在使用Carrierwave保存之前修改文件名

Question

我有一個上傳器，我實現了#filename方法來獲取自定義和唯一的文件名，但它看起來像在保存文件之前忽略此方法（我正在上傳到rackspace霧寶石）

這裏是上傳：

class MyImageUploader < CarrierWave::Uploader::Base 
    include CarrierWave::RMagick 

    ... 

    def filename 
    if original_filename.present? 
     "#{secure_token}.#{file.path.split('.').last.downcase}" 
    else 
     super 
    end 
    end 

    ... 

    private 

    def secure_token 
    var = :"@#{mounted_as}_secure_token" 
    model.instance_variable_get(var) or model.instance_variable_set(var, SecureRandom.uuid) 
    end 
end 

這裏是在控制檯測試（我測試的大文件名的問題，我認爲用自定義#filename方法解決） ：

1.9.3-p392 :002 > f = File.open('/Users/myuser/Desktop/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.png') 
=> #<File:/Users/myuser/Desktop/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.png> 
1.9.3-p392 :003 > my_model_instance.image = f 
Errno::ENAMETOOLONG: File name too long - /Users/myuser/app/tmp/uploads/20130509-1723-16769-8458/thumb_lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat4lolcat.png 
    from /Users/myuser/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/fileutils.rb:1371:in `initialize' 
    from /Users/myuser/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/fileutils.rb:1371:in `open' 
    from /Users/myuser/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/fileutils.rb:1371:in `block in copy_file' 
    from /Users/myuser/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/fileutils.rb:1370:in `open' 
    from /Users/myuser/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/fileutils.rb:1370:in `copy_file' 
    from /Users/myuser/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/fileutils.rb:477:in `copy_file' 
    from /Users/myuser/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/fileutils.rb:396:in `block in cp' 
    from /Users/myuser/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/fileutils.rb:1515:in `block in fu_each_src_dest' 
    from /Users/myuser/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/fileutils.rb:1531:in `fu_each_src_dest0' 
    from /Users/myuser/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/fileutils.rb:1513:in `fu_each_src_dest' 
    from /Users/myuser/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/fileutils.rb:395:in `cp' 
    from /Users/myuser/.rvm/gems/ruby-1.9.3-p392@app/gems/carrierwave-0.6.2/lib/carrierwave/sanitized_file.rb:205:in `copy_to' 
    from /Users/myuser/.rvm/gems/ruby-1.9.3-p392@app/gems/carrierwave-0.6.2/lib/carrierwave/uploader/cache.rb:121:in `block in cache!' 
    from /Users/myuser/.rvm/gems/ruby-1.9.3-p392@app/gems/carrierwave-0.6.2/lib/carrierwave/uploader/callbacks.rb:17:in `with_callbacks' 
    from /Users/myuser/.rvm/gems/ruby-1.9.3-p392@app/gems/carrierwave-0.6.2/lib/carrierwave/uploader/cache.rb:112:in `cache!' 
    from /Users/myuser/.rvm/gems/ruby-1.9.3-p392@app/gems/carrierwave-0.6.2/lib/carrierwave/uploader/versions.rb:231:in `block in cache_versions!' 
    from /Users/myuser/.rvm/gems/ruby-1.9.3-p392@app/gems/carrierwave-0.6.2/lib/carrierwave/uploader/versions.rb:216:in `each' 
    from /Users/myuser/.rvm/gems/ruby-1.9.3-p392@app/gems/carrierwave-0.6.2/lib/carrierwave/uploader/versions.rb:216:in `cache_versions!' 
    from /Users/myuser/.rvm/gems/ruby-1.9.3-p392@app/gems/carrierwave-0.6.2/lib/carrierwave/uploader/callbacks.rb:18:in `block in with_callbacks' 
    from /Users/myuser/.rvm/gems/ruby-1.9.3-p392@app/gems/carrierwave-0.6.2/lib/carrierwave/uploader/callbacks.rb:18:in `each' 
    from /Users/myuser/.rvm/gems/ruby-1.9.3-p392@app/gems/carrierwave-0.6.2/lib/carrierwave/uploader/callbacks.rb:18:in `with_callbacks' 
    from /Users/myuser/.rvm/gems/ruby-1.9.3-p392@app/gems/carrierwave-0.6.2/lib/carrierwave/uploader/cache.rb:112:in `cache!' 
    from /Users/myuser/.rvm/gems/ruby-1.9.3-p392@app/gems/carrierwave-0.6.2/lib/carrierwave/mount.rb:315:in `cache' 
    from /Users/myuser/.rvm/gems/ruby-1.9.3-p392@app/gems/carrierwave-0.6.2/lib/carrierwave/mount.rb:173:in `image=' 
    from /Users/myuser/.rvm/gems/ruby-1.9.3-p392@app/bundler/gems/carrierwave-mongoid-28a9b718d42b/lib/carrierwave/mongoid.rb:39:in `image=' 

所以我認爲我需要被保存，以獲得自定義文件名完全工作，因爲實際的文件只被上傳到Rackspace公司（只有文件名就不是那麼大）

Answer 1

後改名之前修改文件名上傳在緩存步驟（本地發生）中爆炸，而不是保存步驟（發生在霧中）。閱讀the source，它看起來像載波有一個方法，你可以重寫這樣做：full_original_filename

如果你想解決的問題是使緩存的文件名更短，以下可能工作。如果您想稍後更改該文件名，則還需要另外使用official solution for that。

MAX_FILENAME_LENGTH = 64 # arbitrary limit, your milage may vary 

def full_original_filename 
    filename = super 

    return filename if !filename.present? 

    extension = File.extname(filename) 
    basename = File.basename(filename, extension)[0...MAX_FILENAME_LENGTH] 
    basename + extension 
end