Module: ActiveStorage::AsyncVariants::ReflectionExtension

Defined in:
lib/active_storage/async_variants/reflection_extension.rb

Overview

Eagerly warm the digest-keyed Registry when a named variant is declared via has_X_attached’s block:

has_one_attached :avatar do |attachable|
  attachable.variant :thumb, resize_to_limit: [150, 150], format: "webp",
    transformer: Crucible, processing: "/spinner.svg"
end

Without this, the Registry only warms when view-side code calls ‘attachment.variant(:thumb)` – so a Puma worker that has never rendered a view for the variant misses on URL-reconstructed lookups.

Caveat: registration uses the declared transformations. Rails applies a blob-dependent default ‘format:` at runtime via default_to. Variants that specify `format:` explicitly register the same digest the URL carries (cold-resolvable). Variants that rely on the format default still warm lazily on first view-side call against a blob of that content type.

Instance Method Summary collapse

Instance Method Details

#variant(name, transformations) ⇒ Object 



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# File 'lib/active_storage/async_variants/reflection_extension.rb', line 23

def variant(name, transformations)
  super
  return unless transformations.is_a?(Hash)
  # Mirror Blob#variant at runtime: wrap and default_to. The default_to
  # call reorders hash keys (default key first) so the registered digest
  # matches the URL-side digest for variants that declare an explicit
  # `format:`. Variants without an explicit `format:` still warm lazily
  # on first view-side call against a blob of that content type.
  ActiveStorage::Variation.wrap(transformations).default_to(format: :png)
end