signals

Jobs

Jobs are actions that a module can do, which are either done periodically or are triggered upon a certain outside event.

Scheduled Tasks

Jobs that are performed periodically are called scheduled tasks.

Modules can create scheduled tasks on a site with the Scheduled Task Manager Module running.

Any module that registers a scheduled task will be called upon periodically to perform an action (the frequency can be controlled by the administrator who enables the scheduled task, but you can specify a default frequency).

Incoming Email Handlers

Jobs that are performed when an email is received by the CMS are called incoming email handlers.

Modules can create incoming email handlers on a site with the Incoming Email Manager Module running.

Any module that registers an incoming email handler will be called upon whenever an email is received to process that email.

Writing a Job

From a Module developer's point of view jobs are a lot like signals, in that you need to create a static function to perform a job, which the manager module will then call when it wants to run the job.

However the key difference is that signals are sent upon a specific event inside the CMS and are usually called in the context of a visitor visiting a site, whereas jobs are called either periodically or due to an outside event such as an incoming email.

Logging Output from a Job

Each time a job is run, any output you echo will be logged.

Depending on how the Admin configures the job, this output will either be ignored, logged in a record in the database, or sent to a support address via email.