author | Nicholas George <wirlaburla@worlio.com> |
Tue, 21 May 2024 01:09:12 -0500 | |
changeset 5915 | e7584fd5b191 |
parent 5903 | 694b62d8a82f |
permissions | -rw-r--r-- |
1807 | 1 |
--- |
5903
694b62d8a82f
various/README: Fix 'labels' metadata, should be a list
Kim Alvefur <zash@zash.se>
parents:
1807
diff
changeset
|
2 |
labels: |
694b62d8a82f
various/README: Fix 'labels' metadata, should be a list
Kim Alvefur <zash@zash.se>
parents:
1807
diff
changeset
|
3 |
- Stage-Beta |
1807 | 4 |
summary: Subscribe to pubsub nodes using the HTML5 EventSource API |
5 |
... |
|
6 |
||
7 |
Introduction |
|
8 |
------------ |
|
9 |
||
10 |
[Server-Sent Events](https://en.wikipedia.org/wiki/Server-sent_events) |
|
11 |
is a simple HTTP/line-based protocol supported in HTML5, making it easy |
|
12 |
to receive a stream of "events" in realtime using the Javascript |
|
13 |
[EventSource |
|
14 |
API](https://developer.mozilla.org/en-US/docs/Web/API/EventSource). |
|
15 |
||
16 |
EventSource is supported in [most modern |
|
17 |
browsers](http://caniuse.com/#feat=eventsource), and for the remainder |
|
18 |
there are 'polyfill' compatibility layers such as |
|
19 |
[EventSource.js](https://github.com/remy/polyfills/blob/master/EventSource.js) |
|
20 |
and [jquery.eventsource](https://github.com/rwldrn/jquery.eventsource). |
|
21 |
||
22 |
Details |
|
23 |
------- |
|
24 |
||
25 |
Subscribing to a node from Javascript is easy: |
|
26 |
||
27 |
var source = new EventSource('http://pubsub.example.org:5280/eventsource/mynode'); |
|
28 |
source.onmessage = function (event) { |
|
29 |
console.log(event.data); // Do whatever you want with the data here |
|
30 |
}; |
|
31 |
||
32 |
### Cross-domain issues |
|
33 |
||
34 |
The same cross-domain restrictions apply to EventSource that apply to |
|
35 |
BOSH, and support for CORS is not clearly standardized yet. You may want |
|
36 |
to proxy connections through your web server for this reason. See [BOSH: |
|
37 |
Cross-domain |
|
38 |
issues](https://prosody.im/doc/setting_up_bosh#proxying_requests) for |
|
39 |
more information. |
|
40 |
||
41 |
Configuration |
|
42 |
------------- |
|
43 |
||
44 |
There is no special configuration for this module. Simply load it onto a |
|
45 |
pubsub component like so: |
|
46 |
||
47 |
Component "pubsub.example.org" "pubsub" |
|
48 |
modules_enabled = { "pubsub_eventsource" } |
|
49 |
||
50 |
As it uses HTTP to serve the event streams, you can use Prosody's |
|
51 |
standard [HTTP configuration options](https://prosody.im/doc/http) to |
|
52 |
control how/where the streams are served. |
|
53 |
||
54 |
**Note about URLs:** It is important to get the event streams from the |
|
55 |
correct hostname (that of the pubsub host). An example stream URL is |
|
56 |
`http://pubsub.example.org:5280/eventsource/mynode`. If you need to |
|
57 |
access the streams using another hostname (e.g. `example.org`) you can |
|
58 |
use the `http_host` option under the Component, e.g. |
|
59 |
`http_host = "example.org"`. For more information see the ['Virtual |
|
60 |
Hosts'](https://prosody.im/doc/http#virtual_hosts) section of our HTTP |
|
61 |
documentation. |
|
62 |
||
63 |
Compatibility |
|
64 |
------------- |
|
65 |
||
66 |
------- -------------- |
|
67 |
0.9 Works |
|
68 |
0.8 Doesn't work |
|
69 |
Trunk Works |
|
70 |
------- -------------- |