Pretty URLs for SPGM

Since putting a photo gallery on my site I have always used SPGM, the Simple Picture Gallery Manager. It's a great application in that it does not require a database, is totally configurable and is very easy to manage. The latest version, 1.4.4, is mature and stable and I look forward to many more years of using it.

However, one thing that's always bugged me about it, and for that matter many other web applications, is the lack of pretty URLs. Now my favorite web framework does away with this issue entirely but web applications written in other languages such as PHP typically do not take this into account. Ugly URLs often do not get indexed by search engines, are more prone to linkrot, and just look darned ugly. So I decided to do something about it.

First, I went about upgrading my version of SPGM. Wow what a difference a year can make! Version 1.4.4 was quite a jump with newly updated themes and a really cool shadow effect that makes my pictures seem as if they are floating above the page. Aside from some minor stylesheet integration issues that I eventually fixed, the upgrade went very well.

My next task was to change the output of SPGM itself so that it would make every link a pretty URL. I started out by replacing every instance of '&', '=' and '?' with constant values named SEP_AMP, SEP_EQL and SEP_QM, respectively. I then defined a constant called PRETTY_URLS which, if set to true, would create URLs that looked like /spgm/spgmGal/gallery_name/spgmPic/picture_id. This modified version of the SPGM engine can be found on my website.

Lastly, I had to put my mod_rewrite skills to use to direct these pretty URLs to their correct locations. For instance, a link to /spgm/spgmGal/Spring_Break/spgmPic/3 would actually be a link to /spgm/index.php?spgmGal=Spring_Break&spgmPic=3. Also, because SPGM relies on relative links, mod_rewrite had to redirect image links from within the galleries in order to display the thumbnails properly. Eventually I was able to accomplish everything with just six RewriteRules in my .htaccess file.


RewriteEngine on
RewriteRule ([a-zA-Z0-9,_]+)/gal/(.*)$ /spgm/gal/$2
RewriteRule ([a-zA-Z0-9,_]+)/flavors/(.*)$ /spgm/flavors/$2
RewriteRule spgmGal/([a-zA-Z0-9,_]+)$ /spgm/index.php?spgmGal=$1
RewriteRule spgmGal/([a-zA-Z0-9,_]+)/spgmPic/([0-9]+)/spgmFilters/(.*)$ /spgm/index.php?spgmGal=$1&spgmPic=$2&spgmFilters=$3 [L,QSA]
RewriteRule spgmGal/([a-zA-Z0-9,_]+)/spgmPage/([0-9]+)/spgmFilters/(.*)$ /spgm/index.php?spgmGal=$1&spgmPage=$2&spgmFilters=$3 [L,QSA]
RewriteRule spgmFilters/$ /spgm


Both the .htaccess file and the modified version of the SPGM engine can be found bundled on my site. Please email me if you have any questions or comments on using it.

Using CSS constants with PHP

I ran across an article the other day using my favorite Web 2.0 app that described how to use constants in CSS with PHP. The author's method I felt was a bit overly complicated however since it required the use of an additional file that would essentially replace the embeded PHP variables with their respective values. I think there is a much easier way to do this which I will demonstrate.

** file: mycss.php **

<? $mycolor = "blue"; ?>

.myclass {
font-size: 12pt;
color: <? echo $mycolor ?>
}

** file: index.php **

<html>
<head>
<link rel="stylesheet" href="mycss.php" type="text/css">
<body>
<span class="myclass">Hello world!</span>
</body>
</html> 

This works because PHP is interpreting the CSS file as if it were PHP code. After it interprets it, what is left is CSS code and thanks to the type directive in the link tag, that is how it is rendered by the browser. Hence, no need for an additional file that does a massive search and replace. An online example can be found at my site.

The next challenge for me is to get something like this working in Ruby on Rails.