {
          db_query("INSERT INTO {node_field_multireference_data}
                  SET nid = %d, vid = %d, field_name = '%s', reference = '%s', r_id = %s, r_text = '%s', description = '%s', description2 = '%s', weight = %d",
                  $node->nid, $node->vid, $field['field_name'], $field['r_type'], $ref['id'], $ref['text'], $desc, $desc2, $weight++);
        }
      }
      break;

    case 'delete':
      db_query("DELETE FROM {node_field_multireference_data} WHERE vid = %d and field_name= '%s'", $node->vid, $field['field_name']);
      break;
  }
}

/**
 * Implementation of hook_field_formatter_info().
 */
function multireference_field_formatter_info() {
  return array(
    'default' => array(
      'label' => 'list',
      'field types' => array('multireference'),
    ),
    'table' => array(
      'label' => 'table',
      'field types' => array('multireference'),
    ),
  );
}

/**
 * Implemenation of hook_field_formatter
 */
function multireference_field_formatter($field, $item, $formatter, $node) {
  static $run_only_once = array();
  if (!isset($run_only_once[$field['field_name']])) {
    $run_only_once[$field['field_name']] = TRUE;
    switch ($formatter) {   // being careful for eval()
      case 'table' :
        break;
      default :
        $formatter = 'default';
        break;
    }
    eval('$output = multireference_display_'. $formatter .'( $node->$field[\'field_name\'], $field );');
    return $output;
  }
}


/*------ CCK widget API ------*/


/**
 * Implementation of hook_widget_info
 */
function multireference_widget_info() {
  return array(
    'multireference' => array(
      'label' => 'Multi-reference List',
      'field types' => array('multireference'),
    ),
  );
}

/**
 * Implementation of hook_widget
 */
function multireference_widget($op, &$node, $field, &$items) {
  $fieldname = $field['field_name'];
  $reference = _multireference_filter_reference_type($field['r_type']);

  /*
   * determine how many items to prepare form elements for
   */
  static $num_lines = array();
  // defaults
  if (!isset($num_lines[$fieldname])) {
    $num_lines[$fieldname] = count($items) ? count($items) : 3;
  }
  // use the number returned from the form, if extant
  // (handles creating new elements with javascript)
  if (isset($_POST[$fieldname])) {
    $num_lines[$fieldname] = count($_POST[$fieldname]);
  }

  switch ($op) {
    case 'form':
      // cap # of lines at desired maximum
      if ($num_lines[$fieldname] > $field['r_num']) {
        $num_lines[$fieldname] = $field['r_num'];
      }

      $path = drupal_get_path('module', 'multireference');
      drupal_add_js($path .'/multireference.js');
      drupal_add_css($path .'/multireference.css');

      // select / text entry for descriptions
      $desc_options  = _multireference_get_desc_options($field['desc_values']);
      $desc_type     = (empty($desc_options)) ? 'textfield' : 'select';
      $desc2_options = _multireference_get_desc_options($field['desc2_values']);
      $desc2_type    = (empty($desc2_options)) ? 'textfield' : 'select';

      $form = array();
      $form[$fieldname] = array(
        '#tree'   => true,
        '#prefix' => '<table><tr><td><a name="multireference_anchor_'. $fieldname .'">'. t($field['widget']['label']) .'</a></td><td></td></tr>',
        '#suffix' => '</table>',
      );

      // the 'form' op has to return something (for 'default value') when the
      // field is being created (and, thus, before r_type is defined).
      if (!$reference) {
        $reference = 'nodereference';
      }

      /*
       * get reference options
       */
      $options = _multireference_get_options($field);
      if ($reference == 'nodereference') {
        foreach ($options as $key => $value) {
          $options[$key] = _nodereference_item($field, $value);
        }
      }
      $options[0] = '';
      asort($options);

      // add description fields
      $header = '<td>'. $field['t_desc'] .'</td><td>'. $field['t_ref'] .'<td></td>';
      if ($field['desc2_provide']) {
        $header .= '<td>'. $field['t_desc2'] .'</td>';
      }
      $form[$fieldname]['header'] = array(
          '#prefix' => '<tr>',
          '#suffix' => '</tr>',
          '#value'  => $header,
        );

      for ($tbl_i = 0; $tbl_i < $num_lines[$fieldname]; $tbl_i++) {
        $form[$fieldname]["item_$tbl_i"] = array(
          '#tree' => true,
          '#prefix' => '<tr class="multireference" id="'. $fieldname .'_'. $tbl_i .'">',
          '#suffix' => '</tr>',
        );

