继承HTTParty模块

Question

如何继承HTTParty模块以设置某些默认值？

module SuperClient
  include HTTParty

  headers 'Auth' => 'Basic'
end

module ServiceApiClient
  include SuperClient

  headers 'X-Prop' => 'Some specific data'
  base_uri 'https://example.com'

  def self.posts
    self.get '/posts'
    # Expected to send headers Auth and X-Prop
  end
end

我需要一些定制模块，这些模块可以包含在客户机类中，并且行为类似于本机HTTParty模块。

Answer 1

如果唯一的目的是设置默认值，而不是重新定义方法，那么下面的操作就会奏效：

module SuperClient
  def self.included(base)
    base.include HTTParty

    # defaults
    base.headers 'Auth' => 'Basic'
    # or
    base.class_eval do
      headers 'Auth' => 'Basic'
    end
  end
end

当您包含SuperClient时，它将包含HTTParty并设置一些默认值。如果这是您需要的唯一功能，这就是您的答案，如果您也计划重新定义方法，请进一步阅读。

如果您计划重新定义方法，这会使不起的作用。HTTParty将在SuperClient之前添加到祖先堆栈中。当调用由SuperClient和HTTParty定义的方法时，将首先调用HTTParty变量，这意味着永远不会到达SuperClient变量。

这可能比您需要的信息更多，但是以上问题可以通过这样做来解决：

module SuperClient
  def self.included(base)
    base.include HTTParty
    base.include InstanceMethods
    base.extend  ClassMethods

    # defaults
    # ...
  end

  module InstanceMethods
    # ...
  end

  module ClassMethods
    # ...
  end
end

通过包含InstanceMethods和在包含HTTParty之后扩展ClassMethods，它们将位于堆栈的更高的位置，从而允许您重新定义方法并调用super。

class C
  include SuperClient
end

# methods are search for from top to bottom
puts C.ancestors
# C
# SuperClient::InstanceMethods
# HTTParty::ModuleInheritableAttributes
# HTTParty
# SuperClient
# Object
# JSON::Ext::Generator::GeneratorMethods::Object
# Kernel
# BasicObject

puts C.singleton_class.ancestors
# #<Class:C>
# SuperClient::ClassMethods
# HTTParty::ModuleInheritableAttributes::ClassMethods
# HTTParty::ClassMethods
# #<Class:Object>
# #<Class:BasicObject>
# Class
# Module
# Object
# JSON::Ext::Generator::GeneratorMethods::Object
# Kernel
# BasicObject

Answer 2

您可以将SuperClient保持为类，并从它继承其他客户端。就像这样。两个标题'Auth‘和’X‘都将包含在请求中。

require 'httparty'

class SuperClient 
    include HTTParty

    headers 'Auth' => 'Basic'
    # Uncomment below line to print logs in terminal
    # debug_output STDOUT
end

class ServiceApiClient < SuperClient

    headers 'X-Prop' => 'Some specific data'
    base_uri 'https://example.com'

    def posts
        self.class.get '/posts'
        # Expected to send headers Auth and X-Prop
  end
end         

client = ServiceApiClient.new

client.posts()