WordPress Plugin for kitten placeholders. Defines an action and a shortcode.

placekitten.php

<?php
/*
Plugin Name: Placekitten
Description: Shortcode [placekitten w=100 h=300 g=1 alt=kitten] and action.
Version:     1.0
Author:      Thomas Scholz
Author URI:  http://toscho.de
License:     GPL
*/

if ( ! function_exists( 'placekitten' ) )
{
	/**
	 * Creates an image from placekitten.com. Shortcode handler.
	 *
	 * Usage: [placekitten w=100 h=300 g=1 alt=kitten]
	 *
	 * @param  array $atts
	 * @return string
	 */
	function placekitten( $atts = array() )
	{
		$args = (object) array_merge( array ( 'w' => 300, 'h' => 200,	'alt' => 'Kitten', 'g' => 0 ), $atts );

		return "<img src='http://placekitten.com/"
			. ( 0 !== (int) $args->g ? 'g/' : '' )
			. "$args->w/$args->h' alt='$args->alt'>";
	}

	/**
	 * Prints a placekitten.
	 *
	 * Usage: do_action( 'placekitten', array ( 'w' => 100 ) );
	 *
	 * @param  array $args
	 * @return void
	 */
	function print_placekitten( $args )
	{
		print placekitten( $args );
	}
	add_shortcode( 'placekitten', 'placekitten' );
	add_action( 'placekitten', 'print_placekitten', 10, 1 );
}