# Unfortunately we need to require multipart_progress here and not in
# uplaod_status_for because if the upload happens to hit a fresh FCGI instance
# the upload_status_for method will be called after the CGI object is created
# Requiring here means that multipart progress will be enabled for all multipart
# postings.
require 'action_controller/cgi_ext/multipart_progress'
module ActionController #:nodoc:
# == THIS IS AN EXPERIMENTAL FEATURE
#
# Which means that it doesn't yet work on all systems. We're still working on full
# compatibility. It's thus not advised to use this unless you've verified it to work
# fully on all the systems that is a part of your environment. Consider this an extended
# preview.
#
# == Action Pack Upload Progress for multipart uploads
#
# The UploadProgress module aids in the process of viewing an Ajax driven
# upload status when working with multipart forms. It offers a macro that
# will prepare an action for handling the cleanup of the Ajax updating including
# passing the redirect URL and custom parameters to the Javascript finish handler.
#
# UploadProgress is available for all multipart uploads when the +upload_status_for+
# macro is called in one of your controllers.
#
# The progress is stored as an UploadProgress::Progress object in the session and
# is accessible in the controller and view with the +upload_progress+ method.
#
# For help rendering the UploadProgress enabled form and supported elements, see
# ActionView::Helpers::UploadProgressHelper.
#
# === Automatic updating on upload actions
#
# class DocumentController < ApplicationController
# upload_status_for :create
#
# def create
# # ... Your document creation action
# end
# end
#
# The +upload_status_for+ macro will override the rendering of the action passed
# if +upload_id+ is found in the query string. This allows for default
# behavior if Javascript is disabled. If you are tracking the upload progress
# then +create+ will now return the cleanup scripts that will terminate the polling
# of the upload status.
#
# === Customized status rendering
#
# class DocumentController < ApplicationController
# upload_status_for :create, :status => :custom_status
#
# def create
# # ... Your document creation action
# end
#
# def custom_status
# # ... Override this action to return content to be replaced in
# # the status container
# render :inline => "<%= upload_progress.completed_percent rescue 0 %> % complete", :layout => false
# end
#
# The default status action is +upload_status+. The results of this action
# are added used to replace the contents of the HTML elements defined in
# +upload_status_tag+. Within +upload_status+, you can load the Progress
# object from the session with the +upload_progress+ method and display your own
# results.
#
# Completion of the upload status updating occurs automatically with an +after_filter+ call to
# +finish_upload_status+. Because the upload must be posted into a hidden IFRAME to enable
# Ajax updates during the upload, +finish_upload_status+ overwrites the results of any previous
# +render+ or +redirect_to+ so it can render the necessary Javascript that will properly terminate
# the status updating loop, trigger the completion callback or redirect to the appropriate URL.
#
# ==== Basic Example (View):
#
# <%= form_tag_with_upload_progress({:action => 'create'}, {:finish => 'alert("Document Uploaded")'}) %>
# <%= upload_status_tag %>
# <%= file_field 'document', 'file' %>
# <%= end_form_tag %>
#
# ==== Basic Example (Controller):
#
# class DocumentController < ApplicationController
# upload_status_for :create
#
# def create
# @document = Document.create(params[:document])
# end
# end
#
# ==== Extended Example (View):
#
# <%= form_tag_with_upload_progress({:action => 'create'}, {}, {:action => :custom_status}) %>
# <%= upload_status_tag %>
# <%= file_field 'document', 'file' %>
# <%= submit_tag "Upload" %>
# <%= end_form_tag %>
#
# <%= form_tag_with_upload_progress({:action => 'add_preview'}, {:finish => 'alert(arguments[0])'}, {:action => :custom_status}) %>
