I was able to get background processes to work pretty well. I have an import
script that takes a minute or two to run and is started by an ajax call from
a button in one of my views, and the progress is reported back to the page
as the script runs. The way I did this was to use multiprocessing. Here is
an example class:
from miltiprocessing import Process, Queue
class ImportScript(Process):
queue = Queue()
progress = (0, 0, 'Idle')
def __init__(self, environment, db):
Process.__init__(self)
self.db = db
def run(self):
self._do_import(arg1, arg2)
def _do_import(self, arg1, arg2):
# long running task here
self._update_progress((1,100, 'Importing'))
def _updatre_progress(self, progress):
ImportScript.queue.put(progress)
print '%s: %s of %s' % (progress[2], progress[0], progress[1])
@staticmethod
def get_progress():
queue = ImportScript.queue
progress = ImportScript.progress
while not queue.empty():
progress = queue.get(False)
ImportScript.progress = progress
return progress
I called this file scripts.py, and added to my modules folder. Then in
db.py, I initialize it by calling:
scripts_module = local_import('scripts', reload=False) # reload=False is
important
In my controller, when I want to start this process, I call:
import_script = scripts_module.ImportScript(globals(), db)
import_script.start()
The script starts and the controller continues execution while the script
runs in the background. Then if I want to check progress on the script, I
make an ajax call to another action in the controller that returns progress:
progress = scripts_module.ImportScript.get_progress()
return '%s: %s of %s' % (progress[2], progress[0], progress[1])
This would return something similar to:
Importing records: 5 of 100
