WPSEO_Option{}Yoast 1.0

This abstract class and its concrete classes implement defaults and value validation for all WPSEO options and subkeys within options.

Some guidelines: [Retrieving options]

  • Use the normal get_option() to retrieve an option. You will receive a complete array for the option. Any subkeys which were not set, will have their default values in place.
  • In other words, you will normally not have to check whether a subkey isset() as they will always be set. They will also always be of the correct variable type. The only exception to this are the options with variable option names based on post_type or taxonomy as those will not always be available before the taxonomy/post_type is registered. (they will be available if a value was set, they won't be if it wasn't as the class won't know that a default needs to be injected).
[Updating/Adding options]
  • For multisite site_options, please use the WPSEO_Options::update_site_option() method.
  • For normal options, use the normal add/update_option() functions. As long as the classes here are instantiated, validation for all options and their subkeys will be automatic.
  • On (successful) update of a couple of options, certain related actions will be run automatically. Some examples:
  • on change of wpseo[yoast_tracking], the cron schedule will be adjusted accordingly
  • on change of wpseo and wpseo_title, some caches will be cleared
[Important information about add/updating/changing these classes]
  • Make sure that option array key names are unique across options. The WPSEO_Options::get_all() method merges most options together. If any of them have non-unique names, even if they are in a different option, they will overwrite each other.
  • When you add a new array key in an option: make sure you add proper defaults and add the key to the validation routine in the proper place or add a new validation case. You don't need to do any upgrading as any option returned will always be merged with the defaults, so new options will automatically be available. If the default value is a string which need translating, add this to the concrete class translate_defaults() method.
  • When you remove an array key from an option: if it's important that the option is really removed, add the WPSEO_Option::clean_up( $option_name ) method to the upgrade run. This will re-save the option and automatically remove the array key no longer in existence.
  • When you rename a sub-option: add it to the clean_option() routine and run that in the upgrade run.
  • When you change the default for an option sub-key, make sure you verify that the validation routine will still work the way it should. Example: changing a default from '' (empty string) to 'text' with a validation routine with tests for an empty string will prevent a user from saving an empty string as the real value. So the test for '' with the validation routine would have to be removed in that case.
  • If an option needs specific actions different from defined in this abstract class, you can just overrule a method by defining it in the concrete class.
Хуки из класса

Использование

$WPSEO_Option = new WPSEO_Option();
// use class methods

Методы

  1. protected __construct()
  2. public add_default_filters()
  3. public add_default_filters_if_not_changed( $value, $option_name, $old_value )
  4. public add_default_filters_if_same_option( $option_name )
  5. public add_option_filters()
  6. protected array_filter_merge( $options = null )
  7. public clean( $current_version = null )
  8. public get_defaults()
  9. public get_option( $options = null )
  10. public get_option_name()
  11. protected get_original_option()
  12. protected get_override_option()
  13. public get_patterns()
  14. protected get_switch_key( $key )
  15. public import( $option_value, $current_version = null, $all_old_option_values = null )
  16. public is_disabled( $key )
  17. public maybe_add_option()
  18. protected prevent_disabled_options_update( $updated, $old )
  19. public register_setting()
  20. public remove_default_filters()
  21. public remove_option_filters()
  22. protected retain_variable_keys( $dirty, $clean )
  23. public update_site_option( $value )
  24. public validate( $option_value )
  25. public validate_option( $dirty, $clean, $old )
  26. public validate_url( $key, $dirty, $old, &$clean )
  27. public validate_verification_string( $key, $dirty, $old, &$clean )

Код WPSEO_Option{} Yoast 22.4

abstract class WPSEO_Option {

	/**
	 * Prefix for override option keys that allow or disallow the option key of the same name.
	 *
	 * @var string
	 */
	public const ALLOW_KEY_PREFIX = 'allow_';

	/**
	 * Option name - MUST be set in concrete class and set to public.
	 *
	 * @var string
	 */
	protected $option_name;

	/**
	 * Option group name for use in settings forms.
	 *
	 * Will be set automagically if not set in concrete class (i.e.
	 * if it conforms to the normal pattern 'yoast' . $option_name . 'options',
	 * only set in concrete class if it doesn't).
	 *
	 * @var string
	 */
	public $group_name;

	/**
	 * Whether to include the option in the return for WPSEO_Options::get_all().
	 *
	 * Also determines which options are copied over for ms_(re)set_blog().
	 *
	 * @var bool
	 */
	public $include_in_all = true;

	/**
	 * Whether this option is only for when the install is multisite.
	 *
	 * @var bool
	 */
	public $multisite_only = false;

