modules/search/views_handler_filter_search.inc

<?php

class views_handler_filter_search extends views_handler_filter {
  var $always_multiple = TRUE;

  var $search_query = NULL;

  var $parsed = FALSE;

  function option_definition() {
    $options = parent::option_definition();

    $options['operator']['default'] = 'optional';

    return $options;
  }

  function operator_form(&$form, &$form_state) {
    $form['operator'] = array(
      '#type' => 'radios',
      '#title' => t('On empty input'),
      '#default_value' => $this->operator,
      '#options' => array(
        'optional' => t('Show All'),
        'required' => t('Show None'),
      ),
    );
  }

  function value_form(&$form, &$form_state) {
    $form['value'] = array(
      '#type' => 'textfield',
      '#size' => 15,
      '#default_value' => $this->value,
      '#attributes' => array('title' => t('Enter the terms you wish to search for.')),
      '#title' => empty($form_state['exposed']) ? t('Value') : '',
    );
  }

  function exposed_validate(&$form, &$form_state) {
    if (!isset($this->options['expose']['identifier'])) {
      return;
    }

    $key = $this->options['expose']['identifier'];
    if (!empty($form_state['values'][$key])) {
      $this->query_parse_search_expression($form_state['values'][$key]);
      if (count($this->search_query->words()) == 0) {
        form_set_error($key, format_plural(variable_get('minimum_word_size', 3), 'You must include at least one positive keyword with 1 character or more.', 'You must include at least one positive keyword with @count characters or more.'));
      }
    }
  }

  function query_parse_search_expression($input) {
    if (!isset($this->search_query)) {
      $this->parsed = TRUE;
      $this->search_query = db_select('search_index', 'i', array('target' => 'slave'))->extend('viewsSearchQuery');
      $this->search_query->searchExpression($input, $this->view->base_table);
      $this->search_query->publicParseSearchExpression();
    }
  }

  function query() {
    // Since attachment views don't validate the exposed input, parse the search
    // expression if required.
    if (!$this->parsed) {
      $this->query_parse_search_expression($this->value);
    }
    $required = FALSE;
    if (!isset($this->search_query)) {
      $required = TRUE;
    }
    else {
      $words = $this->search_query->words();
      if (empty($words)) {
        $required = TRUE;
      }
    }
    if ($required) {
      if ($this->operator == 'required') {
        $this->query->add_where($this->options['group'], 'FALSE');
      }
    }
    else {
      $search_index = $this->ensure_my_table();

      $search_condition = db_and();

      // Create a new join to relate the 'serach_total' table to our current 'search_index' table.
      $join = new views_join;
      $join->construct('search_total', $search_index, 'word', 'word');
      $search_total = $this->query->add_relationship('search_total', $join, $search_index);

      $this->search_score = $this->query->add_field('', "SUM($search_index.score * $search_total.count)", 'score', array('aggregate' => TRUE));

      if (empty($this->query->relationships[$this->relationship])) {
        $base_table = $this->query->base_table;
      }
      else {
        $base_table = $this->query->relationships[$this->relationship]['base'];
      }
      $search_condition->condition("$search_index.type", $base_table);
      if (!$this->search_query->simple()) {
        $search_dataset = $this->query->add_table('search_dataset');
        $conditions = $this->search_query->conditions();
        $condition_conditions =& $conditions->conditions();
        foreach ($condition_conditions  as $key => &$condition) {
          // Take sure we just look at real conditions.
          if (is_numeric($key)) {
            // Replace the conditions with the table alias of views.
            $this->search_query->condition_replace_string('d.', "$search_dataset.", $condition);
          }
        }
        $search_conditions =& $search_condition->conditions();
        $search_conditions = array_merge($search_conditions, $condition_conditions);
      }
      else {
        // Stores each condition, so and/or on the filter level will still work.
        $or = db_or();
        foreach ($words as $word) {
          $or->condition("$search_index.word", $word);
        }

        $search_condition->condition($or);
      }

      $this->query->add_where($this->options['group'], $search_condition);
      $this->query->add_groupby("$search_index.sid");
      $matches = $this->search_query->matches();
      $placeholder = $this->placeholder();
      $this->query->add_having_expression($this->options['group'], "COUNT(*) >= $placeholder", array($placeholder => $matches));
    }
    // Set to NULL to prevent PDO exception when views object is cached.
    $this->search_query = NULL;
  }
}

class viewsSearchQuery extends SearchQuery {
  public function &conditions() {
    return $this->conditions;
  }
  public function words() {
    return $this->words;
  }

  public function simple() {
    return $this->simple;
  }

  public function matches() {
    return $this->matches;
  }

  public function publicParseSearchExpression() {
    return $this->parseSearchExpression();
  }

  function condition_replace_string($search, $replace, &$condition) {
    if ($condition['field'] instanceof DatabaseCondition) {
      $conditions =& $condition['field']->conditions();
      foreach ($conditions as $key => &$subcondition) {
        if (is_numeric($key)) {
          $this->condition_replace_string($search, $replace, $subcondition);
        }
      }
    }
    else {
      $condition['field'] = str_replace($search, $replace, $condition['field']);
    }
  }
}