CMSC141_LAB10_XUAN_MA/event.js at main · XuanMabard/CMSC141_LAB10_XUAN_MA · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
module.exports = event

function event() {
    const listeners = []
    return {
        _listeners: listeners,
        addListener: (l => {
            const found = listeners.find(l2 => l === l2)
            if (found === undefined)
                listeners.push(l)
            else
                console.log(`listener already in event: ${l}`);
        }),
        removeListener: (l => {
            const found = listeners.find(l2 => l === l2)
            if (found !== undefined)
                listeners.splice(listeners.indexOf(l), 1)
            else
                console.log(`listener not found: ${l}`);
        }),
        invoke: (args => listeners.forEach(l => l(args)))
    }
}