insideout10 / wordlift-plugin

src/includes/class-wordlift-schema-service.php

Indentation +786 added lines, -786 removed lines

@@ -15,791 +15,791 @@
  */
 class Wordlift_Schema_Service {
 
-	/**
-	 * The 'location created' field name.
-	 *
-	 * @since 3.5.0
-	 */
-	const FIELD_LOCATION_CREATED = 'wl_location_created';
-
-	/**
-	 * The 'topic' field name.
-	 *
-	 * @since 3.5.0
-	 */
-	const FIELD_TOPIC = 'wl_topic';
-
-	/**
-	 * The 'author' field name.
-	 *
-	 * @since 3.1.0
-	 */
-	const FIELD_AUTHOR = 'wl_author';
-
-	/**
-	 * The 'same as' field name.
-	 *
-	 * @since 3.1.0
-	 */
-	const FIELD_SAME_AS = 'entity_same_as';
-
-	/**
-	 * The 'date start' field name.
-	 *
-	 * @since 3.1.0
-	 */
-	const FIELD_DATE_START = 'wl_cal_date_start';
-
-	/**
-	 * The 'date end' field name.
-	 *
-	 * @since 3.1.0
-	 */
-	const FIELD_DATE_END = 'wl_cal_date_end';
-
-	/**
-	 * The 'location' field name.
-	 *
-	 * @since 3.1.0
-	 */
-	const FIELD_LOCATION = 'wl_location';
-
-	/**
-	 * The 'founder' field name.
-	 *
-	 * @since 3.1.0
-	 */
-	const FIELD_FOUNDER = 'wl_founder';
-
-	/**
-	 * The 'knows' field name.
-	 *
-	 * @since 3.1.0
-	 */
-	const FIELD_KNOWS = 'wl_knows';
-
-	/**
-	 * The 'birth date' field name.
-	 *
-	 * @since 3.1.0
-	 */
-	const FIELD_BIRTH_DATE = 'wl_birth_date';
-
-	/**
-	 * The 'birth place' field name.
-	 *
-	 * @since 3.1.0
-	 */
-	const FIELD_BIRTH_PLACE = 'wl_birth_place';
-
-	/**
-	 * The 'latitude' field name.
-	 *
-	 * @since 3.1.0
-	 */
-	const FIELD_GEO_LATITUDE = 'wl_geo_latitude';
-
-	/**
-	 * The 'longitude' field name.
-	 *
-	 * @since 3.1.0
-	 */
-	const FIELD_GEO_LONGITUDE = 'wl_geo_longitude';
-
-	/**
-	 * The 'streetAddress' field name.
-	 *
-	 * @since 3.1.0
-	 */
-	const FIELD_ADDRESS = 'wl_address';
-
-	/**
-	 * The 'postOfficeBoxNumber' field name.
-	 *
-	 * @since 3.3.0
-	 */
-	const FIELD_ADDRESS_PO_BOX = 'wl_address_post_office_box';
-
-	/**
-	 * The 'postalCode' field name.
-	 *
-	 * @since 3.3.0
-	 */
-	const FIELD_ADDRESS_POSTAL_CODE = 'wl_address_postal_code';
-
-	/**
-	 * The 'addressLocality' field name.
-	 *
-	 * @since 3.3.0
-	 */
-	const FIELD_ADDRESS_LOCALITY = 'wl_address_locality';
-	/**
-	 * The 'addressRegion' field name.
-	 *
-	 * @since 3.3.0
-	 */
-	const FIELD_ADDRESS_REGION = 'wl_address_region';
-
-	/**
-	 * The 'addressCountry' field name.
-	 *
-	 * @since 3.3.0
-	 */
-	const FIELD_ADDRESS_COUNTRY = 'wl_address_country';
-
-	/**
-	 * The 'entity type' field name.
-	 *
-	 * @since 3.1.0
-	 */
-	const FIELD_ENTITY_TYPE = 'wl_entity_type_uri';
-
-	/**
-	 * The 'email' field name.
-	 *
-	 * @since 3.2.0
-	 */
-	const FIELD_EMAIL = 'wl_email';
-
-	/**
-	 * The 'affiliation' field name.
-	 *
-	 * @since 3.2.0
-	 */
-	const FIELD_AFFILIATION = 'wl_affiliation';
-
-	/**
-	 * The 'telephone' field name.
-	 *
-	 * @since 3.8.0
-	 */
-	const FIELD_TELEPHONE = 'wl_schema_telephone';
-
-	/**
-	 * The 'URI' data type name.
-	 *
-	 * @since 3.1.0
-	 */
-	const DATA_TYPE_URI = 'uri';
-
-	/**
-	 * The 'date' data type name.
-	 *
-	 * @since 3.1.0
-	 */
-	const DATA_TYPE_DATE = 'date';
-
-	/**
-	 * The 'double' data type name.
-	 *
-	 * @since 3.1.0
-	 */
-	const DATA_TYPE_DOUBLE = 'double';
-
-	/**
-	 * The 'string' data type name.
-	 *
-	 * @since 3.1.0
-	 */
-	const DATA_TYPE_STRING = 'string';
-
-	/**
-	 * The 'integer' data type name.
-	 *
-	 * @since 3.1.0
-	 */
-	const DATA_TYPE_INTEGER = 'int';
-
-	/**
-	 * The 'boolean' data type name.
-	 *
-	 * @since 3.1.0
-	 */
-	const DATA_TYPE_BOOLEAN = 'bool';
-
-	/**
-	 * The schema.org Event type URI.
-	 *
-	 * @since 3.1.0
-	 */
-	const SCHEMA_EVENT_TYPE = 'http://schema.org/Event';
-
-	/**
-	 * The Schema service singleton instance.
-	 *
-	 * @since  3.1.0
-	 * @access private
-	 * @var \Wordlift_Schema_Service $instance The Schema service singleton instance.
