form_response.c

embedded_ethernet_complete_code_rabbit

// Web Form Demo.
// The Rabbit hosts a Web page containing a form that enables the user to
// enter two temperature values. When the user clicks the form's Submit button,
// the server receives the form data in an HTTP POST request and returns
// a response that redirects the user's browser to a page that acknowledges
// receiving the data.

// This file and other embedded Ethernet and Internet code and resources are
// available from www.Lvr.com.

// Select a network configuration from \lib\tcpip\tcp_config.lib
// in the Dynamic C distribution.
#define TCPCONFIG 1

// This program uses the ServerSpec structure in zserver.lib instead of the
// HttpSpec structure in http.lib. When HttpSpec is unneeded, the
// HTTP_NO_FLASHSPEC directive saves code space.
#define HTTP_NO_FLASHSPEC

// This buffer must be large enough to hold the name, value, and
// four additional bytes for each form variable.
#define FORM_ERROR_BUF 256

// The IP address clients will use to access the Web server.
// _PRIMARY_STATIC_IP is defined in tcp_config.lib.
#define REDIRECTHOST		_PRIMARY_STATIC_IP

// On receiving a form, the server redirects the client's browser to this URL.
#define FORM_RESPONSE_REDIRECTTO 		"http://" REDIRECTHOST "/formresponse.shtml"

// All C functions not declared as root go to extended memory.
#memmap xmem

// The dcrtcp library supports IP and TCP; the http library supports HTTP functions.
#use "dcrtcp.lib"
#use "http.lib"

// ximport loads files from the development PC into the Rabbit's flash memory.
// The symbol form_response_shtml is a macro that gives the file's length and physical address
// in the Rabbit's memory.

// YOU MUST CHANGE THIS PATH to match the location of the file in your system.
// OK to use forward or back slashes as separators.
#ximport "c:\embedded_ethernet_code\rabbit\formresponse\formresponse.shtml" form_response_shtml

// The HttpType structure names the handler to use with specific file extensions.
// The first item in the structure is the handler used when a request
// doesn't name a page or other resource.
// Requests with .html, extensions use the default handler, which
// serves the resource unchanged.
// A request for a resource with the .shtml extension uses shtml_handler, which
// handles requests for HTML pages that include SSI directives.
const HttpType http_types[] = {
   { ".html", "text/html", NULL},
   { ".shtml", "text/html", shtml_handler}
};

int form_response(HttpState* state) {

	// On receiving form data, the server returns a response that advises the
	// client's browser to request the resource named in FORM_RESPONSE_REDIRECTTO.
	cgi_redirectto(state, FORM_RESPONSE_REDIRECTTO );
	return 0;
} // end form_response

void main(void) {

	// Create the form and handle HTTP requests.

	// The FormVar array holds information about the form variables.
	FormVar setup[2];
	int var;
	int form;
	int function;

	// The form variables
   int maximum_temperature;
   int minimum_temperature;

	// Initialize the form variables.
	maximum_temperature = 80;
	minimum_temperature = 65;

	// Add the file containing the Web page that users see after submitting form data.
	sspec_addxmemfile("formresponse.shtml", form_response_shtml, SERVER_HTTP);

 	// Add the form to zserver's ServerSpec structure.
	// "setup.html" is the form's name.
	// setup is the FormVar array.
	// 2 is the number of entries in FormVar.
	// SERVER_HTTP specifies that the HTTP server can serve the form.
	form = sspec_addform("setup.html", setup, 2, SERVER_HTTP);

	// Set the title the form will display.
	sspec_setformtitle(form, "Temperature Alarm Setup");

   // Add a function to the list of objects the server recognizes.
   // "form_response" is the function's name.
   // form_response is a pointer to the function.
 	// SERVER_HTTP specifies that the HTTP server can access the function.
	function = sspec_addfunction("form_response", form_response, SERVER_HTTP);

   // Name the function the server will call after receiving form data from a client.
   // form is the array index returned by sspec_addform.
   // function is the value returned by sppec_addfunction.
	sspec_setformepilog(form, function);

	// Add a variable to the setup array.
	// "maximum_temperature" is the variable's name.
	// &maximum_temperature is the variable's location in memory.
	// INT16 is the variable type.
	// "%d" specifies the output format.
	// SERVER_HTTP specifies that the HTTP server can access the variable.
	var = sspec_addvariable("maximum_temperature", &maximum_temperature, INT16, "%d", SERVER_HTTP);

	// Add the variable (var) to the form (form).
	var = sspec_addfv(form, var);

	// Set the name the form will display for the variable.
	sspec_setfvname(form, var, "Maximum Temperature");

	// Set a variable description the form will display.
	sspec_setfvdesc(form, var, "Range 0 - 212 °F");

	// Set the maximum number of characters required to display the variable's value.
	sspec_setfvlen(form, var, 3);

	// Set the minimum and maximum allowed values of the variable.
	sspec_setfvrange(form, var, 0, 212);

	// Add the next variable and set it up for the form in the same way.
	var = sspec_addvariable("minimum_temperature", &minimum_temperature, INT16, "%d", SERVER_HTTP);
	var = sspec_addfv(form, var);
	sspec_setfvname(form, var, "Minimum Temperature");
	sspec_setfvdesc(form, var, "Range 0 - 212 °F");
	sspec_setfvlen(form, var, 3);
	sspec_setfvrange(form, var, 0, 212);

	// Enable requesting the form as "index.html" or as the default Web page ("/")
	// (as well as by the form's name "setup.html".
	sspec_aliasspec(form, "index.html");
	sspec_aliasspec(form, "/");

	// Initialize the TCP/IP stack and the web server.
   sock_init();
   http_init();

   // For improved performance, reserve port 80 for the Web server.
   tcp_reserveport(80);

   while (1) {

     	// Handle HTTP requests.
      http_handler();

      // Code to perform other tasks can go here.
   }

} // end main