php auto-save code

You'll need to use javascript.

You'll need to look up the following:

1. How to post a form using AJAX.
2. window.setInterval

I'd use jQuery, as it makes the JS easy for this.

I don't think you can do this using PHP alone but there's an interesting jQuery function that sounds like what you need:

http://rikrikrik.com/jquery/autosave/

That uses cookies but perhaps you can modify it to use a database?

The following code uses jQuery to send some data to a php file called store.php every second.

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.5.0/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript">
function callback() {
 // make ajax request
 $.ajax('store.php',{
 data:'<contains-the-data-to-store>',
 success:function() {
 }
 });
}
$(document).ready(function() {
 setInterval("callback()", 1000);
});
</script>

I'd suggest using JS to run some code every 30 seconds ( setTimeout() ) which either stores your data in a cookie, or sends it to the server via ajax (though I would recommend cookies)

function sendQuery(){
 AjaxArr = $('#formID *').serializeJSON();
 toAjax(AjaxArr,'yourPHPToSave.php');
 setTimeout('sendQuery',30000);
}
function toAjax(arr,ajaxAdr){
 JsHttpRequest.query( siteAdr+ajaxAdr+'?x=c'+Math.random(), AjaxArr,
 function(result, errors) {
 if(errors)alert(errors);
 else{
 if(result['error'] && result['error']!='')alert(result['error']);
 if(result['callback'] && result['callback']!='')eval(result['callback']);
 }
 }
 );
}
jQuery.fn.serializeJSON=function() {
 var json = {};
 jQuery.map($(this).serializeArray(), function(n, i){
 json[n['name']] = n['value'];
 });
 return json;
}

Call sendQuery and retrive POST data in yourPHPToSave.php

UPDATE: You need JsHttpRequest library http://www.phpclasses.org/package/3637-PHP-Process-regular-and-file-upload-AJAX-requests.html and jQuery

Using Javascript :

var refreshId = setInterval(function()
{
 //get your data here and make an ajax call to update your db table
}, 10000);

This code will run for every 10 seconds on your page.

<script type="text/javascript">
function func()
{
 // collect data like that
 //var your_data_array = {}
 // your_data_array.Ans1 = $('#someID').val(); 
 $.ajax({ 
 type: "POST", 
 url:"path/to/page/which/will/save_data.php", 
 data:your_data_array,
 //dataType:'json',
 beforeSend: function()
 {
 },
 success: function(resp)
 { 
 $("#activity").html(resp);
 /*$("#db").html(resp.db);
 $("#time").html(resp.time);*/
 }, 
 complete: function()
 {
 },
 error: function(e)
 { 
 alert('Error: ' + e); 
 } 
 }); 
 var t = setTimeout("func()",30000); 
}
var t = setTimeout("func()",30000);
</script>

add this to your head section after preapare according to your data func() function will be fire up after every 30 seconds.

• php
• javascript
• ajax