-	 */
-	private static $instance;
-
-	/**
-	 * WordLift's schema.
-	 *
-	 * @since  3.1.0
-	 * @access private
-	 * @var array $schema WordLift's schema.
-	 */
-	private $schema;
-
-	/**
-	 * The Log service.
-	 *
-	 * @since  3.1.0
-	 * @access private
-	 * @var \Wordlift_Log_Service $log_service The Log service.
-	 */
-	private $log_service;
-
-	/**
-	 * Wordlift_Schema_Service constructor.
-	 *
-	 * @since 3.1.0
-	 */
-	public function __construct() {
-
-		$this->log_service = Wordlift_Log_Service::get_logger( 'Wordlift_Schema_Service' );
-
-		// Create a singleton instance of the Schema service, useful to provide static functions to global functions.
-		self::$instance = $this;
-
-		// Set the taxonomy data.
-		// Note: parent types must be defined before child types.
-		$this->schema = array(
-			'thing'         => $this->get_thing_schema(),
-			'creative-work' => $this->get_creative_work_schema(),
-			'event'         => $this->get_event_schema(),
-			'organization'  => $this->get_organization_schema(),
-			'person'        => $this->get_person_schema(),
-			'place'         => $this->get_place_schema(),
-			'localbusiness' => $this->get_local_business_schema(),
-		);
-
-	}
-
-	/**
-	 * Get a reference to the Schema service.
-	 *
-	 * @since 3.1.0
-	 *
-	 * @return Wordlift_Schema_Service A reference to the Schema service.
-	 */
-	public static function get_instance() {
-
-		return self::$instance;
-	}
-
-	/**
-	 * Get the properties for a field with the specified key. The key is used as
-	 * meta key when the field's value is stored in WordPress meta data table.
-	 *
-	 * @since 3.6.0
-	 *
-	 * @param string $key The field's key.
-	 *
-	 * @return null|array An array of field's properties or null if the field is not found.
-	 */
-	public function get_field( $key ) {
-
-		// Parse each schema's fields until we find the one we're looking for, then
-		// return its properties.
-		foreach ( $this->schema as $_ => $schema ) {
-
-			if ( ! isset( $schema['custom_fields'] ) ) {
-				break;
-			}
-
-			foreach ( $schema['custom_fields'] as $field => $props ) {
-				if ( $key === $field ) {
-					return $props;
-				}
-			}
-		}
-
-		return null;
-	}
-
-	/**
-	 * Get the WordLift's schema.
-	 *
-	 * @param string $name The schema name.
-	 *
-	 * @return array|null An array with the schema configuration or NULL if the schema is not found.
-	 *
-	 * @since 3.1.0
-	 */
-	public function get_schema( $name ) {
-
-		// Check if the schema exists and, if not, return NULL.
-		if ( ! isset( $this->schema[ $name ] ) ) {
-			return null;
-		}
-
-		// Return the requested schema.
-		return $this->schema[ $name ];
-	}
-
-	/**
-	 * Get the WordLift's schema trough schema type uri.
-	 *
-	 * @param string $uri The schema uri.
-	 *
-	 * @return array|null An array with the schema configuration or NULL if the schema is not found.
-	 *
-	 * @since 3.3.0
-	 */
-	public function get_schema_by_uri( $uri ) {
-
-		foreach ( $this->schema as $name => $schema ) {
-			if ( $schema['uri'] === $uri ) {
-				return $schema;
-			}
-		}
-
-		return null;
-	}
-
-	/**
-	 * Get the 'thing' schema.
-	 *
-	 * @return array An array with the schema configuration.
-	 *
-	 * @since 3.1.0
-	 */
-	private function get_thing_schema() {
-
-		return array(
-			'css_class'     => 'wl-thing',
-			'uri'           => 'http://schema.org/Thing',
-			'same_as'       => array( '*' ),
-			// set as default.
-			'custom_fields' => array(
-				self::FIELD_SAME_AS                            => array(
-					'predicate'   => 'http://schema.org/sameAs',
-					'type'        => self::DATA_TYPE_URI,
-					'export_type' => 'http://schema.org/Thing',
-					'constraints' => array(
-						'cardinality' => INF,
-					),
-					// we need a custom metabox
-					'input_field' => 'sameas',
-				),
-				// Add the schema:url property.
-				Wordlift_Schema_Url_Property_Service::META_KEY => Wordlift_Schema_Url_Property_Service::get_instance()
-				                                                                                      ->get_compat_definition(),
-			),
-			// {{sameAs}} not present in the microdata template,
-			// because it is treated separately in *wl_content_embed_item_microdata*
-			'templates'     => array(
-				'subtitle' => '{{id}}',
-			),
-		);
-
-	}
-
-	/**
-	 * Get the 'creative work' schema.
-	 *
-	 * @return array An array with the schema configuration.
-	 *
-	 * @since 3.1.0
-	 */
-	private function get_creative_work_schema() {
-
-		$schema = array(
-			'label'         => 'CreativeWork',
-			'description'   => 'A creative work (or a Music Album).',
-			'parents'       => array( 'thing' ),
-			// Give term slug as parent.
-			'css_class'     => 'wl-creative-work',
-			'uri'           => 'http://schema.org/CreativeWork',
-			'same_as'       => array(
-				'http://schema.org/MusicAlbum',
-				'http://schema.org/Product',
-			),
-			'custom_fields' => array(
-				self::FIELD_AUTHOR => array(
-					'predicate'   => 'http://schema.org/author',
-					'type'        => self::DATA_TYPE_URI,
-					'export_type' => 'http://schema.org/Person',
-					'constraints' => array(
-						'uri_type'    => array( 'Person', 'Organization' ),
-						'cardinality' => INF,
-					),
-				),
-			),
-			'templates'     => array(
-				'subtitle' => '{{id}}',
-			),
-		);
-
-		// Merge the custom fields with those provided by the thing schema.
