My MochiWeb Faq

I recently started using the mochiweb web server, it is a very nicely designed library, however it does have scarce (non existent) documentation, the code is readable enough to extract what you need, but I just thought I would make a quick FAQ to save some time. I will just be adding these as I go along, and they aren"t necessarily right so feel free to correct.

How do I get at POST / GET data?

Req:parse_qs() and Req:parse_post() to get a proplist for each, Req:recv_body() will give you back the raw POST data in binary.

How do I get the IP / Port of the request?

Req:get_header_value("host") will give you back this as a string, not sure how it handles behind a revproxy for now, will update

How do I detect the client disconnecting (long polling)

Just to stop those nasty messages when the client goes to another page, I found the answer here. Listing the code because its handy.

%% mochiwebs callback loop
loop(Req) ->
    %% parse request or what ever
    %% assume we send out something, waiting for response here
    case wait_data(Req) of
        {error, socket_closed} ->
             %% socket has closed, need not response anymore
             ok;
        {error, timeout} ->
             %% perform timeout response, let them call again
             response(Req, timeout);
        {ok, Data} ->
             %% perform data response, and, let them call again
             response(Req, Data)
    end.

wait_data(Req) ->
    Socket = Req:get(socket),
    inet:setopts(Socket, [{active, once}]),
    receive
         {tcp_closed, Socket} ->
             {error, socket_closed};
         Data ->
             {ok, Data}
    after
         &TimeOut ->
             {error, timeout}
    end. 

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