Gets a query param.

@param string $param
@return string|NULL
430667
protected function getQueryParam(string $param) : ?string
    {
        if ($this->queryParams === null) {
            $this->parseQueryParams();
        }
        return $this->queryParams[$param] ?? null;
    }
761992
public function getQuery($queryParams)
    {
        return array_key_exists($queryParams, $this->query) ? $this->query[$queryParams] : null;
    }
494894
private function GetParamString($param)
    {
        if ($param === null)
            return "null";
        if (is_string($param))
            return "'" .  addcslashes($param, "'") . "'";
        
        else if (is_bool($param))
            return $param ? "true" : "false";
        
        else if (is_int($param) || is_float($param))
            return (string)$param;
        
        else if ($param instanceof WritableClass)
            return $param->GetNewStatement();
        
        else if (is_array($param))
        {
            $resultArr = array();
            foreach ($param as $key=>$val)
            {
                $resultArr[] = $this->GetParamString($key) . '=>' . $this->GetParamString($val);
            }
            return 'array(' . join (', ' , $resultArr) .')';
        }
        else if ($param instanceof \Phine\Framework\System\Enum)
        {
            $value = $param->Value();
            $class = get_class($param);
            return "\\$class::ByValue('$value')";
        }
        throw new \InvalidArgumentException('A writable class must have primitive types, Enums, arrays and PhpWritable classes as construct params only.');
    }
370922
public function getParameter($parameter) {
        $value = NULL;
        if ($parameter != NULL) {
            if (isset($this->params[$parameter])) {
                $value = $this->params[$parameter];
            }
        }
        if (is_null($value)) {
            if (isset($_POST[$parameter])) {
                $value = $_POST[$parameter];
            }
        }
        if (is_null($value)) {
            if (isset($_GET[$parameter])) {
                $value = $_GET[$parameter];
            }
        }
        if (is_string($value)) {
            $value = urldecode($value);
        }
        return $value;
    }
697894
public function route( $param = null ) {
		$route = call_user_func( $this->get_route_resolver() );

		if ( is_null( $route ) || is_null( $param ) ) {
			return $route;
		}

		return array_key_exists( $param, $route[2] ) ? $route[2][ $param ] : null;
	}
125421
public function one($param = true){
        $this->isAr = true;
        if($this->isPretreatment){
            self::$Pre = $this->bindSql();
            if(!$param) return self::$Pre->queryString;
            return $this->dbh->pone($this->bindSql());
        }
        $bind = $this->bindSql();
        if(!$param) return $this->PrintSQL();
        $this->initialize();
        return $bind->one();
    }
804423
public function getQueryParameter($key)
    {
        $queryStringArray = $this->getQueryStringAsArray();

        if (array_key_exists($key, $queryStringArray)) {
            return $queryStringArray[$key];
        }

        return null;
    }
1171564
public function getParam($param, $default = null) 
    {
        if(array_key_exists($param, $this->params)) {
            return $this->params[$param];
        }
        
        return $default;
    }
1310538
public function get($param = '') {
        $this->validate();

        if ($param) {
            if (array_key_exists($param, $this->config)) {
                return $this->config[$param];
            }
            else {
                throw new ArgumentConfigException('argument param not valid: ' . $param);
            }
        }

        return $this->config;
    }
642521
public function getQueryParam(UriInterface $uri, $param)
    {
        if (!$query = $uri->getQuery()) {
            return null;
        }

        parse_str($query, $params);
        if (!array_key_exists($param, $params)) {
            return null;
        }

        return $params[$param];
    }
418784
public function queryRow($params = array())
    {
        $this->mergeParams($params);
        $this->beginQuery();
        $rst = $this->statement->fetch(\PDO::FETCH_ASSOC);
        $this->statement->closeCursor();
        return $rst;
    }
838674
public function getQueryParam($key)
    {
        if (isset($this->queryParams[$key])) {
            return $this->queryParams[$key];
        }
        return null;
    }
907240
public function getBackup($param)
    {
        if ($this->isOpened()) {
            if (!empty($param)) {
                return isset($this->request_session[$param]) ?
                    $this->request_session[$param] : null;
            }
            return $this->request_session;
        }
    }
351316
public static function setParams(&$param)
    {
        $arr_req = array();
        foreach($param as $key=>$value){
            if(is_array($value)) {
                $arr_req[] = "${key}=".implode("&",$value);
            } else {
                if ($value == '') {
                    continue;
                }
                $arr_req[] = "${key}=${value}";
            }
        }
        $str = implode("&",$arr_req);

        return $str;
    }
149887
public function all($param = true){
        $this->isAr = true;
        if($this->isPretreatment){
            self::$Pre = $this->bindSql();
            if(!$param) return self::$Pre->queryString;
            return $this->dbh->pall(self::$Pre);
        }
        $bind = $this->bindSql();
        if(!$param) return $this->PrintSQL();
        $this->initialize();
        return  $bind->all();
    }
860456
public String getParam(String param) {
        int i = findParam(param);
        return i < 0 ? null : StrUtil.piece(extraInfo[i], "=", 2);
    }
496311
public function getArg($num)
    {
        return isset($this->args[$num]) ? $this->args[$num] : null;
    }