Events

Selectable fires a number of custom events that the instance can listen for.

You can attach a number of custom event listeners using the on() method and pass the event name and a callback as the first two arguments:

const selectable = new Selectable();

selectable.on('event_name', myCallback);

Event listeners can be detached by calling the off() method with the same arguments:

selectable.off('event_name', myCallback);

Both the on() and off() methods function the same as the native addEventListener and removeEventListener methods respectively.

This means that in order to remove a custom event listener from the instance, you must pass the same function expression to the off() method as you did to the on() method - declared / anonymous functions cannot be removed.

Incorrect

selectable.on('end', function(e, selected, unselected) {
    counter.value = selected.length;
});

Correct

const myCallback = function(e, selected, unselected) {
    counter.value = selected.length;
};

// add the event listener
selectable.on('end', myCallback);

// remove the event listener
selectable.off('end', myCallback);

Listening for an event once

const myCallback = function(e, selected, unselected) {
    // Do something once

    // Remove the event listener
    this.off('select', myCallback);
};

// Add the event listener
selectable.on('select', myCallback);