ActiveStorage::Variation (original) (raw)

Active Storage Variation

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_to_limit: [100, 100], colourspace: "b-w", rotate: "-90", saver: { trim: true })

The options map directly to ImageProcessing commands.

Methods

C

• content_type

D

• decode,
• default_to,
• digest

E

• encode

F

• format

K

• key

N

• new

T

• transform

W

• wrap

Attributes

Class Public methods

decode(key)Link

Returns a Variation instance with the transformations that were encoded by encode.

Source: show | on GitHub

def decode(key) new ActiveStorage.verifier.verify(key, purpose: :variation) end

encode(transformations)Link

Returns a signed key for the transformations, which can be used to refer to a specific variation in a URL or combined key (like ActiveStorage::Variant#key).

Source: show | on GitHub

def encode(transformations) ActiveStorage.verifier.generate(transformations, purpose: :variation) end

new(transformations)Link

Source: show | on GitHub

def initialize(transformations) @transformations = transformations.deep_symbolize_keys end

wrap(variator)Link

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 ActiveStorage::Variation.decode. Otherwise, it is assumed to be a transformations Hash and is passed directly to the constructor.

Source: show | on GitHub

def wrap(variator) case variator when self variator when String decode variator else new variator end end

Instance Public methods

content_type()Link

Source: show | on GitHub

def content_type Marcel::MimeType.for(extension: format.to_s) end

default_to(defaults)Link

Source: show | on GitHub

def default_to(defaults) self.class.new transformations.reverse_merge(defaults) end

digest()Link

Source: show | on GitHub

def digest OpenSSL::Digest::SHA1.base64digest Marshal.dump(transformations) end

format()Link

Source: show | on GitHub

def format transformations.fetch(:format, :png).tap do |format| if Marcel::Magic.by_extension(format.to_s).nil? raise ArgumentError, "Invalid variant format (#{format.inspect})" end end end

key()Link

Returns a signed key for all the transformations that this variation was instantiated with.

Source: show | on GitHub

def key self.class.encode(transformations) end

transform(file, &block)Link

Accepts a File object, performs the transformations against it, and saves the transformed image into a temporary file.

Source: show | on GitHub

def transform(file, &block) ActiveSupport::Notifications.instrument("transform.active_storage") do transformer.transform(file, format: format, &block) end end