CODEWITHSUNDEEP
javascript
alkhader
alkhader

Reputation: 998

Error message in Javascript

I have a PHP code:

  if($billing_total>$limit_to_send){

    echo '<script type="text/javascript">
    window.onload = function() {
    alert("Sorry, you do not have enough credit");
 }
   </script>';

When I am printing this message, it is being printed at the beginning of the PHP page as below:

  <script type="text/javascript">
                window.onload = function() {
                alert("Sorry, you do not have enough credit");
             }
               </script>

        <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

        <html xmlns="http://www.w3.org/1999/xhtml">
        <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        -----------------------------------------------------------

This caused the header (logo) of my page in the browser to move down one line.

and the page will look very bad because all the items there will be moved down one line.

I hope it is clear to you. Please any solution ?

===========================================================================

Thanks for All ...

Solution:

$alert_message=<script type="text/javascript">
    window.onload = function() {
    alert("Sorry, you do not have enough credit");
 }
   </script>

Printing $alert_message somewhere in the HTML code before the body tag ^_^

Upvotes: 0

Views: 174

Answers (3)

Martin Hennings
Martin Hennings

Reputation: 16866

Make sure you never output anything before the DTD (doctype declaration).

See this question for more information...

The doctype declaration must be the first element of your html page, it's from what the browser decides how to handle the rest of the html code. Outputting anything before that will probably put your browser in quirks mode so you can't be sure how the browser will render your page.

How to avoid this?

The echo command gets executed as its line is reached, and it seems that the rest of your html code follows after that.

You could either

  • move the html DTD and header to the top of your php (but sometimes that is not possible) OR
  • store the error html in a variable, so instead of echo '<script ... do $errorhtml = '<script ... and output that string, if not empty, at a specific place in the head or body generating code of your php.
  • If you have no control over the original source, you could consider redirecting to an error page with its own html DTD, header and body which you can design as fits you best.

Upvotes: 2

filype
filype

Reputation: 8400

This shows a bad design of your application. I would suggest you change it to something like:

$errors = array();
if($billing_total>$limit_to_send){
  $errors[] = 'Sorry, you do not have enough credit'; 
}

Then on your HTML file, before the <body> tag closes, read your array and display any errors

<?php if(is_array($errors)): ?>
  <script type="text/javascript">
   <?php foreach($errors as $error): ?>         
        alert('<?php echo $error; ?>');
   <?php endforeach; ?>
  </script>
<?php endif; ?>

Upvotes: 1

Manishearth
Manishearth

Reputation: 16198

Either append die() into the if codeblock or have your php print the script somewhere in the body or head.

Upvotes: 1

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