	/**
	 * Array of defaults for the option - MUST be set in concrete class.
	 *
	 * Shouldn't be requested directly, use $this->get_defaults();
	 *
	 * @var array
	 */
	protected $defaults;

	/**
	 * Array of variable option name patterns for the option - if any.
	 *
	 * Set this when the option contains array keys which vary based on post_type
	 * or taxonomy.
	 *
	 * @var array
	 */
	protected $variable_array_key_patterns;

	/**
	 * Array of sub-options which should not be overloaded with multi-site defaults.
	 *
	 * @var array
	 */
	public $ms_exclude = [];

	/**
	 * Name for an option higher in the hierarchy to override setting access.
	 *
	 * @var string
	 */
	protected $override_option_name;

	/**
	 * Instance of this class.
	 *
	 * @var WPSEO_Option
	 */
	protected static $instance;


	/* *********** INSTANTIATION METHODS *********** */

	/**
	 * Add all the actions and filters for the option.
	 */
	protected function __construct() {

		/* Add filters which get applied to the get_options() results. */
		$this->add_default_filters(); // Return defaults if option not set.
		$this->add_option_filters(); // Merge with defaults if option *is* set.

		if ( $this->multisite_only !== true ) {
			/**
			 * The option validation routines remove the default filters to prevent failing
			 * to insert an option if it's new. Let's add them back afterwards.
			 */
			add_action( 'add_option', [ $this, 'add_default_filters_if_same_option' ] ); // Adding back after INSERT.

			add_action( 'update_option', [ $this, 'add_default_filters_if_same_option' ] );

			add_filter( 'pre_update_option', [ $this, 'add_default_filters_if_not_changed' ], PHP_INT_MAX, 3 );

			// Refills the cache when the option has been updated.
			add_action( 'update_option_' . $this->option_name, [ 'WPSEO_Options', 'clear_cache' ], 10 );
		}
		elseif ( is_multisite() ) {
			/*
			 * The option validation routines remove the default filters to prevent failing
			 * to insert an option if it's new. Let's add them back afterwards.
			 *
			 * For site_options, this method is not foolproof as these actions are not fired
			 * on an insert/update failure. Please use the WPSEO_Options::update_site_option() method
			 * for updating site options to make sure the filters are in place.
			 */
			add_action( 'add_site_option_' . $this->option_name, [ $this, 'add_default_filters' ] );
			add_action( 'update_site_option_' . $this->option_name, [ $this, 'add_default_filters' ] );
			add_filter( 'pre_update_site_option_' . $this->option_name, [ $this, 'add_default_filters_if_not_changed' ], PHP_INT_MAX, 3 );

			// Refills the cache when the option has been updated.
			add_action( 'update_site_option_' . $this->option_name, [ 'WPSEO_Options', 'clear_cache' ], 1, 0 );
		}

		/*
		 * Make sure the option will always get validated, independently of register_setting()
		 * (only available on back-end).
		 */
		add_filter( 'sanitize_option_' . $this->option_name, [ $this, 'validate' ] );

		/* Register our option for the admin pages */
		add_action( 'admin_init', [ $this, 'register_setting' ] );

		/* Set option group name if not given */
		if ( ! isset( $this->group_name ) || $this->group_name === '' ) {
			$this->group_name = 'yoast_' . $this->option_name . '_options';
		}

		/* Translate some defaults as early as possible - textdomain is loaded in init on priority 1. */
		if ( method_exists( $this, 'translate_defaults' ) ) {
			add_action( 'init', [ $this, 'translate_defaults' ], 2 );
		}

		/**
		 * Enrich defaults once custom post types and taxonomies have been registered
		 * which is normally done on the init action.
		 *
		 * @todo [JRF/testers] Verify that none of the options which are only available after
		 * enrichment are used before the enriching.
		 */
		if ( method_exists( $this, 'enrich_defaults' ) ) {
			add_action( 'init', [ $this, 'enrich_defaults' ], 99 );
		}
	}

	/*
	 * All concrete classes *must* contain the get_instance method.
	 *
	 * {@internal Unfortunately I can't define it as an abstract as it also *has* to be static...}}
	 *
	 * ```
	 * abstract protected static function get_instance();
	 * ```
	 * ---------------
	 *
	 * Concrete classes *may* contain a translate_defaults method.
	 * ```
	 * abstract public function translate_defaults();
	 * ```
	 * ---------------
	 *
	 * Concrete classes *may* contain an enrich_defaults method to add additional defaults once
	 * all post_types and taxonomies have been registered.
	 *
	 * ```
	 * abstract public function enrich_defaults();
	 * ```
	 */

