How to use the cortex.app.logger.warn function in cortex

# Validate and extract ordering column. This parameter is the index of the
	# column on the HTML table to order by
	if 'order[0][column]' in request.form:
		order_column = int(request.form['order[0][column]'])
	else:
		order_column = 0

	# Validate and extract ordering direction. 'asc' for ascending, 'desc' for
	# descending.
	if 'order[0][dir]' in request.form:
		if request.form['order[0][dir]'] == 'asc':
			order_asc = True
		elif request.form['order[0][dir]'] == 'desc':
			order_asc = False
		else:
			app.logger.warn('Invalid \'order[0][dir]\' parameter in DataTables request')
			abort(400)
	else:
		order_asc = False

	# Handle the search parameter. This is the textbox on the DataTables
	# view that the user can search by typing in
	search = None
	if 'search[value]' in request.form:
		if request.form['search[value]'] != '':
			if type(request.form['search[value]']) is not str and type(request.form['search[value]']) is not str:
				search = str(request.form['search[value]'])
			else:
				search = request.form['search[value]']

	return (draw, start, length, order_column, order_asc, search)

return False

	# Check if VM recipe exists
	elif entity is "vm":
		
		cursor.execute("SELECT COUNT(`name`) AS count FROM `vm_recipes` WHERE `name`=%s AND `service_name` = %s;", (recipe_name, service_recipe_name))
		
		result = cursor.fetchone()
		
		if result['count'] == 1:
			return True
		return False
	
	# If the entity is something else, abort
	else:
		app.logger.warn('There is no entity of this type')
		return abort(400)

# Validate and extract ordering column. This parameter is the index of the
	# column on the HTML table to order by
	if 'order[0][column]' in request.form:
		order_column = int(request.form['order[0][column]'])
	else:
		order_column = 0

	# Validate and extract ordering direction. 'asc' for ascending, 'desc' for
	# descending.
	if 'order[0][dir]' in request.form:
		if request.form['order[0][dir]'] == 'asc':
			order_asc = True
		elif request.form['order[0][dir]'] == 'desc':
			order_asc = False
		else:
			app.logger.warn('Invalid \'order[0][dir]\' parameter in DataTables request')
			abort(400)
	else:
		order_asc = False

	# Handle the search parameter. This is the textbox on the DataTables
	# view that the user can search by typing in
	search = None
	if 'search[value]' in request.form:
		if request.form['search[value]'] != '':
			if type(request.form['search[value]']) is not str and type(request.form['search[value]']) is not unicode:
				search = str(request.form['search[value]'])
			else:
				search = request.form['search[value]']

	return (draw, start, length, order_column, order_asc, search)

def _systems_extract_datatables():
	# Validate and extract 'draw' parameter. This parameter is simply a counter
	# that DataTables uses internally.
	if 'draw' in request.form:
		draw = int(request.form['draw'])
	else:
		app.logger.warn('\'draw\' parameter missing from DataTables request')
		abort(400)

	# Validate and extract 'start' parameter. This parameter is the index of the
	# first row to return.
	if 'start' in request.form:
		start = int(request.form['start'])
	else:
		app.logger.warn('\'start\' parameter missing from DataTables request')
		abort(400)

	# Validate and extract 'length' parameter. This parameter is the number of
	# rows that we should return
	if 'length' in request.form:
		length = int(request.form['length'])
		if length < 0:
			length = None
	else:
		app.logger.warn('\'length\' parameter missing from DataTables request')
		abort(400)

	# Validate and extract ordering column. This parameter is the index of the
	# column on the HTML table to order by
	if 'order[0][column]' in request.form:
		order_column = int(request.form['order[0][column]'])

def _extract_datatables():
	# Validate and extract 'draw' parameter. This parameter is simply a counter
	# that DataTables uses internally.
	if 'draw' in request.form:
		draw = int(request.form['draw'])
	else:
		app.logger.warn('`draw` parameter missing from DataTables request')
		abort(400)

