Modifica nome file prima di salvare con Carrierwave

Question

Ho un uploader in cui ho implementato il metodo #filename per ottenere un nome file personalizzato e univoco, ma sembra che questo metodo venga ignorato prima di salvare il file (sto caricando su rackspace con la nebbia gemma)

Ecco l'uploader:

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 

E qui è un test nella console (sto testando un problema con i grandi nomi di file che ho pensato è stato risolto con il metodo #filename personalizzato) :

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=' 

quindi penso che ho bisogno di modificare il nome del file prima di essere salvati al fine di ottenere il nome del file personalizzato completamente funzionante perché in realtà il file solo è rinominare dopo essere stato caricato a Rackspace (solo se il nome del file non è così grande)

Answer 1

Il caricamento esplode durante la fase di memorizzazione nella cache (che avviene localmente) piuttosto che nella fase di salvataggio (che si verifica nella nebbia). Leggendo the source, sembra che carrierwave abbia un metodo che puoi sovrascrivere per fare proprio questo: full_original_filename

Se il problema che stai cercando di risolvere è quello di accorciare il nome del file memorizzato nella cache, il seguente potrebbe funzionare. Se si desidera modificare il nome file in seguito, sarà necessario utilizzare anche lo 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