-		$thing_schema            = $this->get_thing_schema();
-		$schema['custom_fields'] = array_merge( $schema['custom_fields'], $thing_schema['custom_fields'] );
-
-		return $schema;
-	}
-
-	/**
-	 * Get the 'event' schema.
-	 *
-	 * @return array An array with the schema configuration.
-	 *
-	 * @since 3.1.0
-	 */
-	private function get_event_schema() {
-
-		$schema = array(
-			'label'         => 'Event',
-			'description'   => 'An event . ',
-			'parents'       => array( 'thing' ),
-			'css_class'     => 'wl-event',
-			'uri'           => self::SCHEMA_EVENT_TYPE,
-			'same_as'       => array( 'http://dbpedia.org/ontology/Event' ),
-			'custom_fields' => array(
-				self::FIELD_DATE_START => array(
-					'predicate'   => 'http://schema.org/startDate',
-					'type'        => self::DATA_TYPE_DATE,
-					'export_type' => 'xsd:datetime',
-					'constraints' => '',
-				),
-				self::FIELD_DATE_END   => array(
-					'predicate'   => 'http://schema.org/endDate',
-					'type'        => self::DATA_TYPE_DATE,
-					'export_type' => 'xsd:datetime',
-					'constraints' => '',
-				),
-				self::FIELD_LOCATION   => array(
-					'predicate'   => 'http://schema.org/location',
-					'type'        => self::DATA_TYPE_URI,
-					'export_type' => 'http://schema.org/PostalAddress',
-					'constraints' => array(
-						'uri_type'    => array( 'Place', 'LocalBusiness' ),
-						'cardinality' => INF,
-					),
-				),
-			),
-			'templates'     => array(
-				'subtitle' => '{{id}}',
-			),
-		);
-
-		// Merge the custom fields with those provided by the thing schema.
-		$thing_schema            = $this->get_thing_schema();
-		$schema['custom_fields'] = array_merge( $schema['custom_fields'], $thing_schema['custom_fields'] );
-
-		return $schema;
-	}
-
-	/**
-	 * Get the 'organization' schema.
-	 *
-	 * @return array An array with the schema configuration.
-	 *
-	 * @since 3.1.0
-	 */
-	private function get_organization_schema() {
-
-		$schema = array(
-			'label'         => 'Organization',
-			'description'   => 'An organization, including a government or a newspaper.',
-			'parents'       => array( 'thing' ),
-			'css_class'     => 'wl-organization',
-			'uri'           => 'http://schema.org/Organization',
-			'same_as'       => array(
-				'http://rdf.freebase.com/ns/organization.organization',
-				'http://rdf.freebase.com/ns/government.government',
-				'http://schema.org/Newspaper',
-			),
-			'custom_fields' => array(
-				self::FIELD_FOUNDER             => array(
-					'predicate'   => 'http://schema.org/founder',
-					'type'        => self::DATA_TYPE_URI,
-					'export_type' => 'http://schema.org/Person',
-					'constraints' => array(
-						'uri_type'    => 'Person',
-						'cardinality' => INF,
-					),
-				),
-				self::FIELD_ADDRESS             => array(
-					'predicate'   => 'http://schema.org/streetAddress',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => '',
-					// To build custom metabox.
-					'input_field' => 'address',
-				),
-				self::FIELD_ADDRESS_PO_BOX      => array(
-					'predicate'   => 'http://schema.org/postOfficeBoxNumber',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => '',
-					// To build custom metabox.
-					'input_field' => 'address',
-				),
-				self::FIELD_ADDRESS_POSTAL_CODE => array(
-					'predicate'   => 'http://schema.org/postalCode',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => '',
-					// To build custom metabox.
-					'input_field' => 'address',
-				),
-				self::FIELD_ADDRESS_LOCALITY    => array(
-					'predicate'   => 'http://schema.org/addressLocality',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => '',
-					// To build custom metabox.
-					'input_field' => 'address',
-				),
-				self::FIELD_ADDRESS_REGION      => array(
-					'predicate'   => 'http://schema.org/addressRegion',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => '',
-					// To build custom metabox.
-					'input_field' => 'address',
-				),
-				self::FIELD_ADDRESS_COUNTRY     => array(
-					'predicate'   => 'http://schema.org/addressCountry',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => '',
-					// To build custom metabox.
-					'input_field' => 'address',
-				),
-				self::FIELD_EMAIL               => array(
-					'predicate'   => 'http://schema.org/email',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => '',
-				),
-				self::FIELD_TELEPHONE           => array(
-					'predicate'   => 'http://schema.org/telephone',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => '',
-				),
-			),
-			'templates'     => array(
-				'subtitle' => '{{id}}',
-			),
-		);
-
-		// Merge the custom fields with those provided by the thing schema.
-		$thing_schema            = $this->get_thing_schema();
-		$schema['custom_fields'] = array_merge( $schema['custom_fields'], $thing_schema['custom_fields'] );
-
-		return $schema;
-	}
-
-	/**
-	 * Get the 'person' schema.
-	 *
-	 * @return array An array with the schema configuration.
