Ruby特别重写父类方法

Question

如何重写ruby父类中的一行或多行代码？ 例如：我有方法create Rails的控制器类：

class GenericController < ApplicationController 
def create 
    @resource = SomeClass.new 
    if @resource.save 
     ... 
    else 
     ... 
    end 
    end 
end 

而且我还有一个控制器，孩子该控制器的

class ChildController < GenericController 
    def create 
    super do 
     # HERE I WANT TO DO SOME ACTIONS BEFORE SAVE. 
    end 
    end 
end 

我怎样才能做到这一点？我试过这个（通用控制器）：

def create 
    @resource = SomeClass.new 
    yield if block_given? 
    if @resource.save 
     ... 
    end 
    end 

但是如果我想通过多个块呢？例如，如果我想做回调：after_init，：before_save，：after_save等？

Answer 1

def create 
    super do 
     # HERE I WANT TO DO SOME ACTIONS BEFORE SAVE. 
    end 
    end 

但是，如果我想传递一个街区更是什么？例如，如果我想 进行回调：after_init，：before_save，：after_save的等

您需要的块传递给超类方法外您create()方法：

class Dog < GenericController 
    before_save do 
    puts 'before1' 
    end 

    after_save do 
    puts 'after1' 
    end 

    before_save do 
    puts 'before2' 
    end 

    def create 
    super 
    end 

end 

---

class GenericController 
    class <<self 
    attr_accessor :before, :after 

    def before_save(&block) 
     @before << block 
    end 

    def after_save(&block) 
     @after << block 
    end 
    end 

    def self.inherited(subclass) 
    subclass.instance_variable_set(:@before, []) 
    subclass.instance_variable_set(:@after, []) 
    end 

    def create 

    self.class.before.each do |proc| 
     proc.call 
    end 

    puts 'saving resource...' 
    #@resource.save 

    self.class.after.each do |proc| 
     proc.call 
    end 

    end 

end 

---

Dog.new.create 

--output:-- 
before1 
before2 
saving resource... 
after1