[php] Call php function from JavaScript

Is there a way I can run a php function through a JS function?

something like this:

<script type="text/javascript">
function test(){
document.getElementById("php_code").innerHTML="<?php 
query("hello");       ?>";    
}
</script>

<a href="#" style="display:block; color:#000033; font-family:Tahoma; font-size:12px;"     
onclick="test(); return false;"> test </a>
<span id="php_code"> </span>

I basically want to run the php function query("hello"), when I click on the href called "Test" which would call the php function.

The only way to execute PHP from JS is AJAX. You can send data to server (for eg, GET /ajax.php?do=someFunction) then in ajax.php you write:

function someFunction() {
    echo 'Answer';
}

if ($_GET['do'] === "someFunction") {
    someFunction();
}

and then, catch the answer with JS (i'm using jQuery for making AJAX requests)

Probably you'll need some format of answer. See JSON or XML, but JSON is easy to use with JavaScript. In PHP you can use function json_encode($array); which gets array as argument.

PHP is evaluated at the server; javascript is evaluated at the client/browser, thus you can't call a PHP function from javascript directly. But you can issue an HTTP request to the server that will activate a PHP function, with AJAX.

I recently published a jQuery plugin which allows you to make PHP function calls in various ways: https://github.com/Xaxis/jquery.php

Simple example usage:

// Both .end() and .data() return data to variables
var strLenA = P.strlen('some string').end();
var strLenB = P.strlen('another string').end();
var totalStrLen = strLenA + strLenB;
console.log( totalStrLen ); // 25

// .data Returns data in an array
var data1 = P.crypt("Some Crypt String").data();
console.log( data1 ); // ["$1$Tk1b01rk$shTKSqDslatUSRV3WdlnI/"]