server_http_ex.cpp

// The contents of this file are in the public domain. See LICENSE_FOR_EXAMPLE_PROGRAMS.txt
/*

    This example illustrates the use of the HTTP extension to the server object 
    from the dlib C++ Library.
    It creates a server that always responds with a simple HTML form.

    To view the page this program displays you should go to http://localhost:5000

*/

#include <iostream>
#include <sstream>
#include <string>
#include "dlib/server.h"
#include "dlib/ref.h" // for ref()

using namespace dlib;
using namespace std;

class web_server : public server::http_1a_c
{
    const std::string on_request ( 
        const incoming_things& incoming,
        outgoing_things& outgoing
    )
    {
        try
        {
            ostringstream sout;
            // We are going to send back a page that contains an HTML form with two text input fields.
            // One field called name.  The HTML form uses the post method but could also use the get
            // method (just change method='post' to method='get').
            sout << " <html> <body> "
                << "<form action='/form_handler' method='post'> "
                << "User Name: <input name='user' type='text'><br>  "
                << "User password: <input name='pass' type='text'> <input type='submit'> "
                << " </form>"; 

            // Write out some of the inputs to this request so that they show up on the
            // resulting web page.
            sout << "<br>  path = "         << incoming.path << endl;
            sout << "<br>  request_type = " << incoming.request_type << endl;
            sout << "<br>  content_type = " << incoming.content_type << endl;
            sout << "<br>  foreign_ip = "   << incoming.foreign_ip << endl;
            sout << "<br>  foreign_port = " << incoming.foreign_port << endl;
            sout << "<br>  local_ip = "     << incoming.local_ip << endl;
            sout << "<br>  local_port = "   << incoming.local_port << endl;
            sout << "<br>  body = \""         << incoming.body << "\"" << endl;


            // If this request is the result of the user submitting the form then echo back
            // the submission.
            if (incoming.path == "/form_handler")
            {
                sout << "<h2> Stuff from the query string </h2>" << endl;
                sout << "<br>  user = " << incoming.queries["user"] << endl;
                sout << "<br>  pass = " << incoming.queries["pass"] << endl;

                // save these form submissions as cookies.  
                outgoing.cookies["user"] = incoming.queries["user"];
                outgoing.cookies["pass"] = incoming.queries["pass"];
            }


            // Echo any cookies back to the client browser 
            sout << "<h2>Cookies we sent to the server</h2>";
            for ( key_value_map::const_iterator ci = incoming.cookies.begin(); ci != incoming.cookies.end(); ++ci )
            {
                sout << "<br/>" << ci->first << " = " << ci->second << endl;
            }

            sout << "<br/><br/>";

            sout << "<h2>HTTP Headers we sent to the server</h2>";
            // Echo out all the HTTP headers we received from the client web browser
            for ( key_value_map::const_iterator ci = incoming.headers.begin(); ci != incoming.headers.end(); ++ci )
            {
                sout << "<br/>" << ci->first << ": " << ci->second << endl;
            }


            sout << "</body> </html>";

            return sout.str();
        }
        catch (exception& e)
        {
            return e.what();
        }
    }

};

void thread(web_server& the_server)
{
    try
    {
        // Start the server.  start() blocks until the server is shutdown
        // by a call to clear()
        the_server.start();
    }
    catch (socket_error& e)
    {
        cout << "Socket error while starting server: " << e.what() << endl;
    }
    catch (exception& e)
    {
        cout << "Error while starting server: " << e.what() << endl;
    }
}

int main()
{
    try
    {
        // create an instance of our web server
        web_server our_web_server;

        // make it listen on port 5000
        our_web_server.set_listening_port(5000);

        // create a thread that will start the server.   The ref() here allows us to pass 
        // our_web_server into the threaded function by reference.
        thread_function t(thread, dlib::ref(our_web_server));

        cout << "Press enter to end this program" << endl;
        cin.get();
        // this will cause the server to shut down 
        our_web_server.clear();
    }
    catch (exception& e)
    {
        cout << e.what() << endl;
    }
}