mitcho.com » PHP

Extending WordPress talk at the Boston WordPress Meetup

mitcho — Tue, 29 Sep 2009 17:40:19 +0000

Yesterday I gave a talk at the Boston WordPress Meetup. The Boston WordPress Meetup meets monthly at the Microsoft Cambridge Research Center which is a fantastic venue right on the Charles river. Last night we got to be up on the 10th floor which has a great view of Boston right over the river. There was pretty good turnout, with about thirty or fourty people there.

My talk was a general introduction to WordPress plugin development, beginning with the concepts of actions and filters, and concluding with a description of HookPress, my new plugin which enables webhooks in WordPress. Here are the slides:

Extending WordPress with (Web)Hooks

View more documents from Michael Yoshitaka Erlewine.

The talk included some live coding which is always dangerous, but it all went off without a hitch.

Kurt Eng was kind enough to get video of the talk as well which hopefully we’ll get up on wordpress.tv in the near future. Bryan also sent me a link with some photos on Flickr.

Thank you to all who attended¹ and of course to Microsoft who provided the venue and food! The Boston WordPress Meetup is a great community and I hope to keep supporting it and its activities.

For anyone who attended, I would greatly appreciate feedback on the talk at SpeakerRate. ↩

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HookPress: Webhooks for WordPress

mitcho — Fri, 07 Aug 2009 02:23:25 +0000

I recently have spent a little time putting together a new WordPress plugin called HookPress. HookPress lets you add webhooks to WordPress, letting you easily develop push notifications or extend WordPress in languages other than PHP.

WordPress itself is built on a powerful plugin API which provides actions and filters. Actions correspond to events, so you can set a webhook to fire when a post is published or a comment is made.¹ Filters let you modify some text when it is saved or displayed, so you can have your external webhook script reformat some text or insert some other content dynamically. Not all actions and filters are supported at this time, but I will continue to add more in.

There’s a webhooks meetup in San Francisco today but I unfortunately left SF this morning, so I created a video which will be played there as a lightning talk. A demo of both types of webhooks are in the video as well.

HookPress: add webhooks to WordPress from mitcho on Vimeo.

I’m really excited by this very simple but potentially high-impact plugin. I’d love to get your comments and feedback on this new plugin and hope to hear how you’re using HookPress!

ADDENDUM: Please also follow HookPress on twitter!

My friend Abi actually has already blogged about HookPress and how it can be used to tweet on post publication. ↩

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Fixing Geshi on line 2132

mitcho — Sat, 13 Jun 2009 15:15:44 +0000

I recently noticed that some of my blog posts, most notably my Templates in YARPP 3 article, was producing a PHP error:

Warning: preg_match() [function.preg-match]: Compilation failed: unrecognized character after (?< at offset 3 in /…/html/blog/wp-content/plugins/wp-syntax/geshi/geshi.php on line 2132

This seemed to be coming from the version 1.0.8.4 version of Geshi I had installed. A quick google search for “geshi line 2132” gives you over a thousand errors, so this seems to be common issue. Geshi is a fabulous and popular syntax highlighter and is the core component of the WP-Syntax plugin for WordPress.

I did some digging around and realized that the issue was with the compilation of this monstrosity of a regular expression, used (as far as I can tell) to identify PHP code snippets, for example the keywords:

/(?<\\?(?>php\b)?)(?:
(?>[^\"'?\\/<]+)|
\\?(?!>)|
(?>'(?>[^'\\\\]|\\\\'|\\\\\\\|\\\\)*')|
(?>\"(?>[^\"\\\\]|\\\\\"|\\\\\\\\|\\\\)*\")|
(?>\\/\\*(?>[^\\*]|(?!\\*\\/)\\*)*\\*\\/)|
\\/\\/(?>.*?$)|
\\/(?=[^*\\/])|
<(?!<<)|
<<<(?\w+)\s.*?\s\k
)*(?\\?>|\Z)/sm

Not knowing exactly where to start in diagnosing this crazy expression, I simply disabled those “script delimiters” in the geshi/php.php file. The sections I commented out are lines 1080-1101. Now the script delimiters like <?php don’t get highlighted nicely, but I feel that’s a small price to pay for eliminating these errors. Another solution for the WP-Syntax users seems to be to downgrade to 0.9.4. Hopefully in the near future an update to Geshi will come out which fixes this issue once and for all.