# <%= upload_status_tag %>
# <%= submit_tag "Upload" %>
# <%= file_field 'preview', 'file' %>
# <%= end_form_tag %>
#
# ==== Extended Example (Controller):
#
# class DocumentController < ApplicationController
# upload_status_for :add_preview, :create, {:status => :custom_status}
#
# def add_preview
# @document = Document.find(params[:id])
# @document.preview = Preview.create(params[:preview])
# if @document.save
# finish_upload_status "'Preview added'"
# else
# finish_upload_status "'Preview not added'"
# end
# end
#
# def create
# @document = Document.new(params[:document])
#
# upload_progress.message = "Processing document..."
# session.update
#
# @document.save
# redirect_to :action => 'show', :id => @document.id
# end
#
# def custom_status
# render :inline => '<%= upload_progress_status %> <div>Updated at <%= Time.now %></div>', :layout => false
# end
module UploadProgress
def self.append_features(base) #:nodoc:
super
base.extend(ClassMethods)
base.helper_method :upload_progress, :next_upload_id, :last_upload_id, :current_upload_id
end
module ClassMethods #:nodoc:
# Creates an +after_filter+ which will call +finish_upload_status+
# creating the document that will be loaded into the hidden IFRAME, terminating
# the status polling forms created with +form_with_upload_progress+.
#
# Also defines an action +upload_status+ or a action name passed as
# the <tt>:status</tt> option. This status action must match the one expected
# in the +form_tag_with_upload_progress+ helper.
#
def upload_status_for(*actions)
after_filter :finish_upload_status, :only => actions
define_method(actions.last.is_a?(Hash) && actions.last[:status] || :upload_status) do
render(:inline => '<%= upload_progress_status %>', :layout => false)
end
end
end
# Overwrites the body rendered if the upload comes from a form that tracks
# the progress of the upload. After clearing the body and any redirects, this
# method then renders the helper +finish_upload_status+
#
# This method only needs to be called if you wish to pass a
# javascript parameter to your finish event handler that you optionally
# define in +form_with_upload_progress+
#
# === Parameter:
#
# client_js_argument:: a string containing a Javascript expression that will
# be evaluated and passed to your +finish+ handler of
# +form_tag_with_upload_progress+.
#
# You can pass a String, Number or Boolean.
#
# === Strings
#
# Strings contain Javascript code that will be evaluated on the client. If you
# wish to pass a string to the client finish callback, you will need to include
# quotes in the +client_js_argument+ you pass to this method.
#
# ==== Example
#
# finish_upload_status("\"Finished\"")
# finish_upload_status("'Finished #{@document.title}'")
# finish_upload_status("{success: true, message: 'Done!'}")
# finish_upload_status("function() { alert('Uploaded!'); }")
#
# === Numbers / Booleans
#
# Numbers and Booleans can either be passed as Number objects or string versions
# of number objects as they are evaluated by Javascript the same way as in Ruby.
#
# ==== Example
#
# finish_upload_status(0)
# finish_upload_status(@document.file.size)
# finish_upload_status("10")
#
# === Nil
#
# To pass +nil+ to the finish callback, use a string "undefined"
#
# ==== Example
#
# finish_upload_status(@message || "undefined")
#
# == Redirection
#
# If you action performs a redirection then +finish_upload_status+ will recognize
# the redirection and properly create the Javascript to perform the redirection in
# the proper location.
#
# It is possible to redirect and pass a parameter to the finish callback.
#
# ==== Example
#
# redirect_to :action => 'show', :id => @document.id
# finish_upload_status("'Redirecting you to your new file'")
#
#
def finish_upload_status(client_js_argument='')
if not @rendered_finish_upload_status and params[:upload_id]
@rendered_finish_upload_status = true
erase_render_results
location = erase_redirect_results || ''
## TODO determine if #inspect is the appropriate way to marshall values
## in inline templates
template = "<%= finish_upload_status({"
template << ":client_js_argument => #{client_js_argument.inspect}, "
template << ":redirect_to => #{location.to_s.inspect}, "
template << "}) %>"
render({ :inline => template, :layout => false })
end
end
# Returns and saves the next unique +upload_id+ in the instance variable
# <tt>@upload_id</tt>
def next_upload_id
@upload_id = last_upload_id.succ
end
# Either returns the last saved +upload_id+ or looks in the session
# for the last used +upload_id+ and saves it as the intance variable
# <tt>@upload_id</tt>
def last_upload_id
@upload_id ||= ((session[:uploads] || {}).keys.map{|k| k.to_i}.sort.last || 0).to_s
end
# Returns the +upload_id+ from the query parameters or if it cannot be found
# in the query parameters, then return the +last_upload_id+
def current_upload_id
params[:upload_id] or last_upload_id
end
# Get the UploadProgress::Progress object for the supplied +upload_id+ from the
# session. If no +upload_id+ is given, then use the +current_upload_id+
#
# If an UploadProgress::Progress object cannot be found, a new instance will be
# returned with <code>total_bytes == 0</code>, <code>started? == false</code>,
# and <code>finished? == true</code>.
def upload_progress(upload_id = nil)
upload_id ||= current_upload_id
session[:uploads] && session[:uploads][upload_id] || UploadProgress::Progress.new(0)
