YAML Custom Fields

Description

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:

1. Go to YAML Custom Fields admin page
2. Enable YAML for your template (e.g., page.php)
3. Click Add Template Global to define the template global schema
4. Define fields that should have shared default values
5. 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:

1. Page-specific value (if “use template global” is unchecked)
2. Template global value (if “use template global” is checked)
3. Site-wide global value (if template has site-wide global enabled)
4. 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