Adding Custom Fields to Your Template File

If you followed along in theprevious sections and added the mood Custom
Field to your own site, notice that the data doesn’t appear on your site the
way it does on Lisa’s. To get the data to display properly, you must open the
template files and dig into the code a little bit. If the idea of digging into the
code of your template files intimidates you, you can put this section aside
and read up on WordPress themes, template files, and template tags in
Book VI.

You can add Custom Fields, in several ways, to your templates in order to
display the output of the fields you’ve set; we think the easiest way involves
using the get_post_meta(); template tag function, which looks like this:

<?php $key=”NAME”; echo get_post_meta($post->ID, $key, true); ?>

Here’s how that function breaks down:

✦ <?php: Part of the functions begins PHP. (Every template tag or function
needs to first start PHP with <?php. You can read more about basic PHP
in Book II, Chapter 3.)
✦ $key=”NAME”;: Defines the name of the key that you want to appear.
You define the Name when you add the Custom Field to your post.
✦ echo get_post_meta: Grabs the Custom Field data and displays it on
your site.

Book IV
Chapter 5

324 Adding Custom Fields to Your Template File
✦ $post->ID,: A parameter of the get_post_meta function that
dynamically defines the specific ID of the post being displayed so that WordPress knows which metadata to display.
✦ $key,: A parameter of the get_post_meta function that gets the
value of the Custom Field based on the name, as defined in the
$key=”NAME”; setting earlier in the code string.
✦ true);: A parameter of the get_post_meta function that tells
WordPress to return a single result, rather than multiple results. (By
default, this parameter is set to true; typically, don’t change it unless
you’re using multiple definitions in the Value setting of your Custom
Field.)
✦ ?>: Ends the PHP function.

Based on the preceding code, to make our mood Custom Field example, you define the key name as mood (replace the NAME in the preceding code with the word mood); it looks like this:

<?php $key=”mood”; echo get_post_meta($post->ID, $key, true); ?>

The part of the functions that says $key=”mood”; tells WordPress to return the Value for the Custom Field with the Name field of mood.