Source: Kyle Simpson, You Don't Know JS: Async & Performance
This is a model for handling asynchrony when two concurrent events need to interact. Both of the callbacks will set values, but only the second callback to fire will also invoke baz().
const http = require('http');
let url = 'http://www.example.com';
const myGetAsync = f => {
http.get(url, response => {
console.log(response.statusCode);
f();
}).on('error', e => console.log(e.message));
};
let a, b;
const foo = () => {
a = 0;
if (a !== undefined && b !== undefined) baz();
};
const bar = () => {
b = 1;
if (a !== undefined && b !== undefined) baz();
};
const baz = () => console.log([a, b]);
myGetAsync(foo);
myGetAsync(bar);
no comments
sign in to comment