module ActionController #:nodoc: # Methods for sending arbitrary data and for streaming files to the browser, # instead of rendering. module Streaming extend ActiveSupport::Concern include ActionController::Renderer DEFAULT_SEND_FILE_OPTIONS = { :type => 'application/octet-stream'.freeze, :disposition => 'attachment'.freeze, :stream => true, :buffer_size => 4096, :x_sendfile => false }.freeze X_SENDFILE_HEADER = 'X-Sendfile'.freeze protected # Sends the file, by default 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. You can optionally turn off streaming # and send the whole file at once. # # Be careful to sanitize the path parameter if it is 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'. You can specify # either a string or a symbol for a registered type register with Mime::Type.register, for example :json # * :length - used to manually override the length (in bytes) of the content that # is going to be sent to the client. Defaults to File.size(path). # * :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'. # * :url_based_filename - set to +true+ if you want the browser guess the filename from # the URL, which is necessary for i18n filenames on certain browsers # (setting :filename overrides this option). # * :x_sendfile - uses X-Sendfile to send the file when set to +true+. This is currently # only available with Lighttpd/Apache2 and specific modules installed and activated. Since this # uses the web server to send the file, this may lower memory consumption on your server and # it will not block your application for further requests. # See http://blog.lighttpd.net/articles/2006/07/02/x-sendfile and # http://tn123.ath.cx/mod_xsendfile/ for details. Defaults to +false+. # # 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) in # 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) unless options[:url_based_filename] send_file_headers! options @performed_render = false if options[:x_sendfile] logger.info "Sending #{X_SENDFILE_HEADER} header #{path}" if logger head options[:status], X_SENDFILE_HEADER => path else if options[:stream] # TODO : Make render :text => proc {} work with the new base 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| while buf = file.read(len) output.write(buf) 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 end # Sends the given binary data to the browser. This method is similar to # render :text => data, but also allows you to specify whether # the browser should display the response as a file attachment (i.e. in a # download dialog) or as inline data. You may also set the content type, # the apparent file name, and other things. # # Options: # * :filename - suggests a filename for the browser to use. # * :type - specifies an HTTP content type. Defaults to 'application/octet-stream'. You can specify # either a string or a symbol for a registered type register with Mime::Type.register, for example :json # * :disposition - specifies whether the file will be shown inline or downloaded. # Valid values are 'inline' and 'attachment' (default). # * :status - specifies the status code to send with the response. Defaults to '200 OK'. # # 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. # # Tip: if you want to stream large amounts of on-the-fly generated # data to the browser, then use render :text => proc { ... } # instead. See ActionController::Base#render for more information. def send_data(data, options = {}) #:doc: logger.info "Sending data #{options[:filename]}" if logger 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] content_type = options[:type] if content_type.is_a?(Symbol) raise ArgumentError, "Unknown MIME type #{options[:type]}" unless Mime::EXTENSION_LOOKUP.key?(content_type.to_s) self.content_type = Mime::Type.lookup_by_extension(content_type.to_s) else self.content_type = content_type end headers.merge!( 'Content-Length' => options[:length].to_s, '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