-	 *
-	 * @since 3.1.0
-	 */
-	private function get_person_schema() {
-
-		$schema = array(
-			'label'         => 'Person',
-			'description'   => 'A person (or a music artist).',
-			'parents'       => array( 'thing' ),
-			'css_class'     => 'wl-person',
-			'uri'           => 'http://schema.org/Person',
-			'same_as'       => array(
-				'http://rdf.freebase.com/ns/people.person',
-				'http://rdf.freebase.com/ns/music.artist',
-				'http://dbpedia.org/class/yago/LivingPeople',
-			),
-			'custom_fields' => array(
-				self::FIELD_KNOWS       => array(
-					'predicate'   => 'http://schema.org/knows',
-					'type'        => self::DATA_TYPE_URI,
-					'export_type' => 'http://schema.org/Person',
-					'constraints' => array(
-						'uri_type'    => 'Person',
-						'cardinality' => INF,
-					),
-				),
-				self::FIELD_BIRTH_DATE  => array(
-					'predicate'   => 'http://schema.org/birthDate',
-					'type'        => self::DATA_TYPE_DATE,
-					'export_type' => 'xsd:date',
-					'constraints' => '',
-				),
-				self::FIELD_BIRTH_PLACE => array(
-					'predicate'   => 'http://schema.org/birthPlace',
-					'type'        => self::DATA_TYPE_URI,
-					'export_type' => 'http://schema.org/Place',
-					'constraints' => array(
-						'uri_type' => 'Place',
-					),
-				),
-				self::FIELD_AFFILIATION => array(
-					'predicate'   => 'http://schema.org/affiliation',
-					'type'        => self::DATA_TYPE_URI,
-					'export_type' => 'http://schema.org/Organization',
-					'constraints' => array(
-						'uri_type'    => array(
-							'Organization',
-							'LocalBusiness',
-						),
-						'cardinality' => INF,
-					),
-				),
-				self::FIELD_EMAIL       => array(
-					'predicate'   => 'http://schema.org/email',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => array(
-						'cardinality' => INF,
-					),
-				),
-			),
-			'templates'     => array(
-				'subtitle' => '{{id}}',
-			),
-		);
-
-		// Merge the custom fields with those provided by the thing schema.
-		$thing_schema            = $this->get_thing_schema();
-		$schema['custom_fields'] = array_merge( $schema['custom_fields'], $thing_schema['custom_fields'] );
-
-		return $schema;
-
-	}
-
-	/**
-	 * Get the 'place' schema.
-	 *
-	 * @return array An array with the schema configuration.
-	 *
-	 * @since 3.1.0
-	 */
-	private function get_place_schema() {
-
-		$schema = array(
-			'label'         => 'Place',
-			'description'   => 'A place.',
-			'parents'       => array( 'thing' ),
-			'css_class'     => 'wl-place',
-			'uri'           => 'http://schema.org/Place',
-			'same_as'       => array(
-				'http://rdf.freebase.com/ns/location.location',
-				'http://www.opengis.net/gml/_Feature',
-			),
-			'custom_fields' => array(
-				self::FIELD_GEO_LATITUDE        => array(
-					'predicate'   => 'http://schema.org/latitude',
-					'type'        => self::DATA_TYPE_DOUBLE,
-					'export_type' => 'xsd:double',
-					'constraints' => '',
-					// To build custom metabox.
-					'input_field' => 'coordinates',
-				),
-				self::FIELD_GEO_LONGITUDE       => array(
-					'predicate'   => 'http://schema.org/longitude',
-					'type'        => self::DATA_TYPE_DOUBLE,
-					'export_type' => 'xsd:double',
-					'constraints' => '',
-					// To build custom metabox.
-					'input_field' => 'coordinates',
-				),
-				self::FIELD_ADDRESS             => array(
-					'predicate'   => 'http://schema.org/streetAddress',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => '',
-					// To build custom metabox.
-					'input_field' => 'address',
-				),
-				self::FIELD_ADDRESS_PO_BOX      => array(
-					'predicate'   => 'http://schema.org/postOfficeBoxNumber',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => '',
-					// To build custom metabox.
-					'input_field' => 'address',
-				),
-				self::FIELD_ADDRESS_POSTAL_CODE => array(
-					'predicate'   => 'http://schema.org/postalCode',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => '',
-					// To build custom metabox.
-					'input_field' => 'address',
-				),
-				self::FIELD_ADDRESS_LOCALITY    => array(
-					'predicate'   => 'http://schema.org/addressLocality',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => '',
-					// To build custom metabox.
-					'input_field' => 'address',
-				),
-				self::FIELD_ADDRESS_REGION      => array(
-					'predicate'   => 'http://schema.org/addressRegion',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => '',
-					// To build custom metabox.
-					'input_field' => 'address',
-				),
-				self::FIELD_ADDRESS_COUNTRY     => array(
-					'predicate'   => 'http://schema.org/addressCountry',
-					'type'        => self::DATA_TYPE_STRING,
-					'export_type' => 'xsd:string',
-					'constraints' => '',
-					// To build custom metabox.
-					'input_field' => 'address',
-				),
-			),
-			'templates'     => array(
-				'subtitle' => '{{id}}',
-			),
-		);
-
-		// Merge the custom fields with those provided by the thing schema.
-		$thing_schema            = $this->get_thing_schema();
-		$schema['custom_fields'] = array_merge( $schema['custom_fields'], $thing_schema['custom_fields'] );
-
-		return $schema;
-	}
-
-	/**
-	 * Get the 'local business' schema.
-	 *
-	 * @return array An array with the schema configuration.
-	 *
-	 * @since 3.1.0
-	 */
-	private function get_local_business_schema() {
-
-		$schema = array(
-			'label'         => 'LocalBusiness',
-			'description'   => 'A local business.',
-			'parents'       => array( 'place', 'organization' ),
-			'css_class'     => 'wl-local-business',
-			'uri'           => 'http://schema.org/LocalBusiness',
-			'same_as'       => array(
-				'http://rdf.freebase.com/ns/business/business_location',
-				'https://schema.org/Store',
-			),
-			'custom_fields' => array(),
-			'templates'     => array(
-				'subtitle' => '{{id}}',
-			),
-		);
-
-		// Merge the custom fields with those provided by the place and organization schema.
