有没有一种干净的方法来避免在嵌套的params散列中调用nil方法？ [英] Is there a clean way to avoid calling a method on nil in a nested params hash?

问题描述

我有兴趣获取params散列的嵌套'name'参数。调用类似于

  params [：subject] [：name] 
   
 
 
会引发错误。为避免这种错误，我通常会写这样的内容：
  if params [：subject]&& params [：subject] [：name] 
  
是否有一个更简洁的方法来实现它？
解决方案
检查 Ick 的也许。您不需要对代码进行重构，只需在必要时使用代理即可：
 [：subject] .maybe [：name] 
  

同一作者（ raganwald ）也写了 andand ，具有相同的想法。

I'm interested in getting the nested 'name' parameter of a params hash. Calling something like

params[:subject][:name]

throws an error when params[:subject] is empty. To avoid this error I usually write something like this:

if params[:subject] && params[:subject][:name]

Is there a cleaner way to implement this?

解决方案

Check Ick's maybe. You don't need to significantly refactor your code, just intersperse maybe proxies when necessary:

params[:subject].maybe[:name]

The same author (raganwald) also wrote andand, with the same idea.

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