module ActionController #:nodoc: # Methods for sending files and streams to the browser instead of rendering. module Streaming DEFAULT_SEND_FILE_OPTIONS = { :type => 'application/octet-stream'.freeze, :disposition => 'attachment'.freeze, :stream => true, :buffer_size => 4096 }.freeze protected # Sends the file by streaming it 4096 bytes at a time. This way the # whole file doesn't need to be read into memory at once. This makes # it feasible to send even large files. # # Be careful to sanitize the path parameter if it coming from a web # page. send_file(params[:path]) allows a malicious user to # download any file on your server. # # Options: # * :filename - suggests a filename for the browser to use. # Defaults to File.basename(path). # * :type - specifies an HTTP content type. # Defaults to 'application/octet-stream'. # * :disposition - specifies whether the file will be shown inline or downloaded. # Valid values are 'inline' and 'attachment' (default). # * :stream - whether to send the file to the user agent as it is read (true) # or to read the entire file before sending (false). Defaults to true. # * :buffer_size - specifies size (in bytes) of the buffer used to stream the file. # Defaults to 4096. # * :status - specifies the status code to send with the response. Defaults to '200 OK'. # # The default Content-Type and Content-Disposition headers are # set to download arbitrary binary files in as many browsers as # possible. IE versions 4, 5, 5.5, and 6 are all known to have # a variety of quirks (especially when downloading over SSL). # # Simple download: # send_file '/path/to.zip' # # Show a JPEG in the browser: # send_file '/path/to.jpeg', :type => 'image/jpeg', :disposition => 'inline' # # Show a 404 page in the browser: # send_file '/path/to/404.html, :type => 'text/html; charset=utf-8', :status => 404 # # Read about the other Content-* HTTP headers if you'd like to # provide the user with more information (such as Content-Description). # http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.11 # # Also be aware that the document may be cached by proxies and browsers. # The Pragma and Cache-Control headers declare how the file may be cached # by intermediaries. They default to require clients to validate with # the server before releasing cached responses. See # http://www.mnot.net/cache_docs/ for an overview of web caching and # http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9 # for the Cache-Control header spec. def send_file(path, options = {}) #:doc: raise MissingFile, "Cannot read file #{path}" unless File.file?(path) and File.readable?(path) options[:length] ||= File.size(path) options[:filename] ||= File.basename(path) send_file_headers! options @performed_render = false if options[:stream] render :status => options[:status], :text => Proc.new { |response, output| logger.info "Streaming file #{path}" unless logger.nil? len = options[:buffer_size] || 4096 File.open(path, 'rb') do |file| if output.respond_to?(:syswrite) begin while true output.syswrite(file.sysread(len)) end rescue EOFError end else while buf = file.read(len) output.write(buf) end end end } else logger.info "Sending file #{path}" unless logger.nil? File.open(path, 'rb') { |file| render :status => options[:status], :text => file.read } end end # Send binary data to the user as a file download. May set content type, apparent file name, # and specify whether to show data inline or download as an attachment. # # Options: # * :filename - Suggests a filename for the browser to use. # * :type - specifies an HTTP content type. # Defaults to 'application/octet-stream'. # * :disposition - specifies whether the file will be shown inline or downloaded. # * :status - specifies the status code to send with the response. Defaults to '200 OK'. # Valid values are 'inline' and 'attachment' (default). # # Generic data download: # send_data buffer # # Download a dynamically-generated tarball: # send_data generate_tgz('dir'), :filename => 'dir.tgz' # # Display an image Active Record in the browser: # send_data image.data, :type => image.content_type, :disposition => 'inline' # # See +send_file+ for more information on HTTP Content-* headers and caching. def send_data(data, options = {}) #:doc: logger.info "Sending data #{options[:filename]}" unless logger.nil? send_file_headers! options.merge(:length => data.size) @performed_render = false render :status => options[:status], :text => data end private def send_file_headers!(options) options.update(DEFAULT_SEND_FILE_OPTIONS.merge(options)) [:length, :type, :disposition].each do |arg| raise ArgumentError, ":#{arg} option required" if options[arg].nil? end disposition = options[:disposition].dup || 'attachment' disposition <<= %(; filename="#{options[:filename]}") if options[:filename] @headers.update( 'Content-Length' => options[:length], 'Content-Type' => options[:type].strip, # fixes a problem with extra '\r' with some browsers 'Content-Disposition' => disposition, 'Content-Transfer-Encoding' => 'binary' ) # Fix a problem with IE 6.0 on opening downloaded files: # If Cache-Control: no-cache is set (which Rails does by default), # IE removes the file it just downloaded from its cache immediately # after it displays the "open/save" dialog, which means that if you # hit "open" the file isn't there anymore when the application that # is called for handling the download is run, so let's workaround that @headers['Cache-Control'] = 'private' if @headers['Cache-Control'] == 'no-cache' end end end