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Drop task

This is the way to create a droppable task.

This will cancel any new instances of the task. You can also provide a max that will only drop the task instances if the threshold is exceeded.

To specify a task as droppable, you can either use the dot notation or the options notation.

import { task } from '@sheepdog/vanilla';
const dropTask = task.drop(async () => {
// your code
});

This is how you can specify the maximum number of concurrent instances. The default is 1, here we’re setting it to 5.

import { task } from '@sheepdog/vanilla';
const dropTask = task.drop(
async () => {
// your code
},
{ max: 5 },
);

The return value of the task function will be an object with getters where you can access state from all the instances running and eventually cancel them with cancelAll.

While defining a task, if the function that you pass in has some arguments, those will be required by the perform function (and it will be strongly typed too).

import { task } from '@sheepdog/vanilla';
const dropTask = task.drop(async (id: string) => {
// your code
});
button.addEventListener('click', () => {
dropTask.perform('42');
});

If you return something from your task you can access the return value by awaiting the perform function.

import { task } from '@sheepdog/vanilla';
const dropTask = task.drop(async () => {
return 42;
});
button.addEventListener('click', () => {
const number = await dropTask.perform();
console.log(number); // 42
});

If you don’t await the perform function, then you’ll get back the task instance that you can use either to cancel it or to get its current state. The TaskInstance is also an object with getters you can access the current value with instance.value or register events on it with instance.on.

import { task } from '@sheepdog/vanilla';
const dropTask = task.drop(async () => {
// your code
});
button.addEventListener('click', () => {
const lastRun = dropTask.perform();
lastRun.on('success', () => {
console.log(lastRun.value);
});
lastRun.cancel();
});