如何测试参数是否存在在轨道

我使用Ruby on Rails中的IF语句来尝试和测试是否设置了请求参数。无论是否设置了两个参数，都会触发下面if块的第一部分。我怎么能让这部分只被触发，如果两个params[:one]和params[:two]都设置了?

if (defined? params[:one]) && (defined? params[:two])
 ... do something ...
elsif (defined? params[:one])
 ... do something ...
end

当前回答

你可以这样写得更简洁:

required = [:one, :two, :three]
if required.all? {|k| params.has_key? k}
  # here you know params has all the keys defined in required array
else
  ...
end

2015-01-20 16:44:06

其他回答

我是这么做的，

before_action :validate_presence

然后是以下几种方法:

    def check_presence
  params[:param1].present? && params[:param2].present?
 end

 def validate_presence
  if !check_presence
    render json:  {
                      error:  {
                                message: "Bad Request, parameters missing.",
                                status: 500
                              }
                    }
  end
 end

2016-03-03 05:24:07

if params[:one] && params[:two]
 ... do something ...
elsif params[:one]
 ... do something ...
end

2011-04-12 01:26:03

params[:foo] ||= '默认值'

2012-06-02 01:44:49

你可以这样写得更简洁:

required = [:one, :two, :three]
if required.all? {|k| params.has_key? k}
  # here you know params has all the keys defined in required array
else
  ...
end

2015-01-20 16:44:06

我刚在RubyInRails类上读到这个 http://api.rubyonrails.org/classes/Object.html#method-i-blank-3F

你可以用空白?方法，该方法等价于params[:one].nil?| | params[:]空虚吗?

(如)

if params[:one].blank? 
  # do something if not exist
else
  # do something if exist
end

2015-06-01 02:30:06

如何测试参数是否存在在轨道

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