Mark Comments by Current User

To highlight comments of the currenly logged-in user, add this plugin:

<?php
/*
Plugin Name: Comment Class for Logged-In User
Plugin URI: n/a
Description: add the comment_class .comment-author-logged-in for the comments of logged-in users.
Version: 1.0
Author: alchymyth
Author URI: http://transformationpowertools.com
License: GPL2
*/

add_filter( 'comment_class', 'comment_class_logged_in_user' );

function comment_class_logged_in_user( $classes ) {
	global $comment;
	if ( $comment->user_id > 0 && is_user_logged_in() ) {  
		global $current_user; get_currentuserinfo(); 
		$logged_in_user = $current_user->ID;  
		if( $comment->user_id == $logged_in_user ) $classes[] = 'comment-author-logged-in';
	}
return $classes;
}

//  requires formatting of the css class: 
//  .comment-author-logged-in { }
?>

Add a file with the above code into the /wp-content/plugins folder; activate the plugin under ‘appearance – plugins – installed plugins’; and add a corresponding style to the stylesheet of the currently used theme.

The code compares the comment author’s ID with the ID of the logged-in user, and adds the class .comment-author-logged-in to the ‘comment_class’ output.

Posts in Two Or Three Columns – Twenty Twelve

If your index and archive pages are getting too long, or if you want to compact the information within those pages a little bit, for instance because the featured images above each post are just too large, consider to change the template to show the posts in two columns.

This is easier done than said, with some useful css classes injected into the output of the ‘post_class()’ in the div of each post, together with some rather simple css.

For instance, to change the category archive into two columns, without editing category.php itself, add a filter function into functions.php (as always with the default themes of WordPress, this  is done within a child theme):

add_filter('post_class','category_two_column_classes');

function category_two_column_classes( $classes ) {
global $wp_query;
if( is_category() ) :
$classes[] = 'two-column-post';
if( $wp_query->current_post%2 == 0 ) $classes[] = 'two-column-post-left';
endif;
return $classes;
}

The minimum css for this is:

.two-column-post { width: 47%; float: left; margin-left: 5.9%; }
.two-column-post-left { clear: left; margin-left: 0; }

If you want to apply the same principle for instance to the posts page or other archives, replace

is_category()

with another conditional tag like

is_home()

.
The code is easily adapted to three columns (or actually any number of columns) by changing the number in the modulus operator:

add_filter('post_class','category_three_column_classes');

function category_three_column_classes( $classes ) {
global $wp_query;
if( is_category() ) :
$classes[] = 'three-column-post';
if( $wp_query->current_post%3 == 0 ) $classes[] = 'column-post-left';
endif;
return $classes;
}

the css for three columns would be:

.three-column-post { width: 30%; float: left; margin-left: 4.9%; }
.column-post-left { clear: left; margin-left: 0; }

Advanced Filter for Tag Cloud Widget Css Classes

tag cloud widget colored with css
tag cloud widget advanced color styling

The default tag cloud widget does not offer a lot of formatting possibilities, partly because it only outputs one css class with a reference to the tag ID.
It uses an inline style, which outputs the font-size, to distinguish the tags according the number of post they belong to.

This filter function is coded to add a css class with the tag slug .tag-slug-{slug} and with a rounded tag size .tag-size-{number}, and to remove the inline style.

add_filter ( 'wp_tag_cloud', 'tag_cloud_widget_advanced_classes' );  

function tag_cloud_widget_advanced_classes( $taglinks ) { 
	$tags = explode('</a>', $taglinks);
	$regex1 = "#(.*tag-link[-])(.*)(' title.*)#e";         
	$regex2 = "#(.*style='font-size:)(.*)((pt|px|em|pc|%);'.*)#e"; 
	$regex3 = "#(style='font-size:)(.*)((pt|px|em|pc|%);')#e";         
	$regex4 = "#(.*class=')(.*)(' title.*)#e";         
	foreach( $tags as $tag ) {         
		$tag = preg_replace($regex1, "('$1$2 tag-slug-'.get_tag($2)->slug.'$3')", $tag ); //add .tag-slug-{slug} class   
		$size = preg_replace($regex2, "(''.round($2).'')", $tag ); //get the rounded font size       
		$tag = preg_replace($regex3, "('')", $tag ); //remove the inline font-size style
		$tag = preg_replace($regex4, "('$1tag-size-'.($size).' $2$3')", $tag ); //add .tag-size-{nr} class
		$tagn[] = $tag;
	}     
	$taglinks = implode('</a>', $tagn);     
return $taglinks; 
}

For the code, also see the pastebin.

