Class: ActiveStorage::Previewer::MuPDFPreviewer

Inherits:
ActiveStorage::Previewer show all
Defined in:
lib/active_storage/previewer/mupdf_previewer.rb

Instance Attribute Summary

Attributes inherited from ActiveStorage::Previewer

#blob

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from ActiveStorage::Previewer

#initialize

Constructor Details

This class inherits a constructor from ActiveStorage::Previewer

Class Method Details

.accept?(blob) ⇒ Boolean

Returns:

  • (Boolean) 


6
7
8
 
# File 'lib/active_storage/previewer/mupdf_previewer.rb', line 6

def accept?(blob)
  pdf?(blob.content_type) && mutool_exists?
end

.mutool_exists? ⇒ Boolean

Returns:

  • (Boolean) 


18
19
20
21
22
23
24
 
# File 'lib/active_storage/previewer/mupdf_previewer.rb', line 18

def mutool_exists?
  return @mutool_exists unless @mutool_exists.nil?

  system mutool_path, out: File::NULL, err: File::NULL

  @mutool_exists = $?.exitstatus == 1
end

.mutool_path ⇒ Object 



14
15
16
 
# File 'lib/active_storage/previewer/mupdf_previewer.rb', line 14

def mutool_path
  ActiveStorage.paths[:mutool] || "mutool"
end

.pdf?(content_type) ⇒ Boolean

Returns:

  • (Boolean) 


10
11
12
 
# File 'lib/active_storage/previewer/mupdf_previewer.rb', line 10

def pdf?(content_type)
  Marcel::Magic.child? content_type, "application/pdf"
end

Instance Method Details

#preview(**options) ⇒ Object 



27
28
29
30
31
32
33
 
# File 'lib/active_storage/previewer/mupdf_previewer.rb', line 27

def preview(**options)
  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", **options
    end
  end
end