Module: CarrierWave::Mount

Included in:
ActiveRecord
Defined in:
lib/carrierwave/mount.rb

Overview

If a Class is extended with this module, it gains the mount_uploader method, which is used for mapping attributes to uploaders and allowing easy assignment.

You can use mount_uploader with pretty much any class, however it is intended to be used with some kind of persistent storage, like an ORM. If you want to persist the uploaded files in a particular Class, it needs to implement a read_uploader and a write_uploader method.

Defined Under Namespace

Modules: Extension

Instance Method Summary collapse

Instance Method Details

#mount_uploader(column, uploader = nil, options = {}, &block) ⇒ Object

Mounts the given uploader on the given column. This means that assigning and reading from the column will upload and retrieve files. Supposing that a User class has an uploader mounted on image, you can assign and retrieve files like this:

@user.image # => <Uploader>
@user.image.store!(some_file_object)

@user.image.url # => '/some_url.png'

It is also possible (but not recommended) to omit the uploader, which will create an anonymous uploader class.

Passing a block makes it possible to customize the uploader. This can be convenient for brevity, but if there is any significant logic in the uploader, you should do the right thing and have it in its own file.

Added instance methods

Supposing a class has used mount_uploader to mount an uploader on a column named image, in that case the following methods will be added to the class:

[image] Returns an instance of the uploader only if anything has been uploaded [image=] Caches the given file

[image_url] Returns the url to the uploaded file

[image_cache] Returns a string that identifies the cache location of the file [image_cache=] Retrieves the file from the cache based on the given cache name

[remote_image_url] Returns previously cached remote url [remote_image_url=] Retrieve the file from the remote url

[remove_image] An attribute reader that can be used with a checkbox to mark a file for removal [remove_image=] An attribute writer that can be used with a checkbox to mark a file for removal [remove_image?] Whether the file should be removed when store_image! is called.

[store_image!] Stores a file that has been assigned with image= [remove_image!] Removes the uploaded file from the filesystem.

[image_integrity_error] Returns an error object if the last file to be assigned caused an integrity error [image_processing_error] Returns an error object if the last file to be assigned caused a processing error [image_download_error] Returns an error object if the last file to be remotely assigned caused a download error

[image_identifier] Reads out the identifier of the file

Parameters

[column (Symbol)] the attribute to mount this uploader on [uploader (CarrierWave::Uploader)] the uploader class to mount [options (Hash=> Object)] a set of options [&block (Proc)] customize anonymous uploaders

Options

[:mount_on => Symbol] if the name of the column to be serialized to differs you can override it using this option [:ignore_integrity_errors => Boolean] if set to true, integrity errors will result in caching failing silently [:ignore_processing_errors => Boolean] if set to true, processing errors will result in caching failing silently

Examples

Mounting uploaders on different columns.

class Song
  mount_uploader :lyrics, LyricsUploader
  mount_uploader :alternative_lyrics, LyricsUploader
  mount_uploader :file, SongUploader
end

This will add an anonymous uploader with only the default settings:

class Data
  mount_uploader :csv
end

this will add an anonymous uploader overriding the store_dir:

class Product
  mount_uploader :blueprint do
    def store_dir
      'blueprints'
    end
  end
end


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# File 'lib/carrierwave/mount.rb', line 134

def mount_uploader(column, uploader=nil, options={}, &block)
  mount_base(column, uploader, options.merge(multiple: false), &block)

  mod = Module.new
  include mod
  mod.class_eval <<-RUBY, __FILE__, __LINE__+1

    def #{column}
      _mounter(:#{column}).uploaders[0] ||= _mounter(:#{column}).blank_uploader
    end

    def #{column}=(new_file)
      _mounter(:#{column}).cache([new_file])
    end

    def #{column}_url(*args)
      #{column}.url(*args)
    end

    def #{column}_cache
      _mounter(:#{column}).cache_names[0]
    end

    def #{column}_cache=(cache_name)
      _mounter(:#{column}).cache_names = [cache_name]
    end

    def remote_#{column}_url
      [_mounter(:#{column}).remote_urls].flatten[0]
    end

    def remote_#{column}_url=(url)
      _mounter(:#{column}).remote_urls = url
    end

    def remote_#{column}_request_header=(header)
      _mounter(:#{column}).remote_request_headers = [header]
    end

    def #{column}_identifier
      _mounter(:#{column}).read_identifiers[0]
    end

    def #{column}_integrity_error
      #{column}_integrity_errors.last
    end

    def #{column}_processing_error
      #{column}_processing_errors.last
    end

    def #{column}_download_error
      #{column}_download_errors.last
    end
  RUBY
end

#mount_uploaders(column, uploader = nil, options = {}, &block) ⇒ Object

Mounts the given uploader on the given array column. This means that assigning and reading from the array column will upload and retrieve multiple files. Supposing that a User class has an uploader mounted on images, and that images can store an array, for example it could be a PostgreSQL JSON column. You can assign and retrieve files like this:

@user.images # => []
@user.images = [some_file_object]
@user.images # => [<Uploader>]

@user.images[0].url # => '/some_url.png'

It is also possible (but not recommended) to omit the uploader, which will create an anonymous uploader class.