        /*
         * description
         */
        $form[$fieldname]["item_$tbl_i"]['desc'] = array(
          '#type'          => $desc_type,
          '#title'         => '',
          '#prefix'        => '<td>',
          '#suffix'        => '</td>',
        );
        // select
        if ($desc_type == 'select') {
          $form[$fieldname]["item_$tbl_i"]['desc']['#options'] = $desc_options;
          $form[$fieldname]["item_$tbl_i"]['desc']['#default_value'] = isset($items[$tbl_i]['desc']) ? $items[$tbl_i]['desc'] : '';
        // textfield
        }
        else {
          $form[$fieldname]["item_$tbl_i"]['desc']['#size'] = 10;
          $form[$fieldname]["item_$tbl_i"]['desc']['#default_value'] = isset($items[$tbl_i]['desc']) ? $items[$tbl_i]['desc'] : '';
        }

        /*
         * reference
         */
        $default_value['id']    = isset($items[$tbl_i]['r_id']) ? $items[$tbl_i]['r_id'] : 0;
        $default_value['text'] = isset($items[$tbl_i]['r_text']) ? $items[$tbl_i]['r_text'] : '';

        $form[$fieldname]["item_$tbl_i"]['r_data'] = array(
          '#title'         => '',
          '#prefix'        => '<td>',
          '#suffix'        => '</td>',
        );

        // select
        if ($field['r_field_type'] == 'select') {
          $form[$fieldname]["item_$tbl_i"]['r_data']['#type'] = 'select';
          $form[$fieldname]["item_$tbl_i"]['r_data']['#options'] = $options;
          $form[$fieldname]["item_$tbl_i"]['r_data']['#default_value'] = $default_value['id'];

          // alternates to select
          // TODO: creating a target via addnode or something similar
          if ($field['r_action'] == 'text') {
            $form[$fieldname]["item_$tbl_i"]['r_data']['#suffix'] = '';
            $form[$fieldname]["item_$tbl_i"]['r_data']['#description'] = t('Choose from this list or enter some text below.');
            $form[$fieldname]["item_$tbl_i"]['r_text'] = array(
              '#type'          => 'textfield',
              '#size'          => 10,
              '#title'         => '',
              '#suffix'        => '</td>',
              '#default_value' => $default_value['id'] ? '' : $default_value['text'],
            );
          }

        // autocomplete
        }
        else {
          $form[$fieldname]["item_$tbl_i"]['r_data']['#type'] = 'textfield';
          $form[$fieldname]["item_$tbl_i"]['r_data']['#autocomplete_path'] = '/multireference/autocomplete_'. $field['r_type'] .'/'. $fieldname;
          $form[$fieldname]["item_$tbl_i"]['r_data']['#default_value'] = $default_value['text'];
        }

        /*
         * additional description
         */
        if ($field['desc2_provide']) {
          $form[$fieldname]["item_$tbl_i"]['desc2'] = array(
            '#type'          => $desc2_type,
            '#title'         => '',
            '#prefix'        => '<td>',
            '#suffix'        => '</td>',
          );
          // select
          if ($desc2_type == 'select') {
            $form[$fieldname]["item_$tbl_i"]['desc2']['#options'] = $desc2_options;
            $form[$fieldname]["item_$tbl_i"]['desc2']['#default_value'] = isset($items[$tbl_i]['desc2']) ? $items[$tbl_i]['desc2'] : '';
          // textfield
          }
          else {
            $form[$fieldname]["item_$tbl_i"]['desc2']['#size'] = 10;
            $form[$fieldname]["item_$tbl_i"]['desc2']['#default_value'] = isset($items[$tbl_i]['desc2']) ? $items[$tbl_i]['desc2'] : '';
          }
        }
      }

      // JS UI element
      // TODO: client-side validation of max no. of items
      $form[$fieldname]['item_add'] = array(
        '#value' => '<tr><td><a href="#multireference_anchor_'. $fieldname .'" class="multireference_add_fields" next_item="'. $tbl_i .'" field_name="'. $fieldname .'">[+] add another field</a></td></tr>',
      );

      return $form;

    case 'validate' :
      // test # of lines
      $num = $num_lines[$field['field_name']];
      if ($num > $field['r_num']) {
        form_set_error('', t('The '. t($field['widget']['label']) .' field can hold a maximum of '. $field['r_num'] .' items.'));
      }

