How to convert a PDF into an array of images, with Carrierwave and MiniMagick (Ruby on Rails) -


i'm converting uploaded pdfs images, 1 image per page. have figured out how generate images using minimagick::tool::convert, don't know how write version block uploader, can access array of image urls.

here's uploader far:

class documentuploader < carrierwave::uploader::base   include carrierwave::minimagick    storage :file   # storage :fog    def store_dir     "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"   end    version :jpg     process :convert_to_images     process :set_content_type_jpg      def convert_to_images(*args)       image = minimagick::image.open(current_path)       image.pages.each_with_index |page, index|         minimagick::tool::convert.new |convert|           convert.background 'white'           convert.flatten           convert.density 300           convert.quality 95           convert << page.path           convert << "#{carrierwave.root}/#{store_dir}/image-#{index}.jpg"         end       end     end   end    def set_content_type_jpg(*args)     self.file.instance_variable_set(:@content_type, "image/jpg")   end    # add white list of extensions allowed uploaded.   def extension_white_list     %w(jpg jpeg gif png doc docx pdf)   end end

this generates image-0.jpg, image-1.jpg, etc. in correct directory. have no way of referencing images in views, or knowing how many there are. not work when need upload images s3. how can carrierwave handle file storage collection of images, instead of single image?

it looks need add new database column store number of pages. there way make uploader return array of image urls, based on count?

i'm willing switch gem. easier paperclip, shrine, or refile?

with shrine can make each page different version:

class imageuploader < shrine   plugin :versions   plugin :processing    process(:store) |io, context|     pdf      = io.download     versions = {}      image = minimagick::image.new(pdf.path)     image.pages.each_with_index |page, index|       page_image = tempfile.new("version-#{index}", binmode: true)       minimagick::tool::convert.new |convert|         convert.background 'white'         convert.flatten         convert.density 300         convert.quality 95         convert << page.path         convert << page_image.path       end       page_image.open # refresh updated file       versions[:"page_#{index + 1}"] = page_image     end      versions   end end

assuming have document model , attached pdf file attachment field, can retrieve array of pages using hash#values:

pages = document.file.values pages #=> [...array of pages...] pages.count #=> number of pages

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