// start ajaxrequest.js // Following is a javascript function that makes a httprequest - AJAX. This is the AJAX bit and all that is needed in that manner. // Only in this one we won't be using XML in our response, we will accept and handle // pure text and html and display this response directly to the user within the // desired
'; // or use an animated gif instead: var MyHttpLoading = '
';
var ErrorMSG = 'Sorry - No XMLHTTP support in your browser, buy a newspaper instead';
if(check_div)
{
var check_value = document.getElementById(check_div).value;
}
else
{
var check_value = '';
}
if(window.XMLHttpRequest) // client use Firefox, Opera etc - Non Microsoft product
{
try
{
MyHttpRequest = new XMLHttpRequest();
}
catch(e)
{
MyHttpRequest = false;
}
}
else if(window.ActiveXObject) // client use Internet Explorer
{
try
{
MyHttpRequest = new ActiveXObject("Msxml2.XMLHTTP");
}
catch(e)
{
try
{
MyHttpRequest = new ActiveXObject("Microsoft.XMLHTTP");
}
catch(e)
{
MyHttpRequest = false;
}
}
}
else
{
MyHttpRequest = false;
}
if(MyHttpRequest) // browser supports httprequest
{
var random = Math.random() * Date.parse(new Date()); // make a random string to prevent caching
var file_array = file.split('.'); // prepare to check if we have a query string or a html/htm file
if(file_array[1] == 'php') // no query string, just calling a php file
{
var query_string = '?rand=' + random;
}
else if(file_array[1] == 'htm' || file_array[1] == 'html') // calling a htm or html file
{
var query_string = '';
}
else // we have presumable a php file with a query string attached
{
var query_string = check_value + '&rand=' + random;
}
MyHttpRequest.open("get", url_encode(file + query_string), true); // <-- run the httprequest using GET
// handle the httprequest
MyHttpRequest.onreadystatechange = function ()
{
if(MyHttpRequest.readyState == 4) // done and responded
{
document.getElementById(target_div).innerHTML = MyHttpRequest.responseText; // display result
}
else
{
document.getElementById(target_div).innerHTML = MyHttpLoading; // still working
}
}
MyHttpRequest.send(null);
}
else
{
document.getElementById(target_div).innerHTML = ErrorMSG; // the browser was unable to create a httprequest
}
}
// end of "AJAX" function
// Here follows a function to urlencode the string we run through our httprequest, it has nothing to do with AJAX itself
// If you look carefully in the above httprequest you se that we use this url_encode function around the file and query_string
// This is very handy since we are using GET in our httprequest and for instance
// any occurrance of the char # (from textboxes etc) will brake the string we are sending to our file - we don't want that to brake!
// It will also convert spaces to +
function url_encode(string){
var string;
var safechars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz/-_.&?=";
var hex = "0123456789ABCDEF";
var encoded_string = "";
for(var i = 0; i < string.length; i++)
{
var character = string.charAt(i);
if(character == " ")
{
encoded_string += "+";
}
else if(safechars.indexOf(character) != -1)
{
encoded_string += character;
}
else
{
var hexchar = character.charCodeAt(0);
if(hexchar > 255)
{
encoded_string += "+";
}
else
{
encoded_string += "%";
encoded_string += hex.charAt((hexchar >> 4) & 0xF);
encoded_string += hex.charAt(hexchar & 0xF);
}
}
}
return encoded_string;
}
// end .js file