[RESOLVED] Pass PHP vars to Javascript

Sherman

Ok, have spent 3 days trying to figure this out.
What I want to do is more complex than this, such as passing PHP array values to a Javascript array, but I decided to first try do something simpler, and I just haven't managed.
So here is the code of this very short program, if anyone can help:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script type="text/javascript">
function showalert(what){
alert(what);
}

function showonscreen(){
document.write(val);
}
</script>

<body>

<?php
$myvar = 'Welcome to my web site';
echo '<script type="text/javascript" language="javascript">)';
echo "var val = '<?=$myvar?>'";
echo 'showalert(val)';
echo 'showonscreen()';
echo "showalert('this text')";
echo '</script>';

</body>
</html>

None of the 3 function calls in the body part do what they are supposed to. Any ideas please?

😕

phaseonemedia

Personally I would just use ajax, but somethings just take time to wrap your head around.


<?php $myvar = 'Welcome to my web site'; ?>
<script type="text/javascript" language="javascript">
var val = '<?=$myvar?>';
showalert(val);
showonscreen();
showalert('this text');
</script>

Sherman

Yes, I have looked into many possible Ajax solutions, but for now I need to get this basic thing of passing a PHP variable to a Javascript one, and nothing is working...

I replaced my code for yours:

<?php $myvar = 'Welcome to my web site'; ?>
<script type="text/javascript" language="javascript">
var val = '<?=$myvar?>';
showalert(val);
showonscreen();
showalert('this text');
</script>

Result:

Two alert boxes come out on screen:

First one contains: <?=$myvar?>
Second one: this text

So still can't get the value of the php variable into the javascript value. Why is this so difficult? I've seen a ton of post on this but none of them is working.

phaseonemedia

try this...

<?php $myvar = 'Welcome to my web site'; ?>
<script type="text/javascript" language="javascript">
var val = '<?php echo $myvar;?>';
showalert(val);
showonscreen();
showalert('this text');
</script>

dougal85

If its simple variables I just put them in the URL (like a $_GET var) and then used javascript to get them back out...

I personally don't like writing JavaScript with PHP...

reddrum

You could also set your vars as session data or just use cookies.

dougal85

Session data is stored on the server actually...

dclamp

phaseonemedia wrote:

try this...

<?php $myvar = 'Welcome to my web site'; ?>
<script type="text/javascript" language="javascript">
var val = '<?php echo $myvar;?>';
showalert(val);
showonscreen();
showalert('this text');
</script>

that should work.

You should never use Short tags. As of PHP5 they are no long supported. 🙂

reddrum

Session data is stored on the server actually...

yes you would need to do somthing like this in the head of the doc to use sessions

session_start();
  print"<script language='JavaScript' type='text/javascript'>";
     print"var test = ".$_SESSION['name'].";";
  print"</script>";

phaseonemedia

not to be a smart @$$, but just to keep you all informed corectly, short tags are in fact supported in php 5, just not on by default 🙂

dclamp

phaseonemedia wrote:
not to be a smart @$$, but just to keep you all informed corectly, short tags are in fact supported in php 5, just not on by default 🙂

it looks cleaner using long tags though 🙂

phaseonemedia

agreed, it is rather sexy looking, and definitely more compatible with other setups.

dougal85

They will still be around in PHP6 too... just turned off by default like PHP5.

The ASP style tags <% and %> are being removed. I don't think I've ever seen those being used...

Sherman

phaseonemedia wrote:

try this...

<?php $myvar = 'Welcome to my web site'; ?>
<script type="text/javascript" language="javascript">
var val = '<?php echo $myvar;?>';
showalert(val);
showonscreen();
showalert('this text');
</script>

This WOOOORRRRKSSSSS ! Thanks.
Now for the next step, passing a php array to a javascript array...but I will be back on that one.
🙂

phaseonemedia

you welcome

bpat1434

You might want to look into PHP's [man]JSON[/man] library. Could help you make things much much easier. Especially since it would take care of arrays and stuff for you 😉

As an example you could just do:

<?php $json = json_encode(array('mydata'=>'test Item', 'something else'=>3.14159652)); ?>
<script language="text/javascript"><!-- // --><![CDATA[
var php = <?php echo $json; ?>

alert(php['mydata']);
// ]]></script>

dougal85

Although, as I previously said I don't much like this method of passing to JS. You can pass arrays like this;

<?php $myarray = array("item1", "item2"); ?>

<script type="text/javascript" language="javascript">
var myarray = <?php json_encode($myarray); ?>;

alert(myarray[0]);

</script>

That should work. PHP5 only though.

EDIT: DAMN! Didn't see the second page of replies...