ruby - rails路由constraints问题

Question

初学rails，有几个问题不明白。

class NamespaceConstraint
  def self.matches?(request)
    name = request.fullpath.split('/').second.downcase
    if name[0] == '~' then name = name[1..-1] end
    ns = Namespace.where(name_lower: request.fullpath.split('/').second.downcase).first
    not ns.nil?
  end
end

Rails.application.routes.draw do

  constraints(NamespaceConstraint) do
    get  ':namespace' => 'namespaces#show'
  end

end

• 这段代码大致是什么意思？

• self.matches?这个函数名问号是什么意思？

• 这个request变量名并没有定义，是rails自动生成的吗？

• not ns.nil?这个是啥意思？

Answer 1

• In ruby, the return value of methods with ? is agreed to be true/false

• request is a custom variable in rails controller, and the corresponding response is also

• not means negation, for example, not true means false, ns.nil? What is returned is a boolean type, not negated

• This method is used to match routes. request.fullpath returns a relative path. For example, blogs.com/blogs returns /blogs. Then the first line finally obtains 'blogs', and then uses 'blogs' to find the current path. Whether the route matches it, true if yes, false if not.

• You can try all of these methods locally and run them step by step. This is not a complicated thing

Answer 2

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