Controller Action to Delayed Job

问题

I am uploading a tab-delimited document and processing in the controller. Everything works fine, but can take some time on a large file. I want to move this to a delay_job, which I have working elsewhere in my app, but as this is in the controller, cannot be called in the same way.

The form calls on the process_file action, which in turn calls on the salesupload action. How should I turn this into a background job?

class SalesController < ApplicationController

  def salesupload(file)
    uploaded_io = file.read
    numrows = "uploaded_io.size"
    FasterCSV.parse(uploaded_io, {:headers => true, :col_sep =>"\t"}).each do |row_data|
        full, upc, _discard, isrc = row_data[26].match(/^([^_]+)(_(.+))?/).to_a
          new_record = AppleSale.new(
              'provider' =>  row_data[0],
              'provider_country' => row_data[1],
              'vendor_identifier' => row_data[2]
          )
      new_record.save
    end
  end

    def process_file
        file = params[:apple_sale][:tsv_file]
        salesupload(file)
    end

end

回答1:

I found when I had to do this that the method defined in the controller has to be a class method. I can't remember why this was, I think it had to do with having a more explicit receiver. So what I would do is make the salesupload method a class method, and then just call .delay on it.

def self.salesupload(files)
  # code
end

def process_file
  file = params[:apple_sale][:tsv_file]
  SalesController.delay.salesupload(file)
  head :no_content
end

And you should be good to go! I also made my original method (process_file in this case) called via AJAX, and then I appended the head :no_content so that it returned something without needing a redirect or anything.

回答2:

I wrote a gem called delayed_action to do this.

In this case you'd write delayed_action [:sales_upload]

and that's it.

回答3:

I guess you should move this code to a model or a separated class (for instance inside the lib folder). But that is just a matter of organization and best practices.

About the running this code in background, you have many options. If you want to use delayed_job I guess you should watch this screencast: http://railscasts.com/episodes/171-delayed-job

but basically, after setting up delayed job, you just use something like send_later(:process_file) to tell to run that project in background. It is pretty straightforward, your command and data structure will be saved in a database table and later a separated process can execute it. I imagine that after watching the railscast you will have your answers ;)

来源：https://stackoverflow.com/questions/12956661/controller-action-to-delayed-job