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Class: ActiveStorage::Analyzer

Relationships & Source Files
Namespace Children
Classes:
Extension / Inclusion / Inheritance Descendants
Subclasses:
Inherits: Object
Defined in: activestorage/lib/active_storage/analyzer.rb

Overview

This is an abstract base class for analyzers, which extract metadata from blobs. See VideoAnalyzer for an example of a concrete subclass.

Class Attribute Summary

Class Method Summary

Instance Attribute Summary

Instance Method Summary

Constructor Details

.new(blob) ⇒ Analyzer

[ GitHub ]

  
# File 'activestorage/lib/active_storage/analyzer.rb', line 23

def initialize(blob)
  @blob = blob
end

Class Attribute Details

.analyze_later?Boolean (readonly)

Implement this method in concrete subclasses. It will determine if blob analysis should be done in a job or performed inline. By default, analysis is enqueued in a job.

[ GitHub ]

  
# File 'activestorage/lib/active_storage/analyzer.rb', line 19

def self.analyze_later?
  true
end

Class Method Details

.accept?(blob) ⇒ Boolean

Implement this method in a concrete subclass. Have it return true when given a blob from which the analyzer can extract metadata.

[ GitHub ]

  
# File 'activestorage/lib/active_storage/analyzer.rb', line 13

def self.accept?(blob)
  false
end

Instance Attribute Details

#blob (readonly)

[ GitHub ]

  
# File 'activestorage/lib/active_storage/analyzer.rb', line 9

attr_reader :blob

Instance Method Details

#download_blob_to_tempfile(&block) (private)

Downloads the blob to a tempfile on disk. Yields the tempfile.

[ GitHub ]

  
# File 'activestorage/lib/active_storage/analyzer.rb', line 34

def download_blob_to_tempfile(&block) # :doc:
  blob.open tmpdir: tmpdir, &block
end

#instrument(analyzer, &block) (private)

[ GitHub ]

  
# File 'activestorage/lib/active_storage/analyzer.rb', line 46

def instrument(analyzer, &block) # :doc:
  ActiveSupport::Notifications.instrument("analyze.active_storage", analyzer: analyzer, &block)
end

#logger (private)

[ GitHub ]

  
# File 'activestorage/lib/active_storage/analyzer.rb', line 38

def logger # :doc:
  ActiveStorage.logger
end

#metadata

Override this method in a concrete subclass. Have it return a ::Hash of metadata.

Raises:

  • (NotImplementedError)
[ GitHub ]

  
# File 'activestorage/lib/active_storage/analyzer.rb', line 28

def 
  raise NotImplementedError
end

#tmpdir (private)

[ GitHub ]

  
# File 'activestorage/lib/active_storage/analyzer.rb', line 42

def tmpdir # :doc:
  Dir.tmpdir
end