I have a PHP page that loads a session variable:
$user_id = $_SESSION['USER_ID'];
Previously, I included my Javascript/jQuery within that page, and added <? echo $user_id; ?> to set the Javascript variable:
$(document).ready(function() {
$(".button").click(function() {
var user_id = <? echo $user_id; ?>
var dataString = 'user_id=' + user_id;
$.ajax({
type: "POST",
url: "../add_user.php",
data: dataString,
});
return false
});
});
However, I'd like to move my Javascript to a separate page and call the script from my PHP page:
<script src="add_user.js" type="text/javascript"></script>
If I do this, I can no longer user <? echo $user_id; ?>, so what is the best way to pass my PHP variable into the Javascript/jQuery function?
You can configure your webserver to treat .js files as PHP scripts, which would let you execute your PHP code from within the .js file.
However, if that's not acceptable, you can always do something like:
<script type="text/javascript">var user_id = <?php echo json_encode($user_id) ?>;</script>
<script type="text/javascript" src="add_user.js"></script>
to define the variable at your PHP script level, and then include the external .js as usual.
If $user_id is always numeric, then the json_encode() bit is overkill, but I've gotten into the habit of using that everywhere I'm generating JS code dynamically. Using json_encode guarantees you're inserting a syntactically correct JS snippet.
<script>
var user_id = <?php echo $user_id; ?>
</script>
<script src="add_user.js" type="text/javascript"></script>
Now you can use user_id in your add_user.js file. Also, I would advise against using PHP short tags.
You will still be able to reference your varible in your external js file
<script type="text/javascript">
var yourvar = <? echo $user_id; ?>;
</script>
<script src="add_user.js" type="text/javascript"></script>
Just start the session on the other side. Its is also more secured, considering that JS data may be corrupted, even deliberately and may be exploited (security).
After starting the session - read the value there.
Of course, this is valid for scripts on the same vhost.
Related
I found on stackoverflow how to use a php variable in jquery, but on my test page, it simply isn't working:
$('#q').keyup(function(e) {
var test = "<?php echo 'test123'; ?>";
alert(test);
});
The code above outputs "" literally in the box where I want it to say "test123". I tried using single quotes instead of double, other small changes ... Didn't get it to work. Am I missing something?
The code above sits in a .js file which is linked in a .php page, which is (again) linked in my index.php file via require_once.
You should not use PHP in javascript files (.js). Javascript and PHP are different languages. PHP works on the server-side and Javascript on the client-side.
You have to put this code in your <head> under the jquery.js file, like this:
<script type="text/javascript" src="link-to-jquery-file.js"></script>
<script type="text/javascript">
$('#q').keyup(function(e) {
var test = "<?php echo 'test123'; ?>";
alert(test);
});
</script>
Also make sure your file extension ends with .php
There is also an advanced solution for this, and that would be using the header() function. Save as javascript.php or someting Example:
<?php
header("Content-Type: text/javascript");
?>
$('#q').keyup(function(e) {
var test = "<?php echo 'test123'; ?>";
alert(test);
});
Then attach the file in your <head> like this:
<script type="text/javascript" src="javascript.php"></script>
Goodluck!
The Idea is:
<script type="text/javascript">
var supervar = 'u can reach me anywhere on the page';
</script>
[...some PHP and HTML...]
<script type="text/javascript">
$('#output').html(supervar);
</script>
so basicly i need it because I use php includes and need to send the exact location of my PHP file to jQ.
Your supervar variable is already in scope inside jQuery, because it is declared above the jQuery script. The question is how to assign a variable from PHP and pass it over to supervar. Inside your .php file, you can simply escape into php when needed within the <script> element.
For example, if you want to assign is the public path of your PHP script, you can do something like:
<script type="text/javascript">
var supervar = <?php echo $_SERVER['PHP_SELF']; ?>;
</script>
Your server will execute the php script before serving the following output to the client:
<script type="text/javascript">
var supervar = '/your-app/your-file.php';
</script>
I have an php variable like this:
PHP Code:
$php_value = 'Am from PHP';
And I want to be able to change this variable with jQuery and the jQuery is on the same page?
You can't.
By the time the page has been delivered to the browser and the JavaScript has run, the PHP program that generated the page will have finished running and the variable will no longer exist.
JavaScript will allow you to send new data to the server (Ajax), where the server could store the data somewhere (a database is usual), and read the response.
JavaScript will also allow you to modify the page in in the browser (DOM) (including with the data included in the response for an Ajax request).
PHP code is run server-side, and jQuery runs on the client. The way to update a PHP variable from jQuery is to have a jQuery call which submits to the PHP page, and have the PHP look for it:
$php_value = 'Am from PHP';
if exists($_POST['php_value_from_jquery']) {
$php_value = $_POST['php_value_from_jquery'];
}
If I understand your question correctly, AJAX cannot post data to PHP code on the same page. I've been told that it can, but it is not trivial - still, I cannot imagine how that is possible. At any rate, AJAX is easy if a secondary PHP file is used.
Here is an example of what I mean. If you try this:
<?php
echo 'Hello';
?>
<html>
<head>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function() {
$.ajax({
type: 'POST',
url: '',
success: function(data) {
alert(data);
}
});
}); //END $(document).ready()
</script>
</head>
<body>
</body>
</html>
The popup will contain the HTML for the page.
