add context to Upload model to allow sending data-context

- allows for not polluting the session object, or when the session
  object isn't suitable for passing additional context information

Author: rockrep

app/controllers/s3_multipart/uploads_controller.rb

@@ -1,6 +1,6 @@
 module S3Multipart
   class UploadsController < ApplicationController
-  
+
     def create
       begin
         upload = Upload.create(params)
@@ -20,9 +20,9 @@ def update
       return complete_upload if params[:parts]
       return sign_batch if params[:content_lengths]
       return sign_part if params[:content_length]
-    end 
+    end
 
-    private 
+    private
 
       def sign_batch
         begin

app/models/s3_multipart/upload.rb

@@ -7,12 +7,12 @@ class Upload < ::ActiveRecord::Base
 
     def self.create(params)
       response = initiate(params)
-      super(key: response["key"], upload_id: response["upload_id"], name: response["name"], uploader: params["uploader"], size: params["content_size"])
+      super(key: response["key"], upload_id: response["upload_id"], name: response["name"], uploader: params["uploader"], size: params["content_size"], context: params["context"].to_s)
     end
 
     def execute_callback(stage, session)
       controller = deserialize(uploader)
-      
+
       case stage
       when :begin
         controller.on_begin_callback.call(self, session) if controller.on_begin_callback

javascripts/s3mp.js

@@ -155,6 +155,7 @@ S3MP.prototype.initiateMultipart = function(upload, cb) {
   body = JSON.stringify({ object_name  : upload.name,
                           content_type : upload.type,
                           content_size : upload.size,
+                          context      : $(this.fileInputElement).data("context"),
                           uploader     : $(this.fileInputElement).data("uploader")
                         });
 

lib/generators/s3_multipart/install_new_migrations_generator.rb

@@ -8,6 +8,7 @@ class InstallNewMigrationsGenerator < Rails::Generators::Base
 
     def create_latest_migrations
       copy_file "add_size_column_to_s3_multipart_uploads.rb", "db/migrate/#{migration_time}_add_size_to_s3_multipart_uploads.rb"
+      copy_file "add_context_column_to_s3_multipart_uploads.rb", "db/migrate/#{migration_time}_add_context_to_s3_multipart_uploads.rb"
     end
 
     private

lib/generators/s3_multipart/templates/add_context_to_s3_multipart_uploads.rb

@@ -0,0 +1,6 @@
+class AddContextToS3MultipartUploads < ActiveRecord::Migration
+  def change
+    add_column :s3_multipart_uploads, :context, :text
+  end
+end
+

lib/generators/s3_multipart/templates/uploads_table_migration.rb

@@ -8,6 +8,8 @@ def change
       t.string :name
       t.string :uploader
       t.integer :size
+      # additional options useful for constructing associations for the uploaded model
+      t.text :context
 
       t.timestamps
     end

vendor/assets/javascripts/s3_multipart/lib.js

@@ -169,6 +169,7 @@ S3MP.prototype.initiateMultipart = function(upload, cb) {
   body = JSON.stringify({ object_name  : upload.name,
                           content_type : upload.type,
                           content_size : upload.size,
+                          context      : $(this.fileInputElement).data("context"),
                           uploader     : $(this.fileInputElement).data("uploader")
                         });