upload file in rails

http://www.tutorialspoint.com/ruby-on-rails/rails-file-uploading.htm
http://manuals.rubyonrails.com/read/chapter/79
http://manuals.rubyonrails.com/read/chapter/78
http://manuals.rubyonrails.com/read/chapter/77
http://www.practicalecommerce.com/blogs/post/432-Multiple-Attachments-in-Rails
http://izumi.plan99.net/blog/index.php/2007/04/07/ruby-on-railss-handling-of-uploaded-files/

About the uploaded file object

While the uploaded file is a special beast,it is not difficult to use. The object
rails receives are processed by a CGI object. The object that CGI returns to Rails
isn’t actually a file object, but it’s close enough for our purposes.
Details from the CGI class documentation

... the value is not a string, but an IO object, either an IOString for small files,
or a Tempfile for larger ones.
This object also has the additional singleton methods:
local_path(): the path of the uploaded file on the local filesystem
original_filename(): the name of the file on the client computer 
content_type(): the content type of the file

<br />class UserController < ApplicationController<br /> ...<br /> def save_picture<br /> @user = User.find(@params['user']['id'])<br /> File.open("#{RAILS_ROOT}/public/pictures/#{@user.id}.jpg", "wb") do |f| <br /> f.write(@params['picture_file'].read)<br /> end<br /> redirect_to :action => 'show', :id => @user.id<br /> end<br /> ...<br />end<br />
<br />class Content < ActiveRecord::Base<br /> def file=(incomming_file)<br /> @temp_file = incomming_file<br /> @filename = incomming_file.original_filename<br /> @content_type = incomming_file.content_type<br /> end<br /><br /> def after_save<br /> if @temp_file<br /> logger.debug("saving '#{RAILS_ROOT}/media/#{@filename}'")<br /> File.open("#{RAILS_ROOT}/media/#{@filename}", "wb") do |f| <br /> f.write(@temp_file.read)<br /> end<br /> end<br /> end<br /> end<br />
<br />def sanitize_filename(file_name)<br /> # get only the filename, not the whole path (from IE)<br /> just_filename = File.basename(file_name) <br /> # replace all none alphanumeric, underscore or perioids with underscore<br /> just_filename.sub(/[^\w\.\-]/,'_') <br />end<br />