MongrelUploadProgressDb
by David Stevenson
ds@elctech.com
=======================

This plugin extends the mongrel_upload_progress gem to allow upload progress information to be stored in a database table, rather than in memory or using distributed ruby.  Every 3 seconds, upload_progress for a given upload_id is stored in the database table.

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Usage
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After installing the plugin, you should invoke the setup method at the end of environment.rb as follows:

Upload.setup

The following options are possible to the setup method:

  :object_name -- model where statuses are stored (default => :upload_status)
  :id_method_name -- method where upload_id's are stored (default => :upid)
  :remaining_method_name -- method where remaining byte count is to be stored (default => :remaining)
  :total_size_method_name -- method where total byte count is to be stored (default => :total)

You'll also need a table to store upload statuses.  Here's a sample migration:

def self.up
  create_table :upload_statuses do |t|
    t.column :upid, :string, :null => false
    t.column :remaining, :integer, :default => 0
    t.column :total, :integer, :default => 0
    t.column :updated_at, :datetime
  end
  
  add_index(:upload_statuses, :upid, :unique => true)
end

Like mongrel_upload_progress, you must also pass a parameter in your form called "upload_status", and set its value to something unique.  Here's how I accomplished that:

<% @upid = Time.now.to_i.to_s + (rand * 10000).to_i.to_s %>
<% form_for :stuff, :url => stuff_path(:upload_id => @upid), :html => {:multipart => true, :onsubmit => "UploadProgress.monitor('#{escape_javascript @upid}', '#{progress_stuff_path}')"} do |f| %>

Finally, in the controller, you must make a method which reports upload status back to the browser.  Here's mine:

def progress
  render :update do |page|
    @status = UploadStatus.find_by_upid(params[:upload_id])
    page.upload_progress.update(@status.total, @status.progress) if @status && @status.total > 0
  end
end