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Using Templates with YARPP 3

mitcho — Wed, 14 Jan 2009 13:26:38 +0000

Post updated January 2012 to reflect cleaner template code available with YARPP 3.4.

If you have a YARPP support question not directly related to the templating feature, please use the YARPP support forums.

Version 3 of Yet Another Related Posts Plugin is a major rewrite which adds two new powerful features: caching and templating. Today I’m going to show you how you can use templates to customize the look of your related posts output.¹

Previously with YARPP you were relatively limited in the ways you could present related posts. You were able to set some HTML tags to wrap your posts in and choose how much of an excerpt (if any) to display. This limited interface worked great for many users—indeed, these options still exists in YARPP 3.0. However, there’s also a new option for those of you who want to put your PHP skills to work and have complete control over your related posts display. The option will let you choose any files in the templates subdirectory of YARPP.

The structure of a YARPP template

Let’s take a look inside the example template, included with YARPP 3 (yarpp-template-example.php):

Related Posts
 if (have_posts()):?>

	 while (have_posts()) : the_post(); ?>
	 the_permalink() ?>" rel="bookmark"> the_title(); ?>
	 endwhile; ?>

 else: ?>
No related posts.
 endif; ?>

There are two basic parts to this (and most all) YARPP template: (a) what you display when there are related posts and (b) what you display when there aren’t. We make this switch with the conditional on line 6. If there are related posts, we introduce an ordered list and use the while loop to loop over all the related posts. For each post, we use the snippet the_post(); to load the appropriate post data, then print the line item.

You’ll notice that we’re using familiar template tags here such as the_permalink() and the_title(). If you’ve ever had to tweak or build a WordPress theme before, you’ll immediately feel at home. I’ll touch on this again later.

The power of PHP

One big advantage of this new templating system is that you can control exactly how the posts are listed, breaking out of all of the previous structural limitations. For example, in the template-list.php template, we put the information for each related post in an array and then concatenate the strings with implode. This way, we produce a comma-separated list for our readers without any stray commas before or after the list, which was impossible until now.

	$postsArray = array();
	while (have_posts()) : the_post();
		$postsArray[] = '.get_the_permalink().'" rel="bookmark">'.get_the_title().'
';
	endwhile;
 
echo implode(', ',$postsArray); // print out a list of the related items, separated by commas

You can also run any arbitrary PHP in the template file—even roll another WP_Query, as in the case of template-random.php, where a random post is returned when there are no related posts.

Familiar template tags

As mentioned before, the tags we use in these YARPP templates are the same as the template tags used in any WordPress template. In fact, any WordPress template tag will work in the YARPP Loop. You can use these template tags to display the excerpt, the post date, the comment count, or even some custom metadata. I’ve also written two special template tags which only work within a YARPP Loop: the_score() and get_the_score(). As you may expect, this will print or return the match score of that particular related post.

In addition, template tags from other plugins will also work. For an example, take a look at the yarpp-template-photoblog.php file:

	 while (have_posts()) : the_post(); ?>
		 if (function_exists('yapb_is_photoblog_post')): if (yapb_is_photoblog_post()):?>
		 the_permalink() ?>" rel="bookmark"> yapb_get_thumbnail(); ?>
		 endif; endif; ?>
	 endwhile; ?>

In this template’s YARPP Loop, we use some template tags introduced by the Yet Another Photoblog plugin. If you have the Yet Another Photoblog plugin installed, you can use this template to display thumbnails of related posts in lieu of the titles. Notice that here we’re checking first whether each related post is indeed a photo post or not using yapb_is_photoblog_post() and then using the Yet Another Photoblog yapb_get_thumbnail() template tag to get the location of the thumbnail.

