如何使用Ajax使用URL或其他方法注入特定的PHP函数？

Question

I'm moving from the realm of just JS to php and Ajax. I've dabbled some with PHP in the past. I really appreciate how much help stackoverflow has been in helping me with basic questions.

let says I have a div called #divName.

I use the following JS for Ajax. Some of this is just pseudo code.

var request = false;
   try {
     request = new XMLHttpRequest();
   } catch (trymicrosoft) {
     try {
       request = new ActiveXObject("Msxml2.XMLHTTP");
     } catch (othermicrosoft) {
       try {
         request = new ActiveXObject("Microsoft.XMLHTTP");
       } catch (failed) {
         request = false;
       }  
     }
   }

   if (!request)
     alert("Error initializing XMLHttpRequest!");

   function getAjaxInfo(<name of the php function???>) { //<<<<< this is the function I need help with
    var myFunction= nameOfPHPfunctionIJustGot;
     var url = "filename.php?func=" + myFunction;
     request.open("GET", url, true);
     request.onreadystatechange = updatePage;
     request.send(null);
   }

  function updatePage() {
     if (request.readyState == 4) {
       if (request.status == 200) {
         var response = request.responseText;
             document.getElementById("divName").innerHTML = response; //probably going to use Jquery append here, but this example works.
               } else
         alert("status is " + request.status);
     }
   }

The I have my fileName.php file:

<?php

function header() { ?>
   header content goes here
<?php }

function footer() { ?>
    footer content goes here
<?php }

?>

My goal is that when I execute getAjaxInfo(), I can pull whatever PHP function I want.

So lets say if I do a onClick="getAjaxInfo(header)" it will get the php header function, apply it to a javascript function, and then apply that to a div.

Any help would be appreciated!

Answer 1

Try with:

$func=$_GET['func'];
if(function_exists($func)) $func();

In this way you get the function name passed by GET and the execute it.

If you want to be able to call only certain functions:

$allowedFunctions=array("header","footer");
$func=$_GET['func'];
if(in_array($func,$allowedFunctions) && function_exists($func)) $func();