Async iterators are [an open issue on the Nim
github](https://github.com/nim-lang/Nim/issues/6576), so your concern is
normal. Here is how you would do it in a template:
template forStream(req: Request, chunkSize: int, body: untyped): untyped
{.dirty.} = # dirty means all the variable names in the template are usable in
the block
var remainder = req.contentLength
while true:
let data = await req.client.recv(min(remainder, chunkSize))
body
remainder -= len(data)
if remainder == 0:
break
proc cb(req: Request) {.async.} =
var
contentLength = 0
bodyLength = 0
if req.reqMethod == HttpPost:
contentLength = req.headers["Content-length"].parseInt
if stream:
req.forStream(8*1024):
echo data
bodyLength += len(data)
else:
bodyLength += req.body.len
await req.respond(Http200, htmlpage(contentLength, bodyLength))
Run
If you want the variable name to be customizable and not just data, you can use
identifier construction in templates:
template forStream(req: Request, chunkSize: int, name, body: untyped):
untyped =
var remainder = req.contentLength
while true:
let `name` = await req.client.recv(min(remainder, chunkSize))
body
remainder -= len(`name`)
if remainder == 0:
break
req.forStream(8*1024, d):
echo d
Run