end
# == THIS IS AN EXPERIMENTAL FEATURE
#
# Which means that it doesn't yet work on all systems. We're still working on full
# compatibility. It's thus not advised to use this unless you've verified it to work
# fully on all the systems that is a part of your environment. Consider this an extended
# preview.
#
# Upload Progress abstracts the progress of an upload. It's used by the
# multipart progress IO that keeps track of the upload progress and creating
# the application depends on. It contians methods to update the progress
# during an upload and read the statistics such as +received_bytes+,
# +total_bytes+, +completed_percent+, +bitrate+, and
# +remaining_seconds+
#
# You can get the current +Progress+ object by calling +upload_progress+ instance
# method in your controller or view.
#
class Progress
unless const_defined? :MIN_SAMPLE_TIME
# Number of seconds between bitrate samples. Updates that occur more
# frequently than +MIN_SAMPLE_TIME+ will not be queued until this
# time passes. This behavior gives a good balance of accuracy and load
# for both fast and slow transfers.
MIN_SAMPLE_TIME = 0.150
# Number of seconds between updates before giving up to try and calculate
# bitrate anymore
MIN_STALL_TIME = 10.0
# Number of samples used to calculate bitrate
MAX_SAMPLES = 20
end
# Number bytes received from the multipart post
attr_reader :received_bytes
# Total number of bytes expected from the mutlipart post
attr_reader :total_bytes
# The last time the upload history was updated
attr_reader :last_update_time
# A message you can set from your controller or view to be rendered in the
# +upload_status_text+ helper method. If you set a messagein a controller
# then call <code>session.update</code> to make that message available to
# your +upload_status+ action.
attr_accessor :message
# Create a new Progress object passing the expected number of bytes to receive
def initialize(total)
@total_bytes = total
reset!
end
# Resets the received_bytes, last_update_time, message and bitrate, but
# but maintains the total expected bytes
def reset!
@received_bytes, @last_update_time, @stalled, @message = 0, 0, false, ''
reset_history
end
# Number of bytes left for this upload
def remaining_bytes
@total_bytes - @received_bytes
end
# Completed percent in integer form from 0..100
def completed_percent
(@received_bytes * 100 / @total_bytes).to_i rescue 0
end
# Updates this UploadProgress object with the number of bytes received
# since last update time and the absolute number of seconds since the
# beginning of the upload.
#
# This method is used by the +MultipartProgress+ module and should
# not be called directly.
def update!(bytes, elapsed_seconds)#:nodoc:
if @received_bytes + bytes > @total_bytes
#warn "Progress#update received bytes exceeds expected bytes"
bytes = @total_bytes - @received_bytes
end
@received_bytes += bytes
# Age is the duration of time since the last update to the history
age = elapsed_seconds - @last_update_time
# Record the bytes received in the first element of the history
# in case the sample rate is exceeded and we shouldn't record at this
# time
@history.first[0] += bytes
@history.first[1] += age
history_age = @history.first[1]
@history.pop while @history.size > MAX_SAMPLES
@history.unshift([0,0]) if history_age > MIN_SAMPLE_TIME
if history_age > MIN_STALL_TIME
@stalled = true
reset_history
else
@stalled = false
end
@last_update_time = elapsed_seconds
self
end
# Calculates the bitrate in bytes/second. If the transfer is stalled or
# just started, the bitrate will be 0
def bitrate
history_bytes, history_time = @history.transpose.map { |vals| vals.inject { |sum, v| sum + v } }
history_bytes / history_time rescue 0
end
# Number of seconds elapsed since the start of the upload
def elapsed_seconds
@last_update_time
end
# Calculate the seconds remaining based on the current bitrate. Returns
# O seconds if stalled or if no bytes have been received
def remaining_seconds
remaining_bytes / bitrate rescue 0
end
# Returns true if there are bytes pending otherwise returns false
def finished?
remaining_bytes <= 0
end
# Returns true if some bytes have been received
def started?
@received_bytes > 0
end
# Returns true if there has been a delay in receiving bytes. The delay
# is set by the constant MIN_STALL_TIME
def stalled?
@stalled
end
private
def reset_history
@history = [[0,0]]
end
end
end
end
