Regular scheduled jobs¶
Any component used by your application can have jobs that need to be run at regular intervals. Executing the following runs all jobs that are scheduled to run:
reahl runjobs etc
The tutorial.jobsbootstrap example needs its Address.clear_added_flags() to run automatically, once a day.
class Address(Base):
__tablename__ = 'jobsbootstrap_address'
id = Column(Integer, primary_key=True)
email_address = Column(UnicodeText)
name = Column(UnicodeText)
added_today = Column(Boolean, nullable=False, default=True)
@classmethod
def clear_added_flags(cls):
for address in Session.query(cls).filter_by(added_today=True):
address.added_today = False
@exposed
def fields(self, fields):
fields.name = Field(label='Name', required=True)
fields.email_address = EmailField(label='Email', required=True)
@exposed
def events(self, events):
events.save = Event(label='Save', action=Action(self.save))
def save(self):
Session.add(self)
To register this job with the component, add a <schedule> tag in the .reahlproject file:
<schedule locator="reahl.doc.examples.tutorial.jobsbootstrap.jobsbootstrap:Address.clear_added_flags"/>
A job, such as Address.clear_added_flags() should
include code that makes sure it only does its work when necessary. You
can then use your operating system tools (such as cron) to run
reahl runjobs etc very regularly – say once every 10
minutes. Each scheduled job will now be invoked regularly, and can
check at each invocation whether it is time for it to do its work, or
whether it should ignore the current run until a future time. This
way, all jobs can get a chance to be run, and be in control of when
they should run.