Module: Paperclip::Storage::Database

Defined in:
lib/paperclip/storage/database.rb

Overview

Store files in a database.

Usage is identical to the file system storage version, except:

  1. In your model specify the “database” storage option; for example:

has_attached_file :avatar, :storage => :database

The files will be stored in a new database table named with the plural attachment name by default, “avatars” in this example.

  1. You need to create this new storage table with at least these columns:

- file_contents
- style
- the primary key for the parent model (e.g. user_id)

Note the “binary” migration will not work for the LONGBLOG type in MySQL for the file_cotents column. You may need to craft a SQL statement for your migration, depending on which database server you are using. Here’s an example migration for MySQL:

create_table :avatars do |t|

t.string :style
t.integer :user_id
t.timestamps

end execute ‘ALTER TABLE avatars ADD COLUMN file_contents LONGBLOB’

You can optionally specify any storage table name you want and whether or not deletion is done by cascading or not as follows:

has_attached_file :avatar, :storage => :database, :database_table => 'avatar_files', :cascade_deletion => true

  1. By default, URLs will be set to this pattern:

/:relative_root/:class/:attachment/:id?style=:style

Example:

/app-root-url/users/avatars/23?style=original

The idea here is that to retrieve a file from the database storage, you will need some controller’s code to be executed.

Once you pick a controller to use for downloading, you can add this line to generate the download action for the default URL/action (the plural attachment name), “avatars” in this example:

downloads_files_for :user, :avatar

Or you can write a download method manually if there are security, logging or other requirements.

If you prefer a different URL for downloading files you can specify that in the model; e.g.:

has_attached_file :avatar, :storage => :database, :url => '/users/show_avatar/:id/:style'

  1. Add a route for the download to the controller which will handle downloads, if necessary.

The default URL, /:relative_root/:class/:attachment/:id?style=:style, will be matched by the default route: :controller/:action/:id

Defined Under Namespace

Modules: ControllerClassMethods

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.extended(base) ⇒ Object 



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# File 'lib/paperclip/storage/database.rb', line 59

def self.extended(base)
  base.instance_eval do
    setup_attachment_class
    setup_paperclip_file_model
    setup_paperclip_files_association
    override_default_options base
  end
  Paperclip.interpolates(:database_path) do |attachment, style|
    attachment.database_path(style)
  end
  Paperclip.interpolates(:relative_root) do |attachment, style|
    begin
      if ActionController::AbstractRequest.respond_to?(:relative_url_root)
        relative_url_root = ActionController::AbstractRequest.relative_url_root
      end
    rescue NameError
    end
    if !relative_url_root && ActionController::Base.respond_to?(:relative_url_root)
      ActionController::Base.relative_url_root
    end
  end

  ActiveRecord::Base.logger.info("[paperclip] Database Storage Initalized.")
end

Instance Method Details

#copy_to_local_file(style, dest_path) ⇒ Object 



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# File 'lib/paperclip/storage/database.rb', line 121

def copy_to_local_file(style, dest_path)
  File.open(dest_path, 'wb+'){|df| to_file(style).tap{|sf| File.copy_stream(sf, df); sf.close;sf.unlink} }
end

#database_path(style) ⇒ Object 



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# File 'lib/paperclip/storage/database.rb', line 137

def database_path(style)
  paperclip_file = file_for(style)
  if paperclip_file
    "#{database_table}(id=#{paperclip_file.id},style=#{style.to_s})"
  else
    "#{database_table}(id=new,style=#{style.to_s})"
  end
end

#database_table ⇒ Object 



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# File 'lib/paperclip/storage/database.rb', line 133

def database_table
  @database_table
end

#exists?(style = default_style) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/paperclip/storage/database.rb', line 146

def exists?(style = default_style)
  if original_filename
    instance.send("#{@paperclip_files_association_name}").where(:style => style).exists?
  else
    false
  end
end

#file_contents(style = default_style) ⇒ Object 



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# File 'lib/paperclip/storage/database.rb', line 183

def file_contents(style = default_style)
  file_for(style).file_contents
end

#file_for(style) ⇒ Object

Raises:

  • (RuntimeError) 


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# File 'lib/paperclip/storage/database.rb', line 177

def file_for(style)
  db_result = instance.send("#{@paperclip_files_association_name}").send(:file_for, style.to_s)
  raise RuntimeError, "More than one result for #{style}" if db_result.size > 1
  db_result.first
end

#files ⇒ Object 



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# File 'lib/paperclip/storage/database.rb', line 173

def files
  instance.send("#{@paperclip_files_association_name}")
end

#flush_deletes ⇒ Object

:nodoc:



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# File 'lib/paperclip/storage/database.rb', line 205

def flush_deletes #:nodoc:
  ActiveRecord::Base.logger.info("[paperclip] Deleting files for #{name}")
  @queued_for_delete.uniq! ##This is apparently necessary for paperclip v 3.x
  @queued_for_delete.each do |path|
    /id=([0-9]+)/.match(path)
    if @options[:cascade_deletion] && !instance.class.exists?(instance.id)
      raise RuntimeError, "Deletion has not been done by through cascading." if @paperclip_file_model.exists?($1)
    else
      @paperclip_file_model.destroy $1
    end
  end
  @queued_for_delete = []
end

#flush_writes ⇒ Object 



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# File 'lib/paperclip/storage/database.rb', line 187

def flush_writes
  ActiveRecord::Base.logger.info("[paperclip] Writing files for #{name}")
  @queued_for_write.each do |style, file|
      case ActiveModel::VERSION::MAJOR
      when 3
        paperclip_file = instance.send(@paperclip_files_association_name).send(:find_or_create_by_style, style.to_s)
      when 4
        paperclip_file = instance.send(@paperclip_files_association_name).send(:find_or_create_by, style: style.to_s)
      else
        raise "ActiveModel version #{ActiveModel::VERSION::STRING} is not supported (yet)"
      end
    paperclip_file.file_contents = file.read
    paperclip_file.save!
    instance.reload
  end
  @queued_for_write = {}
end

#to_file(style = default_style) ⇒ Object Also known as: to_io

Returns representation of the data of the file assigned to the given style, in the format most representative of the current storage.



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# File 'lib/paperclip/storage/database.rb', line 156

def to_file style = default_style
  if @queued_for_write[style]
    @queued_for_write[style]
  elsif exists?(style)
    tempfile = Tempfile.new instance_read(:file_name)
    tempfile.binmode
    tempfile.write file_contents(style)
    tempfile.flush
    tempfile.rewind
    tempfile
  else
    nil
  end

end