-		$place_schema            = $this->get_place_schema();
-		$organization_schema     = $this->get_organization_schema();
-		$schema['custom_fields'] = array_merge( $schema['custom_fields'], $place_schema['custom_fields'], $organization_schema['custom_fields'] );
-
-		return $schema;
-	}
+    /**
+     * The 'location created' field name.
+     *
+     * @since 3.5.0
+     */
+    const FIELD_LOCATION_CREATED = 'wl_location_created';
+
+    /**
+     * The 'topic' field name.
+     *
+     * @since 3.5.0
+     */
+    const FIELD_TOPIC = 'wl_topic';
+
+    /**
+     * The 'author' field name.
+     *
+     * @since 3.1.0
+     */
+    const FIELD_AUTHOR = 'wl_author';
+
+    /**
+     * The 'same as' field name.
+     *
+     * @since 3.1.0
+     */
+    const FIELD_SAME_AS = 'entity_same_as';
+
+    /**
+     * The 'date start' field name.
+     *
+     * @since 3.1.0
+     */
+    const FIELD_DATE_START = 'wl_cal_date_start';
+
+    /**
+     * The 'date end' field name.
+     *
+     * @since 3.1.0
+     */
+    const FIELD_DATE_END = 'wl_cal_date_end';
+
+    /**
+     * The 'location' field name.
+     *
+     * @since 3.1.0
+     */
+    const FIELD_LOCATION = 'wl_location';
+
+    /**
+     * The 'founder' field name.
+     *
+     * @since 3.1.0
+     */
+    const FIELD_FOUNDER = 'wl_founder';
+
+    /**
+     * The 'knows' field name.
+     *
+     * @since 3.1.0
+     */
+    const FIELD_KNOWS = 'wl_knows';
+
+    /**
+     * The 'birth date' field name.
+     *
+     * @since 3.1.0
+     */
+    const FIELD_BIRTH_DATE = 'wl_birth_date';
+
+    /**
+     * The 'birth place' field name.
+     *
+     * @since 3.1.0
+     */
+    const FIELD_BIRTH_PLACE = 'wl_birth_place';
+
+    /**
+     * The 'latitude' field name.
+     *
+     * @since 3.1.0
+     */
+    const FIELD_GEO_LATITUDE = 'wl_geo_latitude';
+
+    /**
+     * The 'longitude' field name.
+     *
+     * @since 3.1.0
+     */
+    const FIELD_GEO_LONGITUDE = 'wl_geo_longitude';
+
+    /**
+     * The 'streetAddress' field name.
+     *
+     * @since 3.1.0
+     */
+    const FIELD_ADDRESS = 'wl_address';
+
+    /**
+     * The 'postOfficeBoxNumber' field name.
+     *
+     * @since 3.3.0
+     */
+    const FIELD_ADDRESS_PO_BOX = 'wl_address_post_office_box';
+
+    /**
+     * The 'postalCode' field name.
+     *
+     * @since 3.3.0
+     */
+    const FIELD_ADDRESS_POSTAL_CODE = 'wl_address_postal_code';
+
+    /**
+     * The 'addressLocality' field name.
+     *
+     * @since 3.3.0
+     */
+    const FIELD_ADDRESS_LOCALITY = 'wl_address_locality';
+    /**
+     * The 'addressRegion' field name.
+     *
+     * @since 3.3.0
+     */
+    const FIELD_ADDRESS_REGION = 'wl_address_region';
+
+    /**
+     * The 'addressCountry' field name.
+     *
+     * @since 3.3.0
+     */
+    const FIELD_ADDRESS_COUNTRY = 'wl_address_country';
+
+    /**
+     * The 'entity type' field name.
+     *
+     * @since 3.1.0
+     */
+    const FIELD_ENTITY_TYPE = 'wl_entity_type_uri';
+
+    /**
+     * The 'email' field name.
+     *
+     * @since 3.2.0
+     */
+    const FIELD_EMAIL = 'wl_email';
+
+    /**
+     * The 'affiliation' field name.
+     *
+     * @since 3.2.0
+     */
+    const FIELD_AFFILIATION = 'wl_affiliation';
+
+    /**
+     * The 'telephone' field name.
+     *
+     * @since 3.8.0
+     */
+    const FIELD_TELEPHONE = 'wl_schema_telephone';
+
+    /**
+     * The 'URI' data type name.
+     *
+     * @since 3.1.0
+     */
+    const DATA_TYPE_URI = 'uri';
+
+    /**
+     * The 'date' data type name.
+     *
+     * @since 3.1.0
+     */
+    const DATA_TYPE_DATE = 'date';
+
+    /**
+     * The 'double' data type name.
+     *
+     * @since 3.1.0
+     */
+    const DATA_TYPE_DOUBLE = 'double';
+
+    /**
+     * The 'string' data type name.
+     *
+     * @since 3.1.0
+     */
+    const DATA_TYPE_STRING = 'string';
+
+    /**
+     * The 'integer' data type name.
+     *
+     * @since 3.1.0
+     */
+    const DATA_TYPE_INTEGER = 'int';
+
+    /**
+     * The 'boolean' data type name.
+     *
+     * @since 3.1.0
+     */
+    const DATA_TYPE_BOOLEAN = 'bool';
+
+    /**
+     * The schema.org Event type URI.
+     *
+     * @since 3.1.0
+     */
+    const SCHEMA_EVENT_TYPE = 'http://schema.org/Event';
+
+    /**
+     * The Schema service singleton instance.
+     *
+     * @since  3.1.0
+     * @access private
+     * @var \Wordlift_Schema_Service $instance The Schema service singleton instance.
+     */
+    private static $instance;
+
+    /**
+     * WordLift's schema.
+     *
+     * @since  3.1.0
+     * @access private
+     * @var array $schema WordLift's schema.
+     */
+    private $schema;
+
+    /**
+     * The Log service.
