A set of transformations that can be applied to a blob to create a variant. This class is exposed via the ActiveStorage::Blob::Representable#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_to_fit: [100, 100], monochrome: true, trim: true, rotate: "-90")
The options map directly to ImageProcessing commands.
Returns a Variation instance with the
transformations that were encoded by
# File activestorage/app/models/active_storage/variation.rb, line 31 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 37 def encode(transformations) ActiveStorage.verifier.generate(transformations, purpose: :variation) end
# File activestorage/app/models/active_storage/variation.rb, line 42 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 19 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 57 def key self.class.encode(transformations) end
Accepts a File object, performs the
transformations against it, and saves the transformed image
into a temporary file. If
format is specified it will be the
format of the result image, otherwise the result image retains the source
# File activestorage/app/models/active_storage/variation.rb, line 50 def transform(file, format: nil, &block) ActiveSupport::Notifications.instrument("transform.active_storage") do transformer.transform(file, format: format, &block) end end