How to pass data from Javascript to PHP and vice versa? [duplicate]
Solution 1:
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
Solution 2:
I run into a similar issue the other day. Say, I want to pass data from client side to server and write the data into a log file. Here is my solution:
My simple client side code:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js" type="text/javascript"></script>
<title>Test Page</title>
<script>
function passVal(){
var data = {
fn: "filename",
str: "this_is_a_dummy_test_string"
};
$.post("test.php", data);
}
passVal();
</script>
</head>
<body>
</body>
</html>
And php code on server side:
<?php
$fn = $_POST['fn'];
$str = $_POST['str'];
$file = fopen("/opt/lampp/htdocs/passVal/".$fn.".record","w");
echo fwrite($file,$str);
fclose($file);
?>
Hope this works for you and future readers!