      $label = $field['widget']['label'];
      foreach ($items as $key => $data) {
        // are the description fields required?
        if ($field['desc_required'] == 'true' && !empty($data['r_data']) && empty($data['desc'])) {
          form_set_error('', t("The first description is required for items in the $label field"));
          break;
        }
        if ($field['desc2_required'] == 'true' && !empty($data['r_data']) && empty($data['desc2'])) {
          form_set_error('', t("The second description is required for items in the $label field."));
          break;
        }

        // no all-numeric text fields
        if (isset($data['r_text']) && is_numeric($data['r_text'])) {
          form_set_error('', t("All-numeric values are not allowed in the $label text entry fields."));
        }
        if ($field['r_field_type'] == 'autocomplete' && is_numeric($data['r_data'])) {
          form_set_error('', t("All-numeric values are not allowed in the $label reference field."));
        }
      }
      break;
  }
}


/*---- Theming functions ----*/

/**
 *  Theme function: prepares data and calls defaut line formatter
 */
function multireference_display_default(&$node_field, &$field) {
  $item_i    = 0;
  $output    = '';
  foreach ($node_field as $item) {
    $desc  = check_plain($item['desc']);
    $desc  = !empty($desc) ? $desc. ': ' : '';
    $value = _multireference_get_link($field, $item['r_id'], $item['r_text']);
    $desc2 = '';
    if ($field['desc2_provide'] && $item['desc2']) {
      $desc2 = check_plain($item['desc2']);
      $desc2 = !empty($desc2) ? $desc2 : '';
    }
    if (!empty($value)) {
      $output .= theme('multireference_default_item', $desc, $value, $desc2);
    }
  }
  return $output;
}


/**
 *  Theme function: renders each line in a <div>
 */
function theme_multireference_default_item($desc, $value, $desc2) {
  return "<div>$desc $value $desc2</div>\n";
}


/**
 *  Theme function: prepares data and calls table row formatter
 */
function multireference_display_table(&$node_field, &$field) {
  // header
  $header[] = $field['t_desc'];
  $header[] = $field['t_ref'];
  if ($field['desc2_provide']) {
    $header[] = $field['t_desc2'];
  }

  // items
  $reference = _multireference_filter_reference_type($field['r_type']);
  foreach ($node_field as $item) {
    $row   = array();
    $desc  = check_plain($item['desc']);
    $value = _multireference_get_link($field, $item['r_id'], $item['r_text']);
    $desc2 = ($field['desc2_provide']) ? check_plain($item['desc2']) : ' ';
    if ($value) {
      $row = array($desc, $value);
      if ($field['desc2_provide']) {
        $row[] = $desc2;
      }
      $data[] = $row;
    }
  }

  return theme_multireference_theme_table($header, $data);
}

/**
 *  Theme function: returns tabular display of field
 */
function theme_multireference_theme_table($header, $data) {
  return theme_table($header, $data);
}


/*---- Views functions ----*/


/**
 *  Returns views field information for hook_field_settings
 */
function _multireference_views_field_table($field) {
  $fieldname  = $field['field_name'];
  $fieldtype  = $field['type'];
  $reference  = _multireference_filter_reference_type($field['r_type']);

  $options = array(
    '#type'     => 'select',
    '#options'  => array(
      'default' => t('Default display'),
      'table'   => t('Table display'),
      ),
  );

  $filters = array(
    'description' => array(
      'name'     => "Multireference: description ($fieldname)",
      'help'     => "Filter on the descriptions of items in the $fieldname field.",
      'field'    => $fieldname,
      'operator' => array('contains' => 'Contains'),
      'handler'  => 'multireference_views_filter_handler_description',
    ),
    'reference' => array(
      'name'     => "Multireference: $reference ($fieldname)",
      'help'     => "Filter on the references in the $fieldname field.",
      'field'    => $fieldname,
      'operator' => array('contains' => 'Contains'),
      'handler'    => 'multireference_views_filter_handler_reference',
    ),
  );

  $tables[$fieldname] = array(
     'name'     => 'node_field_multireference_data',
     'provider' => 'multireference',
     'join'     => array(
                     'left'  => array('table' => 'node', 'field' => 'nid'),
                     'right' => array('field' => 'nid'),
                     'extra' => array('field_name' => $fieldname),
                     ),
     'fields'   => array(
                     $fieldname => array(
                       'name'      => "Multireference ($fieldname)",
                       'help'      => t('Multireference field'),
                       'handler'   => 'multireference_views_field_handler',
                       'notafield' => TRUE,
                       'option'    => $options,
                       ),
                   ),
      'filters' => $filters,
  );

  return $tables;
}

/**
 *  Display field in views
 */
function multireference_views_field_handler($fieldinfo, $fielddata, $value, $data) {
  $fieldname = $fielddata['field'];
  $field     = content_fields($fieldname);
  $contents  = _multireference_load_values($data->nid, $fieldname);

  switch ($fielddata['options']) {
    case 'table' :
      $theme_function = 'table';
      break;
    default :
      $theme_function = 'default';
      break;
  }

  eval('$return = multireference_display_'. $theme_function .'( $contents, $field );');
  return $return;
}