Templating in YARPP 3.0 enables the blog admin to uber-customize their related posts display using the lingua franca of PHP and template tags. Feel free to comment here with ideas, comments, and of course links to your YARPP-powered blogs. I look forward to seeing what the WordPress community does with this new feature!

For those of you interested in the WP and SQL voodoo used to make this happen, I’ve posted a more technical article. ↩

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selecting from Ubiquity

mitcho — Wed, 07 Jan 2009 15:50:13 +0000

I created a new Ubiquity command that gives you super fast access to your MySQL database’s data: select.

select Command for Ubiquity from mitcho on Vimeo.

Get the command and set it up here.

External orders in WordPress queries

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External orders in WordPress queries

mitcho — Sat, 29 Nov 2008 15:34:40 +0000

The advanced WordPress user is intimately familiar with query_posts, the function which controls which posts are displayed in “The Loop.” query_posts gives plugin and theme writers the ability to display only posts written in Janary (query_posts("monthnum=1")) or disallow posts from a certain category (query_posts("cat=-529")¹). One of the parameters you can set here is orderby which affects the ordering of the posts returned, with allowed values such as author, date, or title. But what if you want to order your posts in some other order, defined outside of your wp_posts table? Here I’m going to lay out some thoughts on rolling your own external ordering source for WordPress queries.

In order to introduce an external ordering source, we need to do four things: 1. create the external ordering source, 2. hook up (read “join”) the external ordering source 3. make sure we use that order, and 4. make it play nice. ^^

By the way, I’m going to assume you, dear reader, are PHP-savvy, proficient in MySQL, and already know a little about WordPress. This how-to is not for the PHPhobic.

The ordering source

For this example, suppose we want to display posts by order of “interestingness.” We’ll just create a table called wp_interestingness with two columns, ID and interestingness and populate it with some data. We’ll even be nice to our database by making sure the ID is the primary key. Easy.

Hook up the external ordering source

When you run a query through query_posts() (or use WP_Query’s query method²), what it’s doing is taking your special request and translating it into a MySQL statement. This means a query like "monthnum=1" is turned into SELECT ... wp_posts.* FROM wp_posts WHERE 1=1 AND MONTH(wp_posts.post_date)='1' .... Every different query introduces something new to the basic SELECT command—in this case, the AND MONTH(wp_posts.post_date)='1'.

We first want to introduce the interestingness for each post and that means joining the new table into the query. We’ll do this using the posts_join filter. This filter lets you add a join statement to the MySQL request.

add_filter('posts_join','my_join_filter');
function my_join_filter($arg) {
	$arg .= " natural join wp_interestingness ";
	return $arg;
}

Note that here we’re using natural join as wp_posts and wp_interestingness have only one key in common, ID, and that’s exactly the column we want to join them on.

Use the new order

Now that we’ve joined wp_interestingness in, we can refer to wp_interestingness.interestingness in our query. Note now that, by default, an $wpdb->posts.post_date will be used to order the posts. We’ll use another filter here; this time posts_orderby, to patch this part of the query. We’ll search for the default ORDER BY value and replace it with our own interestingness.

add_filter('posts_orderby','my_orderby_filter');
function my_orderby_filter($arg) {
	global $wpdb;
	$arg = str_replace("$wpdb->posts.post_date","wp_interestingness.interestingness",$arg);
	return $arg;
}

By the way, you can now check the resulting MySQL query by echoing $wp_query->request. (If you’re using the WP_Query method I advocated below in footnote (2), you’ll of course have to change $wp_query to the WP_Query object you’re using.)

