app2

Asynchronus Alerts

This is a sample cmd2 application to showcase async rich console integration.

1. Cmd2 Thread registration
2. CommandSet interaction with main cmd2 instance
3. Rich console integration

Application Design

app.py is responsible for setting up all of the thread functionality and does not contain any user commands. While the first.py file houses the main featured logic for showing off the rich Live panel. It should be noted that the add and complete commands are superflous and not necessary for execution.

App.py

init

The scaffolding of the application is here in this function. We instantiate two class variables called active and completed. These queues hold data to be processed. We also create a stop_event that make sure the sim_thread stops gracefully. Finally we register the pre and postloop hooks.

sim_jobs

Sim jobs is a simulation function meant to fill the active queues with data for pretty viewing.

preloop_hook

Here we clear thread events (as a precausion), then create the sim_thread fo the based on the sim_jobs target function and finally start the thread.

postloop_hook

Gracefully shutdown the sim thread.

first.py

update_tables

This fuction is responsible for adding content to the rich.layout object via a rich.table interface. This function accepts two queues as input data originating from the main cmd2.Cmd instance.

App Commands

add

This command adds an arbitrary random word to the active job queue.

complete

This command will perform a complete action. For simulation purposes this means choosing a random active task and moving it to the completed queue.

show

This command is the main draw in this application. It creates a rich.console and rich.layout instance to render a rich.live screen. This creates a real time window that updates the layout table based on the queue input.

Notice that this command creates an infinite loop continually updating the layout until the user presses ctrl-c to exit. The keyboard interrupt is captured and handled gracefully so as to return execution focus the cmd2 application.

While this command executes a mode change it may not be necessary to have a live feed for information.

Requirements

• python >= 3.7
• rich >= 11.0.0