How can I use jQuery to submit a form using Ajax and then get the output of the page it submitted to?
I'm learning PHP and JavaScript, and I'm building a blogging platform. I'm working on the comment system. I want to check if the name field matches any users in the database, and if it does, then I want to display a message that the name is taken.
Here's the page that contains the form. (fullpost.php)
<!DOCTYPE html>
<html>
<?php
include ('functions.php');
connectDB();
$id = $_GET['id'];
$result = queryDB('SELECT * FROM posts WHERE id='.$id);
$post = mysql_fetch_array($result);
?>
<head>
<title><?php echo $post['title']; ?> - SimpleBlog</title>
<link rel="stylesheet" href="style.css" />
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js" type="text/javascript"></script>
<script src="http://ajax.microsoft.com/ajax/jQuery.Validate/1.6/jQuery.Validate.min.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function(){
$(".commentform").validate();
});
</script>
</head>
<body>
<div id="header">
<a href="index.php">SimpleBlog</a>
</div>
<div id="wrapper">
<?php
//post found, display it
if (mysql_num_rows($result) >0) {
echo '<div class="post">';
echo 开发者_JAVA百科'<div class="postheader">';
echo '<h1>'.$post['title'].'</h1>';
echo '<h5>by '.$post['author'].' at '.$post['date'].' in '.$post['category'].'</h5>';
echo '</div>';
echo '<p>'.$post['fullpost'].'</p>';
echo '</div>';
//display comments form
?>
<div id="commentform">
<form action="commentsubmit.php" method="POST" class="commentform"/>
<?php
//if not logged in, display a name field
if (!loggedIn()) {
echo '<label for="author">Name: </label><br />';
echo '<input type="text" name="author" class="required"/><br />';
}
?>
<label for="comment">Comment: </label><br />
<textarea type="text" name="comment" class="required"></textarea><br />
<input type="hidden" value="<?php echo $id; ?>" name="postid"/>
<input type="submit" name="submit" Value="Submit" id="sendbutton" class="button"/>
</form>
</div>
<?php
}
else {
//no posts found
echo "That post doesn't exist!";
}
$result = queryDB('SELECT * FROM comments WHERE postid='.$id.' ORDER BY date DESC');
$numcomments = mysql_num_rows($result);
//comments found, display them
if (mysql_num_rows($result) >0) {
if (mysql_num_rows($result) == 1) {
echo '<h5>'.$numcomments.' Comment:</h5>';
}
if (mysql_num_rows($result) > 1) {
echo '<h5>'.$numcomments.' Comments:</h5>';
}
while($comment = mysql_fetch_array($result)) {
echo '<h6> by '.$comment['author'].' on '.$comment['date'].'</h6>';
echo '<p>'.$comment['text'].'</p>';
}
}
else {
//no comments found
echo '<h4>No comments</h4>';
}
?>
</div>
</body>
</html>
Here's the page it submits to. (commentnew.php)
<?php
//creates a new comment
include('functions.php');
//form submitted
if (isset($_POST['submit'])) {
//set $author if not logged in
if(!loggedIn()) {
//check if username is taken
connectDB();
$result = queryDB("SELECT * FROM users WHERE username='".$_POST['author']."'");
if (mysql_num_rows($result) > 0) {
die('That name is taken!');
}
else {
//username is not taken
$author = mysql_real_escape_string($_POST['author']);
}
}
else {
//user is logged in, set author to their username
$author = $_SESSION['username'];
}
//$author is set, submit
if (!empty($author)) {
$postid = mysql_real_escape_string($_POST['postid']);
$comment = mysql_real_escape_string($_POST['comment']);
$date = mysql_real_escape_string(date("Y-m-d")." ".date("H:i:s"));
queryDB('INSERT INTO comments (postid,date,author,text) VALUES ("'.$postid.'","'.$date.'","'.$author.'","'.$comment.'")');
echo 'Comment Sent!';
}
}
?>
I tried using $.ajax in the script tags, but it seems to do nothing. Can I get an example of how to properly use it? How do I get it to pull the message from commentnew.php? Am I going about checking for the username the wrong way? Should I be using jQuery's validation plugin somehow?
in general:
var form = $("form.commentform");
$.post(form.attr('action') , form.serialize(), function(data) {
alert("Response: " + data);
});
Try this
$("form.commentform").submit(function(e){
e.preventDefault();
$.post({
url: $(this).attr('action'),
data: $(this).serialize(),
success: function(reponse){
//here response will contain whatever you send from the server side page
}
});
}):
Look into jquery ajax function. That's what I use. http://api.jquery.com/jQuery.ajax/
加载中,请稍侯......
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