-
Notifications
You must be signed in to change notification settings - Fork 0
/
chapter17.js
76 lines (68 loc) · 1.78 KB
/
chapter17.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
// Your code here.
function getWithAccept(accept) {
var req = new XMLHttpRequest();
req.open("GET", "http://eloquentjavascript.net/author", true);
req.setRequestHeader("Accept", accept);
console.log(req);
req.addEventListener("load", function() {
console.log(req.status);
console.log(req.responseText);
});
req.send(null);
}
getWithAccept("application/rainbows");
//Promise
function all(promises) {
return new Promise(function(success, fail) {
// Your code here.
var result = [];
var noop = "noop";
if (promises.length == 0) {
success(result);
}
for (var i = 0; i < promises.length; i ++) {
result.push(noop);
}
function inArray(noop, array) {
return array.indexOf(noop) == -1
}
promises.forEach(function(promise) {
promise.then(function(value) {
var index = promises.indexOf(promise);
result[index] = value;
if (inArray(noop, result)) {
success(result);
}
}).catch(function(error) {
fail(error);
});
});
})
}
// Test code.
all([]).then(function(array) {
console.log("This should be []:", array);
});
function soon(val) {
return new Promise(function(success) {
setTimeout(function() { success(val); },
Math.random() * 500);
});
}
all([soon(1)]).then(function(array) {
console.log("This should be [1]:", array);
});
all([soon(1), soon(2), soon(3)]).then(function(array) {
console.log("This should be [1, 2, 3]:", array);
});
function fail() {
return new Promise(function(success, fail) {
fail(new Error("boom"));
});
}
all([soon(1), fail(), soon(3)]).then(function(array) {
console.log("We should not get here");
}, function(error) {
if (error.message != "boom")
console.log("Unexpected failure:", error);
});