analyze

Extracts and stores metadata from the file associated with this blob using a relevant analyzer. Active Storage comes with built-in analyzers for images and videos. See ActiveStorage::Analyzer::ImageAnalyzer and ActiveStorage::Analyzer::VideoAnalyzer for information about the specific attributes they extract and the third-party libraries they require.

To choose the analyzer for a blob, Active Storage calls accept? on each registered analyzer in order. It uses the first analyzer for which accept? returns true when given the blob. If no registered analyzer accepts the blob, no metadata is extracted from it.

In a Rails application, add or remove analyzers by manipulating Rails.application.config.active_storage.analyzers in an initializer:

# Add a custom analyzer for Microsoft Office documents:
Rails.application.config.active_storage.analyzers.append DOCXAnalyzer

# Remove the built-in video analyzer:
Rails.application.config.active_storage.analyzers.delete ActiveStorage::Analyzer::VideoAnalyzer

Outside of a Rails application, manipulate ActiveStorage.analyzers instead.

You won’t ordinarily need to call this method from a Rails application. New blobs are automatically and asynchronously analyzed via #analyze_later when they’re attached for the first time.