This gem adds support for Mongoid and MongoDB's GridFS to CarrierWave

This functionality used to be part of CarrierWave but has since been extracted into this gem.

Install the latest release:

gem install carrierwave-mongoid

Require it in your code:

require 'carrierwave/mongoid'

Or, in Rails you can add it to your Gemfile:

gem 'carrierwave-mongoid', :require => 'carrierwave/mongoid'

Follow the "Getting Started" directions in the main Carrierwave repository.

[Suggested] Add the field to your attr_accessor list for mass assignment protection:

attr_accessible :avatar, :avatar_cache

Now you can cache files by assigning them to the attribute; they will automatically be stored when the record is saved. Ex:

u = User.new
u.avatar = File.open('somewhere')
u.save!

You can configure Carrierwave to use GridFS instead of the filesystem. For example:

CarrierWave.configure do |config|
  config.grid_fs_database = 'my_mongo_database'
  config.grid_fs_host = 'mongo.example.com'
end

The defaults are carrierwave and localhost.

And then in your uploader, set the storage to :grid_fs:

class AvatarUploader < CarrierWave::Uploader::Base
  storage :grid_fs
end

Since GridFS doesn't make the files available via HTTP, you'll need to stream them yourself. In Rails for example, you could use the send_data method. You can optionally tell CarrierWave the URL you will serve your images from, allowing it to generate the correct URL, by setting eg:

CarrierWave.configure do |config|
  config.grid_fs_access_url = "/image/show"
end

Bringing it all together, you can also configure Carrierwave to use Mongoid's database connection and default all storage to GridFS. That might look something like this:

CarrierWave.configure do |config|
  config.grid_fs_connection = Mongoid.database
  config.storage = :grid_fs
  config.root = Rails.root.join('tmp')
  config.cache_dir = "uploads"
end

carrierwave-mongoid ~> 0.2.0 is only compatible with Rails 3.2 or higher.

carrierwave-mongoid ~> 0.1.1 depends on carrierwave ~> 0.5.7. This version of carrierwave is only compatible with Rails 3.1 or earlier.

CarrierWave used to have built-in Mongoid support. This gem replaces that support and only only supports Mongoid ~> 2.1

You can use upload_identifier to retrieve the original name of the uploaded file.

In the earlier version, the mount_uploader-method for mongoid had been defined in lib/carrierwave/orm/mongoid. This code has been moved to carrierwave/mongoid. If you update from earlier versions, don't forget to adjust your require accordingly in your carrierwave-initializer.

The default mount column used to be the name of the upload column plus _filename. Now it is simply the name of the column. Most of the time, the column was called upload, so it would have been mounted to upload_filename. If you'd like to avoid a database migration, simply use the :mount_on option to specify the field name explicitly. Therefore, you only have to add a _filename to your column name. For example, if your column is called :upload:

class Dokument
  mount_uploader :upload, DokumentUploader, mount_on: :upload_filename
end

Note that files mounted in embedded documents aren't saved when parent documents are saved. By default, mongoid does not cascade callbacks on embedded documents. In order to save the attached files on embedded documents, you must either explicitly call save on the embedded documents or you must configure the embedded association to cascade the callbacks automatically. For example:

class User
  embeds_many :pictures, cascade_callbacks: true
end

You can read more about this here