This document summarizes how tasks work within Butter Bot, what functionality they offer, and how they can be scheduled.
A package is a regular package, not unlike any other node package, that can introduce new functionality and behaviors to Butter Bot.
At the time of writing, only packages hosted on npm are fully supported. However, any package available to the bot during runtime can work.
Most commonly, packages provide Tasks that we can then schedule to be executed by the bot.
A task (or package task to be exact) is, in its simplest form, a piece of code provided by a package that can be executed by Butter Bot.
For information on developing packages that can provide tasks for Butter Bot, please refer to the Package development guide.
We can schedule tasks to be executed by the bot. One task can be scheduled multiple times, with variations on the parameters or schedule.
A scheduled task (or planned task) is unique to each Butter Bot instance, and tells the bot when and how to execute a task.
When a task is executed, that single unit of work is referred to as a job. A job can succeed or fail. This is where the real work happens.
Summary of how jobs are executed:
- Based on the scheduled tasks, their schedule expressions and their priorities, Butter Bot determines which task should be executed next.
- The task to be executed is instantiated as a new Job. The scheduled task data tells that job what task to execute, and how (parameters).
- The Executor reads the Job information, loads the specified task, and tries to execute that task.
- The result is passed back and the job has finished. The task loop restarts, and the next job is scheduled, and so forth.