+     *
+     * @since  3.1.0
+     * @access private
+     * @var \Wordlift_Log_Service $log_service The Log service.
+     */
+    private $log_service;
+
+    /**
+     * Wordlift_Schema_Service constructor.
+     *
+     * @since 3.1.0
+     */
+    public function __construct() {
+
+        $this->log_service = Wordlift_Log_Service::get_logger( 'Wordlift_Schema_Service' );
+
+        // Create a singleton instance of the Schema service, useful to provide static functions to global functions.
+        self::$instance = $this;
+
+        // Set the taxonomy data.
+        // Note: parent types must be defined before child types.
+        $this->schema = array(
+            'thing'         => $this->get_thing_schema(),
+            'creative-work' => $this->get_creative_work_schema(),
+            'event'         => $this->get_event_schema(),
+            'organization'  => $this->get_organization_schema(),
+            'person'        => $this->get_person_schema(),
+            'place'         => $this->get_place_schema(),
+            'localbusiness' => $this->get_local_business_schema(),
+        );
+
+    }
+
+    /**
+     * Get a reference to the Schema service.
+     *
+     * @since 3.1.0
+     *
+     * @return Wordlift_Schema_Service A reference to the Schema service.
+     */
+    public static function get_instance() {
+
+        return self::$instance;
+    }
+
+    /**
+     * Get the properties for a field with the specified key. The key is used as
+     * meta key when the field's value is stored in WordPress meta data table.
+     *
+     * @since 3.6.0
+     *
+     * @param string $key The field's key.
+     *
+     * @return null|array An array of field's properties or null if the field is not found.
+     */
+    public function get_field( $key ) {
+
+        // Parse each schema's fields until we find the one we're looking for, then
+        // return its properties.
+        foreach ( $this->schema as $_ => $schema ) {
+
+            if ( ! isset( $schema['custom_fields'] ) ) {
+                break;
+            }
+
+            foreach ( $schema['custom_fields'] as $field => $props ) {
+                if ( $key === $field ) {
+                    return $props;
+                }
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * Get the WordLift's schema.
+     *
+     * @param string $name The schema name.
+     *
+     * @return array|null An array with the schema configuration or NULL if the schema is not found.
+     *
+     * @since 3.1.0
+     */
+    public function get_schema( $name ) {
+
+        // Check if the schema exists and, if not, return NULL.
+        if ( ! isset( $this->schema[ $name ] ) ) {
+            return null;
+        }
+
+        // Return the requested schema.
+        return $this->schema[ $name ];
+    }
+
+    /**
+     * Get the WordLift's schema trough schema type uri.
+     *
+     * @param string $uri The schema uri.
+     *
+     * @return array|null An array with the schema configuration or NULL if the schema is not found.
+     *
+     * @since 3.3.0
+     */
+    public function get_schema_by_uri( $uri ) {
+
+        foreach ( $this->schema as $name => $schema ) {
+            if ( $schema['uri'] === $uri ) {
+                return $schema;
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * Get the 'thing' schema.
+     *
+     * @return array An array with the schema configuration.
+     *
+     * @since 3.1.0
+     */
+    private function get_thing_schema() {
+
+        return array(
+            'css_class'     => 'wl-thing',
+            'uri'           => 'http://schema.org/Thing',
+            'same_as'       => array( '*' ),
+            // set as default.
+            'custom_fields' => array(
+                self::FIELD_SAME_AS                            => array(
+                    'predicate'   => 'http://schema.org/sameAs',
+                    'type'        => self::DATA_TYPE_URI,
+                    'export_type' => 'http://schema.org/Thing',
+                    'constraints' => array(
+                        'cardinality' => INF,
+                    ),
+                    // we need a custom metabox
+                    'input_field' => 'sameas',
+                ),
+                // Add the schema:url property.
+                Wordlift_Schema_Url_Property_Service::META_KEY => Wordlift_Schema_Url_Property_Service::get_instance()
+                                                                                                        ->get_compat_definition(),
+            ),
+            // {{sameAs}} not present in the microdata template,
+            // because it is treated separately in *wl_content_embed_item_microdata*
+            'templates'     => array(
+                'subtitle' => '{{id}}',
+            ),
+        );
+
+    }
+
+    /**
+     * Get the 'creative work' schema.
+     *
+     * @return array An array with the schema configuration.
+     *
+     * @since 3.1.0
+     */
+    private function get_creative_work_schema() {
+
+        $schema = array(
+            'label'         => 'CreativeWork',
+            'description'   => 'A creative work (or a Music Album).',
+            'parents'       => array( 'thing' ),
+            // Give term slug as parent.
+            'css_class'     => 'wl-creative-work',
+            'uri'           => 'http://schema.org/CreativeWork',
+            'same_as'       => array(
+                'http://schema.org/MusicAlbum',
+                'http://schema.org/Product',
+            ),
+            'custom_fields' => array(
+                self::FIELD_AUTHOR => array(
+                    'predicate'   => 'http://schema.org/author',
+                    'type'        => self::DATA_TYPE_URI,
+                    'export_type' => 'http://schema.org/Person',
+                    'constraints' => array(
+                        'uri_type'    => array( 'Person', 'Organization' ),
+                        'cardinality' => INF,
+                    ),
+                ),
+            ),
+            'templates'     => array(
+                'subtitle' => '{{id}}',
+            ),
+        );
+
+        // Merge the custom fields with those provided by the thing schema.
+        $thing_schema            = $this->get_thing_schema();
+        $schema['custom_fields'] = array_merge( $schema['custom_fields'], $thing_schema['custom_fields'] );
+
+        return $schema;
+    }
+
+    /**
+     * Get the 'event' schema.
+     *
+     * @return array An array with the schema configuration.
