form validation: display error messages questions.

[duuudie]

Hi dears

I have a little question about the best logical way to display error messages when a user forgot to fill in a form field. I am trying to avoid the awful 'echo-blank-page' solution here. I have been trying a few things instinctively, but I think that I need a little boost here from more knowledgeable people than me.

Here we go (that's my actual code, in progress, and that's as far as I can go by myself):

//if the member has submitted the text to be edited yet.

$error='';

if ( isset($_POST['edit']) ) {
    
    //just a patanoid check.
    if ( $_POST['userID'] != $_SESSION['userID'] ) {
        $auth->logout();
    }else{
    
    //check that the fields are not empty
    
        if ( ($_POST['title']='') or ($_POST['text']!='') ) {
            $error .= 'Please make sure that you have filled in all the fields.';
            $errorCheck = true;
        }else{
            $title=$_POST['title'];
            $text=$_POST['text'];
            $textID=$_POST['textID'];
            $userID=$_SESSION['userID'];
    
            $sql =
             "UPDATE userstexts 
             SET
             textTitle = '$title'
             , textText = '$text'
             , newAdmin = 1
             WHERE
             textID = $textID
             AND userID = $userID";
 
             $db->query($sql);

            header("Location:userCP_index.php"); 
            exit;
        }
    }
} 

//if the member has not submitted the text to be edited yet.
if ( !isset($_POST['edit']) ) {
    
    //**********checks that both textID and userID are set, if not, log out!**********
        
    if ( (!isset($_GET['textID'])) or (!isset($_SESSION['userID'])) ) {
        $auth->logout();
    }else{
        $textID=$_GET['textID'];
        $userID=$_SESSION['userID'];
    }

    $sql =
    "SELECT textID
    , textTitle
    , textText 
    FROM userstexts 
    WHERE textID = $textID 
    AND userID = $userID
    ORDER BY textID DESC"; 
        
    $result=$db->query($sql);
        
    //**********the users must have texts to edit**********
    //**********if he tries to access this page without any texts to edit,**********
    //**********he gets logged out.**********
        
    if ( $result->size() == 0 ) {
        $auth->logout();
    }
        
    $row = $result->fetch(); 

and here is the form (in the same page) with the error message to display:

            <p><?=$error?></p>
            
            
            
            <form action="<?=$_SERVER['PHP_SELF']?>" method="POST">
    
            <div class="quickReply">
                <p class="centre" style="text-align:centre;">
                <input type="text" name="title" id="title" value="<?=$row['textTitle']?>" />
                </p>
                <p class="centre" style="text-align:centre;">
                <textarea rows="10" cols="30" name="text" id="text"><?=$row['textText']?></textarea>
                </p>
                <input type="hidden" name="textID" value="<?=$textID?>" />
                <input type="hidden" name="userID" value="<?=$userID?>" />
                <p class="centre" style="text-align:centre;">
                <input type="submit" name="edit" value="edit" />
            </div>
        
            </form>

thanks in advance for your help

[duuudie]

Hi again

Ok I have found the solution. It was about the place of my ifs and elses.

Here is the solution, just in case. Please feel free to critic my code, that's the best way for me to improve my skills:

//if the member has submitted the text to be edited yet.

$error='';

if ( isset($_POST['edit']) ) {
    //check that the fields are not empty
    if ( ($_POST['title']=='') or ($_POST['text']=='') ) {
        $error .= 'Please make sure that you have both the title and text fields are not empty';
        $errorCheck = 1;
    }else{
        $title=$_POST['title'];
        $text=$_POST['text'];
        $textID=$_POST['textID'];
        $userID=$_SESSION['userID'];
    
        $sql =
         "UPDATE userstexts 
         SET
         textTitle = '$title'
         , textText = '$text'
         , newAdmin = 1
         WHERE
         textID = $textID
         AND userID = $userID";
 
         $db->query($sql);

        header("Location:userCP_index.php"); 
        exit;
    }
}

//if the member has not submitted the text to be edited yet.
if ( !isset($_POST['edit']) or $errorCheck == 1 ) {
    
    //**********checks that both textID and userID are set, if not, log out!**********
        
    if ( (!isset($_GET['textID'])) or (!isset($_SESSION['userID'])) ) {
        $auth->logout();
    }else{
        $textID=$_GET['textID'];
        $userID=$_SESSION['userID'];
    }

    $sql =
    "SELECT textID
    , textTitle
    , textText 
    FROM userstexts 
    WHERE textID = $textID 
    AND userID = $userID
    ORDER BY textID DESC"; 
        
    $result=$db->query($sql);
        
    //**********the users must have texts to edit**********
    //**********if he tries to access this page without any texts to edit,**********
    //**********he gets logged out.**********
        
    if ( $result->size() == 0 ) {
        $auth->logout();
    }
        
    $row = $result->fetch(); 

[dklynn]

duuudie,

Hi again!

What you've done is learn about "sticky forms" about a day or so after I'd studied up on them (good section in Ullman's book, too).

The LOGIC I've used has been:

1. Test for 'submit' and VALUE of 'submit' to ensure it came 
    from my form.

1a. Create a blank $error message.
1b. Test each form value and, if error, ADD to $error (including 
     <p style='color:red;' > ... </p> tags)

2. Test if $error NOT still empty

2a. PREpend a header on the $error message (<h3 style ...)

ELSE

2b. use header('Location: Processing.php'); to send to the 
     processing page (if different)
2c. exit;

3.  Write webpage header info down to text that you want to 
     replace with the $error message.

4.  Test 'submit' again ... same as above.

4a.  echo $error message

ELSE

4b.  echo original introductory (PRIOR to form) text

5.  Write form

5a.  Be sure to include 
      value="<?= isset($_POST['formelementname'])
      ? echo $_POST['formelementname]' 
      : echo 'default value'; ?>" 
      to retain the values submitted in any form submission 
      which failed.

Okay, you'd said you'd found your error (placement of IF and ELSE constructs) but I hope that this helped anyway.

Regards,

DK

[duuudie]

duuudie,
Okay, you'd said you'd found your error (placement of IF and ELSE constructs) but I hope that this helped anyway.

indeed

thanks a lot

[dklynn]

duuudie,

indeed

thanks a lot

You're very welcome.

Regards,

DK

[warjockey]

Also if you wanted the errors to appear beside the field it's for, you could put the form in a function and have the errors passed as parameters to it and echo the errors wherever you like.