However, if you use two files:
file1.php
<?php
echo 'Hello';
?>
file2.php
<html>
<head>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function() {
$.ajax({
type: 'POST',
url: 'file1.php',
success: function(data) {
alert(data);
}
});
}); //END $(document).ready()
</script>
</head>
<body></body>
</html>
The popup will contain only the word "Hello".
To use ajax, you must call an external PHP file.
After considering the above, note that Quentin's answer is important -- even if you use AJAX to set a PHP variable on the server, that variable disappears after the AJAX completes -- just like the PHP variables all disappear after your index.php has finished rendering the DOM and presenting it to the visitor's browser.
So, what's to be done? Two options.
(1) As Quentin points out, you can store values permanently in a database, or
(2) You can use a PHP superglobal, such as a $_SESSION variable. For example:
Client side: file2.php
var storeme = "Hello there";
$.ajax({
type: 'POST',
url: 'file1.php',
data: 'stored_on_server=' +storeme,
success: function(data) {
alert(data);
}
});
file1.php
<?php
session_start();
$SESSION['a_variable_name'] = $_POST['stored_on_server'];
You can later retrieve that variable value thus:
$.ajax({
type: 'POST',
url: 'file3.php',
success: function(data) {
alert(data); //a popup will display Hello There
}
});
file3.php
<?php
session_start();
echo $SESSION['a_variable_name'];
You can't able to change the php value using javascript. i.e Server scripts runs first after that client side script will take effect in that case you cant able to modify the same, since they already rendered in browsers
If jQuery is going to be processing the data, then you can assign the PHP variable to a jQuery variable like this:
<script>
var jquery_value = <?php echo $php_value; ?>
</script>
As far as I know, because jQuery is client-side and php is server side, it's not possible to assign a jQuery variable back to PHP.
I have a JavaScript file which has a hard coded BASEURL variable, this value is then used by other functions in the file.
I would like for this url value to be set dynamically so that I don't need to manually change it for different installs. Is it possible to insert a PHP variable value into a JavaScript file?
Rather than try to mix PHP into javascript files, here's what I do in the HTML template:
<head>
<script>
var BASEURL = "<?php echo base_url(); ?>";
</script>
<script src="/path/to/my_script1.js"></script>
<script src="/path/to/my_script2.js"></script>
</head>
This sets the variable and allows all your embedded scripts to access it. base_url() would be replaced by whatever method you use to fetch the base url with PHP.
Suppose you have a JS file written on the fly by PHP; file1.php
<?php
header('Content-Type: application/javascript');
$var = $_GET['var1'];
echo "jsvar = ".$var.";";
?>
The client-side source code of file1.php?var1=10 will then be
jsvar=10;
There exists several ways:
Load the baseurl via AJAX, but maybe this is to slow, maybe you need it earlier.
let the javascript file running through the php parser. Then you could use inline echos.
The most convenient and easiest way, is to make a <script>var baseurl = '...';</script> in the html/php output of your page.
You will need to make your file a php file, not a js file. From there you can include any PHP tags in the file to work your dynamic magic. The key to make this whole thing work is in the headers, which you will need to set like so:
<?php
Header("content-type: application/x-javascript");
echo 'var js_var = ' . $php_var;
?>
alert (js_var);
This technique can be used to for CSS files as well.
Heredoc worked for me today:
<?php
echo <<<ANYNAME
<script LANGUAGE="JavaScript" type="text/javascript">
<!--
// code ...
var myLatlng = new google.maps.LatLng($lat, $lon);
// code cont. ...
//-->
</script>
ANYNAME;
?>
http://php.net/manual/en/language.types.string.php#language.types.string.syntax.heredoc
php variable in html no other way then: <?php echo $var; ?>
I have got this code
/* Popup for hot news */
$(document).ready(function() {
var $dialog = $('<div></div>')
.html('text to be shown')
.dialog({
autoOpen: false,
title: 'Table'
});
This code is in my JavaScript files which are included by header.php.
How to pass PHP output to this function?
Inputing <?php echo($mydata)?> in .html('') above does not solve anything.
Any reason why this gives an error?
Thanks for helping!
First of all your code is having some problem, $ in php is a prefix of variable and $ in jQuery is a selection sign. You can view the html source(the output) on browser for debug.
I can think of three ways to do so:
(1)The way you have mentioned should work, see the code below
<?php $foo='hi'?>
<script>
alert("<?php echo $foo?>");
</script>
(2)Another way is to separate server side and client slide code clearly for better maintenance
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js" type="text/javascript"></script>
<?php echo"<div id='foo' style='visibility:hidden;'>HI</div>"?>
<script>
alert($('#foo').text());
</script>
(3)The last way is by passing variable from the URL http://example.com/example.php#hi
<script>
var foo= location.href.split('#')[1];
alert(foo);
</script>
Adding <?php //code?> to your JS files do nothing because JS files are not executed by Apache. You can either use Ajax to request for data once your page loads (if the data doesn't need to be there at start) or you can add those PHP code blocks to your HTML code.
Using Ajax (goes in your JS file)
$(document).ready(function(){
var u = 'data.php';
var d = {};//data
$.get(u, d, function(data){
//got by data. lets invoke some methods here
});
});
Putting it in your HTML (goes in your HTML file)
var __DATA = '<?php //output some data I prepared earlier ?>';
//I'm using __ and capitol case to denote a global variable. Just personal preference
<script src='myjsfile.js' type='text/javascript'></script>
//the variable __DATA is available to your JS file and you can use it