使用jQuery从PHP获取变量值

Question

So how do i get variable value from php file with jquery...? the jquery code is in other file (tpl)

for example i have register.php and register.tpl (template file for register.php)

register.php

 ...some includes here...



if(isset($_POST['submit'])) {
    $username = mysql_real_escape_string(trim($_POST['username']));
    $email = mysql_real_escape_string(trim($_POST['email']));
    $check = $mysql->query("SELECT username FROM ".TBL_USERS." WHERE username = '".$username."' OR email = '".$email."'");
$rows_check = mysql_num_rows($check);
if($rows_check > 0) {
    echo 1;
} else {
    $password = mysql_real_escape_string($_POST['password']);
        $salt = generate_salt($email);
        $hash = hash_password($password, $salt);
        $q = $mysql->query("INSERT INTO ".TBL_USERS." (username, password, email, salt) VALUES ('".$username."', '".$hash."', '".$email."', '".$salt."')");
        if($q) {
            header("Location: index.php");
        } else {
            die(mysql_error());
        }   
    }
} else {
.. calling parse template function ...
}

register.tpl

 ..jquery library included..
    <form id="register" action="register.php" method="post">
       <tr>
       <td>Username</td>
       <td><input type="text" id="username" name="username" class="register" style="width: 200px;" />
    </td>

email ...other inputs... $("#username").blur(function() {

var email_v = $("#email").val();
 $("#msgbox").removeClass().addClass('messagebox').text('Checking...').fadeIn("slow");
 $.post("register.php",{ username:$(this).val(), email: email_v, submit: true } ,function(data)
 {
  if(data=="1") 
  {
   $("#msgbox").fadeTo(200,0.1,function()
   {

    $(this).html('This User name Already exists').addClass('messageboxerror').fadeTo(900,1);
   });
  }
  else
  {
   $("#msgbox").fadeTo(200,0.1,function() 
   {
    $(this).html('Username available to register').addClass('messageboxok').fadeTo(900,1);
   });
  }
 });
});
</script>

when i changed the whole register.php for testing purposes to or the script worked...however with the original version it shows always that username is available...

Answer 1

Best bet is to output the PHP variable as a hidden field or a JavaScript variable:

<input type="hidden" id="my_var" name="my_var" value="<?php echo($my_var); ?>" />

// access it like this:    
alert($('#my_var').val());

or

<script type="text/javascript">
    var my_var = <?php echo($my_var); ?>;
</script>

// access it like this
alert(my_var);

That should do it :-)

Answer 2

Either you make a Jquery Ajax Request that will request a php page which will return whatever you want or you echo a javascript variable with php

<?php 
  echo '<script> var javascript_variable = "whatever"; </script>'; 
?>

Answer 3

It will work if you do

echo "1";

and then

if(result == "1") {

If it doesn't (but I've checked on a code of mine without the quotes, it didn't work, with, it was ok), check the response from Firebug console.

Answer 4

In situations where my company's application needs to call Jquery on a dynamic element and we have the Jquery call IN the php file we'll directly call php in the Jquery call.

For example:

alert($('#').val());

Not for all situations, certainly. If you have to call a variable where you don't have PHP access to the file (possibly such as a .tpl file, depending on your setup) you might resort to setting a hidden input as detailed above.