How do I call PHP variables or queries in JavaScript?
<script>
var foo = <?php echo $foo; ?>;
// or, if foo is a string;
var foo = '<?php echo addslashes($foo); ?>';
// for anything more complex, you'll need to use json_encode, if available in your version of PHP
var foo = <?php echo json_encode($foo); ?>;
</script>
Please note, you can only do this one way. Don't expect any changes you make in javascript to come through to PHP.
PHP and JavaScript cannot mix directly. You use PHP server-side to generate and send JavaScript to the client. the JavaScript executes client-side and can communicate with PHP code on the server only via AJAX calls. This can be simplified drastically through the use of an AJAX library like jQuery.
You have to keep in mind that your PHP code is evaluated on the server, while JavaScript (normally) runs in the browser. The evaluations happen in different times, at different places. Therefore you cannot call a JavaScript function (or variable) from PHP, simply because you cannot call a function that exists on another computer.
You may want to check if Ajax is an appropriate solution for your problem.
Generally, you can't. PHP is server-side and Javascript is client-side (processed by the browser).
The exception is to use AJAX, which allows you to access PHP pages, which should then execute the action needed.
You can use JSON for this purpose which serves well for sending a big array to Javascript from PHP. We need to echo JavaScript code in PHP script or we can use Ajax for this. But usually we may need to send a big array. So we can do like this
<script>
<?php
$arr = array ('a'=>1,'b'=>2,'c'=>3,'d'=>4,'e'=>5);
?>
var foo = echo json_encode($arr);
</script>
The json_encode function will handle all escaping and other issues. Bug also make sure json_encode is available in your PHP version.
Related
I have some PHP code inside the script so I need
the JavaScript value as a PHP variable, as follows:
<script>
;
var js_var = 123;
var php_var = <?php js_var ?>;
alert(php_var);
;
</script>
Using jQuery to send the value to a PHP page will return the value but not as a PHP variable:
$.get("page.php", {js_var_name: js_var}, function(data) {alert(data)});
I tried also all jQuery AJAX functions: load(), post() and the ajax() method, none of them pass back the value of PHP as above requested.
Is it possible to implement the above with jQuery?
Likely you have a syntax issue with :
var php_var = <?php js_var ?>;
Unless you used define() your php variable should start with $ and you need to echo it so that it gets printed to the page
var php_var = <?php echo $js_var ?>;
If you are assuming that php will read the prior javascript js_var=123 it won't. Javscript is a client side language and php is server side.
You cannot simply mix PHP and JavaScript. The former is executed on the server, the latter on the client, namely in the user's browser. In order to hand a value from PHP to JavaScript you need to output JavaScript code via PHP or do a AJAX-Request to a PHP-Script, as you tried. When using AJAX, it is the easiest solutions to have PHP script that returns a JSON string. When calling this script using $.get() the result will be stored in a JavaScript variable and you can access all the values from there.
Take a moment and a deep breath...and then start thinking about your scopes again.
I have a Javascript variable which I am setting a PHP variable to.
function cancel(number) {
var message = "<?= $message[" + number + "]; ?>";
}
$message is an array. "number" is the element of the array I want to set message to. Basically, I want to set a Javascript variable to a PHP variable using a Javascript variable as the element picker. So if "number" was 2, it would select:
$message[2];
However, the above approach doesn't work, and I'm not even sure if this is possible.
It isn't. Use XHR to retrieve the value from the server.
It doesn't seem at all possible; PHP is evaluated server-side, and javascript is evaluated client-side. So PHP would see it as $message["+number+"], and try to find the value at the index of "+number+". You'd probably have to do something like an AJAX request to get the data you're looking for.
What you are doing isn't possible; since php is a server-side language, it's executed first, and the js is executed after; there isn't any way to control which is executed first. You must retrieve the variable using AJAX.
Something like this will work:
<script type="text/javascript">
var messages = <?= json_encode($message) ?>;
function cancel(number) {
var message = messages[number];
}
</script>
Of course this will output the entire array in the JavaScript source. If it is large, then you are better off using AJAX.
Tip: if you "view source" it should be painfully obvious why your method doesn't work.
You simply cannot do this using this methodology. PHP is server-side code, meaning that it runs on the server, while JavaScript is client-side code, meaning it runs on the client, or your browser.
Once the PHP runs, it generates an HTML document and sends that document in the response to the browser. Once that's complete, the only way you can get data back to the server is to send it via a form POST, send it via AJAX, or send it via script tag remoting.
Consider looking at some examples on the Internet of how to POST data back to the server via a form and via AJAX. It's clear you're struggling with some concepts regarding how to properly architect your program, and looking at some examples would be a great way for you to learn and master these techniques.
PHP Submit Form Example
PHP Tutorial
You need to use AJAX call to resolve your issue.
I have a function that is in PHP that I need to use in my Javascript program... how would I go about doing so? The javascript function takes in a name, and returns an array derived from that name. I'm going to assume that I'll have to make the name into a json object (and edit the php function so that it also returns it as a json object). Is there any way to do this? Thanks.
There's basically this function written in javascript, let's say getData, which is written in javascript. It is used like var fizz = getData(bar). I have a php program that needs to be able to input the bar as well as get the returning fizz.
