<%= f.file_field :avatar %> <%= f.hidden_field :avatar_cache %>
<% end %> ```` It might be a good idea to show the user that a file has been uploaded, in the case of images, a small thumbnail would be a good indicator: ```erb <%= form_for @user, html: { multipart: true } do |f| %><%= image_tag(@user.avatar_url) if @user.avatar? %> <%= f.file_field :avatar %> <%= f.hidden_field :avatar_cache %>
<% end %> ``` ## Removing uploaded files If you want to remove a previously uploaded file on a mounted uploader, you can easily add a checkbox to the form which will remove the file when checked. ```erb <%= form_for @user, html: { multipart: true } do |f| %><%= image_tag(@user.avatar_url) if @user.avatar? %> <%= f.file_field :avatar %>
<% end %> ``` If you want to remove the file manually, you can call
remove_avatar!, then save the object.
```erb
@user.remove_avatar!
@user.save
#=> true
```
## Uploading files from a remote location
Your users may find it convenient to upload a file from a location on the Internet
via a URL. CarrierWave makes this simple, just add the appropriate attribute to your
form and you're good to go:
```erb
<%= form_for @user, html: { multipart: true } do |f| %>
<%= image_tag(@user.avatar_url) if @user.avatar? %> <%= f.text_field :remote_avatar_url %>
<% end %> ``` If you're using ActiveRecord, CarrierWave will indicate invalid URLs and download failures automatically with attribute validation errors. If you aren't, or you disable CarrierWave's `validate_download` option, you'll need to handle those errors yourself. ### Retry option for download from remote location If you want to retry the download from the Remote URL, enable the download_retry_count option, an error occurs during download, it will try to execute the specified number of times every 5 second. This option is effective when the remote destination is unstable. ```rb CarrierWave.configure do |config| config.download_retry_count = 3 # Default 0 end ``` ## Providing a default URL In many cases, especially when working with images, it might be a good idea to provide a default url, a fallback in case no file has been uploaded. You can do this easily by overriding the `default_url` method in your uploader: ```ruby class MyUploader < CarrierWave::Uploader::Base def default_url(*args) "/images/fallback/" + [version_name, "default.png"].compact.join('_') end end ``` Or if you are using the Rails asset pipeline: ```ruby class MyUploader < CarrierWave::Uploader::Base def default_url(*args) ActionController::Base.helpers.asset_path("fallback/" + [version_name, "default.png"].compact.join('_')) end end ``` ## Recreating versions You might come to a situation where you want to retroactively change a version or add a new one. You can use the `recreate_versions!` method to recreate the versions from the base file. This uses a naive approach which will re-upload and process the specified version or all versions, if none is passed as an argument. When you are generating random unique filenames you have to call `save!` on the model after using `recreate_versions!`. This is necessary because `recreate_versions!` doesn't save the new filename to the database. Calling `save!` yourself will prevent that the database and file system are running out of sync. ```ruby instance = MyUploader.new instance.recreate_versions!(:thumb, :large) ``` Or on a mounted uploader: ```ruby User.find_each do |user| user.avatar.recreate_versions! end ``` Note: `recreate_versions!` will throw an exception on records without an image. To avoid this, scope the records to those with images or check if an image exists within the block. If you're using ActiveRecord, recreating versions for a user avatar might look like this: ```ruby User.find_each do |user| user.avatar.recreate_versions! if user.avatar? end ``` ## Configuring CarrierWave CarrierWave has a broad range of configuration options, which you can configure, both globally and on a per-uploader basis: ```ruby CarrierWave.configure do |config| config.permissions = 0666 config.directory_permissions = 0777 config.storage = :file end ``` Or alternatively: ```ruby class AvatarUploader < CarrierWave::Uploader::Base permissions 0777 end ``` If you're using Rails, create an initializer for this: config/initializers/carrierwave.rb If you want CarrierWave to fail noisily in development, you can change these configs in your environment file: ```ruby CarrierWave.configure do |config| config.ignore_integrity_errors = false config.ignore_processing_errors = false config.ignore_download_errors = false end ``` ## Testing with CarrierWave It's a good idea to test