Javascript function in PHP? - php

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>

Related

Passing jQuery Value to PHP

I am calculating the distance between two places using jQuery and I want to pass this value (pickup_distance) for use in PHP.
I am wanting to send this value to tariff.fare.controller.php for use in the following function:
private static function getFare($int_terminate) {
// Function
if pickup_distance(<-- jQuery Value) > 5 {
// Do Something
}
}
How could I go about doing this? I'm aware I can do this via AJAX but being quite new to programming I'm not quite sure how I can do this.
Any help would be much appreciated!
using Jquery it's quite easy:
var your_var_value=1200;
$.post("your_php_script.php", {var_value: your_var_value}, function(data){
alert("data sent and received: "+data);
});
then in your PHP script you get the variable like this:
$distance=$_POST['var_value'];
And what you echo in "your_php_script.php" is returned as the data variable.
As jQuery is client side code and PHP is Server side code, the variables must somehow be passed to the server.
There are a few decent ways of doing this, by far the most common is GET and POST variables.
then you can pick them up in php and do whatever you wish with it.
A very simple example is to have an iframe/php image whatever and just load the src with JavaScript or jquery file.php?EEEE=YYY then fetch that variable $_GET['EEEE']
Best way to do it is to use jQueries built in Ajax functionality. Either use .ajax or .post and send in your required parameters to your PHP script.

PHP Array in Javascript Variable - JS Element

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.

Pass a php function instead of a file to jquery $post method

i started to learn jquery yesterday so i'm not so good.
I've a question:
as title there's a way to pass a php function instead of a file to jquery $.post method?
Here's an example of what i would to do:
function send(str)
{
$.post
(
"<?php PHPfunction(); ?>",
{send:str},
function(data)
{
$("#output-text").html(data.reply);
},
"json"
);
}
there's a way to do that? or i need always to pass a file to the first parameter?
Just another question:
how can i pass more than 1 row from php to jquery in the ajax reply?
You'll want to use AJAX to make a request for that function. For more information, see http://api.jquery.com/jQuery.ajax/. Google can also provide you a ton of examples because what you're asking is a fairly common problem with plenty of good solutions.
PHP is run on the server before the page is fully loaded, so you can't call a PHP function on the fly like that. Javascript runs within the browser afterwards, on the clients machine. They are two separate environments, code wise.
You're better off calling a page that uses the function, using Ajax or something.

JQuery .GET call/function

Ok so trying to get a page together that needs to connect to our SQL database. So on the javascript page I have functions that will autocomplete a textbox with data out of our mysql DB and then I need to send it to other functions and classes so that it will then look in our SQL DB and return some data. The problem I have is trying to get the .GET call to call in the php page, with the function that calls the class in which I need to get into for the SQL call. I have it setup somewhat but trying to figure out how to send the data through with it as well as just get clarification on how to work the .GET function.
Javascript page:
$.get("dsl_validate.php", calldsl(job));
Php Page
function calldsl($job){
var $dsljob = $job
hasfunctioncode($dsljob);
}
The hasfunctioncode function is in my DSL class page that will return the info I need. Any help on if I am in the right direction or not?
It looks like you're trying to physically call the PHP function calldsl() from the JavaScript. This... isn't right. (I'm assuming the $.get() you're using is from jQuery, please correct me if that assumption is incorrect.)
What $.get() does is simply call a resource on the web server. It doesn't have any knowledge of the server-side code (nor should it, for a number of reasons). From the perspective of the server-side code, there's no difference between a page being called via $.get() vs. one that's just loaded in a web browser.
What you essentially need to do is create a PHP page which accepts arguments either as a form post or query string (if you're using $.get() then the query string is the way to go), does its server-side logic, and then simply outputs the results to the "page." In the case of calling the page via AJAX as you are here, it's a good idea to render the page content using JSON notation. (Don't forget to set the content-type header to "application/json" as well.)
Then what you're getting on the client-side from the $.get() call is the response body, which would be that JSON data. It's really just a "page" like any other, the only difference is the content-type telling the browser that it's JSON data and that it doesn't have HTML, just JavaScript objects. The success callback on the $.get() call (the function you pass it, or create in-line) would receive that response data as an argument and can do what you need to with it.
The way I understand jQuery.get(), the second argument is the "callback" (http://api.jquery.com/jQuery.get/). The callback will hand the results from your server therefore should be a function. Currently your code actually executes the function "calldsl" where you should be only passing a reference like so...
Javascript:
$.get("dsl_validate.php", function(response){
alert("yay I haz ajax! "+response)
});
PHP: "dsl_validate.php"
echo "this is some data from the server";
No, your are not in the right direction. The first parameter of the get method have to br the complete URL of the page, not just the script (this works if the script resides on the same directory of the javascript file, though). The .php file shall return somehting "usable" for you javascript (JSON, or HTML, or text, or... whatever). The "calldsl" function will be called AFTER the data has been returned from the call. Something like that:
$.get('dsl_validate.php?value=somevalue', function(data) {
alert("Data returned from dsl_Validate: " + data)
});
i think you are better off passing the function as a param to your php page
$.get("dsl_validate.php?calldsl="+job, function(data) {
$response = $(data);// create a jquery object from the response
});
`
and in your php file
create a switch statement that call the function based on the parameter
Mmm I think you are wrong, the second argument on your get function is the javascript function that will process de data returned by "dsl_validate.php". I mean, if that page returns "foo", job will contain "foo".
But in my experience is better to use the autocomplete plugin from Jquery UI
jquery autocomplete plugin

How do I access a PHP variable from JavaScript?

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.

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