google app engine problem of post method in flash and php - php

Question

I'm trying to deploy flash files embeded in html to the google app engine.
Flash(action script 2.0) uses "post" method to send hostname and get its ip address through php function gethostbyname().
In fact, I know google app engine does not support php.
So I tried to use another way to deploy ipPHP.php in other free web server and only flash file in google app engine.
But it does not work and I can not know why.
Can you give me a tip for this problem ?
--------------domaintoip.fla ---------------------
result_lv = new LoadVars();
result_lv.byname = _root.domainnm;
trace("Sending... " + result_lv.byname);
result_lv.onLoad = function (success)
{
if (success)
{
_root.ip = unescape(this.result);
trace("Return value from the PHP : " + unescape(this));
if(_root.ip.length==5){
_root.flag=1;
}
else{
var mystring=_root.ip;
arr=mystring.split(".");
_root.ipby1=arr[0];
_root.ipby2=arr[1];
_root.ipby3=arr[2];
if(arr[3].length==15)
{
_root.ipby4=arr[3].substr(0,3);
}
if(arr[3].length==14)
{
_root.ipby4=arr[3].substr(0,2);
}
if(arr[3].length==13)
{
_root.ipby4=arr[3].substr(0,1);
}
_root.flag=0;
}
}
else
{
trace("Cannot call the PHP file...");
_root.flag=1;
}
}
result_lv.sendAndLoad("http://anotherserver../ipPHP.php", result_lv, "POST");
-------------- ipPHP.php ---------------------
<?php
$Var1 = $_POST['byname'];
$rtnValue = gethostbyname(trim($Var1));
if(ip2long($rtnValue) == -1 || $rtnValue == $Var1 ) {
$rtnValue =0;
echo (result=$rtnValue");
}
else {
echo("result=$rtnValue");
}
?>

Answer 1

If your site is hosted on the app engine, you cannot make AJAX calls to a host other than the app engine due to the Same Origin Policy. This limitation is generally true, and is not specific to the app engine. To generalize, for any web page hosted at domain X, that web page cannot make AJAX requests to domain Y.
You actually are experiencing a much more fundamental problem: When the only tool you have is a hammer, every problem looks like a nail. In fact, you can trivially handle POST requests with the app engine using the doPost method, and you can very easily get the client's IP address in a very similar manner as your PHP script. There is absolutely no reason to use PHP here; you've set up a completely new server to call one built-in PHP function? That's insane; you can do the exact same thing with an app engine servlet.
Consider the following code:
public void doPost(HttpServletRequest request,HttpServletResponse response) {
/* get "byname" param, equivalent to $POST['byname'] */
String rtnValue = request.getParameter("byname");
/* TODO: your if statements and other logic */
/* print response to client, equivalent to your echo statement */
response.getWriter().print("result=" + rtnValue);
}