62 lines
2.4 KiB
Ruby
62 lines
2.4 KiB
Ruby
# frozen_string_literal: true
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require "active_storage/analyzer/null_analyzer"
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module ActiveStorage::Blob::Analyzable
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# Extracts and stores metadata from the file associated with this blob using a relevant analyzer. Active Storage comes
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# with built-in analyzers for images and videos. See ActiveStorage::Analyzer::ImageAnalyzer and
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# ActiveStorage::Analyzer::VideoAnalyzer for information about the specific attributes they extract and the third-party
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# libraries they require.
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#
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# To choose the analyzer for a blob, Active Storage calls +accept?+ on each registered analyzer in order. It uses the
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# first analyzer for which +accept?+ returns true when given the blob. If no registered analyzer accepts the blob, no
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# metadata is extracted from it.
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#
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# In a Rails application, add or remove analyzers by manipulating +Rails.application.config.active_storage.analyzers+
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# in an initializer:
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#
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# # Add a custom analyzer for Microsoft Office documents:
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# Rails.application.config.active_storage.analyzers.append DOCXAnalyzer
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#
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# # Remove the built-in video analyzer:
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# Rails.application.config.active_storage.analyzers.delete ActiveStorage::Analyzer::VideoAnalyzer
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#
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# Outside of a Rails application, manipulate +ActiveStorage.analyzers+ instead.
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#
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# You won't ordinarily need to call this method from a Rails application. New blobs are automatically and asynchronously
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# analyzed via #analyze_later when they're attached for the first time.
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def analyze
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update! metadata: metadata.merge(extract_metadata_via_analyzer)
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end
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# Enqueues an ActiveStorage::AnalyzeJob which calls #analyze, or calls #analyze inline based on analyzer class configuration.
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#
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# This method is automatically called for a blob when it's attached for the first time. You can call it to analyze a blob
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# again (e.g. if you add a new analyzer or modify an existing one).
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def analyze_later
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if analyzer_class.analyze_later?
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ActiveStorage::AnalyzeJob.perform_later(self)
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else
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analyze
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end
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end
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# Returns true if the blob has been analyzed.
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def analyzed?
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analyzed
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end
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private
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def extract_metadata_via_analyzer
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analyzer.metadata.merge(analyzed: true)
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end
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def analyzer
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analyzer_class.new(self)
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end
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def analyzer_class
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ActiveStorage.analyzers.detect { |klass| klass.accept?(self) } || ActiveStorage::Analyzer::NullAnalyzer
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end
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end
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