Modify the server side functions using jquery - php

Question

I am developing one website using cakephp and jquery technologies.
Server-side there are some functions which handles SQL queries.
As per requirement I want to modify server side functions on client side using jQuery AJAX call.
E.g. : Below is the function on server side to modify users information.
function modifyUser(username,userid) {
//update query statements
}
Then jquery AJAX call will be like this:
$.ajax({
url: 'users/modiyUser',
success: function() {
alert("Updation done") or any statements.
}
});
and I want to modify above i.e. server side function depending upon client input criteria.
$.ajax({
function users/modiyUser(username,userid) {
// I will write here any other statements which gives me some other output.
}
});
Above AJAX call syntax may not present, but i think you all understood what I am trying to do I simply wants to modify/override server side functions on client side.
Please let me know is there any way to resolve above mentioned requirement.
Thanks in advance

Answer 1

You cannot call a PHP functions from the client directly. You can only make an HTTP request to a URI.
The URI determines the PHP script run. Input can be taken via $_GET, $_POST, and $_COOKIE (among others, but those are the main ones).
You can either write separate scripts for each function or determine what to do based on the user input.

Answer 2

You could have a server-side function in a separate PHP file to do this, and make an AJAX call call into that function first to perform the modification. But client-side changes to server-side code are just not possible.
I can't actually imagine why you would want to do this, though.

Answer 3

why override a function???
can i suggest this?
in PHP
try {
// functions here....
function modifyUser($username,$userid) {
//update query statements
if(!is_string($username)) throw new Exception("argument to " . __METHOD__ . " must be a string");
if(!is_string($userid)) throw new Exception("argument to " . __METHOD__ . " must be a string");
// do some modification codes....
}
function delete($userid){
// do stuff blah blahh...
}
// $_POST or $_GET etc. here
if(isset($_GET["modify"])){ // I make use of get for simplicity sake...
$username = $_GET['username'];
$userid = $_GET['userid'];
modifyUser($username,$userid);
$ret = array();
$ret["error"] = false;
$ret["msg"] = "$username has been modified";
echo json_encode($ret);
} else if(isset($_GET["delete"])) {
$userid = $_GET['userid'];
delete($userid);
$ret = array();
$ret["error"] = false;
$ret["msg"] = "$username has been deleted";
echo json_encode($ret);
}else {
// the client asked for something we don't support
throw new Exception("not supported operation");
}
}
catch(Exception $e){
// something bad happened
$ret = array();
$ret["error"] = true;
$ret["msg"] = $e->getMessage();
echo json_encode($ret);
}
in jQuery ajax
$.ajax({
url: 'ajax.php',
data : { modify : true, // sample for modify... can also be delete : true,
username : $('#username').val(),
userid : $('#userid').val() },
type: 'GET',
dataType: 'json',
timeout: 1000,
error: function(){
alert('error in connection');
},
success: function(data){
if(data.error)
alert('Something went wrong: ' + data.msg);
else {
alert('Success: ' + data.msg);
}
}
});