Wordpress Templates and Meta Information

Maybe I am slow, but I just discovered some pretty sweet features of Wordpress today. The first involves themes and the templating system and the second involves custom fields and meta information. I figured it is very possible that others have not stumbled across these features so I thought I would share them.

The Templating Trick

This is so easy that it is barely a trick and probably many already know this but…ever notice that when you go to write a page it has the page template drop down? I don’t know about you, but I was wondering how in the heck that list was populated. I mean, I figured out that if you created an archives page and used the archives template from the drop down that it would use the archives.php file in your theme folder. This was nice because then you can write all your magical php functions to make your archives pretty. I also did this with my links page. The funny thing is, that I never thought twice about the lines at the top of those files.


/*
Template Name: Archives
*/


It dawned on me today that Wordpress is using those lines to populate the template drop down when you write a page. I was like, “No, that is to stinkin easy!” Really, I was like that. I laughed giddilly like a little schoolboy because that is what geeks do when they figure out something that they think is cool. Ok, so maybe you already know this, but I’m sure someone out there doesn’t, in which case, they too are probably laughing like a schoolboy. Go ahead, try it out. Just create a new file in your theme directory called test.php. Copy and paste the source code from your archives.php or links.php file into test.php. The last step is to change the code in the test.php file where it says Template Name: Archives to Template Name: Test. The final step is to open up your admin area (which you hopefully have themed with my buddy Steve Smith’s Tiger Admin) and go to Write Page. If you check out the Page Template drop down you will notice the new test template you just created is now there.

Now you can create any template you want by creating a new php file in your theme directory, adding the Template Name code at the top, and selecting your new template as the Page Template when you create the page.

The Meta Information

Even cooler than the simple templating trick is the meta information. For a new site that my friend and I are creating, I wanted to store a thumbnail and a large image for each post. The site will be featuring photos and I wanted a way to show just the photo or just the thumbnail or just the photo and the description. I headed over to the wordpress codex to see if I could find a way to accomplish that. The ‘Add New Custom’ field section in the advanced editing of a post has been intriguing me for a while so I decided to check it out. I read through the article on using custom fields and I had a light bulb go off.

For each post on the new site I am developing, I enter the title, a description, and I create two new custom fields, one named ‘main’ and another named ‘thumb.’ The value of these fields are the respective full size and thumbnail image names for the particular post. Now each post has meta information on the main image and the thumbnail image. So how do I show them? I ran across the get_post_custom() function and new I was in business. This function accepts an article ID as a parameter and returns all the meta information for the post in an array. I wrote the function below to create the URL for whichever type image I pass as a parameter, through it in a few spots in my theme pages and I was good to go.

1. <?php
2. function getPhotoURL($id, $type) {
3. $meta = get_post_custom($id);
5. $url = get_bloginfo('siteurl') . '/images/';
6. if ($type == 'main') {
7. $url .= $meta['main'][0]; // main image name
8. } else {
9. $url .= $meta['thumb'][0]; // thumbnail image name
10. }
12. return $url;
13. }
14. ?>

One thing worth noting is that the above function has to be run in ‘The Loop‘ to work correctly. I’ll have a better write up on how to use custom fields after my friend and I launch our new site. Until then hope this helps somebody out.