/**
 *  Filter on description text
 */
function multireference_views_filter_handler_description($op, $filter, $filterinfo, &$query) {
  $value   = trim($filter['value']);
  if (!$value) {
    return;
  }
  else {
    $value = db_escape_string($value);
  }

  list($table, $field)  = split('\.', $filter['field']);

  switch ($filter['operator']) {
    case 'contains' :
      $clause = "( UPPER($table.description) LIKE UPPER('%$value%') OR UPPER($table.description2) LIKE UPPER('%$value%') )";
      break;
  }

  $query->ensure_table($table);
  $query->add_where($clause);
  $query->set_distinct();
}

/**
 *  Filter on reference text
 */
function multireference_views_filter_handler_reference($op, $filter, $filterinfo, &$query) {
  $value   = trim($filter['value']);
  if (!$value) {
    return;
  }
  else {
    $value = db_escape_string($value);
  }

  list($table, $field)  = split('\.', $filter['field']);
  $field = content_fields($table);

  switch ($field['r_type']) {
    case 'nodereference' :
      $join_table = 'node';
      $join_field = 'title';
      $join_id    = 'nid';
      break;
    case 'userreference' :
      $join_table = 'users';
      $join_field = 'name';
      $join_id    = 'uid';
      break;
  }

  switch ($filter['operator']) {
    case 'contains' :
      $clause = "( ($table.r_id IN (SELECT $join_id FROM $join_table WHERE UPPER($join_table.$join_field) LIKE UPPER('%%%$value%%'))) OR UPPER($table.r_text) LIKE UPPER('%%%$value%%') )";
      break;
  }

  $query->set_distinct();
  $query->ensure_table($table);
  $query->add_where($clause);
}


/*---- utility functions ---- */


/**
 *  Load values from database
 */
function _multireference_load_values($nid = 0, $fieldname = '') {
  $values = array();
  if ($nid && $fieldname) {
    $sql    = "SELECT r_id, r_text, description, description2, weight FROM {node_field_multireference_data} WHERE nid=%d AND field_name='%s' ORDER BY weight";
    $result = db_query($sql, $nid, $fieldname);
    $values = array();
    while ($data = db_fetch_object($result)) {
      $values[] = array(
        'r_id'   => $data->r_id,
        'r_text' => $data->r_text,
        'desc'   => $data->description,
        'desc2'  => $data->description2,
      );
    }
  }
  return $values;
}


/**
 *  filter allowed reference types
 *  (being extra careful because these are eval()-ed)
 */
function _multireference_filter_reference_type($type = NULL) {
  $allowed_values = array('nodereference', 'userreference');
  if (!in_array($type, $allowed_values)) {
    $type = FALSE;
  }
  return $type;
}


/**
 *  determines numeric and text info for a given reference
 */
function _multireference_get_reference_info(&$field, $ref_data) {
  $ref_type  = _multireference_filter_reference_type($field['r_type']);
  if (!$ref_type || !$ref_data) {
    return array('id' => 0, 'text' => '');
  }

  static $return = array();
  $index = $ref_type . $ref_data;

  if (!isset($return["$index"])) {
    $return[$index] = array();
    $id = is_numeric($ref_data) ? (int) $ref_data : 0;
    $constrain = _multireference_get_reference_constraint($field);

    switch ($ref_type) {
      case 'nodereference' :
        if ($id > 0) {
          $text = db_result(db_query("SELECT title FROM {node} WHERE nid = %d $constrain", $id));
        }
        elseif (!empty($ref_data)) {
          $text = $ref_data;
          $id   = db_result(db_query("SELECT nid FROM {node} WHERE title = '%s' $constrain", $ref_data));
        }
        break;

      case 'userreference' :
        if ($id > 0) {
          $text = db_result(db_query("SELECT u.name FROM {users} u, {users_roles} r WHERE u.uid = %d $constrain", $id));
        }
        elseif (!empty($ref_data)) {
          $text = $ref_data;
          $id = db_result(db_query("SELECT u.uid FROM {users} u, {users_roles} r WHERE name = '%s' $constrain", $ref_data));
        }
        break;
    }
    $return[$index]['id']   = !empty($id) ? $id : 0;
    $return[$index]['text'] = !empty($text) ? $text : '';
  }
  return $return[$index];
}