Learn to play nice ^^

The instructions above do indeed work, but they also cause some major breakdowns in other functions of your blog. Why? That’s because the current code will edit your queries for every instance of The Loop: your index page, your archives, and your RSS feeds. You probably only want to search by interestingness in certain situations. What we need is a way to tell our (admittedly stupid) my_join_filter and my_orderby_filter when they should apply their interestingness magic and when they shouldn’t. There are several ways to set up such a system but here I’ll lay out one that I feel is particularly elegant. We’ll set it up so you can actually use query_posts("orderby=interestingness") and it’ll know what you’re talking about.

One of the first things that happens in query_posts—indeed, way before even the posts_join and posts_orderby filters—is an action hook called parse_query. This lets us look at the initial state of the WP_Query object as it starts to run. In particular, we can look at the orderby query variable and see if we want to order by interestingness. If we do, we’ll set a global variable called $use_interestingness_flag to be true.

add_action('parse_query','set_use_interestingness_flag');
function set_use_interestingness_flag($query) {
	global $use_interestingness_flag;
	if ($query->query_vars['orderby'] == 'interestingness')
		$yarpp_score_override = true;
	else
		$yarpp_score_override = false;
}

Now we just have to edit our filters so they only run when $use_interestingness_flag == true. We also will make sure to turn the flag back off in my_orderby_filter, as it’s our last filter to run during each query. It’s just like putting the seat back down after using a unisex bathroom.³

add_filter('posts_join','my_join_filter');
function my_join_filter($arg) {
	global $use_interestingness_flag;
	if ($use_interestingness_flag)
		$arg .= " natural join wp_interestingness ";
	return $arg;
}
add_filter('posts_orderby','my_orderby_filter');
function my_orderby_filter($arg) {
	global $wpdb, $use_interestingness_flag;
	if ($use_interestingness_flag)
		$arg = str_replace("$wpdb->posts.post_date","wp_interestingness.interestingness",$arg);
	$use_interestingness_flag = false;
	return $arg;
}

This method has a great advantage as you can just set it up once and invoke it whenever you want, even together with other parameters, without any additional code. For example, you can try query_posts("monthnum=1&orderby=interestingness") or query_posts("cat=-529&orderby=interestingness").

Conclusion

Adding an external ordering source to your WordPress post queries can be relatively straightforward if you understand what query_posts does and take advantage of its hooks. This tutorial can also serve as the basis for many other patches to WP_Query, not just the orderby parameter. To better understand the way WordPress builds its MySQL queries and the many posts_* filters which you can take advantage of, go to the source: wp-includes/query.php. Finally, you can use the special parse_query hook and global variables as flags to only apply the filters when necessary.

This, incidentally, is precisely what I do to hide, by default, my tweets in my index.php and archives.php. ↩
If you’re going to get serious about rolling your WordPress queries I highly recommend you follow Mark Ghosh’s advice on initializing another object of the WP_Query class and using the query method, rather than just using the global query_posts function. ↩
The perceptive reader will note that we are still searching for the string "$wpdb->posts.post_date" in my_orderby_filter, instead of something like "$wpdb->posts.interestingness". That’s because the orderby value of interestingness is not one of the allowed orderby values (search for $allowed_keys in wp-includes/query.php to see the list). Thus the MySQL ORDER BY value is set to the default of "$wpdb->posts.post_date" before it gets to the posts_orderby filter. Now you know. ↩

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Keep up with Yet Another Related Posts Plugin with RSS!

mitcho — Sat, 04 Oct 2008 16:43:34 +0000

As more and more people have been using my Yet Another Related Posts Plugin for WordPress, I thought it would be nice to have an RSS feed for users to stay on top of the latest releases.

Clicking on a version’s permalink will let you download the plugin. Subscribe now and be the first to find out when the upcoming version 2.1 is released!

I decided to semi-automate this RSS-producing process as well. As a plugin developer using wordpress.org’s plugin hosting, I sync a local copy of the plugin to their server using SVN. I wrote a PHP script to get the modification date information directly from the local files, parse the version log in the read me, and produce the RSS feed. If there’s an interest, perhaps I’ll release this code in the future.

