Jquery validator weird behaviour with remote

问题

I have a registration form which is using jQuery validator as:

$('reg_form').validate({
  ignore:"",
  rules : {
    user_name : {
      required :1,
      minlength :8,
      remote :"check_user_name.php"
    },
    password : {
      required :1,
      minlength :8,
    },
    firstname : {
      required :1,
    },
    lastname : {
      required :1,
    },
    email : {
      required :1,
    },
  }
});

It worked pretty well but the problem is remote. It never detects if the username is already in the DB.

The code in remote is as:

$uname = $_GET["user_name"];

$UserObj = new User();
echo $UserObj->checkUniqueUser($uname);

checkUniqueUser() will check if there is an user with the same name it will return false else true.

I got the URL from the request watch

http://project.localhost/check_user_name.php?user_name=admin

I hot linked the URL and it says false, since the admin is already there in the DB and if I change to something else it shows true (of course its not there in DB)

Can someone please help me on this ? Hope I was able to make it clear what I have done so far and what issue I am facing.

This is my function which I have in the User class.

public function checkUniqueUser($username){
      $return = true ;
      global $db ;
      $db->query("select iduser from user where 
      user_name = '".$this->cleanInput($username)."'");
      if($db->numRows() > 0 ){
        $return = false ;
      }
      return $return ;
}

回答1:

Since you want an output, you need to echo true or false from your function, not return. Technically, there's nowhere to return.

See PHP return and PHP echo.

public function checkUniqueUser($username){
      $return = true ;
      global $db ;
      $db->query("select iduser from user where 
      user_name = '".$this->cleanInput($username)."'");
      if($db->numRows() > 0 ){
        $return = false ;
      }
      echo $return ;  // echo (output) true or false
}

来源：https://stackoverflow.com/questions/21312687/jquery-validator-weird-behaviour-with-remote