Warning: Cannot modify header information – headers already sent

Question

I've checked the offical "How do I solve the Headers already sent warning problem?" and have resolved a whitespace problem, changing:

function mhm_footerheader_position ()

to

function mhm_footerheader_position(), but at /wp-login.php, we still receive the error:

Warning: Cannot modify header information – headers already sent by (output started at /home/username/public_html/wp-content/themes/genesis-sample/mhm-functions.php:281) in /home/username/public_html/wp-login.php on line 394

Here is mhm-functions.php from line 280:

function mhm_footerheader_position() {
    echo '<div id="footer-header"><div class="wrap">';
    genesis_widget_area('footer-header');
    echo '</div></div>';
}

add_action ('widgets_init','mhm_footerheader_position');

Help appreciated.

Answer 1

First of all, you misunderstood "How do I solve the Headers already sent warning problem?"

As you said, you've changed:

function mhm_footerheader_position ()

to:

function mhm_footerheader_position()

The only difference I see is the space between mhm_footerheader_position and (). The whitespace problem in header already sent error, isn't about the space between function_name and (). It's about space that gets into the output before any HTTP header is sent.

Secondly, you don't want to output anything in widgets_init action, this the the wrong place for any output. The error you are getting is because you are giving output in widgets_init action and in wp-login.php HTTP header is being sent after this action hook.

I can't say exactly where you want to output the footer-header widget area, it depends on your theme. However, the following CODE will output it in the footer and solve your Error:

    function mhm_footerheader_position () {
        echo '<div id="footer-header"><div class="wrap">';
        genesis_widget_area('footer-header');
        echo '</div></div>';
    }

    add_action ('wp_footer','mhm_footerheader_position');

You may read this to understand the Hearer Already Send Error better.