How can I properly send a batch request using UCWA 2.0? - ucwa

Question

I am writing a UCWA application to receive each user's presence and note. At the moment, I subscribe to all my desired contacts, I initiate my event stream and then I receive around 200 events. I loop through them to receive my contacts presence and notes using a for loop, meaning I send around 100 requests, which, according to Microsoft documentation, can drain battery on mobile devices or impact performance. I would like to use batching to fix this problem.
onEvent(events) {
for (var i in events) {
const event = events[i]
switch (event.link.rel) { // 250 events filtered down to around 100
case 'contactPresence':
case 'presence':
this.setPresence(event.link.href, this.getUser(event))
break
case 'contactNote':
case 'note':
this.setNote(event.link.href, this.getUser(event))
break
case 'presenceSubscription':
...
break
}
}
}
After searching through Microsoft's documentation, I couldn't find any help on how to format a batch request. I tried following one of the examples provided, but I received a 400 error like this:
{
"code":"BadRequest",
"message":"Your request couldn\u0027t be completed."
}
Eventually I tried sending a batch following formatting that I've seen from this post, like so:
batch() {
const boundary = Date.now()
fetch(this.hub + this.response._links.batch.href, {
method: 'POST',
headers: {
Accept: 'multipart/batching',
Authorization: `Bearer ${this.token}`,
'Content-Type': `multipart/batching;boundary=${boundary}`
},
body: `--${boundary}\r\nContent-Type: application/http; msgtype=request\r\n\r\nGET ${this.response._links.self.href + '/people/contacts'} HTTP/1.1\r\nAccept: application/json\r\nHost: ${this.hub}\r\n\r\n--${boundary}--`
}).then(r => r.json())
.then(data => console.log(data))
}
Here is the request payload:
--1557482296198
Content-Type: application/http; msgtype=request
GET /ucwa/oauth/v1/applications/103357029549/people/contacts HTTP/1.1
Accept: application/json
Host: https://webpoolam41e02.infra.lync.com
--1557482296198--
This returns a 500 error, however, like this:
{
"code":"ServiceFailure","message":"Your request couldn\u0027t be completed.",
"debugInfo":{
"errorReportId":"8d6499597a54443495627bd2b3e3c5b6"
},
"reasonId":"1000005"
}
I have spent a long time searching for an answer but I cannot find one that works.
Does anyone know how to properly format a batch request?

Answer 1

I have found an answer to my own question. It turns out that the final batch requires 3 line breaks:
\r\n\r\n\r\n
Rather than 2:
\r\n\r\n