ACF & PHP-API (WordPress)

How can you automatically manage ACF fields? In particular, fill in, delete and edit?

Not directly at database level

To start with some bad news: While ACF fields are stored in tables wp_options or wp_postmeta, you cannot write directly to these tables to create ACF fields. Then the 'context' is missing, eg a repeater. So you have to do it via an API call.

Two kinds of fields

There seems to be a distinction between two kinds of ACF fields and how to approach them:

• Fields that are associated with specific posts
• Fiels that are not asssociated with specific posts.

The distinction will be clear in the examples below.

Retrieve a post-related field

As an example: The home page of a site has ID=7. It has a custom field hero text. How to fetch its value:

<?php

require_once("/var/www/example.com/wp-load.php");

the_field("hero_text",7);

Output:

Eat more chips!

• Function the_field() displays the value of a field directly
• Alternatively, function get_field() returns the value rather than directly displaying it.

Retrieve an option field

Let's fetch the value of a field that is available through wp-admin » Options:

• Name of the field figured out by looking up its field group at wp-admin » Custom fields » Field Groups: webshop_country_code
• This is a scalar. Not a repeater, array or object. Just a single value

See also

• ACF (general)
• the_field()
• get_field()
• update_sub_field()
• update_sub_row()

Sources

• https://www.advancedcustomfields.com/resources/
• https://www.advancedcustomfields.com/resources/#functions - All PHP functions together. It's not complete, though!
• https://www.advancedcustomfields.com/resources/code-examples/