Function Job

info

CronFrame calls "function job" a function that is:

• defined inside the implementation block of a cron object
• annotated with the fn_job macro

Function jobs are related to the type rather than one of its possible instances.

The fn_job macro attibutes are identical to those of the cron macro:

• expr
  • the cron expression to use for the job's schedule
• timeout
  • the value in ms to use for the timeout which resets daily

Using the code of the cron object defined on the previous page, let us add a function job to it.

#[marco_use] extern crate cronframe;

use cronframe::CronFrame;

#[cron_obj]
struct WeatherJob;

#[cron_impl]
impl WeatherJob{
    #[fn_job(expr="0 0 0/12 * * *", timeout="0")]
    fn my_function_job(){
        println!("I run once every 12 hours every day.");
    }
}

Now that we have the job definition down, we need a framework instance where it can run, and to pass the job to it.

use cronframe::CronFrame;

fn main(){
    let cronframe = CronFrame::default();

    WeatherJob::cf_gather_fn(cronframe.clone());

    cronframe.run(); 
}

note

The function cf_gather_fn is injected inside cron objects by the macros and has effect only the first time it is called on a cron object type. It collects all functions jobs and passes them to a cronframe instance.

Dropping Function Jobs

Function jobs can be dropped by calling the cf_drop_fn associated function of the cron object:

WeatherJob::cf_drop_fn();