	# Validate and extract 'start' parameter. This parameter is the index of the
	# first row to return.
	if 'start' in request.form:
		start = int(request.form['start'])
	else:
		app.logger.warn('`start` parameter missing from DataTables request')
		abort(400)

	# Validate and extract 'length' parameter. This parameter is the number of
	# rows that we should return
	if 'length' in request.form:
		length = int(request.form['length'])
		if length < 0:
			# MySQL Max Length

elif order_column == 2:
		order_by = "end"
	elif order_column == 3:
		order_by = "name"
	elif order_column == 4:
		order_by = "desc"
	elif order_column == 5:
		order_by = "source"
	elif order_column == 6:
		order_by = "username"
	elif order_column == 7:
		order_by = "ipaddr"
	elif order_column == 8:
		order_by = "status"
	else:
		app.logger.warn('Invalid ordering column parameter in DataTables request')
		abort(400)

	# Choose order direction
	order_dir = "DESC"
	if order_asc:
		order_dir = "ASC"

	# Determine the event type and add that to the query
	params = ()
	where_clause = ""
	if event_source == 'all':
		where_clause = '1=1'	# This is just to make 'search' always be able to be an AND and not need an optional WHERE
	elif event_source == 'user':
		where_clause = "`username` != 'scheduler'"
	elif event_source == 'scheduler':
		where_clause = "`username` = 'scheduler'"

# Validate and extract ordering column. This parameter is the index of the
	# column on the HTML table to order by
	if 'order[0][column]' in request.form:
		order_column = int(request.form['order[0][column]'])
	else:
		order_column = 0

	# Validate and extract ordering direction. 'asc' for ascending, 'desc' for
	# descending.
	if 'order[0][dir]' in request.form:
		if request.form['order[0][dir]'] == 'asc':
			order_asc = True
		elif request.form['order[0][dir]'] == 'desc':
			order_asc = False
		else:
			app.logger.warn('Invalid \'order[0][dir]\' parameter in DataTables request')
			abort(400)
	else:
		order_asc = False

	# Handle the search parameter. This is the textbox on the DataTables
	# view that the user can search by typing in
	search = None
	if 'search[value]' in request.form:
		if request.form['search[value]'] != '':
			if type(request.form['search[value]']) is not str and type(request.form['search[value]']) is not str:
				search = str(request.form['search[value]'])
			else:
				search = request.form['search[value]']

	return (draw, start, length, order_column, order_asc, search)

def error_handler(error):
	"""Handles generic exceptions within the application, displaying the
	traceback if the application is running in debug mode."""

	# Record the error in the log
	logerr()

	## If we're handling a workflow view handler we don't need to show the fatal
	## error screen, instead we'll use a standard error screen. the fatal error
	## screen exists in case a flaw occurs which prevents rendering of the 
	## layout - but that can't happen with a workflow.
	if 'workflow' in g:
		if g.workflow:
			app.logger.warn("Workflow error occured")
			return stderr("Workflow error","An error occured in the workflow function - " + type(error).__name__ + ": " + str(error))

	# Get the traceback
	if app.debug:
		debug = traceback.format_exc()
	else:
		debug = "Ask your system administrator to consult the error log for this application."

	# Output a fatal error
	return fatalerr(debug=debug)

def _systems_extract_datatables():
	# Validate and extract 'draw' parameter. This parameter is simply a counter
	# that DataTables uses internally.
	if 'draw' in request.form:
		draw = int(request.form['draw'])
	else:
		app.logger.warn('\'draw\' parameter missing from DataTables request')
		abort(400)

	# Validate and extract 'start' parameter. This parameter is the index of the
	# first row to return.
	if 'start' in request.form:
		start = int(request.form['start'])
	else:
		app.logger.warn('\'start\' parameter missing from DataTables request')
		abort(400)

	# Validate and extract 'length' parameter. This parameter is the number of
	# rows that we should return
	if 'length' in request.form:
		length = int(request.form['length'])
		if length < 0:
			length = None