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Yet Another Related Posts Plugin 2.0

mitcho — Sun, 13 Jul 2008 15:06:06 +0000

Well, it’s been a while since I updated my plugin YARPP—in my humble opinion the best related posts plugin for WordPress. ^^ Today I release version 2.0, incorporating a number of important requests and bug fixes:

New algorithm which considers tags and categories, by frequent request
Order by score, date, or title, by request
Excluding certain tags or categories, by request
Sample output displayed in the options screen
Bugfix: an excerpt length bug
Bugfix: now compatible with the following plugins:
- diggZEt
- WP-Syntax
- Viper’s Video Quicktags
- WP-CodeBox
- WP shortcodes

Check out the Yet Another Related Posts Plugin page on this site, the page on wordpress.org, or download it directly now!

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Markdown for WordPress and bbPress

mitcho — Wed, 21 May 2008 14:07:28 +0000

Markdown for WordPress and bbPress 1.0
30 kb - zip

I like many others am a big fan of John Gruber’s Markdown, a simple typesetting spec for entering text in a clean, legible plain-text fashion and outputting to (X)HTML. Michel Fortin did the fabulous job of porting the Markdown engine to PHP, making it a plugin for WordPress, bBlog, and TextPattern.

I’ve been using Markdown for all my blog posts here. Recently, though, I was in charge of a bbPress bulletin board (the “less is more” sister project to WordPress) for the Shoreland Scav Hunt team, and wanted to use Markdown formatting there. And I wasn’t the only one wanting to do this.

With some experimenting and research into the filters in the bbPress text flow (different than the WordPress one), I was able to make Markdown work in bbPress. This involved adding a special bbPress plugin wrapper to Michel Fortin’s PHP Markdown Extra. I’ve rereleased this plugin as Markdown for WordPress and bbPress, available at both wordpress.org and bbpress.org. Enjoy!

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Display your Last.fm rankings using PHP 4’s XSLT support

mitcho — Fri, 01 Feb 2008 11:23:27 +0000

With all the exciting recent news about Last.fm, I thought I would document a simple bit of code I added to my site the other day.

Last.fm offers a number of Flash-based widgets you can add to your website. Unfortunately, this doesn’t give you much flexibility and, of course, requires Flash. But you, dear friend, have a site written in PHP, and the rankings are just XML files. There is a better way.

Looking around on the web, there are some good instructions and recommendations for using PHP 5’s object-oriented XML support. But, as we know, not everyone is using PHP 5. Here’s what I did on my PHP install, which includes the DOM/XML and DOM/XSLT extensions.¹

Write your XSL Transformation

The first step is to write your XSL Transformation, or XSLT, a special XML “program” which takes an XML file and reformats it into another XML file. Remember when you learned in Algebra class what a function was? An XSLT defines a function from XML to XML. In our case, we need to take a special proprietary XML file like the this one for my weekly top artists and return some solid XHTML.

Let’s take a look at the XSLT I used: (it helps to take a look at the original XML file at the same time.)

:

The full spec description will give you all the juicy details, but you really only need a few basic details (or you can just steal my code). First, we note the and items. Each of these code blocks describe what to do to each and nodes, respectively, in the input XML. In the code above, when a is found, an ordered list is opened and the artist template is applied to the first five (position() < 6) nodes. In the artist template (), the script takes each and prints a list item with the name of the artist, with a link to the url given in the original ’s subnode.

Process the XML with your XSLT

Once your XSLT is written, save it to a file, like last.fm.xml. Now we’ll use the DOM/XSLT extension and apply this XSLT file to the live weekly artist chart XML file from last.fm. Here’s the code I used:

$chartxml = domxml_open_file("…/weeklyartistchart.xml");
$xslt = domxml_xslt_stylesheet_file("last.fm.xsl");
$charthtml = $xslt->process($chartxml);
echo $charthtml->dump_mem();

The code is pretty self explanatory—just four lines: 1. open the remote XML file using domxml_open_file, 2. open the stylesheet (XSL transformation), 3. apply the stylesheet to the remote XML file, and 4. echo the output.

