Cannot PUT a multipart/form-data content

[dariok]

When trying to PUT a multipart/form-data body, roaster will fail with an error due to missing properties, even though they are present in the body as defined in the schema.

The reason is that eXist only auto-parses multipart content in POST requests, not when they are sent by e.g. a PUT or a PATCH request. Also, request:is-multipart() is always false() in requests other than POST, even though the Content-Type is actually set as multipart-dorm-data.

The workaround is to pre-parse the multipart content and add the parameters in the controller when forwarding to roaster.

Roaster should pick this up by not assuming to find the contents of a multipart requests by a call to request:get-parameter(). We need additional handling at

roaster/content/body.xqm

Line 215 in c1e9ca5

if (exists($schema))

like

if ( exists($schema) and request:is-multipart() ) then
   …
else if ( starts-with(request:get-header('Content-Type'), 'multipart/form-data') ) then
  let $parsed := someModule:parse-multipart(request:get-data(), request:get-header('Content-Type'))
  map:merge(
            for-each(
                body:ensure-required-properties(
                    map:keys($parsed), $schema?required?*),
                body:validate-value($schema)))
else …

and a function that produces a map out of the request data.

(I’m assuming that the parse-multipart() function returns a map of the parts, as in https://github.com/dariok/wdbplus/blob/96f2dac861834562b63364c8ebedcfd127a75172/edoc/modules/wdb-request.xqm )

[dariok]

The workaround will not be a complete fill as eXist does not allow adding maps as a parameter.
Hence, it is not possible to create, from within controller.xql, a structure similar to the one returned by eXist’s auto-parsing.

Ideally, eXist should parse any request body that is multipart/form-data, independent of the method. Nothing in the specs prevents a multipart body in PUT or PATCH requests anyway.

For the time being, the addition in body.xqm as outlined above should be used to allow multipart uploads (and hence, uniform handling of POST and PUT)