your uploaders in isolation. In order to speed up your tests, it's recommended to switch off processing in your tests, and to use the file storage. In Rails you could do that by adding an initializer with: ```ruby if Rails.env.test? or Rails.env.cucumber? CarrierWave.configure do |config| config.storage = :file config.enable_processing = false end end ``` Remember, if you have already set `storage :something` in your uploader, the `storage` setting from this initializer will be ignored. If you need to test your processing, you should test it in isolation, and enable processing only for those tests that need it. CarrierWave comes with some RSpec matchers which you may find useful: ```ruby require 'carrierwave/test/matchers' describe MyUploader do include CarrierWave::Test::Matchers let(:user) { double('user') } let(:uploader) { MyUploader.new(user, :avatar) } before do MyUploader.enable_processing = true File.open(path_to_file) { |f| uploader.store!(f) } end after do MyUploader.enable_processing = false uploader.remove! end context 'the thumb version' do it "scales down a landscape image to be exactly 64 by 64 pixels" do expect(uploader.thumb).to have_dimensions(64, 64) end end context 'the small version' do it "scales down a landscape image to fit within 200 by 200 pixels" do expect(uploader.small).to be_no_larger_than(200, 200) end end it "makes the image readable only to the owner and not executable" do expect(uploader).to have_permissions(0600) end it "has the correct format" do expect(uploader).to be_format('png') end end ``` If you're looking for minitest asserts, checkout [carrierwave_asserts](https://github.com/hcfairbanks/carrierwave_asserts). Setting the enable_processing flag on an uploader will prevent any of the versions from processing as well. Processing can be enabled for a single version by setting the processing flag on the version like so: ```ruby @uploader.thumb.enable_processing = true ``` ## Fog If you want to use fog you must add in your CarrierWave initializer the following lines ```ruby config.fog_credentials = { ... } # Provider specific credentials ``` ## Using Amazon S3 [Fog AWS](http://github.com/fog/fog-aws) is used to support Amazon S3. Ensure you have it in your Gemfile: ```ruby gem "fog-aws" ``` You'll need to provide your fog_credentials and a fog_directory (also known as a bucket) in an initializer. For the sake of performance it is assumed that the directory already exists, so please create it if it needs to be. You can also pass in additional options, as documented fully in lib/carrierwave/storage/fog.rb. Here's a full example: ```ruby CarrierWave.configure do |config| config.fog_credentials = { provider: 'AWS', # required aws_access_key_id: 'xxx', # required unless using use_iam_profile aws_secret_access_key: 'yyy', # required unless using use_iam_profile use_iam_profile: true, # optional, defaults to false region: 'eu-west-1', # optional, defaults to 'us-east-1' host: 's3.example.com', # optional, defaults to nil endpoint: 'https://s3.example.com:8080' # optional, defaults to nil } config.fog_directory = 'name_of_bucket' # required config.fog_public = false # optional, defaults to true config.fog_attributes = { cache_control: "public, max-age=#{365.days.to_i}" } # optional, defaults to {} # For an application which utilizes multiple servers but does not need caches persisted across requests, # uncomment the line :file instead of the default :storage. Otherwise, it will use AWS as the temp cache store. # config.cache_storage = :file end ``` In your uploader, set the storage to :fog ```ruby class AvatarUploader < CarrierWave::Uploader::Base storage :fog end ``` That's it! You can still use the `CarrierWave::Uploader#url` method to return the url to the file on Amazon S3. **Note**: for Carrierwave to work properly it needs credentials with the following permissions: * `s3:ListBucket` * `s3:PutObject` * `s3:GetObject` * `s3:DeleteObject` * `s3:PutObjectAcl` ## Using Rackspace Cloud Files [Fog](http://github.com/fog/fog) is used to support Rackspace Cloud Files. Ensure you have it in your Gemfile: ```ruby gem "fog" ``` You'll need to configure a directory (also known as a container), username and API key in the initializer. For the sake of performance it is assumed that the directory already exists, so please create it if need be. Using a US-based account: ```ruby CarrierWave.configure do |config| config.fog_credentials = { provider: 'Rackspace', rackspace_username: 'xxxxxx', rackspace_api_key: 'yyyyyy', rackspace_region: :ord # optional, defaults to :dfw } config.fog_directory = 'name_of_directory' end ``` Using a UK-based account: ```ruby CarrierWave.configure do |config| config.fog_credentials = { provider: 'Rackspace', rackspace_username: 'xxxxxx', rackspace_api_key: 'yyyyyy', rackspace_auth_url: Fog::Rackspace::UK_AUTH_ENDPOINT, rackspace_region: :lon } config.fog_directory = 'name_of_directory' end ``` You can optionally include your CDN host name in the configuration. This is *highly* recommended, as without it every request requires a lookup of this information. ```ruby config.asset_host = "http://c000000.cdn.rackspacecloud.com" ``` In your uploader, set the storage to :fog ```ruby class AvatarUploader < CarrierWave::Uploader::Base storage :fog end ``` That's it! You can still use the `CarrierWave::Uploader#url` method to return the url to the file on Rackspace Cloud Files. ## Using Google Cloud Storage [Fog](http://github.com/fog/fog-google) is used to support Google Cloud Storage. Ensure you have it in your Gemfile: ```ruby gem "fog-google" ``` You'll need to configure a directory (also known as a bucket) and the credentials in the initializer. For the sake of performance it is assumed that the directory already exists, so please create it if need be. Please read the [fog-google README](https://github.com/fog/fog-google/blob/master/README.md) on how to get credentials. For Google Storage JSON API (recommended): ```ruby CarrierWave.configure do |config| config.fog_provider = 'fog/google' config.fog_credentials = { provider: 'Google', google_project: 'my-project', google_json_key_string: 'xxxxxx' # or use google_json_key_location if using an actual file } config.fog_directory = 'google_cloud_storage_bucket_name' end ``` For Google Storage XML API: ```ruby CarrierWave.configure do |config| config.fog_provider = 'fog/google' config.fog_credentials = { provider: 'Google', google_storage_access_key_id: 'xxxxxx', google_storage_secret_access_key: 'yyyyyy' } config.fog_directory = 'google_cloud_storage_bucket_name' end ``` In your uploader, set the storage to :fog ```ruby class AvatarUploader < CarrierWave::Uploader::Base storage :fog end ``` That's it! You can still use the `CarrierWave::Uploader#url` method to return the url to the file on Google. ## Optimized Loading of Fog Since Carrierwave doesn't know which parts of Fog you intend to use, it will just load the entire library (unless you use e.g. [`fog-aws`, `fog-google`] instead of fog proper). If you prefer to load fewer classes into your application, you need to load those parts of Fog yourself *before* loading CarrierWave in your Gemfile. Ex: ```ruby gem "fog", "~> 1.27", require: "fog/rackspace/storage" gem "carrierwave" ``` A couple of notes about versions: * This functionality was introduced in Fog v1.20. * This functionality is slated for CarrierWave v1.0.0. If you're not relying on Gemfile entries alone and are requiring "carrierwave" anywhere, ensure you require "fog/rackspace/storage" before it. Ex: ```ruby require "fog/rackspace/storage" require "carrierwave" ``` Beware that this specific require is only needed when working with a fog provider that was not extracted to its own gem yet. A list of the extracted providers can be found in the page of the `fog` organizations [here](https://github.com/fog). When in doubt, inspect `Fog.constants` to see what has been loaded. ## Dynamic Asset Host The `asset_host` config property can be assigned a proc (or anything that responds to `call`) for generating the host dynamically. The proc-compliant object gets an instance of the current `CarrierWave::Storage::Fog::File` or `CarrierWave::SanitizedFile` as its only argument. ```ruby CarrierWave.configure do |config| config.asset_host = proc do |file| identifier = # some logic "http://#{identifier}.cdn.rackspacecloud.com" end end ``` ## Using RMagick If you're uploading images, you'll probably want to manipulate them in some way, you might want to create thumbnail images for example. CarrierWave comes with a small library to make manipulating images with RMagick easier, you'll need to include it in your Uploader: ```ruby class AvatarUploader < CarrierWave::Uploader::Base include CarrierWave::RMagick end ``` The RMagick module gives you a few methods, like `CarrierWave::RMagick#resize_to_fill` which manipulate the image file in some way. You can set a `process` callback, which will call that method any time a file is uploaded. There is a demonstration of convert here. Convert will only work if the file has the same file extension, thus the use of the filename method. ```ruby class AvatarUploader < CarrierWave::Uploader::Base include CarrierWave::RMagick process