Indicate to an ajax process that the delayed job has completed

Typically, the best way to do this is to store, in your database, an indication of the job's progress. For instance:

class User  def perform_calculation    begin      self.update_attributes :calculation_status => 'started'      do_something_complex      self.update_attributes :calculation_status => 'success'     rescue Exception => e      self.update_attributes :calculation_status => 'error'    end  endend

So that when you enqueue the job:

User.update_attributes :calculation_status => 'enqueued'User.send_later :perform_calculation

You can query, in your controller, the status of the job:

def check_status  @user = User.find(params[:id])  render :json => @user.calculation_statusend

You polling ajax process can then simply call check_status to see how the job is progressing, if it has succeeded or if it has failed.

With this gem you can have progress tracking directly on the Delayed::Job object itself: https://github.com/GBH/delayed_job_progress

Completed jobs are no longer automatically removed, so you can poll against a job until it comes back with completed state.

If you are using any JavaScript framework like prototypejs, then in the optional options hash, you usually provide a onComplete and/or onSuccess callback. API Reference