Use AJAX for this. You will need to make AJAX call to the server-side php code and get whatever you need. You can use jQuery: http://api.jquery.com/category/ajax/
Here you can find some examples for the php (scroll to the bottom). One of the examples is for php+json. Although it does not really matter what server-side technology is.
you can do it like so:
<script type="text/javascript">
var php_func_result = <?=json_encode(my_function($my_param)); ?>;
</script>
i have javascript as below
html="<th>"+<?php echo __(); ?>+"</th>";
I want to add another javascript variable inside to __() function like this
<?php echo __(<js varible>); ?>
I tried
var myvarible=200;
html="<th>"+<?php echo __("'"+myvarible+"'"); ?>+"</th>";
console.log(html);
not working for me
can any one help me please
regards
You have a misunderstanding on how server side and client side code work.
The only way that you could possibly achieve what you are trying to do (apply a PHP localization function to a Javascript variable) would be like this (this code assumes you are using JQuery but can be done without it too):
var myvariable = 'hello';
$.get('http://yoursite.com/localize.php?text='+myvariable, function(localizedText) {
html = "<th>"+localizedText+"</th>";
console.log(html);
});
And then localize.php should look like this:
<?php
include('you localization library');
echo __($_GET['text']);
?>
Explanation: while your client side code (Javascript) is been executed in the browser it will call a URL which will execute your server side code (your PHP __(); function) in the server and then return the value to the client side code.
var myvarible=200;
html="<th>"+<?php echo __("'"+myvarible+"'"); ?>+"</th>";
console.log(html);
This would try to put the PHP variable "myvariable" into the script tag, what you want is closer to:
var myvarible=200;
html="<th>"+"<?php echo __("'myvarible'"); ?>"+"</th>";
console.log(html);
However, in this case, why not just skip PHP completely?
var myvarible=200;
html="<th>" + myvarible + "</th>";
console.log(html);
Javascript runs on client side and php on server side.
So var myvarible=200;
will be executed only on client side .
but will be get executed on server side. at that time myvariable will not be valid.
PHP is executed on the server, JS on the client. You cannot expect PHP to parse JS, in fact PHP will never see the JS statements, because they will be processed only once the server has processed the PHP.
var myvariable='<?php echo __("200"); ?>';
html="<th>"+myvariable+"</th>";
console.log(html);
However for this to work the javascript would need to be in a .php file that is being interpreted.
The OP wants to include a JS variable in a PHP call, which is not possible, unless you use AJAX. And you'll agree with me that code like this is only meant to cause big headaches and should be avoided at all costs.
Well yes and no.. i wouldnt do it this way. I use a helper that lets me do things like this in a consistent way. In my view file i have something like:
<?php js_call('jslib.myFunction(?,?)', __($value), 'some other value'); ?>
js_call its similar to using sprintf or a prepared statement except for js. The params are run through json_encode so the quoting and what not are correct. All these are stored in an array and then in the layout, just before my </body> i call:
<?php include_js_calls(); ?>
which then takes all the calls ive made with a js_call and outputs the string values inside a script tag resulting in something like:
<script type="text/javascript">
jslib.myFunction('first value', 'some other value');
</script>
Borrowed this brilliance from Apostrophe Cms
To do localization in javascript (for whatever reason), echo __() can obviously not be called directly.
There are different possible strategies
Include a localization string table in javascript when the page loads. Do lookup against it when needed. This table could be generated on server-side using echo __() then cached.
Make ajax requests for server-localized data. Might not be suitable for frequent updates.
I was wondering how i could achieve using <?php?> in javascript for url's? There's a certain route you have to go, Anyone know?
the normal way for example:
$fetchContent = $('#div').load('website/members #content');
What i'm trying to do:
$fetchContent = $('#grav').load('<?php?> #poppu');
Yep, thats wrong as hell lol, but i'm sure someone knows
I would also like to know how to tie php with javascript, but thats probably a whole new topic
You said it right :)
Yep, thats wrong as hell lol, but i'm
sure someone knows
Anyway, from your php script, output the url as a javascript code anywhere in the script before the javascript used for ajax call, e.g.
<?php
echo '<script language="javascript"> var g_ajax_url = "'. $the_url . '";</script>';
?>
and in your javascript, use it this way
$fetchContent = $('#grav').load(g_ajax_url + ' #poppu');
What it simply does is define g_ajax_url as a global variable with the proper php value, and you can use that variable in your js as you use other variables.
To tie php with js directly, try looking into xmlrpc topic.
If javascript is in .php file you can use <?php echo $url ?> and if the file is .js you can't use <?php ?>
It is not clear to me what you are trying to achieve. I assume you are using the jQuery load() function, if yes, you should state so.
You can't load php during javascript execution because the php has already been processes and rendered as HTML and sent back to the client. As PHP is processes on the server it is logical that you cannot run it on the client side.
You could of course send an AJAX request to the server that runs a certain php page and you will be able to use the response as you please.
you can't necessarily "tie" them together because they operate in two different spectrums of processing, php being processed on the server, and javascript being processed in the browser.
You can however render javascript within a php file.
if your javascript is included within a <script> tag within your php page your example should work should actually work. The php would render the urls into the script before it is sent to the browser.
if you are wanting to load external javascript files with php inlcuded urls, you will need to set the proper headers and include the php file just as you would a normal .js file.
good article on this topic HERE
You cannot execute <?php ?> inside JavaScript, but inside PHP you can declare a global variable as:
var x = '<?php echo x;?>';
or, if it's an array, store it as JSON:
var x = <?php json_encode(x); ?>
then access the JavaScript variables inside the external JavaScript.