Hi Bridger,

As your query will either return an empty sequence (in the case of success) or a string (in the case of an error), you’ll need to use xs:string? as return type:

declare function local:grab( $url as xs:string, $path as xs:string, $fname as xs:string ) as xs:string? { ...

Hope this helps, cheers, Christian

let $req := http:send-request(<http:request method="get"/>, $url) return if (head($req)/@status = "200") then file:write($path || $fname, tail($req), map { "method": "xml" }) else ("something went wrong!") };

but I've noticed that in version 9.4.3 this returns an  XPTY error:
Stopped at /home/bridger/bin/basex-src/basex-943-xpty0004-error.xq, 1/18:
[XPTY0004] Cannot promote xs:string* to document-node(): (let $req_7 := http:send-request(<http:request method="get"/>, "https://dpla.lib.utk.edu/repox/OAIHa....

While this could be a bug, should I be writing this kind of local function differently? Or could I improve my typing on it?

Thanks very much for any advice or insights you can provide.
Best,
Bridger

And naturally I forgot to mention... On Sun, Oct 11, 2020 at 3:49 PM Bridger Dyson-Smith bdysonsmith@gmail.com wrote:

Hi all -

I'm accustomed to writing something like the following:

declare function local:grab(
  $url as xs:string,
  $path as xs:string,
  $fname as xs:string
) as document-node() {
  let $req := http:send-request(<http:request method="get"/>, $url)
  return
    if (head($req)/@status = "200")
    then file:write($path || $fname, tail($req), map { "method": "xml" })
    else ("something went wrong!")
};

but I've noticed that in version 9.4.3 this returns an XPTY error: Stopped at /home/bridger/bin/basex-src/basex-943-xpty0004-error.xq, 1/18: [XPTY0004] Cannot promote xs:string* to document-node(): (let $req_7 := http:send-request(<http:request method="get"/>, " https://dpla.lib.utk.edu/repox/OAIHa....

that despite the error, the correct response is written to the filepath

specified.

While this could be a bug, should I be writing this kind of local function

differently? Or could I improve my typing on it?

Thanks very much for any advice or insights you can provide.

Apologies for the omission!

Best, Bridger