generic file and image models for uploaded files
These are basic models that store a file in a dedicated files table. Use has_one or has_many to associate this with your actual models. RMagick is required for images.
This is my first code dealing with uploads and rmagick, so please comment if you have suggestions.
Controller Usage:
Model Usage:
This is my first code dealing with uploads and rmagick, so please comment if you have suggestions.
1 class DbFile < ActiveRecord::Base 2 IMAGE_TYPES = ['image/jpeg', 'image/pjpeg', 'image/gif', 'image/png', 'image/x-png'] 3 before_validation :sanitize_filename 4 validates_presence_of :size, :filename, :content_type 5 6 class << self 7 def new_file(file_data) 8 content_type = file_data.content_type.strip 9 (IMAGE_TYPES.include?(content_type) ? DbImage : DbFile).new \ 10 :data => file_data.read, 11 :filename => file_data.original_filename, 12 :size => file_data.size, 13 :content_type => content_type 14 end 15 end 16 17 protected 18 def sanitize_filename 19 # NOTE: File.basename doesn't work right with Windows paths on Unix 20 # get only the filename, not the whole path 21 filename.gsub! /^.*(\\|\/)/, '' 22 23 # Finally, replace all non alphanumeric, underscore or periods with underscore 24 filename.gsub! /[^\w\.\-]/, '_' 25 end 26 end 27 28 require 'rmagick' 29 require 'base64' 30 class DbImage < DbFile 31 def data=(file_data) 32 with_image(file_data, true) do |img| 33 self.width = img.columns 34 self.height = img.rows 35 end 36 end 37 38 def with_image(file_data = nil, save_image = false, &block) 39 img = Magick::Image::read_inline(Base64.b64encode(file_data || self.data)).first 40 block.call(img) 41 write_attribute('data', img.to_blob) if save_image 42 img = nil 43 GC.start 44 end 45 end
Controller Usage:
1 # returns DbImage if content_type matches 2 db_file = DbFile.new_file(params[:file][:data]) 3 db_file.save
Model Usage:
1 # raw binary image data 2 File.open('my_file', 'w') { |f| f.write(db_file.data) } 3 4 # Image resizing with rmagick 5 # automatically creates RMagick::Image and 6 # invokes GC.start 7 db_file.with_image do |img| 8 img.scale(.25) 9 img.write('thumb.jpg') 10 end
