YAML Custom Fields allows you to define structured content schemas with an intuitive interface and ACF-like template functions. Perfect for theme developers who want flexible, schema-based content management without the complexity.

Features

Define YAML schemas for page templates and template partials
15+ field types including string, rich-text, images, blocks, taxonomies, data objects, and more
Easy-to-use admin interface for managing schemas and data
Three-level data hierarchy:
- Per-page data for individual customization (stored in post meta)
- Per-template global data shared across all posts using the same template
- Site-wide global data for partials like headers and footers
Per-field global/local toggle: Each field can independently use template global data or page-specific data
Visual dual-field interface: See both template global and page-specific values side-by-side
Data Objects for managing structured, reusable data (universities, companies, etc.)
Data Validation page for reviewing imported content
Consolidated Export/Import page for all data types (settings, page data, data objects)
Simple template functions with ACF-like syntax and auto-merge behavior
Administrator-only access for security
Clean uninstall removes all database records
WordPress Coding Standards compliant

Supported Field Types

String – Single-line text with min/max length
Text – Multi-line textarea
Rich Text – WordPress WYSIWYG editor
Code – Code editor with syntax highlighting
Boolean – Checkbox for true/false values
Number – Number input with min/max constraints
Date – Date picker with optional time
Select – Dropdown with single/multiple selection
Taxonomy – WordPress categories, tags, or custom taxonomies with single/multiple selection
Post Type – Dropdown to select registered post types (Post, Page, custom post types)
Data Object – Reference to structured data objects managed independently (universities, companies, team members, etc.)
Image – WordPress media uploader for images
File – WordPress media uploader for any file
Object – Nested group of fields
Block – Repeatable blocks for flexible page builders

Usage Example

In your theme template:

<?php
$hero_title = ycf_get_field('hero_title');
$hero_image = ycf_get_image('hero_image', null, 'full');
$category = ycf_get_term('category');
$post_type = ycf_get_post_type('content_type');
$university = ycf_get_data_object('university');
$features = ycf_get_field('features');
?>

<div class="hero">
  <?php if ($hero_image): ?>
    <img src="<?php echo esc_url($hero_image['url']); ?>" alt="<?php echo esc_attr($hero_image['alt']); ?>">
  <?php endif; ?>
  <h1><?php echo esc_html($hero_title); ?></h1>
  <?php if ($category): ?>
    <span class="category"><?php echo esc_html($category->name); ?></span>
  <?php endif; ?>
  <?php if ($university): ?>
    <p><?php echo esc_html($university['name']); ?></p>
  <?php endif; ?>
</div>

Developer Documentation

Template Functions

Get a single field value:

$value = ycf_get_field('field_name');
$value = ycf_get_field('field_name', 123); // Specific post ID
$value = ycf_get_field('logo', 'partial:header.php'); // From partial
$value = ycf_get_field('title', null, $block); // From block context

Get image field with details:

$image = ycf_get_image('field_name', null, 'full');
$image = ycf_get_image('field_name', 123, 'thumbnail'); // Specific post ID
$image = ycf_get_image('icon', null, 'medium', $block); // From block context

// Returns: array('id', 'url', 'alt', 'title', 'caption', 'description', 'width', 'height')

Get file field with details:

$file = ycf_get_file('field_name', null);
$file = ycf_get_file('field_name', 123); // Specific post ID
$file = ycf_get_file('document', null, $block); // From block context

// Returns: array('id', 'url', 'path', 'filename', 'filesize', 'mime_type', 'title')

Get taxonomy field (term or terms):

$term = ycf_get_term('field_name', null);
$term = ycf_get_term('field_name', 123); // Specific post ID
$term = ycf_get_term('category', null, $block); // From block context

// Returns: WP_Term object or array of WP_Term objects (for multiple selection)

Get post type field:

$post_type = ycf_get_post_type('field_name', null);
$post_type = ycf_get_post_type('field_name', 123); // Specific post ID
$post_type = ycf_get_post_type('content_type', null, $block); // From block context

// Returns: WP_Post_Type object or null

Get data object field:

$university = ycf_get_data_object('field_name', null);
$university = ycf_get_data_object('field_name', 123); // Specific post ID
$university = ycf_get_data_object('university', null, $block); // From block context

// Returns: Array with data object entry fields or null

Get all entries of a data object type:

$all_universities = ycf_get_data_objects('universities');
foreach ($all_universities as $entry_id => $university) {
    echo esc_html($university['name']);
}

