Wordpress wp_redirect error

Question

I am trying to redirect this page if the user is logged in or not be i keep getting this error

Warning: Cannot modify header information - headers already sent by (output started at /home/*******/*********.com/wp-content/plugins/graph2.php:54) in /home/*******/*********.com/wp-includes/pluggable.php on line 934

Im using this redirect method

<?php if ( is_user_logged_in() ) { 
        echo ''; 
    } 
        else { 
    wp_redirect( 'http://www.example.com' );    
    } 
?>

I cant seem to figure out what is wrong.

:) thanks

Answer 1

Replace wp_redirect( 'http://www.example.com' ); with wp_redirect( 'http://www.example.com' ); exit;

Answer 2

The problem is most likely from whitespaces in the graph2.php line 54. Delete the white spaces which might be after the closing ?> php tag, that should solve the problem.

Its best practice to follow wp_redirect( 'http://www.example.com' ); with exit();

Answer 3

you might have to delete <?php get_header(); ?> from the top of your file and make your code on the very 1st line of your file

Answer 4

This is the result of a poorly coded plugin I'm afraid. If you know PHP well enough, you might try modifying the wp-content/plugins/graph2.php file that is mentioned, and make sure that the first line starts with <?php (no spaces or blank lines) and that the file does not output anything else when it's first loaded. You should exclude the closing ?> tag in the file as well, just to be on the safe side. (Yes, this is legal PHP)

You'll also likely find that your page output and RSS feed has blank lines or extra content at the top of it, and RSS will be broken in some versions of IE as a result.

Plugin quality REALLY VARIES from author to author, and it takes some effort to screen the quality of the plugins you use, but this unfortunate case shows why that really is necessary.