I had posted a question on Short Codes to the wp-hackers mailing list and got a pointed to an article on the Codex which explained the process of coding up a short code.  I expected it to be more involved than it was and I was pleasantly surprised to find it was really straight forward.  I have already implemented one short code for the wp-SwimTeam plugin and expect I’ll have half a dozen more done by the end of the week.

What I implemented for Flickr was pretty simple – it allows the insertion of a Flickr slideshow in a post or page using the Flickr UserId value (which is different than the username) and the Set Id.  Here is the snippet of code:

/**
 * wpst_flickr_slideshow shortcode handler
 *
 * Build a short code handler to display a Flickr slide show.
 *
 * [wpst_flickr_slideshow userid="id" slideshowid="id"
 *     frameborder="pixels" *     width="pixels" height="pixels"
 *     scrolling="yes|no" align="left|center|right" view="yes|y"]
 *
 * To show this Flickr slide show:
 *
 * http://www.flickr.com/photos/27604893@N04/sets/72157605764227907/show
 *
 * Use this shortcode:
 *
 * [wpst_flickr_slideshow userid="27604893@N04" slideshowid="72157605764227907"]
 *
 * This is the resulting IFRAME tag which is returned to the caller.
 *
 * <iframe align=center src=http://www.flickr.com/slideShow/index.gne?
 *     user_id=27604893@N04&set_id=72157605761943480 frameBorder=0
 *     width=500 scrolling=no height=500></iframe>
 *
 * If the 'view="yes"' or 'view="y"' attribute is include, a linl to the
 * Flickr slideshow will be placed under the IFRAME.
 *    
 * @param array - shortcode attributes
 * @return string -  HTML code
 */
function wpst_flickr_slideshow_sc_handler($atts)
{
    $c = container() ;

    //  Parse the shortcode
 
    extract(shortcode_atts(array(
        'userid' => '',
        'slideshowid' => '',
        'frameborder' => 'default 0',
        'width' => '500',
        'height' => '500',
        'scrolling' => 'no',
        'align' => 'center',
        'view' => 'no',
    ), $atts)) ;

    //  If either the userid or slideshowid are missing then
    //  we have a problem and can't do anything meaningful.

    if (empty($userid) || empty($slideshowid))
    {
        $c->add(html_br(),
            html_b("wpst_flickr_slideshow::Invalid Shortcode Syntax"),
            html_br(2)) ;

        return $c->render() ;
    }

    $if_src = "http://www.flickr.com/slideShow/index.gne?" .
        sprintf("user_id=%s&set_id=%s frameBorder=%s align=%s",
            $userid, $slideshowid, $frameborder, $align) ;

    $c->add(html_iframe($if_src, $width, $height, $scrolling)) ;

    if (($view == 'yes') || ($view == 'y'))
    {
        $link = "http://www.flickr.com/slideShow/index.gne?" .
        sprintf("user_id=%s&set_id=%s", $userid, $slideshowid) ;

        $c->add(html_br(2), html_a($link, "View this slideshow on Flickr."), html_br(2)) ;
    }

 return $c->render() ;
}

The code above makes use of the phpHtmlLib to generate HTML code but the general intent should be pretty obvious.