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
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
// import async to make control flow simplier
var async = require('async');
// import the rest of the normal stuff
var mongoose = require('../../lib');
require('./person.js')();
var Person = mongoose.model('Person');
// define some dummy data
var data = [
{
name: 'bill',
age: 25,
birthday: new Date().setFullYear((new Date().getFullYear() - 25))
},
{
name: 'mary',
age: 30,
birthday: new Date().setFullYear((new Date().getFullYear() - 30))
},
{
name: 'bob',
age: 21,
birthday: new Date().setFullYear((new Date().getFullYear() - 21))
},
{
name: 'lilly',
age: 26,
birthday: new Date().setFullYear((new Date().getFullYear() - 26))
},
{
name: 'alucard',
age: 1000,
birthday: new Date().setFullYear((new Date().getFullYear() - 1000))
}
];
mongoose.connect('mongodb://localhost/persons', function(err) {
if (err) {
throw err;
}
// create all of the dummy people
async.each(data, function(item, cb) {
Person.create(item, cb);
}, function(err) {
if (err) {
// handle error
}
// create a promise (get one from the query builder)
var prom = Person.find({age: {$lt: 1000}}).exec();
// add a callback on the promise. This will be called on both error and
// complete
prom.addBack(function() {
console.log('completed');
});
// add a callback that is only called on complete (success) events
prom.addCallback(function() {
console.log('Successful Completion!');
});
// add a callback that is only called on err (rejected) events
prom.addErrback(function() {
console.log('Fail Boat');
});
// you can chain things just like in the promise/A+ spec
// note: each then() is returning a new promise, so the above methods
// that we defined will all fire after the initial promise is fulfilled
prom.then(function(people) {
// just getting the stuff for the next query
var ids = people.map(function(p) {
return p._id;
});
// return the next promise
return Person.find({_id: {$nin: ids}}).exec();
}).then(function(oldest) {
console.log('Oldest person is: %s', oldest);
}).then(cleanup);
});
});
function cleanup() {
Person.remove(function() {
mongoose.disconnect();
});
}
|
