如何测试是否carrierwave文件改变了吗？ [英] How to test if carrierwave file changed?

问题描述

我想测试一个图形使用载波改变了我的code，但我不能找到一个方法来做到这一点。看来，对象被标记为即使该文件是无效的改变，因此它并没有真正改变。

I'm trying to test if a image was changed with carrier wave on my code, but I can't find a way to do this. It seems that the object is marked as changed even if the file is invalid, and thus it was not really changed.

看看下面的输出：

(rdb:1) job.translated_xliff
#<XliffUploader:0xcd8b380 ...>
(rdb:1) job.changed?
false # As expected, didn't changed yet
(rdb:1) job.translated_xliff = "foo"
"foo"
(rdb:1) job.changed?
true # Changed? "foo" is not a valid file. Lets see the file again...
(rdb:1) job.translated_xliff
#<XliffUploader:0xcd8b380 ...> # same object ID!

我如何检查，如果该对象是真的改变了我的code？

How can I check if this object was really changed on my code?

编辑：我开了一个问题在github ，但问题仍然没有解决，但更多的信息可以在那里找到

I opened an issue on github, but the problem still not solved, yet more information can be found there

推荐答案

在内部Carrierwave定义（重写）的ActiveRecord 的getter / setter 上载列（ translated_xliff ）

Internally Carrierwave define(override) the ActiveRecord getter/setter on uploader column (translated_xliff)

现在，每次一个呼叫setter方法​​job.translated_xliff ='富'（如提及由 Bensie ），它使用的ActiveRecord ::肮脏 _will_change！方法通知对象将其更改

Now every time one call the setter method job.translated_xliff = 'foo' (as mention by Bensie) it uses ActiveRecord::Dirty _will_change! method to notify the object it changing

其次CarrierWave缓存提供的文件

followed by CarrierWave caching the supplied file

在这里你的场景

    job.translated_xliff
    => uploader 

    job.changed?
    => false

    job.translated_xliff = "foo"

    ## Now your trying to change the object so will_change! notify that 
    ##'translated_xliff' is changing after which Carrierwave try to cache the given 'file'(foo)

现在这里只是Carriewave问题之前启动高速缓存的文件时，它执行基本检查像这样

Now here the problem just before Carriewave start caching the file it perform a basic check like this

  new_file = CarrierWave::SanitizedFile.new(new_file)
  unless new_file.empty?
     ## Then  do caching 
  end  

空？是用来确定提供的价值（在你的情况下，它富）是一个路径或文件和$ C>修改

empty? is use to determine is supplied value (in your case it foo) is a Path or File and it neither of two in your case and hence the file is never cache but the object is marked as changed

，因此你得到这个

job.changed?
=> true 

现在作为一个结果，而调用 job.translated_xliff 方法，它拉文件从商店自供应值从来没有缓存，你可以看到它的工作过的这里

Now as a result while calling the job.translated_xliff method it pull the file from the store since the supplied value was never cached , you can see it working over here

因此​​，我提了意见。如果你想实现的东西，那种也许你可以检查对标识符，并决定是否改变了

Hence I mention in the comment If you want to achieve something of that kind perhaps you can check against the identifier and decide whether it changed

job.translated_xliff.identifier ==富

只是一个建议，但：）

希望这有助于

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