JAVASCRIPT &amp; PHP Vars

JAVASCRIPT & PHP Vars

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I have a javascript variable (which is defined by an active X control). I need to pass this value (the javascript var) to a php/mysql query. How can I call a javascript value within a php/mysql query. Can I define the javascript var as a php var? I ultimately really need to do this without the use of a form hidden input field.

Additionally, how would you do the reverse? I.E. redefine a javascript var from a php var?

jamie_kerwick

The only way to pass variables to PHP is either to submit them in a form, add them to the URL or set the value in a cookie.

As javascript is client side, and PHP is server side, they have absolutely no direct interaction.

So the only way PHP can set a javascript variable is by outputing it in your html using a

print " var javavar = new array('1','2',3)"'

type command.

MrAlaska

PHP can populate the javascript with any variable you want when it generates the page. For javascript to give it back it needs to be through GET or POST, there is no way for javascript to directly communicate with PHP.

EDIT: I was typing at the same time as jamie_kerwick it appears, and I also forgot about being able to do it in a cookie lol

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Can you write the javascript value in a php session?

jamie_kerwick

no, as previously stated javascript and PHP have no interaction whatsoever, the only things that PHP gets are things set along with a page request (cookie info, & post / get parametes).

Jamie

juschillinnow

Believe me you won't get an answer from here! I have been posting for the last couple of days trying to figure that one out.

But I figured this out for php values to javascript vars:

you may be able to do this to switch back but haven't tested it...

I don't think that will work but heck, it's worth a shot!

Tracer

Let me clarify, maybe you guys can help,

I am retrieving a digitized signature from a topaz signature tablet using javascript to call active x controls. The Topaz signature capture software is embedded within the webpage as an object. I can sucessfully retrieve the signature and set the ascii equivalent of the signature as a javascript var. After this has been done, I need to save the ASCII signature into a MySQL database with the contents of a PHP array.

I will also have to do the reverse, pull the ASCII from MySql along with a PHP array and set a javascript VAR = to the ASCII. The javascript Var will then pass the VAR to an activeX control, decode the signature and display it to the screen as an object.

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Possible Answer from PHP.Net

http://www.php.net/manual/en/function.fdf-set-javascript-action.php

This way the user would'nt have to submit the form, and the var should be defiend in PHP....I think I can work with this....

MrAlaska

Originally posted by Tracer
Possible Answer from PHP.Net

http://www.php.net/manual/en/function.fdf-set-javascript-action.php

This way the user would'nt have to submit the form, and the var should be defiend in PHP....I think I can work with this....

Forms Data Format (FDF) is a format for handling forms within PDF documents, on an HTML page you would still use standard HTML and javascript methods to auto post your forms and would require no special functions from PHP.

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I was referring to the suer contributed notes posted on that page, specifically the following:

User Contributed Notes
fdf_set_javascript_action

DHARM_SHANKAR at REDIFFMAIL dot COM
01-Jul-2002 07:03

HOW WE ACCESS javascript variable in php code.

bsreddy_m at yahoo dot com
08-Aug-2002 12:46

How to access JavaScript variables in PHP code:

It appears that there is no straight forward way of doing this. I have come out with a small trick to acomplish this as shown below.

Save the following code as test.php and run it.

<?php

$php_var = 1;
echo "Original value: $php_var";

if(isset($form_var) && !empty($form_var))
{
$php_var = $form_var;
echo "
After receiving value from JS variable: $php_var";
}
else
{
?>
<form action="test.php" method="post" name="form1">
<input type="Hidden" name="form_var">
</form>
<script language="JavaScript">
var js_var = 5;
document.form1.form_var.value = js_var;
document.form1.submit();
</script>
<?
}
?>

</body>
</html>

The output will be:
Original value: 1
After receiving value from JS variable: 5

rajbatra52

In fact I need to do a similar thing. I need to pass on a javascript variable value into a php Session variable. I have tried everything possible but nothing seems to work.

I hope someone can help us.

Raj