Last updated: 1st May 2026 for CC Schema & Structured Data version 1.0.0

Overview

CC Schema & Structured Data has been designed with extensibility in mind, allowing developers to modify, extend or completely replace schema output using WordPress hooks and filters.

The plugin follows standard WordPress development patterns, meaning:

Schema output is filterable before rendering
Individual schema blocks can be modified independently
JSON-LD output can be extended or overridden
Additional schema types can be registered programmatically

This document lists all public hooks and filters intended for developers.

Note: Only hooks with valid extension use cases are documented. Internal hooks and anything related to licensing or restricted functionality are intentionally excluded.

Filter: Modify All Schema Output

`cc_schema_output`

Filters the final structured data array before it is encoded and output as JSON-LD.

Parameters

$schema (array) — Complete schema data for the current page
$post_id (int) — Current post ID

Example

add_filter('cc_schema_output', function ($schema, $post_id) {

    // Add a custom publisher
    $schema['publisher'] = [
        '@type' => 'Organization',
        'name'  => get_bloginfo('name'),
    ];

    return $schema;

}, 10, 2);

Use Cases

Add global schema properties
Inject organisation or author data
Modify schema across all types

Filter: Modify Individual Schema Blocks

`cc_schema_block_output`

Filters each individual schema block before it is merged into the final output.

Parameters

$block (array) — Schema block data
$type (string) — Schema type (e.g. faqpage, howto, webpage)
$post_id (int) — Current post ID

Example

add_filter('cc_schema_block_output', function ($block, $type, $post_id) {

    if ($type === 'webpage') {
        $block['inLanguage'] = 'en-GB';
    }

    return $block;

}, 10, 3);

Use Cases

Modify only specific schema types
Add or override properties per schema
Localise schema output

Filter: Register Custom Schema Types

`cc_schema_register_types`

Allows developers to register additional schema types.

Parameters

$types (array) — Registered schema types

Example

add_filter('cc_schema_register_types', function ($types) {

    $types['custom'] = [
        'label' => 'Custom Schema',
        'class' => \CaterhamComputing\CCSchema\Schema\Custom::class,
    ];

    return $types;

});

Use Cases

Add new schema types beyond the default
Extend plugin functionality without modifying core
Integrate with custom post types

Filter: Modify FAQ Extraction

`cc_schema_faq_items`

Filters FAQ items extracted from page content.

Parameters

$items (array) — Array of FAQ question/answer pairs
$post_id (int) — Current post ID

Example

add_filter('cc_schema_faq_items', function ($items, $post_id) {

    // Remove empty answers
    return array_filter($items, function ($item) {
        return !empty($item['answer']);
    });

}, 10, 2);

Use Cases

Clean extracted FAQ data
Modify questions or answers
Integrate external FAQ sources

Filter: Modify HowTo Steps

`cc_schema_howto_steps`

Filters steps used in HowTo schema.

Parameters

$steps (array) — Array of steps
$post_id (int) — Current post ID

Example

add_filter('cc_schema_howto_steps', function ($steps, $post_id) {

    foreach ($steps as &$step) {
        $step['text'] = wp_strip_all_tags($step['text']);
    }

    return $steps;

}, 10, 2);

Use Cases

Sanitise step content
Add structured enhancements
Modify step ordering

Filter: Modify WebPage Schema

`cc_schema_webpage`

Filters the WebPage schema block specifically.

Parameters

$schema (array) — WebPage schema data
$post_id (int) — Current post ID

Example

add_filter('cc_schema_webpage', function ($schema, $post_id) {

    $schema['about'] = [
        '@type' => 'Thing',
        'name'  => get_the_title($post_id),
    ];

    return $schema;

}, 10, 2);

Use Cases

Enhance general page schema
Add contextual relationships
Improve semantic clarity

Action: Before Schema Output

`cc_schema_before_output`

Fires immediately before JSON-LD is printed to the page.

Parameters

$schema (array) — Final schema data
$post_id (int) — Current post ID

Example

add_action('cc_schema_before_output', function ($schema, $post_id) {

    // Debug schema output
    error_log(print_r($schema, true));

}, 10, 2);

Use Cases

Debugging
Logging schema output
Conditional behaviour before rendering

Action: After Schema Output

`cc_schema_after_output`

Fires immediately after JSON-LD has been printed.

Parameters

$post_id (int) — Current post ID

Example

add_action('cc_schema_after_output', function ($post_id) {

    // Trigger additional output if needed

});

Use Cases

Trigger additional scripts
Extend frontend behaviour

Filter: Control Schema Output Location

`cc_schema_output_location`

Controls where schema is output (e.g. wp_head or wp_footer).

Parameters

$location (string) — Output hook name

Example

add_filter('cc_schema_output_location', function ($location) {
    return 'wp_footer';
});

Use Cases

Move schema output location
Improve compatibility with themes/builders

Filter: Enable or Disable Schema Output

`cc_schema_enabled`

Determines whether schema should be output on the current page.

Parameters

$enabled (bool) — Whether schema output is enabled
$post_id (int) — Current post ID

Example

add_filter('cc_schema_enabled', function ($enabled, $post_id) {

    if (is_admin()) {
        return false;
    }

    return $enabled;

}, 10, 2);

Use Cases

Disable schema conditionally
Prevent output on specific pages
Integrate with other SEO tools

Filter: Modify Final JSON Encoding

`cc_schema_json_flags`

Filters the JSON encoding flags used in wp_json_encode.

Parameters

$flags (int) — JSON encoding flags

Example

add_filter('cc_schema_json_flags', function ($flags) {
    return $flags | JSON_PRETTY_PRINT;
});

Use Cases

Enable pretty printing for debugging
Adjust encoding behaviour

Best Practices for Developers

1. Always Return Valid Schema

Ensure your modifications comply with Schema.org standards to avoid validation errors.

2. Avoid Removing Required Fields

Removing required properties may prevent rich results from appearing.

3. Use Conditional Logic

Wrap customisations with conditions such as:

if (is_singular('post')) { ... }

4. Test Your Changes

Use structured data testing tools to verify output after applying filters.

Structured data must be correctly formatted JSON-LD to be interpreted by search engines .

Summary

The CC Schema & Structured Data plugin provides a flexible hook system that allows developers to:

Modify schema globally or per type
Extend schema with custom data
Control output behaviour
Integrate with themes and other plugins

This ensures the plugin can scale from simple use cases to advanced SEO implementations.