Passing a block makes it possible to customize the uploader. This can be convenient for brevity, but if there is any significant logic in the uploader, you should do the right thing and have it in its own file.

Added instance methods

Supposing a class has used mount_uploaders to mount an uploader on a column named images, in that case the following methods will be added to the class:

[images] Returns an array of uploaders for each uploaded file [images=] Caches the given files

[images_urls] Returns the urls to the uploaded files

[images_cache] Returns a string that identifies the cache location of the files [images_cache=] Retrieves the files from the cache based on the given cache name

[remote_image_urls] Returns previously cached remote urls [remote_image_urls=] Retrieve files from the given remote urls

[remove_images] An attribute reader that can be used with a checkbox to mark the files for removal [remove_images=] An attribute writer that can be used with a checkbox to mark the files for removal [remove_images?] Whether the files should be removed when store_image! is called.

[store_images!] Stores all files that have been assigned with images= [remove_images!] Removes the uploaded file from the filesystem.

[image_integrity_errors] Returns error objects of files which failed to pass integrity check [image_processing_errors] Returns error objects of files which failed to be processed [image_download_errors] Returns error objects of files which failed to be downloaded

[image_identifiers] Reads out the identifiers of the files

Parameters

[column (Symbol)] the attribute to mount this uploader on [uploader (CarrierWave::Uploader)] the uploader class to mount [options (Hash=> Object)] a set of options [&block (Proc)] customize anonymous uploaders

Options

[:mount_on => Symbol] if the name of the column to be serialized to differs you can override it using this option [:ignore_integrity_errors => Boolean] if set to true, integrity errors will result in caching failing silently [:ignore_processing_errors => Boolean] if set to true, processing errors will result in caching failing silently

Examples

Mounting uploaders on different columns.

class Song
  mount_uploaders :lyrics, LyricsUploader
  mount_uploaders :alternative_lyrics, LyricsUploader
  mount_uploaders :files, SongUploader
end

This will add an anonymous uploader with only the default settings:

class Data
  mount_uploaders :csv_files
end

this will add an anonymous uploader overriding the store_dir:

class Product
  mount_uploaders :blueprints do
    def store_dir
      'blueprints'
    end
  end
end


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# File 'lib/carrierwave/mount.rb', line 279

def mount_uploaders(column, uploader=nil, options={}, &block)
  mount_base(column, uploader, options.merge(multiple: true), &block)

  mod = Module.new
  include mod
  mod.class_eval <<-RUBY, __FILE__, __LINE__+1

    def #{column}
      _mounter(:#{column}).uploaders
    end

    def #{column}=(new_files)
      _mounter(:#{column}).cache(new_files)
    end

    def #{column}_urls(*args)
      _mounter(:#{column}).urls(*args)
    end

    def #{column}_cache
      names = _mounter(:#{column}).cache_names
      names.to_json if names.present?
    end

    def #{column}_cache=(cache_name)
      _mounter(:#{column}).cache_names = JSON.parse(cache_name) if cache_name.present?
    end

    def remote_#{column}_urls
      _mounter(:#{column}).remote_urls
    end

    def remote_#{column}_urls=(urls)
      _mounter(:#{column}).remote_urls = urls
    end

    def remote_#{column}_request_headers=(headers)
      _mounter(:#{column}).remote_request_headers = headers
    end

    def #{column}_identifiers
      _mounter(:#{column}).read_identifiers
    end
  RUBY
end

#uploader_option(column, option) ⇒ Object

Return a particular option for a particular uploader

Parameters

[column (Symbol)] The column the uploader is mounted at [option (Symbol)] The option, e.g. validate_integrity

Returns

[Object] The option value



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# File 'lib/carrierwave/mount.rb', line 40

def uploader_option(column, option)
  if uploader_options[column].has_key?(option)
    uploader_options[column][option]
  else
    uploaders[column].send(option)
  end
end

#uploader_options ⇒ Object 



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# File 'lib/carrierwave/mount.rb', line 24

def uploader_options
  @uploader_options ||= superclass.respond_to?(:uploader_options) ? superclass.uploader_options.dup : {}
end

#uploaders ⇒ Object

Returns

[Hash=> CarrierWave] what uploaders are mounted on which columns



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# File 'lib/carrierwave/mount.rb', line 20

def uploaders
  @uploaders ||= superclass.respond_to?(:uploaders) ? superclass.uploaders.dup : {}
end