get data from javascript to php
Passing data from PHP is easy, you can generate JavaScript with it. The other way is a bit harder - you have to invoke the PHP script by a Javascript request.
An example (using traditional event registration model for simplicity):
<!-- headers etc. omitted -->
<script>
function callPHP(params) {
var httpc = new XMLHttpRequest(); // simplified for clarity
var url = "get_data.php";
httpc.open("POST", url, true); // sending as POST
httpc.onreadystatechange = function() { //Call a function when the state changes.
if(httpc.readyState == 4 && httpc.status == 200) { // complete and no errors
alert(httpc.responseText); // some processing here, or whatever you want to do with the response
}
};
httpc.send(params);
}
</script>
<a href="#" onclick="callPHP('lorem=ipsum&foo=bar')">call PHP script</a>
<!-- rest of document omitted -->
Whatever get_data.php produces, that will appear in httpc.responseText. Error handling, event registration and cross-browser XMLHttpRequest compatibility are left as simple exercises to the reader ;)
See also Mozilla's documentation for further examples