resize_to_fill: [200, 200] process convert: 'png' def filename super.chomp(File.extname(super)) + '.png' if original_filename.present? end end ``` Check out the manipulate! method, which makes it easy for you to write your own manipulation methods. ## Using MiniMagick MiniMagick is similar to RMagick but performs all the operations using the 'convert' CLI which is part of the standard ImageMagick kit. This allows you to have the power of ImageMagick without having to worry about installing all the RMagick libraries. See the MiniMagick site for more details: https://github.com/minimagick/minimagick And the ImageMagick command line options for more for what's on offer: http://www.imagemagick.org/script/command-line-options.php Currently, the MiniMagick carrierwave processor provides exactly the same methods as for the RMagick processor. ```ruby class AvatarUploader < CarrierWave::Uploader::Base include CarrierWave::MiniMagick process resize_to_fill: [200, 200] end ``` ## Migrating from Paperclip If you are using Paperclip, you can use the provided compatibility module: ```ruby class AvatarUploader < CarrierWave::Uploader::Base include CarrierWave::Compatibility::Paperclip end ``` See the documentation for `CarrierWave::Compatibility::Paperclip` for more details. Be sure to use mount_on to specify the correct column: ```ruby mount_uploader :avatar, AvatarUploader, mount_on: :avatar_file_name ``` ## I18n The Active Record validations use the Rails `i18n` framework. Add these keys to your translations file: ```yaml errors: messages: carrierwave_processing_error: failed to be processed carrierwave_integrity_error: is not of an allowed file type carrierwave_download_error: could not be downloaded extension_allowlist_error: "You are not allowed to upload %{extension} files, allowed types: %{allowed_types}" extension_denylist_error: "You are not allowed to upload %{extension} files, prohibited types: %{prohibited_types}" content_type_allowlist_error: "You are not allowed to upload %{content_type} files, allowed types: %{allowed_types}" content_type_denylist_error: "You are not allowed to upload %{content_type} files" processing_error: "Failed to manipulate, maybe it is not an image?" min_size_error: "File size should be greater than %{min_size}" max_size_error: "File size should be less than %{max_size}" ``` The [`carrierwave-i18n`](https://github.com/carrierwaveuploader/carrierwave-i18n) library adds support for additional locales. ## Large files By default, CarrierWave copies an uploaded file twice, first copying the file into the cache, then copying the file into the store. For large files, this can be prohibitively time consuming. You may change this behavior by overriding either or both of the `move_to_cache` and `move_to_store` methods: ```ruby class MyUploader < CarrierWave::Uploader::Base def move_to_cache true end def move_to_store true end end ``` When the `move_to_cache` and/or `move_to_store` methods return true, files will be moved (instead of copied) to the cache and store respectively. This has only been tested with the local filesystem store. ## Skipping ActiveRecord callbacks By default, mounting an uploader into an ActiveRecord model will add a few callbacks. For example, this code: ```ruby class User mount_uploader :avatar, AvatarUploader end ``` Will add these callbacks: ```ruby before_save :write_avatar_identifier after_save :store_previous_changes_for_avatar after_commit :remove_avatar!, on: :destroy after_commit :mark_remove_avatar_false, on: :update after_commit :remove_previously_stored_avatar, on: :update after_commit :store_avatar!, on: [:create, :update] ``` If you want to skip any of these callbacks (eg. you want to keep the existing avatar, even after uploading a new one), you can use ActiveRecord’s `skip_callback` method. ```ruby class User mount_uploader :avatar, AvatarUploader skip_callback :commit, :after, :remove_previously_stored_avatar end ``` ## Uploader Callbacks In addition to the ActiveRecord callbacks described above, uploaders also have callbacks. ```ruby class MyUploader < ::CarrierWave::Uploader::Base before :remove, :log_removal private def log_removal ::Rails.logger.info(format('Deleting file on S3: %s', @file)) end end ``` Uploader callbacks can be `before` or `after` the following events: ``` cache process remove retrieve_from_cache store ``` ## Contributing to CarrierWave See [CONTRIBUTING.md](https://github.com/carrierwaveuploader/carrierwave/blob/master/CONTRIBUTING.md) ## License The MIT License (MIT) Copyright (c) 2008-2015 Jonas Nicklas Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.