// Returns: Array of all entries for the specified data object type

Get all fields:

$fields = ycf_get_fields();
$fields = ycf_get_fields(123); // Specific post ID
$fields = ycf_get_fields('partial:footer.php'); // From partial

Check if field exists:

if (ycf_has_field('hero_title')) {
    echo ycf_get_field('hero_title');
}

Working with Block fields:

$blocks = ycf_get_field('features');

if (!empty($blocks)) {
    foreach ($blocks as $block) {
        // Access nested fields using context_data parameter
        $title = ycf_get_field('title', null, $block);
        $icon = ycf_get_image('icon', null, 'thumbnail', $block);
        $category = ycf_get_term('category', null, $block);

        echo '<h3>' . esc_html($title) . '</h3>';
        if ($icon) {
            echo '<img src="' . esc_url($icon['url']) . '">';
        }
        if ($category) {
            echo '<span>' . esc_html($category->name) . '</span>';
        }
    }
}

Sample YAML Schema

fields:
  - name: hero_title
    label: Hero Title
    type: string
    required: true
    options:
      maxlength: 100
  - name: hero_image
    label: Hero Image
    type: image
  - name: category
    label: Category
    type: taxonomy
    options:
      taxonomy: category
  - name: tags
    label: Tags
    type: taxonomy
    multiple: true
    options:
      taxonomy: post_tag
  - name: content_type
    label: Content Type
    type: post_type
  - name: university
    label: University
    type: data_object
    options:
      object_type: universities
  - name: features
    label: Features
    type: block
    list: true
    blockKey: type
    blocks:
      - name: feature
        label: Feature Block
        fields:
          - name: title
            label: Title
            type: string
          - name: icon
            label: Icon
            type: image
          - name: description
            label: Description
            type: text

Working with Partials

For custom partials, add the @ycf marker in the file header:

<?php
/**
 * Custom Navigation Partial
 * @ycf
 */

Then click “Refresh Template List” in the YAML Custom Fields admin page.

Template Global Fields

Template Global Fields allow you to define default values that are shared across all posts using the same template, while still allowing individual posts to override specific fields.

Setting up Template Global:

Go to YAML Custom Fields admin page
Enable YAML for your template (e.g., page.php)
Click Add Template Global to define the template global schema
Define fields that should have shared default values
Click Manage Template Global Data to set the default values

Using Template Global in Posts:

When editing a post that uses a template with Template Global fields, you’ll see a dual-field interface for each field:

Template Global (All Pages) – Read-only display showing the default value (with Edit link)
Page-Specific Value – Editable field for this post only
Checkbox – “Use template global for this field” – Toggle per field

Benefits:

Consistency: Set default values once, use across all posts
Flexibility: Override any field on any post individually
Clarity: See both global and local values side-by-side
Efficiency: Update template global to affect all posts at once

Data Priority (when using template functions):

When a field uses template global, ycf_get_field() returns data in this priority order:

Page-specific value (if “use template global” is unchecked)
Template global value (if “use template global” is checked)
Site-wide global value (if template has site-wide global enabled)
null (if no value exists)

Data Storage

Page/Post data: Stored in post meta with key _yaml_cf_data
Template Global preferences: Stored in post meta with key _yaml_cf_use_template_global_fields (per-field array)
Template Global schemas: Stored in options table with key yaml_cf_template_global_schemas
Template Global data: Stored in options table with key yaml_cf_template_global_data
Site-wide global schema: Stored in options table with key yaml_cf_global_schema
Site-wide global data: Stored in options table with key yaml_cf_global_data
Partial data: Stored in options table with key yaml_cf_partial_data
Schemas: Stored in options table with key yaml_cf_schemas
Data Object Types: Stored in options table with key yaml_cf_data_object_types
Data Object Entries: Stored in options table with keys yaml_cf_data_object_entries_{type_slug}

Privacy Policy

YAML Custom Fields does not collect, store, or transmit any user data outside of your WordPress installation. All data is stored locally in your WordPress database.

Third-Party Libraries

This plugin includes the following third-party libraries:

Symfony YAML Component (v6.4) – Licensed under MIT License (GPL-compatible)
- Homepage: https://symfony.com/components/Yaml
- License: https://github.com/symfony/yaml/blob/7.3/LICENSE

Credits

Author: Silvestar Bistrovic

Support

For documentation, examples, and support, visit:
* Plugin Documentation
* Report Issues