您如何处理ActiveSupport :: JSON和JSON gem之间的冲突? [英] How do you deal with the conflict between ActiveSupport::JSON and the JSON gem?

问题描述

我为这个问题感到困惑.

I am stumped with this problem.

ActiveSupport::JSON在各种核心对象上定义to_json，JSON gem也是如此.但是，实现方式并不相同-ActiveSupport版本带有参数，而JSON gem版本没有参数.

ActiveSupport::JSON defines to_json on various core objects and so does the JSON gem. However, the implementation is not the same -- the ActiveSupport version takes arguments and the JSON gem version doesn't.

我安装了需要JSON gem的gem，但我的应用程序坏了.问题是我在返回对象列表的控制器中使用to_json，但是我想控制要返回的属性.

I installed a gem that required the JSON gem and my app broke. The issue is that I'm using to_json in a controller that returns a list of objects, but I want to control which attributes are returned.

当系统中任何地方的代码执行require 'json'时，我都会显示以下错误消息:

When code anywhere in my system does require 'json' I get this error message:

TypeError: wrong argument type Hash (expected Data)

我尝试了一些在线阅读的方法来修复它，但是没有任何效果.我最终重新编写了gem以使用ActiveSupport::JSON.decode而不是JSON.parse.

I tried a couple of things that I read online to fix it, but nothing worked. I ended up re-writing the gem to use ActiveSupport::JSON.decode instead of JSON.parse.

这行得通，但这是不可持续的...我不能每次都想使用需要JSON宝石的宝石时分叉宝石.

This works but it's not sustainable...I can't be forking gems every time I want to use a gem that requires the JSON gem.

更新:此问题的最佳解决方案是升级到Rails 2.3或更高版本，从而对其进行了修复.

Update: The best solution of this problem is to upgrade to Rails 2.3 or higher, which fixed it.

推荐答案

更新 该修补程序仅适用于Rails< 2.3.就像Giles在下面提到的那样，他们使用几乎相同的技术在内部将其固定在2.3中.但是要当心json gem在Rails兼容性上的早期尝试(json/add/rails)，，如果明确要求，则会再次破坏一切.

您是说require 'json'语句本身引发该异常吗?还是说当您致电@something.to_json(:something => value)时收到错误消息?后者是我所期望的，如果您在使用JSON gem时遇到问题，那么我不确定会发生什么.

Do you mean the require 'json' statement itself raises that Exception? Or do you mean when you call @something.to_json(:something => value) you get the error? The latter is what I would expect, if you have a problem requiring the JSON gem then I'm not sure what's going on.

我刚遇到了oauth gem的问题.在我的情况下，没有真正的冲突，因为oauth gem不依赖于to_json实现.因此，问题在于JSON破坏了ActiveSupport声明.我通过在加载ActiveSupport之前只需要json来解决了这个问题.放置

I just ran into this problem with the oauth gem. In my case, there is not a true conflict, because the oauth gem doesn't depend on to_json implementation. Therefore the problem is that JSON is clobbering the ActiveSupport declarations. I solved this by simply requiring json before ActiveSupport is loaded. Putting

require 'json'

在Rails::Initializer内部的

做到了这一点(尽管没有把它放在块后面).

inside the Rails::Initializer did the trick (though putting it after the block did NOT).

这允许ActiveSupport代替默认的JSON实现.

That allows ActiveSupport to clobber the default JSON implementation instead.

现在，如果您使用的宝石实际上依赖于to_json的JSON实现，那么您将大步前进.这绝对是元编程中最糟糕的情况，我会提倡让Rails和JSON gem开发人员解决冲突，尽管这会很痛苦，因为彼此之间都必须打破向后兼容性.

Now if you are using a gem that actually depends on the JSON implementation of to_json then you are up a creek. This is definitely the worst of meta-programming, and I would advocate for the Rails and JSON gem developers to resolve the conflict, though it will be painful because one or the other will have to break backwards compatibility.

从短期来看，gem作者可能能够通过支持这两种实现来弥合差距.根据宝石如何使用该方法，这或多或少是可行的.最坏的情况是使用官方分叉(即gem和gem-rails).

In the short term, gem authors may be able to bridge the gap by supporting both implementations. This is more or less feasible depending on how the gem uses the method. A worst case scenario is an official fork (ie. gem and gem-rails).

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