+     *
+     * @since 3.1.0
+     */
+    private function get_event_schema() {
+
+        $schema = array(
+            'label'         => 'Event',
+            'description'   => 'An event . ',
+            'parents'       => array( 'thing' ),
+            'css_class'     => 'wl-event',
+            'uri'           => self::SCHEMA_EVENT_TYPE,
+            'same_as'       => array( 'http://dbpedia.org/ontology/Event' ),
+            'custom_fields' => array(
+                self::FIELD_DATE_START => array(
+                    'predicate'   => 'http://schema.org/startDate',
+                    'type'        => self::DATA_TYPE_DATE,
+                    'export_type' => 'xsd:datetime',
+                    'constraints' => '',
+                ),
+                self::FIELD_DATE_END   => array(
+                    'predicate'   => 'http://schema.org/endDate',
+                    'type'        => self::DATA_TYPE_DATE,
+                    'export_type' => 'xsd:datetime',
+                    'constraints' => '',
+                ),
+                self::FIELD_LOCATION   => array(
+                    'predicate'   => 'http://schema.org/location',
+                    'type'        => self::DATA_TYPE_URI,
+                    'export_type' => 'http://schema.org/PostalAddress',
+                    'constraints' => array(
+                        'uri_type'    => array( 'Place', 'LocalBusiness' ),
+                        'cardinality' => INF,
+                    ),
+                ),
+            ),
+            'templates'     => array(
+                'subtitle' => '{{id}}',
+            ),
+        );
+
+        // Merge the custom fields with those provided by the thing schema.
+        $thing_schema            = $this->get_thing_schema();
+        $schema['custom_fields'] = array_merge( $schema['custom_fields'], $thing_schema['custom_fields'] );
+
+        return $schema;
+    }
+
+    /**
+     * Get the 'organization' schema.
+     *
+     * @return array An array with the schema configuration.
+     *
+     * @since 3.1.0
+     */
+    private function get_organization_schema() {
+
+        $schema = array(
+            'label'         => 'Organization',
+            'description'   => 'An organization, including a government or a newspaper.',
+            'parents'       => array( 'thing' ),
+            'css_class'     => 'wl-organization',
+            'uri'           => 'http://schema.org/Organization',
+            'same_as'       => array(
+                'http://rdf.freebase.com/ns/organization.organization',
+                'http://rdf.freebase.com/ns/government.government',
+                'http://schema.org/Newspaper',
+            ),
+            'custom_fields' => array(
+                self::FIELD_FOUNDER             => array(
+                    'predicate'   => 'http://schema.org/founder',
+                    'type'        => self::DATA_TYPE_URI,
+                    'export_type' => 'http://schema.org/Person',
+                    'constraints' => array(
+                        'uri_type'    => 'Person',
+                        'cardinality' => INF,
+                    ),
+                ),
+                self::FIELD_ADDRESS             => array(
+                    'predicate'   => 'http://schema.org/streetAddress',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => '',
+                    // To build custom metabox.
+                    'input_field' => 'address',
+                ),
+                self::FIELD_ADDRESS_PO_BOX      => array(
+                    'predicate'   => 'http://schema.org/postOfficeBoxNumber',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => '',
+                    // To build custom metabox.
+                    'input_field' => 'address',
+                ),
+                self::FIELD_ADDRESS_POSTAL_CODE => array(
+                    'predicate'   => 'http://schema.org/postalCode',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => '',
+                    // To build custom metabox.
+                    'input_field' => 'address',
+                ),
+                self::FIELD_ADDRESS_LOCALITY    => array(
+                    'predicate'   => 'http://schema.org/addressLocality',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => '',
+                    // To build custom metabox.
+                    'input_field' => 'address',
+                ),
+                self::FIELD_ADDRESS_REGION      => array(
+                    'predicate'   => 'http://schema.org/addressRegion',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => '',
+                    // To build custom metabox.
+                    'input_field' => 'address',
+                ),
+                self::FIELD_ADDRESS_COUNTRY     => array(
+                    'predicate'   => 'http://schema.org/addressCountry',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => '',
+                    // To build custom metabox.
+                    'input_field' => 'address',
+                ),
+                self::FIELD_EMAIL               => array(
+                    'predicate'   => 'http://schema.org/email',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => '',
+                ),
+                self::FIELD_TELEPHONE           => array(
+                    'predicate'   => 'http://schema.org/telephone',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => '',
+                ),
+            ),
+            'templates'     => array(
+                'subtitle' => '{{id}}',
+            ),
+        );
+
+        // Merge the custom fields with those provided by the thing schema.
+        $thing_schema            = $this->get_thing_schema();
+        $schema['custom_fields'] = array_merge( $schema['custom_fields'], $thing_schema['custom_fields'] );
+
+        return $schema;
+    }
+
+    /**
+     * Get the 'person' schema.
+     *
+     * @return array An array with the schema configuration.