The added css classes can for instance be used to color the tags according to the number of appearance; as you can see here in the tag cloud when you scroll down on the left.

Twenty Eleven – Sidebar on Single Posts and Pages

The new default theme of WP3.2 – Twenty Eleven – is a very versatile theme.
However, the ‘missing’ sidebar on single posts or pages is quite disturbing for some users, loosing their advertising space or the main navigation.
To get the sidebar back is not that simple – style.css is quite complex, and the layout of a single post or page is done with a clever use of a specially introduced css class in the body tag.

First step

Create a child theme.

– create a new sub-folder under the /wp-content/themes folder, for instance: twentyelevenchild;
– add a style.css file to that folder; content:

/*
Theme Name: Twenty Eleven Child
Author: alchymyth
Description: a child theme, based on the 2011 theme for WordPress
Author URI: http://wordpress.org/
Template: twentyeleven
*/

@import url(../twentyeleven/style.css);

– add a functions.php file to that folder; to be used later;
– optional: add a screenshot.jpg image to that folder, depicting the design of your child theme.

Second step

Add the call of the sidebar back.

Edit single.php and/or page.php and add

<?php get_sidebar(); ?>

before the line

<?php get_footer(); ?>

Third step

Suppress the .singular body_class from the single post or page.

To achieve this, add a filter to your new functions.php in your child theme folder.

add_filter('body_class', 'blacklist_body_class', 20, 2);
function blacklist_body_class($wp_classes, $extra_classes) {
if( is_single() || is_page() ) :
// List of the classes to remove from the WP generated classes
$blacklist = array('singular');
// Filter the body classes
  foreach( $blacklist as $val ) {
    if (!in_array($val, $wp_classes)) : continue;
    else:
	  foreach($wp_classes as $key => $value) {
	  if ($value == $val) unset($wp_classes[$key]);
	  }
    endif;
  }
endif;   // Add the extra classes back untouched
return array_merge($wp_classes, (array) $extra_classes);
}

(resources:
http://dev-tips.com/featured/remove-an-item-from-an-array-by-value
http://wordpress.stackexchange.com/questions/15850/remove-classes-from-body-class )

Fourth step

Fine-tuning of style.css

For instance:

.single #author-info {
	background: #f9f9f9;
	border-top: 1px solid #ddd;
	border-bottom: 1px solid #ddd;
	margin: 2.2em 0% 0 0%;
	padding: 20px 35.4%;
}

There might be some more details which can be changed while customizing the styles of the child theme.

edit: thanks to member smijos of the wordpress support forum:
some more styles, for the comment section, to make the theme look good:

#respond {
width: auto;
}
.commentlist {
width: auto;
}
.commentlist > li.comment {
margin: 0px 0px 20px 102px;
width: auto;
}

PS: A Few Different Cases

(updated and expanded)

this all concerns this line of code:

if( is_single() || is_page() ) :

1) if you rather use the sidebar-page template that comes with the theme, to control if and when to show a sidebar on a static page, simply don’t edit page.php, and remove

|| is_page()

from that line.

2) Zeaks pointed out that the code also effects single attachment pages.

if you want the sidebar in these pages, edit image.php and add

<?php get_sidebar(); ?>

before the ‘get_footer’ line; also adapt the style of

.image-attachment div.attachment

.

if you want your single attachment pages without sidebar, change to:

if( (is_single() && !is_attachment()) || is_page() ) :

PPS

If you don’t like coding, please do still create the child theme; however, for the rest, there is a plugin available:
‘Twenty Eleven Theme Extensions’