/**
* @param nc_search_query $query
* @return string|null
*/
public function translate(nc_search_query $query)
{
$root = $query->parse();
// empty query?
if ($root instanceof nc_search_query_expression_empty) {
return null;
}
// queries with only excluded terms are forbidden
if ($root->is_excluded() || $root instanceof nc_search_query_expression_not) {
return null;
}
// initialize variables used for a translation of the query
$this->query_builder = $builder = new nc_search_provider_index_querybuilder($query, $this);
$this->stack = array();
$this->unknown_required_terms = array();
$this->can_skip_fts_query = false;
$this->implicit_field_match = $this->expression_requires_implicit_match($root);
// get language filters chain to use in this.translate_term() etc.
$language = $query->get('language');
if (!$language) {
$language = nc_Core::get_object()->lang->detect_lang();
}
$query_context = new nc_search_context(array("search_provider" => get_class($this->provider), "language" => $language, "action" => "searching"));
$this->text_filters = nc_search_extension_manager::get('nc_search_language_filter', $query_context)->stop_on(array());
// Ready to go!
// translate the expression tree
$index_query = $this->dispatch_translate($root);
if (!$this->can_skip_fts_query) {
// interval search at the root for a numeric field
// index query is required almost always
if (!strlen($index_query)) {
return null;
}
// e.g. if query string consists of stop words
if ($index_query == "____" || $index_query == "(____)") {
// empty query
return null;
}
}
// set query for the combined index in the query builder
if ($index_query && !$root->get_field()) {
$builder->set_index_match($index_query);
}
// there are required terms that are not in the index, so don’t make a query
if ($this->unknown_required_terms) {
return null;
}
// использовать временную таблицу для уточняющих запросов при поиске фраз?
$use_temp_table = !nc_search::get_setting('DatabaseIndex_AlwaysGetTotalCount') && $this->expression_has_phrase($root);
// return SQL query string
$result = $builder->get_sql_query($use_temp_table);
return $result;
}
/**
* @param nc_search_query $query
* @return mixed
*/
public function translate(nc_search_query $query)
{
return $this->dispatch_translate($query->parse());
}
