Question

这很有效，但很冗长。如何缩短这个？

.service{:class => [route.night? ? "night" : "", route.school? ? "school" : ""] * ""}

我希望这个元素有：

class = "service"如果不是route.night?而不是route.school?
class = "night service"如果route.night?而非route.school?
class = "school service"，如果不是route.night?和route.school?
class = "school night service"如果route.night?和route.school?

编辑：matt帮我缩短了三个字符：

.service{:class => [route.night? ? "night" : "", route.school? ? "school" : ""]}

还能做些什么？

Answer 1

我建议实施帮助

def service_class_helper(route)
  classes = ['service']
  classes << 'night' if route.night?
  classes << 'school' if route.school?
  classes
end

并相应地在模板中使用

:class => service_class_helper(route)

如果不需要使用助手，您可以使用

.service{:class => ['night', 'school'].select { |c| c if route.send("#{c}?") } }

这项工作很简单。但是必然存在一些明显的局限性。

Answer 2

您可以这样做：

.service{class: {night: route.night?, school: route.school?}.map{|k,v| k if v} }

或者，如果您可以重构Route课程，则可以将其定义为：

class Route
  def initialize(night: false, school: false)
    @route_type = Set.new
    @route_type.add('night') if night
    @route_type.add('school') if school
  end

  def route_type
    @route_type.to_a
  end

  def night?
    @route_type.include? 'night'
  end

  def school?
    @route_type.include? 'school'
  end
end

现在你可以写

了

.service { class: route.route_type }

HAML中元素的多个动态类

2 个答案: