Javascript variable to php

[edwinv]

Hello,

 

with the following code I am able to pass a variable from js to php.

<script>
    var winW = 630, winH = 460;
    if (document.body && document.body.offsetWidth) {
     winW = document.body.offsetWidth;
     winH = document.body.offsetHeight;
    }
    if (document.compatMode=='CSS1Compat' &&
        document.documentElement &&
        document.documentElement.offsetWidth ) {
     winW = document.documentElement.offsetWidth;
     winH = document.documentElement.offsetHeight;
    }
    if (window.innerWidth && window.innerHeight) {
     winW = window.innerWidth;
     winH = window.innerHeight;
    }
</script>
<?php
    $screen_width = "<script>document.write(winW)</script>";
    $screen_height = "<script>document.write(winH)</script>";
?>

 

Problem:

it is passed as a string and I need it to be passed as an integer.

When I try (int) or intval() in php, it is set to variable type int, but it loses it value.

 

Can anyone help?

[mac_gyver]

with the following code I am able to pass a variable from js to php

 

 

no, it's not passing anything from js to php.

 

the two php variables contain those literal strings - <script>document.write(winW)</script> and <script>document.write(winH)</script>. when you are echoing those php variables in the page that gets output to the browser, at that point there will be the - <script>document.write(winW)</script> and <script>document.write(winH)</script> code. when this code is executed in the browser they do display what you expect, because the browser is where the winW and winH variables exist.

 

to send ANYTHING from the browser to php, you must make a http request to the server and pass the values in the http request. see the following example in the php.net documentation - http://php.net/manual/en/faq.html.php#faq.html.javascript-variable

Edited September 13, 2015 by mac_gyver