/**
 *  Returns link or text for reference
 */
function _multireference_get_link(&$field, $r_id = 0, $r_text = FALSE) {
  $r_type = _multireference_filter_reference_type($field['r_type']);
  if (!$r_type || !$r_text) {
    return FALSE;
  }

  // determine text and path for reference
  $path = '';
  $r_id = (int) $r_id;
  if ($r_id > 0) {
    if ($r_type == 'nodereference') {
      $path = drupal_get_path_alias('node/'. $r_id);
    }
    elseif ($r_type == 'userreference') {
      $path = 'user/'. $r_id;
    }
  }

  if ($path) {
    return l($r_text , $path);
  }
  else {
    return check_plain($r_text);
  }
}


/**
 *  generate a select list for descriptions
 */
function _multireference_get_desc_options($values) {
  $options = array();
  if (!empty($values)) {
    $desc_values = split("\n", $values);
    $options[]   = t('--select--');
    foreach ($desc_values as $value) {
      $value = trim($value);
      $options[$value] = $value;
    }
  }
  return $options;
}


/**
 * Handle autocomplete form elements: node references
 */
function multireference_autocomplete_node($fieldname = '', $string = '') {
  // only bother when we have some actual data
  if (strlen($string) < 2 || is_numeric($string) || !$fieldname) {
    return;
  }
  $field     = content_fields($fieldname);
  $matches   = array();
  $constrain = _multireference_get_reference_constraint($field);
  $sql       = "SELECT nid, title FROM {node} WHERE LOWER(title) LIKE LOWER('%s%%') $constrain";
  $result    = db_query_range($sql, $string, 0, 10);
  while ($node = db_fetch_object($result)) {
    $matches[$node->title] = $node->title;
  }
  print drupal_to_js($matches);
  exit();
}


/**
 * Handle autocomplete form elements: user references
 */
function multireference_autocomplete_user($fieldname = '', $string = '') {
  // only bother when we have some actual data
  if (strlen($string) < 2 || is_numeric($string) || !$fieldname) {
    return;
  }
  $field     = content_fields($fieldname);
  $matches   = array();
  $constrain = _multireference_get_reference_constraint($field);
  $sql = "SELECT u.uid, u.name FROM {users} u, {users_roles} r WHERE LOWER(u.name) LIKE LOWER('%s%%') $constrain";
  $result = db_query_range($sql, $string, 0, 10);
  while ($user = db_fetch_object($result)) {
    $matches[$user->name] = $user->name;
  }
  print drupal_to_js($matches);
  exit();
}


/**
 *  return unprocessed array of options from one of the reference modules
 *  return values are cached for performance
 */
function _multireference_get_options(&$field) {
  static $return = array();
  $reference = _multireference_filter_reference_type($field['r_type']);
  if (!$reference) {
    return array();
  }

  if (!isset($return[$field['field_name']])) {
    if ($reference == 'nodereference') {
      include_once(drupal_get_path('module', 'content') .'/nodereference.module');
      $options = _nodereference_potential_references($field, true);
    }
    elseif ($reference == 'userreference') {
      include_once(drupal_get_path('module', 'content') .'/userreference.module');
      $options = _userreference_potential_references($field);
    }
    $return[$field['field_name']] = $options;
  }

  return $return[$field['field_name']];
}


/**
 *  determine the node type or user role constraints on results
 *  return values are cached for performance
 */
function _multireference_get_reference_constraint(&$field) {
  static $constraints = array();
  if (!isset($constraints[$field['field_name']])) {
    if ($field['r_type'] == 'nodereference') {
      $options = $field['referenceable_types'];
      foreach ($options as $key => $value) {
        if (!empty($value)) {
          $types .= $conj ."'$key'";
          $conj = ',';
        }
      }
      $constraints[$field['field_name']] = empty($types) ? '' : " AND type IN ($types) ";
    }
    else {
      $options = $field['referenceable_roles'];
      foreach ($options as $key => $value) {
        if (!empty($value)) {
          if ($key == 2) {  // authenticated user == in users table, so no constraint
            $types = array();
            break;
          }
          $types .= $conj . $key;
          $conj = ',';
        }
      }
      $constraints[$field['field_name']] = empty($types) ? '' : " AND r.rid IN ($types) AND r.uid=u.uid ";
    }
  }
  return $constraints[$field['field_name']];
}