Add listener.js

This commit is contained in:
Talia 2021-06-23 16:04:33 +02:00
parent 3421f340f7
commit 5cf868a904

25
listener.js Normal file
View file

@ -0,0 +1,25 @@
export const listener = (target={}) => {
let callbacks = new Map()
function listen(prop, callback) {
if ("object" == typeof prop && "forEach" in prop)
prop.forEach(prop => this.listen(prop, callback))
else if (callback)
callbacks.set(prop, callback)
else
callbacks.delete(prop)
}
let proxy = new Proxy(target, {
set: (target, prop, value) => {
if (callbacks.has("*")) callbacks.get("*")(value, prop)
if (callbacks.has(prop)) callbacks.get(prop)(value, prop)
return Reflect.set(target, prop, value)
},
get: (target, prop, value) => {
if (prop == "listen")
return listen
else
return Reflect.get(target, prop)
}
})
return proxy
}