php - preg_match issue with empty form fields on update query - php

Question

The following flags an error if a form field is empty and also flags an error if anything other than letters are entered in the form input.
if (empty($_POST["feedtitle"])) {
$has_errors = true;
$feedtitleErr = "Enter feed title";
} elseif (preg_match('/[^a-zA-Z]/i',$_POST["feedtitle"])) {
$has_errors = false;
$feedtitleErr = "Enter text only";
} else {
$feedtitle = validate_input($_POST["feedtitle"]);
}
When created the form this works fine. When editing the form data however is the input is left empty the empty field error "Enter feed title" does not fire and if I enter anything other than letters e.g. numbers no value is passed i.e. the variable $feedtitle is blank. If I enter text however it saves.
I don't think the query is the issue.
$Query = "UPDATE ccregisterfeed SET author='$author', category='$category',
copyright='$copyright', feeddescription='$feeddescription', feedtitle='$feedtitle',
websitelink='$websitelink', imagelink='$imagelink', imagetitle='$imagetitle',
subtitle='$subtitle' WHERE id='$feedid' AND username ='$user'";
FULL SCRIPT
<?php
include "connect.php";
require "authenticate.php";
error_reporting(E_ERROR);
$message = $_GET['message'];
$user = $_SESSION['UserName'];
//declare form field and form field error variables
$authorErr = $categoryErr = $copyrightErr = $feeddescriptionErr = $feedlinkErr = $feedtitleErr = $websitelinkErr = $imagelinkErr = $imagetitleErr = $subtitleErr = "";
$author = $category = $copyright = $feeddescription = $feedlink = $feedtitle = $websitelink = $imagelink = $imagetitle = $subtitle = "";
//form field validation
function validate_input($data)
{
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
if (isset($_POST['Submit']))
{
$has_errors = false;
if (empty($_POST["author"])) {
$has_errors = true;
$authorErr = "Enter your name";
}else{
$author = validate_input($_POST["author"]);
}
if (empty($_POST["category"])) {
$has_errors = true;
$categoryErr = "Enter a category";
}else {
$category = validate_input($_POST["category"]);
}
if (empty($_POST["copyright"])) {
$has_errors = true;
$copyrightErr = "Enter copyright details";
} else {
$copyright = validate_input($_POST["copyright"]);
}
if (empty($_POST["feeddescription"])) {
$has_errors = true;
$feeddescriptionErr = "Enter feed description";
} else {
$feeddescription = validate_input($_POST["feeddescription"]);
}
if (empty($_POST["feedtitle"])) {
$has_errors = true;
$feedtitleErr = "Enter feed title";
} elseif (preg_match('/[^a-zA-Z]/i',$_POST["feedtitle"])) {
$has_errors = true;
$feedtitleErr = "Enter text only";
} else {
$feedtitle = validate_input($_POST["feedtitle"]);
}
if (empty($_POST["websitelink"])) {
$has_errors = true;
$websitelinkErr = "Enter link to website";
} else {
$websitelink = validate_input($_POST["websitelink"]);
}
if (empty($_POST["imagelink"])) {
$has_errors = true;
$imagelinkErr = "Enter link to image";
} else {
$imagelink = validate_input($_POST["imagelink"]);
}
if (empty($_POST["imagetitle"])) {
$has_errors = true;
$imagetitleErr = "Enter image name";
} else {
$imagetitle = validate_input($_POST["imagetitle"]);
}
if (empty($_POST["subtitle"])) {
$has_errors = true;
$subtitleErr = "Enter feed subtitle";
} else {
$subtitle = validate_input($_POST["subtitle"]);
}
// var_dump ($date);
// var_dump ($feedlink);
// var_dump ($feeddescription);
//write edited data into tables matching logged in user with their data
$feedid = mysql_real_escape_string($_POST['feedid']);
$date = date("Y-m-d H:i:s");
$feeddescription = str_replace("_", "", $feeddescription);
$feeddescription = str_replace("-", "", $feeddescription);
$feeddescription = str_replace("!", "", $feeddescription);
$feeddescription = str_replace("#", "", $feeddescription);
$feeddescription = str_replace("'", "", $feeddescription);
$Query = "UPDATE ccregisterfeed SET author='$author', category='$category', copyright='$copyright', feeddescription='$feeddescription', feedtitle='$feedtitle', websitelink='$websitelink', imagelink='$imagelink', imagetitle='$imagetitle', subtitle='$subtitle' WHERE id='$feedid' AND username ='$user'";
