Castlegate IT WP Schema

Schema is a WordPress plugin that embeds Schema.org structured data into a website as JSON linked data. It requires Advanced Custom Fields Pro.

Organization

The plugin provides an ACF options page called Organization with fields for various company or organization details that will be used to assemble the Organization schema data. All the fields are optional and some will fall back to default values based on the site configuration. For example, if you do not enter an organization name, the site name will be used instead. This schema will be embedded on every page of the website.

Custom fields

You can add custom fields to the Organization options page with the cgit_schema_options_page_custom_field_args filter. You will also need to use the cgit_schema_{$schema_name}_schema filter to include the field data in the resulting schema. For example:

add_filter('cgit_schema_options_page_custom_field_args', function ($fields) {
    $fields['fields'][] = [
        'key' => 'foo',
        'name' => 'foo',
        'label' => 'foo',
        'type' => 'text',
    ];

    return $fields;
});

add_filter('cgit_schema_Organization_schema', function ($schema) {
    $schema['foo'] = get_field('foo', 'option');

    return $schema;
});

Google Maps API

The Google Maps location field on the Organization options page requires an API key. You can find out how to add the API key in the Advanced Custom Fields documentation.

Article

Blog posts will also include the Article schema. This is assembled entirely from the default WordPress blog post data and, therefore, does not require any custom fields.

Post types

The plugin provides two additional post types that can contain structured data: Job Vacancy and Team Member. They are disabled by default and can be activated using the cgit_schema_post_types filter:

add_filter('cgit_schema_post_types', function ($types) {
    $types['job-vacancy']['active'] = true;
    $types['team-member']['active'] = true;

    return $types;
});

Each post type includes the necessary ACF custom fields to generate valid structured data.

Custom fields

You can add custom fields to the post types with the cgit_schema_{$post_type}_custom_field_args filter. You will also need to use the cgit_schema_{$schema_name}_schema filter to include the field data in the resulting schema. For example:

add_filter('cgit_schema_job-vacancy_custom_field_args', function ($fields) {
    $fields['fields'][] = [
        'key' => 'foo',
        'name' => 'foo',
        'label' => 'foo',
        'type' => 'text',
    ];

    return $fields;
});

add_filter('cgit_schema_JobPosting_schema', function ($schema) {
    $schema['foo'] = get_field('foo');

    return $schema;
});

Custom post types and schemas

You can also add entirely custom post types with corresponding structured data using the cgit_schema_post_types filter:

add_filter('cgit_schema_post_types', function ($types) {
    $types['foo'] = [
        'class' => 'FooPostTypeClassName',
        'schema' => 'FooSchemaClassName',
        'active' => true,
    ];

    return $types;
});

The class class should be extended from \Castlegate\Schema\PostType\PostType and defines the post type and its fields. The schema class should be extended from \Castlegate\Schema\Schema\Schema and generates the strucutred data that is output on the page.

Validation

Google's guidelines specify a subset of the Schema.org specification with certain fields required. It is recommended that you use Google's Structured Data Testing Tool to make sure that the data embedded on your site can be read and indexed by Google.

Filters

• cgit_schema_post_types can be used to edit the list of custom post types, including the class used to define the post type and custom fields, the class used to embed the appropriate schema, and whether the post type is currently active or not. If the post type class and schema class do not include a namespace, the default plugin namespace will be used. This allows additional post types and schemas to be added by other plugins.

• cgit_schema_options_pages includes the list of classes used to generate ACF options pages. By default, this only includes the Organization options page.

• cgit_schema_options_page_args filters the options page options.

• cgit_schema_options_page_custom_field_args filters the ACF custom post type definitions for options pages.

• cgit_schema_{$post_type}_post_type_args filters the post type definition options.

• cgit_schema_{$post_type}_custom_field_args filters the post type ACF custom fields definitions.

• cgit_schema_{$schema_name}_schema filters the data for each schema embedded on the page.

• cgit_schema_editor_classes filters the list of schema classes used by the Editor class to generate structured data.

• cgit_schema_schemas filters the final, complete structured data just before it is embedded on the page.

License

Released under the MIT License. See LICENSE for details.