字符串“真"和“假"到布尔值

我有一个 Rails 应用程序，我正在使用 jQuery 在后台查询我的搜索视图.有字段 q(搜索词)、start_date、end_date 和 internal.internal 字段是一个复选框，我使用 is(:checked) 方法来构建被查询的 url:

I have a Rails application and I'm using jQuery to query my search view in the background. There are fields q (search term), start_date, end_date and internal. The internal field is a checkbox and I'm using the is(:checked) method to build the url that is queried:

$.getScript(document.URL + "?q=" + $("#search_q").val() + "&start_date=" + $("#search_start_date").val() + "&end_date=" + $("#search_end_date").val() + "&internal=" + $("#search_internal").is(':checked'));

现在我的问题出在 params[:internal] 因为有一个包含true"或false"的字符串，我需要将它转换为布尔值.我当然可以这样做:

Now my problem is in params[:internal] because there is a string either containing "true" or "false" and I need to cast it to boolean. Of course I can do it like this:

def to_boolean(str)
     return true if str=="true"
     return false if str=="false"
     return nil
end

但我认为必须有一种更像 Ruby 风格的方式来处理这个问题！不是有...?

But I think there must be a more Ruby'ish way to deal with this problem! Isn't there...?