That’s it! You can see the results here on my music page.

To see if these instructions will work for you, check your phpinfo for the lines “DOM/XML enabled” and “DOM/XSLT enabled”. If the items aren’t even showing up, you’re out of luck. There are, however, other comparable methods to process XML and XSLT in PHP 4.
↩

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Modifiying WordPress plugin activation behavior

mitcho — Sat, 05 Jan 2008 10:39:22 +0000

As I continue to work on and debug Yet Another Related Posts Plugin and WP-Smartdate, I’ve come across an issue where plugin activation fails, but I get no useful error message.

When I try to activate the plugin, I am redirected to a url of the type /plugins.php?error=true&plugin=...&_error_nonce=.... This redirect just gives me the plugins control panel with my plugin still disactivated, and with no useful error message.¹ This apparently is an issue with the Plugin Protection mechanism introduced in WP 2.2. A quick fix (hack) is available on the WP forums.

Here’s hoping this helps some people scratching their heads, and that this behavior is reconsidered/fixed in future releases.

Apparently some people get a message like “Plugin could not be activated because it triggered a fatal error.” ↩

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Yet Another Related Posts Plugin

mitcho — Sat, 29 Dec 2007 13:49:20 +0000

UPDATE:

This posting is now outdated… for the latest information on YARPP, please visit YARPP’s very own page on my site, or its page on wordpress.org. If you have questions, please submit on the wordpress.org forum. Thanks!

Description

Today I’m releasing Yet Another Related Posts Plugin (YARPP¹) 1.0 for WordPress. It’s the result of some tinkering with Peter Bowyer’s version of Alexander Malov & Mike Lu’s Related Entries plugin. Modifications made include:

Limiting by a threshold: Peter Bowyer did the great work of making the algorithm use mysql’s fulltext search score to identify related posts. But it currently just displayed, for example, the top 5 most “relevant” entries, even if some of them weren’t at all similar. Now you can set a threshold limit² for relevance, and you get more related posts if there are more related posts and less if there are less. Ha!
Being a better plugin citizen: now it doesn’t require the user to click some sketchy button to alter the database and enable a fulltext key. Using register_activation_hook, it does it automagically on plugin activation. Just install and go!
Miscellany: a nicer options screen, displaying the fulltext match score on output for admins, an option to allow related posts from the future, a couple bug fixes, etc.

Installation

Just put it in your /wp-content/plugins/ directory, activate, and then drop the related_posts function in your WP loop. Change any options in the Related Posts (YARPP) Options pane in Admin > Plugins.

You can override any options in an individual instance of related_posts using the following syntax:

`related_posts(limit, threshold, before title, after title, show excerpt, len, before excerpt, after excerpt, show pass posts, past only, show score);

Most of these should be self-explanatory. They’re also in the same order as the options on the YARPP Options pane.

Example: related_posts(10, null, 'title: ') changes the maximum related posts number to 10, keeps the default threshold from the Options pane, and adds title: to the beginning of every title.

There’s also a related_posts_exist) function. It has three optional arguments to override the defaults: a threshold, the past only boolean, and the show password-protected posts boolean.

Examples

For a barebones setup, just drop right after .

