Simple JSON request with cURL to Mochiweb - json

Question

I have a very simple 'hello world' Mochiweb server (I just started my introduction into it), which takes a JSON request and sends it back:
'POST' ->
case Path of
"dummy" ->
Data = Req:parse_post(),
Json = proplists:get_value("json", Data),
Struct = mochijson2:decode(Json),
Action_value = struct:get_value(<<"action">>, Struct),
Action = list_to_atom(binary_to_list(A)),
Result = [got_json_request, Action],
DataOut = mochijson2:encode(Result),
Req:ok({"application/json",[],[Result]});
The thing is that when I try to make a request to it with cURL it fails:
curl -i -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"action":"dummy"}' http://localhost:8080/dummy
The Mochiweb log is quite difficult to read, but as I understand the error happens at this line:
Json = proplists:get_value("json", Data)
I have put a couple of io:formats in the code and found out that both Data and Json variables are [] after I make a request with cURL.
On the other hand, when I do a very simple request with cURL:
curl -d '{"action":"dummy"}' http://localhost:8080/dummy
both Data and Json are [{"{\"action\":\"dummy\"}",[]}], but in that case the line Struct = mochijson2:decode(Json) fails.
For some strange reason Mochiweb does not see the JSON data in the POST request in case the header has the "application/json" value.
So, the question is: How do I make a correct POST request with JSON data to a Mochiweb server?
EDIT: Json variable has the undefined value.

Answer 1

Try something along the lines of
Data = Req:recv_body(),
Json = mochijson2:decode(Data),
...
You should at least ensure method post and the content type ahead of this.

Answer 2

This is not about POST nor get.
It's about how you post your data to send to your server
When you send a json data to server, you need to make it as key=value
curl -d "key=value" "http://your.domain.com/path"
Therefore, if you want to post json as '{"action":"dummy"}', for GET request
curl -d "json='{\"action\":\"dummy\"}'" http://localhost:8080/dummy
For POST request as a file,
curl -F "json=#filename.json" http://localhost:8080/dummy
of course, when you send as a file, you need to read the posted file from the server side.