+     *
+     * @since 3.1.0
+     */
+    private function get_person_schema() {
+
+        $schema = array(
+            'label'         => 'Person',
+            'description'   => 'A person (or a music artist).',
+            'parents'       => array( 'thing' ),
+            'css_class'     => 'wl-person',
+            'uri'           => 'http://schema.org/Person',
+            'same_as'       => array(
+                'http://rdf.freebase.com/ns/people.person',
+                'http://rdf.freebase.com/ns/music.artist',
+                'http://dbpedia.org/class/yago/LivingPeople',
+            ),
+            'custom_fields' => array(
+                self::FIELD_KNOWS       => array(
+                    'predicate'   => 'http://schema.org/knows',
+                    'type'        => self::DATA_TYPE_URI,
+                    'export_type' => 'http://schema.org/Person',
+                    'constraints' => array(
+                        'uri_type'    => 'Person',
+                        'cardinality' => INF,
+                    ),
+                ),
+                self::FIELD_BIRTH_DATE  => array(
+                    'predicate'   => 'http://schema.org/birthDate',
+                    'type'        => self::DATA_TYPE_DATE,
+                    'export_type' => 'xsd:date',
+                    'constraints' => '',
+                ),
+                self::FIELD_BIRTH_PLACE => array(
+                    'predicate'   => 'http://schema.org/birthPlace',
+                    'type'        => self::DATA_TYPE_URI,
+                    'export_type' => 'http://schema.org/Place',
+                    'constraints' => array(
+                        'uri_type' => 'Place',
+                    ),
+                ),
+                self::FIELD_AFFILIATION => array(
+                    'predicate'   => 'http://schema.org/affiliation',
+                    'type'        => self::DATA_TYPE_URI,
+                    'export_type' => 'http://schema.org/Organization',
+                    'constraints' => array(
+                        'uri_type'    => array(
+                            'Organization',
+                            'LocalBusiness',
+                        ),
+                        'cardinality' => INF,
+                    ),
+                ),
+                self::FIELD_EMAIL       => array(
+                    'predicate'   => 'http://schema.org/email',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => array(
+                        'cardinality' => INF,
+                    ),
+                ),
+            ),
+            'templates'     => array(
+                'subtitle' => '{{id}}',
+            ),
+        );
+
+        // Merge the custom fields with those provided by the thing schema.
+        $thing_schema            = $this->get_thing_schema();
+        $schema['custom_fields'] = array_merge( $schema['custom_fields'], $thing_schema['custom_fields'] );
+
+        return $schema;
+
+    }
+
+    /**
+     * Get the 'place' schema.
+     *
+     * @return array An array with the schema configuration.
+     *
+     * @since 3.1.0
+     */
+    private function get_place_schema() {
+
+        $schema = array(
+            'label'         => 'Place',
+            'description'   => 'A place.',
+            'parents'       => array( 'thing' ),
+            'css_class'     => 'wl-place',
+            'uri'           => 'http://schema.org/Place',
+            'same_as'       => array(
+                'http://rdf.freebase.com/ns/location.location',
+                'http://www.opengis.net/gml/_Feature',
+            ),
+            'custom_fields' => array(
+                self::FIELD_GEO_LATITUDE        => array(
+                    'predicate'   => 'http://schema.org/latitude',
+                    'type'        => self::DATA_TYPE_DOUBLE,
+                    'export_type' => 'xsd:double',
+                    'constraints' => '',
+                    // To build custom metabox.
+                    'input_field' => 'coordinates',
+                ),
+                self::FIELD_GEO_LONGITUDE       => array(
+                    'predicate'   => 'http://schema.org/longitude',
+                    'type'        => self::DATA_TYPE_DOUBLE,
+                    'export_type' => 'xsd:double',
+                    'constraints' => '',
+                    // To build custom metabox.
+                    'input_field' => 'coordinates',
+                ),
+                self::FIELD_ADDRESS             => array(
+                    'predicate'   => 'http://schema.org/streetAddress',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => '',
+                    // To build custom metabox.
+                    'input_field' => 'address',
+                ),
+                self::FIELD_ADDRESS_PO_BOX      => array(
+                    'predicate'   => 'http://schema.org/postOfficeBoxNumber',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => '',
+                    // To build custom metabox.
+                    'input_field' => 'address',
+                ),
+                self::FIELD_ADDRESS_POSTAL_CODE => array(
+                    'predicate'   => 'http://schema.org/postalCode',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => '',
+                    // To build custom metabox.
+                    'input_field' => 'address',
+                ),
+                self::FIELD_ADDRESS_LOCALITY    => array(
+                    'predicate'   => 'http://schema.org/addressLocality',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => '',
+                    // To build custom metabox.
+                    'input_field' => 'address',
+                ),
+                self::FIELD_ADDRESS_REGION      => array(
+                    'predicate'   => 'http://schema.org/addressRegion',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => '',
+                    // To build custom metabox.
+                    'input_field' => 'address',
+                ),
+                self::FIELD_ADDRESS_COUNTRY     => array(
+                    'predicate'   => 'http://schema.org/addressCountry',
+                    'type'        => self::DATA_TYPE_STRING,
+                    'export_type' => 'xsd:string',
+                    'constraints' => '',
+                    // To build custom metabox.
+                    'input_field' => 'address',
+                ),
+            ),
+            'templates'     => array(
+                'subtitle' => '{{id}}',
+            ),
+        );
+
+        // Merge the custom fields with those provided by the thing schema.
+        $thing_schema            = $this->get_thing_schema();
+        $schema['custom_fields'] = array_merge( $schema['custom_fields'], $thing_schema['custom_fields'] );
+
+        return $schema;
+    }
+
+    /**
+     * Get the 'local business' schema.
+     *
+     * @return array An array with the schema configuration.
+     *
+     * @since 3.1.0
+     */
+    private function get_local_business_schema() {
+
+        $schema = array(
+            'label'         => 'LocalBusiness',
+            'description'   => 'A local business.',
+            'parents'       => array( 'place', 'organization' ),
+            'css_class'     => 'wl-local-business',
+            'uri'           => 'http://schema.org/LocalBusiness',
+            'same_as'       => array(
+                'http://rdf.freebase.com/ns/business/business_location',
+                'https://schema.org/Store',
+            ),
+            'custom_fields' => array(),
+            'templates'     => array(
+                'subtitle' => '{{id}}',
+            ),
+        );
+
+        // Merge the custom fields with those provided by the place and organization schema.
+        $place_schema            = $this->get_place_schema();
+        $organization_schema     = $this->get_organization_schema();
+        $schema['custom_fields'] = array_merge( $schema['custom_fields'], $place_schema['custom_fields'], $organization_schema['custom_fields'] );
+
+        return $schema;
+    }
 
 }