Add flag to UnityWebRequest - rest

Question

I am trying to make a POST request to webpage that expects the --data field to be filled with some data to be processed. I'm pretty much trying to recreate this curl request, but with UnityWebRequest.
curl -X POST http://localhost:8000/clic/say?text=Make+the+gene+set --data '{"geneSetMembers":["UST"],"geneSetName":"selection0"}'
The UnityWebRequest documentation mentions that GET requests don't set any flags other than the url, but it's not clear if no other custom options exist for posts. Is there some way to format a WWWform or something that will hold the data such that the server will recognize it?
var form = new WWWForm();
// some way to plug in the jsonified data to the form
webRequest = UnityWebRequest.Post(url + route + to_say, form);
webRequest.downloadHandler = new DownloadHandlerBuffer();
webRequest.SetRequestHeader("Content-Type", "application/json");
webRequest.SendWebRequest();
// etc etc
I've tried just giving the form a field named "data" a la
form.AddField("data", "{ \"geneSetMembers\":[\"UST\"],\"geneSetName\":\"selection0\"}");
but the server does not like it, saying it "got error Invalid JSON literal name: data" So clearly that's the wrong syntax for it
EDIT: put lines in the same order they were in original code. Sorry, I have commented lines between them

Answer 1

Maybe your server doesn't like to receive the data as a field called data.
This ofcourse depends totally on the PHP code we don't see since you didn't share that part. b
But at least I can tell you that --data or also simply -d in curl refer to the entire data section and is not a field called data.
You could try to instead use a MultiPartFormDataSection passing just the data itself without a specific field name
var data = "{\"geneSetMembers\":[\"UST\"],\"geneSetName\":\"selection0\"}";
var form = new List<IMultiFormPart>{ new MultiPartFormDataSection(data) };
webRequest = UnityWebRequest.Post(url + route + to_say, form);
yield return webRequest.SendWebRequest();
which is now sent as content-type multipart/form-data though ...
Another alternative if your server really needs to receive a content-type application/json might be to "manually" compose the request e.g. like
var data = "{\"geneSetMembers\":[\"UST\"],\"geneSetName\":\"selection0\"}";
var request = new UnityWebRequest(url + route + to_say, "POST");
var bodyRaw = Encoding.UTF8.GetBytes(data);
request.uploadHandler = (UploadHandler) new UploadHandlerRaw(bodyRaw);
request.downloadHandler = (DownloadHandler) new DownloadHandlerBuffer();
request.SetRequestHeader("Content-Type", "application/json");
yield return request.SendWebRequest();
Though of you look close now this seems actually not to be the case since if you read the man curl
(HTTP) Sends the specified data in a POST request to the HTTP server, in the same way that a browser does when a user has filled in an HTML form and presses the submit button. This will cause curl to pass the data to the server using the content-type application/x-www-form-urlencoded
which is actually exactly the default content type used by the simple string version of UnityWebRequest.Post.
So thinking about it it should actually be as simple as using the pure string version of UnityWebRequest.Post:
var data = "{\"geneSetMembers\":[\"UST\"],\"geneSetName\":\"selection0\"}";
var request = UnityWebRequest.Post(url + route + to_say, data);
yield return request.SendWebRequest();