Tasks

What are Tasks for?

Tasks are a class based concept and hold the main functionality of bim2sim methods. They are implemented by inherting from the ITask (Interactive Task) class. Every task should have a specific goal to reach, like the loading of a IFC file, the export of a simulation model or the creation of a graph network to analyze the HVAC network topology. To keep the Tasks reusable and modular the goals of a task should not be too broad.

How are Tasks managed? The Playground

The tasks of a project run are managed by the Playground class. The Playground allows two ways to run tasks:

Default
Interactive

In default mode all default_tasks of the selected Plugin are executed in sequence. In interactive mode the user will be prompted will all possible tasks to execute and can choose one. After the task is done, the user gets again all possible tasks to execute next. To make sure that only tasks are executed in sequence which make sense and are implemented, every ITask has two tuples: reads and touches. reads defines which variables this task needs as input and touches defines what the task returns. Every task must also hold a run() method which the Playground runs.

Special variables for Tasks

As mentioned Tasks can have reads and touches, which define the input and output of every task. Two of those variables are:

elements
graph

elements holds a dictionary with all elements that are currently existing at runtime. graph holds the HvacGraph and is therefore only existing for the HVAC plugins. These two variables are stored and hold up2date inside the Playground instance. The graph variable is only available in HVAC related plugins.

Writing your own Task

To write your own task go create a new file inside bim2sim/task/<domain> and fill like this

from bim2sim.task.base import ITask


class AmazingTask(ITask):
   reads = (input_1, )
   touches = (output1,)
   
   def run(self, workflow):
      self.logger.info("Starting my amazing task")
      
      output_1 = self.amazing_function()
      
      return output_1
   
   
   def amazing_function(self):
      amazing_result = 42
      return amazing_result