BuddyPress.org

Success! Solution found here.

The Javascript:

<script type = "text/javascript">

function copyinput()

{

var tmp = document.getElementById('blog_title').value;

tmp = tmp.toLowerCase().replace(/^s+|s+$/g, "").replace(/[_|s]+/g, "");

tmp = tmp.replace(/[^a-z0-9-]+/g, "").replace(/[-]+/g, "-").replace(/^-+|-+$/g, "");

document.getElementById('blogname').value = tmp;

}

</script>

The customized function:

function custom_signup_show_blog_form( $blogname = '', $blog_title = '', $errors = '' ) {

global $current_site;



?>

<div id="blog-details-fields">



<label for="blog_title">Blog title</label>

<?php if ( $errmsg = $errors->get_error_message('blog_title') ) { ?>

<p class="error"><?php echo $errmsg ?></p>

<?php }

echo '<input name="blog_title" type="text" id="blog_title" value="'.wp_specialchars($blog_title, 1).'" maxlength="24" onkeyup="copyinput()"/></p>';



// Blog name

if ( 'no' == constant( "VHOST" ) )

echo '<label for="blogname">' . __('Blog Name:', 'buddypress') . '</label>';

else

echo '<label for="blogname">' . __('Blog Domain:', 'buddypress') . '</label>';



if ( $errmsg = $errors->get_error_message('blogname') ) { ?>

<p class="error"><?php echo $errmsg ?></p>

<?php }



if ( 'no' == constant( "VHOST" ) ) {

echo '<span class="prefix_address">' . $current_site->domain . $current_site->path . '</span><input name="blogname" type="text" id="blogname" value="'.$blogname.'" maxlength="50" /><br />';

} else {

echo '<input name="blogname" type="text" id="blogname" value="'.$blogname.'" maxlength="50" /><span class="suffix_address">.' . $current_site->domain . $current_site->path . '</span><br />';

}



if ( !is_user_logged_in() ) {

echo '<p class="help-text">';

print '(<strong>' . __( 'Your address will be ', 'buddypress'  );

if( 'no' == constant( "VHOST" ) ) {

print $current_site->domain . $current_site->path . __( 'blogname', 'buddypress'  );

} else {

print __( 'domain.', 'buddypress'  ) . $current_site->domain . $current_site->path;

}

echo '</strong>. ' . __( 'Must be at least 4 characters, letters and numbers only. It cannot be changed so choose carefully!)', 'buddypress'  ) . '</p>';

echo '</p>';

}

?>

<p>

<label for="blog_public_on"><?php _e( 'I would like my blog to appear in search engines like Google and Technorati, and in public listings around this site.', 'buddypress' ); ?> </label>

<label class="checkbox" for="blog_public_on">

<input type="radio" id="blog_public_on" name="blog_public" value="1" <?php if( !isset( $_POST['blog_public'] ) || '1' == $_POST['blog_public'] ) { ?>checked="checked"<?php } ?> />

 <?php _e( 'Yes', 'buddypress' ); ?>

</label>

<label class="checkbox" for="blog_public_off">

<input type="radio" id="blog_public_off" name="blog_public" value="0" <?php if( isset( $_POST['blog_public'] ) && '0' == $_POST['blog_public'] ) { ?>checked="checked"<?php } ?> />

 <?php _e( 'No', 'buddypress' ); ?>

</label>

</p>

</div>

<?php

do_action('signup_blogform', $errors);

}

What this does:

When the user starts typing the blog title – limited to 24 chars – the Javascript dynamically fills in the blogname for the URL.

The user can manually change the blogname if he/she wants. Not sure how that would work out…

You could probably also hide the blogname field, either through type=”hidden” or CSS. Haven’t tested all these options yet.

But imho this looks like a very versatile solution.

Or have I overlooked some critical issues? Comments very much appreciated!