How to give Javascript access to PHP variables?

jalperin

I have a PHP script that pulls some information out of a database, and stashes it in Session variables. Within the same script, I'd like to give the user the ability click a link which would cause Javascript to open a new window containing some of the same content. To do that, it seems that I need to give Javascript access to the Session variables? Is there a way to do that? One alternative I can think of (though it seems very cumbersome) would be to write each of the Session variables to a hidden form field; then, Javascript could grab the values from the hidden field objects. Surely there's a better way?! Thanks. --Jeff

ccurle

You can add in php variables in your javascript like this:

etime+=<? global $timer; echo $timer ?>

I have used it plenty of times and it works perfect.

I hope this helped you out.

JMJimmy

If you are just displaying the information in a new window you don't need to give javascript access to them at all. Simply echo the variables into the html once the window is open.

If you do need javascript to access them it's quite easy:

<SCRIPT>
JSvar1 = <?php echo $var; ?>;
JSvar2 = <?php echo $var2; ?>;
[do stuff in js]
</SCRIPT>

no need to make them global as they already are.

JMJimmy

jalperin

Thanks for the responses. Just a couple of things to clarify.

First, if the PHP variable is a string, it looks like I need to put quotes around the entire php clause to make it work.

Example: JSvar1 = "<?php echo $var; ?>"; Is that right?

Also, I don't think I understand what you mean about echoing the variables into HTML after the window is open. Are you saying to open a new window in JS, then have PHP echo a variable? When I do that, the PHP echo goes into the first window, not the new one that I opened with JS.

Thanks for the help; I'm still learning some basics, obviously.

--Jeff

JMJimmy

Ok - lets say you have two pages:

index.php
popup.php

you have a link on index.php that you want to popup and display some session variables:

Now, there are two ways of doing this - if they are plain variables you would write it as:

echo "<A HREF=\"javascript:void(0)\" ONCLICK=\"window.open('/popup.php?var1=$var1&var2=$var2,'','width=600,height=400,directories=no,location=no,menubar=no,scrollbar=no,status=no,toolbar=no,resizable=no,screenX=200,screenY=200,top=200,left=200');\">Link</A>";

That would pass the variables to the page popup.php via the url where you can then echo them using <?php echo $var1; echo $var2; ?>

If they are session variables you don't have to do that, you write the window.open as the first example and then echo them as stated above or below.

For echoing in html it's simple. Just name your file with a .php extention and it will be as so:

<HTML>
<HEAD>
<TITLE><?php echo $var1; ?></TITLE>
<BODY>
Hello <?php echo $var2; ?>
</BODY>
</HTML>

if $var1 = Foobar! and $var2 = Joe that would output a page that said "Hello Joe" with the title "FooBar!"

JMJimmy

jalperin

Got it. Thanks so much for taking the time to illustrate. What I was really trying to do was to pop-up a window containing information from both: a) form fields on an unsubmitted form, and b) information extracted by PHP from a database. I didn't know any way to get the form field data without having the user submit the form except to use Javascript, but then I didn't know how to get data from PHP. But, as you've pointed out, it's really pretty easy; PHP just echos the data before the Javascript runs on the client. Thanks again. --Jeff