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Class: ActiveStorage::Previewer::PopplerPDFPreviewer

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::ActiveStorage::Previewer
Instance Chain:
self, ::ActiveStorage::Previewer, ::ActiveStorage::Downloading
Inherits: ActiveStorage::Previewer
Defined in: activestorage/lib/active_storage/previewer/poppler_pdf_previewer.rb

Class Attribute Summary

Class Method Summary

::ActiveStorage::Previewer - Inherited

.accept?

Implement this method in a concrete subclass.
.new

Instance Attribute Summary

::ActiveStorage::Previewer - Inherited

#blob

Instance Method Summary

::ActiveStorage::Previewer - Inherited

#preview

Override this method in a concrete subclass.
#draw

Executes a system command, capturing its binary output in a tempfile.
#logger

::ActiveStorage::Downloading - Included

#download_blob_to

Efficiently downloads blob data into the given file.
#download_blob_to_tempfile

Opens a new tempfile in #tempdir and copies blob data into it.
#tempdir

Returns the directory in which tempfiles should be opened.

Constructor Details

This class inherits a constructor from ActiveStorage::Previewer

Class Attribute Details

.pdftoppm_exists? ⇒ Boolean (readonly)

[ GitHub ] 

  


# File 'activestorage/lib/active_storage/previewer/poppler_pdf_previewer.rb', line 14



def pdftoppm_exists?
  return @pdftoppm_exists unless @pdftoppm_exists.nil?

  @pdftoppm_exists = system(pdftoppm_path, "-v", out: File::NULL, err: File::NULL)
end


  







Class Method Details



  

    .accept?(blob)  ⇒ Boolean 
  



  

    
  





  


  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/previewer/poppler_pdf_previewer.rb', line 6



def accept?(blob)
  blob.content_type == "application/pdf" && pdftoppm_exists?
end


  








  

    .pdftoppm_path  
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/previewer/poppler_pdf_previewer.rb', line 10



def pdftoppm_path
  ActiveStorage.paths[:pdftoppm] || "pdftoppm"
end


  







Instance Method Details



  

    #preview  
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/previewer/poppler_pdf_previewer.rb', line 21



def preview
  download_blob_to_tempfile do |input|
    draw_first_page_from input do |output|
      yield io: output, filename: "#{blob.filename.base}.png", content_type: "image/png"
    end
  end
end