A set of transformations that can be applied to a blob to create a variant. This class is exposed via the ActiveStorage::Blob#variant method and should rarely be used directly.
In case you do need to use this directly, it's instantiated using a hash of transformations where the key is the command and the value is the arguments. Example:
ActiveStorage::Variation.new(resize: "100x100", monochrome: true, trim: true, rotate: "-90")
A list of all possible transformations is available at www.imagemagick.org/script/mogrify.php.
Returns a Variation instance with the
transformations that were encoded by
# File activestorage/app/models/active_storage/variation.rb, line 30 def decode(key) new ActiveStorage.verifier.verify(key, purpose: :variation) end
Returns a signed key for the
transformations, which can be
used to refer to a specific variation in a URL or combined key (like
# File activestorage/app/models/active_storage/variation.rb, line 36 def encode(transformations) ActiveStorage.verifier.generate(transformations, purpose: :variation) end
# File activestorage/app/models/active_storage/variation.rb, line 41 def initialize(transformations) @transformations = transformations end
Returns a Variation instance based on the given variator. If the variator is a Variation, it is returned unmodified. If it is a String, it is passed to ::decode. Otherwise, it is assumed to be a transformations Hash and is passed directly to the constructor.
# File activestorage/app/models/active_storage/variation.rb, line 18 def wrap(variator) case variator when self variator when String decode variator else new variator end end
Returns a signed key for all the
transformations that this
variation was instantiated with.
# File activestorage/app/models/active_storage/variation.rb, line 60 def key self.class.encode(transformations) end
Accepts an open MiniMagick image instance, like what's returned by
MiniMagick::Image.read(io), and performs the
transformations against it. The transformed image instance is
# File activestorage/app/models/active_storage/variation.rb, line 47 def transform(image) transformations.each do |method, argument| image.mogrify do |command| if eligible_argument?(argument) command.public_send(method, argument) else command.public_send(method) end end end end