使用JQuery .post（）没有响应

Question

I have a very simple form for updating a user's status message. The form does work, but I am not getting any response (using firebug the response after submit is empty).

Here is the html/js:

<form id="StatusUpdateForm" method="post" action="http://www.url.com/process.php">
<input name="StatusUpdate" type="text" id="StatusUpdate" />
<input type="hidden" name="userid" value="<?=$_SESSION['user']['id']?>" />
<input type="submit" value="Update your status" />
</form>
<div id="results"></div>

<script>
/* attach a submit handler to the form */
$("#StatusUpdateForm").submit(function(event) {

/* stop form from submitting normally */
event.preventDefault(); 

/* get some values from elements on the page: */
var $form = $( this ),
StatusUpdate = $form.find( 'input[name="StatusUpdate"]' ).val(),
userid = $form.find( 'input[name="userid"]' ).val(),
url = $form.attr( 'action' );

/* Send the data using post and put the results in a div */
$.post( url , $("#StatusUpdateForm").serialize(),
     function( data ) {
          $('#results').html(data);
     }
);
});
</script>

Here is process.php:

if($_POST['StatusUpdate']&&$_POST['userid']){
    if( StatusMessage::set($_POST['userid'], $_POST['StatusUpdate']) ){
    echo "<div id='content'>Comment updated!</div>";
    } else {
    echo "<div id='content'>Problem updating comment. Try again.</div>";
    }
}

Answer 1

Change return to echo. If it's not outputting anything there won't be any response to send!

if ($_POST['StatusUpdate'] && $_POST['userid']) {
    if (StatusMessage::set($_POST['userid'], $_POST['StatusUpdate'])) {
        echo "<div id='content'>Comment updated!</div>";
    } else {
        echo "<div id='content'>Problem updating comment. Try again.</div>";
    }
} else {
    if (!empty($_SERVER['HTTP_X_REQUESTED_WITH']) 
        && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest'
    ) {
        echo "<div id='content'>Some other error!</div>";
    }
}

To be extra sure it's executing, add an error callback function:

$.post(url , $("#StatusUpdateForm").serialize(), function(data) {
    $('#results').html(data);
}).error(function(eventData) { 
    alert('error: ' + eventData); // try that
});

Or (preferred):

$.ajax({
    type: 'POST',
    url: url,
    success: function(response) {
        $('#results').html(response);
    },
    error: function(xhr, textStatus, errorThrown){
        // alert(errorThrown);
        alert(textStatus);
    }
});