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Class: ActiveStorage::Analyzer

Relationships & Source Files
Namespace Children
Classes:
ImageAnalyzer, VideoAnalyzer
Extension / Inclusion / Inheritance Descendants
Subclasses:
ImageAnalyzer, ActiveStorage::Analyzer::NullAnalyzer, VideoAnalyzer
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 ImageAnalyzer 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 21



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 17



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 11



def self.accept?(blob)
  false
end


  







Instance Attribute Details



  

    #blob   (readonly)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/analyzer.rb', line 7



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 32



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


  








  

    #logger   (private)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/analyzer.rb', line 36



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 26



def metadata
  raise NotImplementedError
end


  








  

    #tmpdir   (private)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/analyzer.rb', line 40



def tmpdir #:doc:
  Dir.tmpdir
end