将字符串"true“和"false”转换为布尔值
将字符串"true“和"false”转换为布尔值
提问于 2011-11-14 18:06:38
我有一个Rails应用程序，并且正在使用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，我正在使用is(:checked)方法来构建要查询的url：
$.getScript(document.URL + "?q=" + $("#search_q").val() + "&start_date=" + $("#search_start_date").val() + "&end_date=" + $("#search_end_date").val() + "&internal=" + $("#search_internal").is(':checked'));现在我的问题出现在params[:internal]中，因为有一个字符串包含"true“或"false”，我需要将其转换为布尔值。我当然可以这样做：
def to_boolean(str)
return true if str=="true"
return false if str=="false"
return nil
end但我认为一定有一种更Ruby的方式来解决这个问题！是不是有...？
Stack Overflow用户
发布于 2015-05-01 04:09:53
ActiveRecord::Type::Boolean.new.type_cast_from_user根据Rails的内部映射ConnectionAdapters::Column::TRUE_VALUES和ConnectionAdapters::Column::FALSE_VALUES执行此操作
[3] pry(main)> ActiveRecord::Type::Boolean.new.type_cast_from_user("true")
=> true
[4] pry(main)> ActiveRecord::Type::Boolean.new.type_cast_from_user("false")
=> false
[5] pry(main)> ActiveRecord::Type::Boolean.new.type_cast_from_user("T")
=> true
[6] pry(main)> ActiveRecord::Type::Boolean.new.type_cast_from_user("F")
=> false
[7] pry(main)> ActiveRecord::Type::Boolean.new.type_cast_from_user("yes")
DEPRECATION WARNING: You attempted to assign a value which is not explicitly `true` or `false` ("yes") to a boolean column. Currently this value casts to `false`. This will change to match Ruby's semantics, and will cast to `true` in Rails 5. If you would like to maintain the current behavior, you should explicitly handle the values you would like cast to `false`. (called from <main> at (pry):7)
=> false
[8] pry(main)> ActiveRecord::Type::Boolean.new.type_cast_from_user("no")
DEPRECATION WARNING: You attempted to assign a value which is not explicitly `true` or `false` ("no") to a boolean column. Currently this value casts to `false`. This will change to match Ruby's semantics, and will cast to `true` in Rails 5. If you would like to maintain the current behavior, you should explicitly handle the values you would like cast to `false`. (called from <main> at (pry):8)
=> false因此，您可以在初始化器中创建自己的to_b (或to_bool或to_boolean)方法，如下所示：
class String
def to_b
ActiveRecord::Type::Boolean.new.type_cast_from_user(self)
end
end页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/8119970
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