是否可以从浏览器创建websockets订阅？我们使用分支功能/ 1181_websockets分支，git版本 5ca6770aa401b52a31293fdcef4a9743fb1de2c4 。
我们让PoC尝试通过websockets订阅浏览器。我们尝试将浏览器中运行的一些JS代码连接到订阅URL。建立连接，但是当通过套接字从客户端发送数据时，orion崩溃了。这个用例是否受支持？你有一个有效的例子吗？ JS代码：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<button id="send" type="button" name="button">send</button>
<script type="text/javascript">
var payload = `{"description": "One subscription to rule them all",
"subject": {
"entities": [{
"idPattern": ".*",
"type": "Room"
}],
"condition": {
"attrs": ["temperature"],
"expression": {
"q": "temperature>40"
}
}
},
"expires": "2016-04-05T14:00:00.00Z",
"throttling": 5
}`;
var ws = new WebSocket('ws://orion-url:9010/v2/subscriptions', 'ngsiv2-json');
var button = document.getElementById('send');
button.addEventListener('click', function(event) {
ws.send(payload)
});
</script>
</body>
</html>
作为替代方案，我们尝试使用REST API创建订阅，要求Orion通过websockets通知我们。我们发布了以下JSON：
{
"description": "One subscription to rule them all",
"subject": {
"entities": [
{
"idPattern": ".*",
"type": "Room"
}
],
"condition": {
"attributes": [
"temperature"
],
"expression": {
"q": "temperature>40"
}
}
},
"notification": {
"callback": "ws://my-websocket-listener:8081"
},
"expires": "2016-04-05T14:00:00.00Z",
"throttling": 5
}
订阅过程失败，Orion返回422状态代码，其中包含以下消息：
{
"error": "BadRequest",
"description": "Invalid URL"
}
我们在订阅请求中是否有任何错误？这个用例是否受支持？
谢谢！
答案 0 :(得分：2)
目前您可以订阅浏览器并接收通知，限制如下：
这里我以一些代码为例，您只需要通过Orion的URL更改网址
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<script type="text/javascript">
$(function() {
window.WebSocket = window.WebSocket || window.MozWebSocket;
// Here change with your URL
var websocket = new WebSocket('ws://127.0.0.1:9010', 'ngsiv2-json');
websocket.onopen = function () {
$('h1').css('color', 'green');
};
websocket.onerror = function () {
$('h1').css('color', 'red');
};
websocket.onmessage = function (message) {
console.log(message.data);
console.log(message);
$('div').append(message.data + '<br/>');
};
$('#send').click(function(e) {
e.preventDefault();
if ($('#txt').val().length > 0)
{
websocket.send($('#txt').val());
$('#txt').val('');
}
});
$('#new').click(function(e) {
e.preventDefault();
var msg = "{\"verb\":\"POST\",\"url\":\"/v2/entities\", \
\"params\":{\"options\":\"keyValues\"}, \
\"payload\":{\"type\":\"1\",\"id\":\"1\",\"temp\":1}}";
$('#txt').val(JSON.stringify(JSON.parse(msg), null, 2));
});
$('#upd').click(function(e) {
e.preventDefault();
var msg = "{\"verb\":\"POST\",\"url\":\"/v2/entities/1\", \
\"params\":{\"options\":\"keyValues\"},\"payload\":{\"temp\": 1}}";
$('#txt').val(JSON.stringify(JSON.parse(msg), null, 2));
});
$('#get').click(function(e) {
e.preventDefault();
var msg = "{\"verb\":\"GET\",\"url\":\"/v2/entities/1\"}";
$('#txt').val(JSON.stringify(JSON.parse(msg), null, 2));
});
$('#del').click(function(e) {
e.preventDefault();
var msg = "{\"verb\":\"DELETE\",\"url\":\"/v2/entities/1\"}";
$('#txt').val(JSON.stringify(JSON.parse(msg), null, 2));
});
$('#sub').click(function(e) {
e.preventDefault();
var msg = "{\"verb\":\"POST\",\"url\":\"/v2/subscriptions\", \
\"payload\":{\"description\":\"My subscription\", \
\"subject\":{\"entities\":[{\"id\":\"1\",\"type\":\"1\"}], \
\"condition\":{\"attributes\":[\"temp\"],\"expression\":{\"q\":\"temp>40\"}}}, \
\"notification\":{\"callback\":\"ws://\",\"attributes\":[\"temp\"], \
\"throttling\":5},\"expires\":\"2017-04-05T14:00:00.00Z\"}}";
$('#txt').val(JSON.stringify(JSON.parse(msg), null, 2));
});
});
</script>
</head>
<body>
<h1>WebSockets test</h1>
<form>
<table border="0">
<tr>
<td colspan="2">
<textarea rows="35" cols="70" id="txt"></textarea>
</td>
</tr>
<tr>
<td>
<button id="new">New</button>
<button id="upd">Update</button>
<button id="get">Show</button>
<button id="del">Delete</button>
<button id="sub">Subcription</button>
</td>
<td align="right">
<button id="send">Send</button>
</td>
</tr>
</table>
</form>
<br/>
<p>Server:</p>
<div></div>
</body>
</html>
我不是JS专家......但是当我在Orion的WS工作时，这对我来说是一项测试
干杯