Codice PHP:
<script type="text/javascript">
// global xmlhttprequest object
var xmlHttp = false;
/** AJAX functions **/
// constants
var REQUEST_GET = 0;
var REQEST_POST = 2;
var REQUEST_HEAD = 1;
var REQUEST_XML = 3;
/**
* instantiates a new xmlhttprequest object
*
* @return xmlhttprequest object or false
*/
function getXMLRequester( )
{
var xmlHttp = false;
// try to create a new instance of the xmlhttprequest object
try
{
// Internet Explorer
if( window.ActiveXObject )
{
for( var i = 5; i; i-- )
{
try
{
// loading of a newer version of msxml dll (msxml3 - msxml5) failed
// use fallback solution
// old style msxml version independent, deprecated
if( i == 2 )
{
xmlHttp = new ActiveXObject( "Microsoft.XMLHTTP" );
}
// try to use the latest msxml dll
else
{
xmlHttp = new ActiveXObject( "Msxml2.XMLHTTP." + i + ".0" );
}
break;
}
catch( excNotLoadable )
{
xmlHttp = false;
}
}
}
// Mozilla, Opera und Safari
else if( window.XMLHttpRequest )
{
xmlHttp = new XMLHttpRequest();
}
}
// loading of xmlhttp object failed
catch( excNotLoadable )
{
xmlHttp = false;
}
return xmlHttp ;
}
/**
* sends a http request to server
*
* @param strSource, String, datasource on server, e.g. data.php
*
* @param strData, String, data to send to server, optionally
*
* @param intType, Integer,request type, possible values: REQUEST_GET, REQUEST_POST, REQUEST_XML, REQUEST_HEAD default REQUEST_GET
*
* @param strData, Integer, ID of this request, will be given to registered event handler onreadystatechange', optionally
*
* @return String, request data or data source
*/
function sendRequest( strSource, strData, intType, intID )
{
if( !strData )
strData = '';
// default type (0 = GET, 1 = xml, 2 = POST )
if( isNaN( intType ) )
intType = 0; // GET
// previous request not finished yet, abort it before sending a new request
if( xmlHttp && xmlHttp.readyState )
{
xmlHttp.abort( );
xmlHttp = false;
}
// create a new instance of xmlhttprequest object
// if it fails, return
if( !xmlHttp )
{
xmlHttp = getXMLRequester( );
if( !xmlHttp )
return;
}
// parse query string
if( intType != 1 && ( strData && strData.substr( 0, 1 ) == '&' || strData.substr( 0, 1 ) == '?' ) )
strData = strData.substring( 1, strData.length );
// data to send using POST
var dataReturn = strData ? strData : strSource;
switch( intType )
{
case 1: // xml
strData = "xml=" + strData;
case 2: // POST
// open the connection
xmlHttp.open( "POST", strSource, true );
xmlHttp.setRequestHeader( 'Content-Type', 'application/x-www-form-urlencoded' );
xmlHttp.setRequestHeader( 'Content-length', strData.length );
break;
case 3: // HEAD
// open the connection
xmlHttp.open( "HEAD", strSource, true );
strData = null;
break;
default: // GET
// open the connection
var strDataFile = strSource + (strData ? '?' + strData : '' );
xmlHttp.open( "GET", strDataFile, true );
strData = null;
}
// set onload data event-handler
xmlHttp.onreadystatechange = new Function( "", "processResponse(" + intID + ")" ); ;
// send request to server
xmlHttp.send( strData ); // param = POST data
return dataReturn;
}
/**
* process the response data from server
*
* @param intID, Integer, ID of this response
*/
function processResponse( intID )
{
// status 0 UNINITIALIZED open() has not been called yet.
// status 1 LOADING send() has not been called yet.
// status 2 LOADED send() has been called, headers and status are available.
// status 3 INTERACTIVE Downloading, responseText holds the partial data.
// status 4 COMPLETED Finished with all operations.
switch( xmlHttp.readyState )
{
// uninitialized
case 0:
// loading
case 1:
// loaded
case 2:
// interactive
case 3:
break;
// complete
case 4:
// check http status
if( xmlHttp.status == 200 ) // success
{
processData( xmlHttp, intID );
}
// loading not successfull, e.g. page not available
else
{
if( window.handleAJAXError )
handleAJAXError( xmlHttp, intID );
else
alert( "ERROR\n HTTP status = " + xmlHttp.status + "\n" + xmlHttp.statusText ) ;
}
}
}
/** End AJAX functions **/
/** real application functions **/
// process data from server
function processData( xmlHttp, intID )
{
// process text data
updateMenu( xmlHttp.responseText );
}
function getData( objSelect )
{
var strURL = "index.php?id=7087&languageid=1&cityID=" + objSelect.options[ objSelect.options.selectedIndex ].value;
sendRequest( strURL );
}
// process data from server, updates second select menu
// data from server comes with this format: value=data&value=data...
function updateMenu( strData )
{
if( strData )
{
var arrOptions = strData.split( '&' );
var arrOption;
var objSelect = document.getElementById( "select2" );
objSelect.options.length = 0;
for( var i = 0; i < arrOptions.length; i++ )
{
arrOption = arrOptions[ i ].split( '=' );
objSelect.options[ i ] = new Option( arrOption[ 1 ], arrOption[ 0 ], false, false );
}
document.getElementById( "seldiv2" ).style.visibility = "visible";
}
}
function showInput( )
{
if (select2.value == 0)
{
document.getElementById( "inputdiv1" ).style.visibility = "visible";
}
else
{
document.getElementById( "inputdiv1" ).style.visibility = "hidden";
input1.value = '';
}
}
</script>
