Modify the server side functions using jquery

Question

Hi, I am developing one website using cakephp and jquery technologies. Server-side there are some functions which handles sql queris.

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 adavance

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);
        }    

    }
});