if($sql = mysql_query($Query)) {
header("location: rss.php");
// header("location: feededit.php");
} else {
die("Query was: $Query. Error: ".mysql_error());
}
}
//show logged in user their updated data
$user = $_SESSION['UserName'];
$result = mysql_query("SELECT * FROM ccregisterfeed WHERE username = '$user'") or die(mysql_error());
while($row = mysql_fetch_array($result)){
$id=$row['id'];
$author = $row['author'];
$category = $row['category'];
$copyright = $row['copyright'];
$feeddescription = $row['feeddescription'];
$feedtitle = $row['feedtitle'];
$websitelink = $row['websitelink'];
$imagelink = $row['imagelink'];
$imagetitle = $row['imagetitle'];
$subtitle = $row['subtitle'];
}
//delete form and image data when users clicks delete button
if (isset($_POST['Delete'])){
$deleteuser = $_POST['Delete'];
mysql_query("DELETE FROM ccregisterfeed WHERE id = '$deleteuser'");
mysql_query("ALTER TABLE ccregisterfeed AUTO_INCREMENT = 1");
$message = 'Feed Deleted';
header("Location: feededit.php?&message=".urlencode($message));
}
?>
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<form action="feededit.php" method="post" enctype="multipart/form-data" name="edit" id="editfeed">
<fieldset>
<div class="legendcreate">Feed Edit</div>
<div class="feedcontainer">
<div class="feedcontainerinner">
<div><label class="labelshow">Author</label><input id="author" class="insetfeed" name="author" type="text" placeholder="Author" value="<?PHP print $author ; ?>"/><p class="errorinput"><?php echo $authorErr;?></p></div>
<?php if(isset($_GET['message']) && !empty($message)): ?>
<div class="messagebox">
<?php echo $message ?>
</div>
<?php endif; ?>
<div><label class="labelshow">Category</label><input id="category" class="insetfeed" name="category" type="text" placeholder="Category" value="<?PHP print $category; ?>"/><p class="errorinput"><?php echo $categoryErr;?></p></div>
<div><label class="labelshow">Copyright</label><input id="copyright" class="insetfeed" name="copyright" type="text" placeholder="Copyright" value="<?PHP print $copyright; ?>"/><p class="errorinput"><?php echo $copyrightErr;?></p></div>
<div><label class="labelshow">Feed Title</label><input id="feedtitle" class="insetfeed" name="feedtitle" type="text" placeholder="Feed Title" value="<?PHP print $feedtitle; ?>"/><p class="errorinput"><?php echo $feedtitleErr;?></p></div>
<div><label class="labelshow">Website Link</label><input id="websitelink" class="insetfeed" name="websitelink" type="text" placeholder="Website Link" value="<?PHP print $websitelink; ?>"/><p class="errorinput"><?php echo $websitelinkErr;?></p></div>
<div><label class="labelshow">Image Link</label><input id="imagelink" class="insetfeed" name="imagelink" type="text" placeholder="Image Link" value="<?PHP print $imagelink; ?>"/><p class="errorinput"><?php echo $imagelinkErr;?></p></div>
<div><label class="labelshow">Image Title</label><input id="imagetitle" class="insetfeed" name="imagetitle" type="text" placeholder="Image Title" value="<?PHP print $imagetitle; ?>"/><p class="errorinput"><?php echo $imagetitleErr;?></p></div>
<div><label class="labelshow">Subtitle</label><input id="subtitle" class="insetfeed" name="subtitle" type="text" placeholder="Subtitle" value="<?PHP print $subtitle; ?>"/><p class="errorinput"><?php echo $subtitleErr;?></p></div>
<div><textarea id="description" name="feeddescription" class="textareadescription" placeholder="Enter feed description"><?php
$out = htmlspecialchars_decode($feeddescription);
$out = str_replace( '\n', '<br />', $out );
echo $out;
?></textarea>
<div class="submit"><input name="Submit" type="submit" class="submitbtn" value="Save"/></div>
<div class="delete"><input name="deletebtn" type="submit" class="resetbtn" value="Delete"/></div>
<input type="hidden" name="feedid" value="<?phpecho $id;?>"/>
</div>
</div>
</div>
</form>
</fieldset>