On my own blog I use the following code with

and

as the before/after entry options:

 if (related_posts_exist()): ?>
Related posts:

 related_posts(); ?>


 else: ?>
No related posts.
 endif; ?>

Coming soon (probably)

Incorporation of tags and categories in the algorithm. I’ve gotten the code working, but I still need to think about what the most natural algorithm would be for weighing these factors against the mysql fulltext score currently used (and works pretty well, I must say).
Um, something else! Let me know if you have any suggestions for improvement. ^^

Version log

1.0 Initial upload (20071229)

1.0.1 Bugfix: 1.0 assumed you had Markdown installed (20070105)

Pronounced “yarp!”, kind of like this, but maybe with a little more joy:
↩
Did you know that threshold has only two h’s!? I’m incensed and just went through and replaced all the instances of threshhold in my code. It’s really not a thresh-hold!? ↩

Introducing Smartdate

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Updating your zenphoto theme for zenphoto 1.1

mitcho — Sun, 04 Nov 2007 13:52:55 +0000

I use zenphoto as the backend to my photos section with a custom theme to hook into my site’s navigation and such. I chose zenphoto for my website a year ago based on it’s main strength: simplicity. It does much less than the competition, but it does what I need it to do—for the most part. It’s a fantastic bare-bones mysql/php photo gallery option.

Since then, though, I (along with many others) have been slightly disappointed by the lack of development in the promising project, without having the time or energy to pitch in myself. Such is life. But now the wait is over: Zenphoto 1.1 is out.

Zenphoto 1.1, I believe, does a good job balancing this tradition of simplicity with some popular new features. Highlights include (there are many) tagging, subalbums, chronological archives, RSS feeds, EXIF support, Google Maps, search, and preliminary video support. Exciting stuff.

As I maintain my own theme, though, some of these new features of course require me to update my theme. Below is my rough guide to editing your theme to take maximum advantage of zenphoto 1.1.

First things first

Between the core components moving from /zen to /zp-core and the addition of subalbums, your old .htaccess will no longer be valid. Make sure to copy over the new .htaccess (in the zenphoto 1.1 zip file, though probably invisible in your filesystem) with necessary updates for your setup, or else none of your images will show up. Ha!

Search and Archives

The first thing you’ll notice if you check out the default theme is the search and archive pages… the easy way to implement these, I think, is to copy over the search.php and archives.php pages and then make the necessary organizational changes. This is of course easier said than done, but everyone’s custom theme exists for different reasons.

To implement search, you first have to add the search box to the index page:

if (getOption('Allow_search')) {  printSearchForm(); }

The default theme has this right above the gallery title, but I put it at the bottom of my main div.

Subalbums

Subalbums are an exciting new feature for organization buffs, but it does require some quick changes. First of all, the subalbum-path breadcrumb must be added to album.php and image.php, right before the current album/image name. Use the three parameters to change the delimiters.

printParentBreadcrumb($before,$between,$after);

By default, subalbums are listed at the top of an album’s page, so we have a new while(next_album()) loop there. The default theme’s additional loop¹ is:

Tag Support

Simply add this line to the bottom of album.php and image.php:

printTags(true, 'Tags: ');

RSS Support

To enable RSS support, simply put the printRSSHeaderLink() in your headers. I used these three lines:

printRSSHeaderLink('Gallery','RSS title');
printRSSHeaderLink('Album','RSS title');
printRSSHeaderLink('Image','RSS title');

Now your RSS feeds are added as links in your header, and will be recognized automagically by a smart browser. You can also add an explicit link:

printRSSLink('Gallery','','RSS', ' | ');

Maps and EXIF

While I haven’t implemented these myself in my theme,² these look fairly simple to add to a theme. The key PHP code to include are:

  if (getImageEXIFData()) {
    printImageMetadata('', false); 
  }

and

printImageMap();

There’s more

There’s of course more advanced stuff that might be of interest to other theme designers. The place to start is probably normalizeColumns().

Feel free to check out my final product, the updated photos section.

listed here as just the php logic, without the organizational html ↩
I use slimbox, the mootools-based lightbox clone and, thus, never use the image page or comments. What I have done, however, is just put some of that EXIF data in the title tag to be displayed by slimbox by manipulating the value of getImageEXIFData() in the while(next_image()) loop. ↩

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