How to assig a PHP variable a value inside a JavaScript block?

Question

if ($page_title->exists()) {
//the rest of the code is in php.here i insert a javascript for the confirm box.
               echo'<script type= "text/javascript" >
var b=confirm("This page already exists.would you want to edit");
if(b == true)
//here i want to assign a php variable , say for eg. $a to 1 so that i can use that value of $a in an if clause outside this javascript code.
</script>';
}

if($a==1)
..some code..

How do I do it?

Answer 1

you can send the result back to php using an ajax call, e.g.:

<script type="text/javascript"
  src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.7.2/jquery-ui.min.js"&gt;&lt;/script&gt;

<script type="text/javascript">
x = confirm('Page exists, would you like to edit it?)
$.post('script.php', {x: x}, function(data) {
  if (data == '1') {
    alert('ok');
  } else {
    alert('not ok');
  }
});
</script>

Answer 2

The PHP code is executed on the server side and is all done at the point where your javascript is executed on the client side.

To communicate the value from the client to the server you typically either use AJAX (tutorial on how to do it here: http://www.w3schools.com/ajax/ajax_httprequest.asp) or store the value in a form and submit it together with data you are going to send down later anyway.

Good luck

Answer 3

Javascript runs on the client (browser) and PHP on your server. So you have to transport the variable to the server.

Most easy way to do this is to use the URL to send this information, for example: http://example.com/myscript.php?a=1. Then you can grab a using $_REQUEST['a'] and use it.

A more sophisticated (and complex) method is to use AJAX to send the variable to your PHP script, so it can return some data which you can use to modify your page.

What you need depends on your application, so you should provide some more details if you do not know what method is best to you in your situation.