	/* *********** METHODS INFLUENCING get_option() *********** */

	/**
	 * Add filters to make sure that the option default is returned if the option is not set.
	 *
	 * @return void
	 */
	public function add_default_filters() {
		// Don't change, needs to check for false as could return prio 0 which would evaluate to false.
		if ( has_filter( 'default_option_' . $this->option_name, [ $this, 'get_defaults' ] ) === false ) {
			add_filter( 'default_option_' . $this->option_name, [ $this, 'get_defaults' ] );
		}
	}

	/**
	 * Adds back the default filters that were removed during validation if the option was changed.
	 * Checks if this option was changed to prevent constantly checking if filters are present.
	 *
	 * @param string $option_name The option name.
	 *
	 * @return void
	 */
	public function add_default_filters_if_same_option( $option_name ) {
		if ( $option_name === $this->option_name ) {
			$this->add_default_filters();
		}
	}

	/**
	 * Adds back the default filters that were removed during validation if the option was not changed.
	 * This is because in that case the latter actions are not called and thus the filters are never
	 * added back.
	 *
	 * @param mixed  $value       The current value.
	 * @param string $option_name The option name.
	 * @param mixed  $old_value   The old value.
	 *
	 * @return string The current value.
	 */
	public function add_default_filters_if_not_changed( $value, $option_name, $old_value ) {
		if ( $option_name !== $this->option_name ) {
			return $value;
		}

		if ( $value === $old_value || maybe_serialize( $value ) === maybe_serialize( $old_value ) ) {
			$this->add_default_filters();
		}

		return $value;
	}

	/**
	 * Validate webmaster tools & Pinterest verification strings.
	 *
	 * @param string $key   Key to check, by type of service.
	 * @param array  $dirty Dirty data with the new values.
	 * @param array  $old   Old data.
	 * @param array  $clean Clean data by reference, normally the default values.
	 *
	 * @return void
	 */
	public function validate_verification_string( $key, $dirty, $old, &$clean ) {
		if ( isset( $dirty[ $key ] ) && $dirty[ $key ] !== '' ) {
			$meta = $dirty[ $key ];
			if ( strpos( $meta, 'content=' ) ) {
				// Make sure we only have the real key, not a complete meta tag.
				preg_match( '`content=([\'"])?([^\'"> ]+)(?:\1|[ />])`', $meta, $match );
				if ( isset( $match[2] ) ) {
					$meta = $match[2];
				}
				unset( $match );
			}

			$meta = sanitize_text_field( $meta );
			if ( $meta !== '' ) {
				$regex   = '`^[A-Fa-f0-9_-]+$`';
				$service = '';

				switch ( $key ) {
					case 'baiduverify':
						$regex   = '`^[A-Za-z0-9_-]+$`';
						$service = 'Baidu Webmaster tools';
						break;

					case 'googleverify':
						$regex   = '`^[A-Za-z0-9_-]+$`';
						$service = 'Google Webmaster tools';
						break;

					case 'msverify':
						$service = 'Bing Webmaster tools';
						break;

					case 'pinterestverify':
						$service = 'Pinterest';
						break;

					case 'yandexverify':
						$service = 'Yandex Webmaster tools';
						break;
				}

				if ( preg_match( $regex, $meta ) ) {
					$clean[ $key ] = $meta;
				}
				else {
					// Restore the previous value, if any.
					if ( isset( $old[ $key ] ) && preg_match( $regex, $old[ $key ] ) ) {
						$clean[ $key ] = $old[ $key ];
					}

					if ( function_exists( 'add_settings_error' ) ) {
						add_settings_error(
							$this->group_name, // Slug title of the setting.
							$key, // Suffix-ID for the error message box. WordPress prepends `setting-error-`.
							/* translators: 1: Verification string from user input; 2: Service name. */
							sprintf( __( '%1$s does not seem to be a valid %2$s verification string. Please correct.', 'wordpress-seo' ), '<strong>' . esc_html( $meta ) . '</strong>', $service ), // The error message.
							'error' // CSS class for the WP notice, either the legacy 'error' / 'updated' or the new `notice-*` ones.
						);
					}

					Yoast_Input_Validation::add_dirty_value_to_settings_errors( $key, $meta );
				}
			}
		}
	}

	/**
	 * Validates an option as a valid URL. Prints out a WordPress settings error
	 * notice if the URL is invalid.
	 *
	 * @param string $key   Key to check, by type of URL setting.
	 * @param array  $dirty Dirty data with the new values.
	 * @param array  $old   Old data.
	 * @param array  $clean Clean data by reference, normally the default values.
	 *
	 * @return void
	 */
	public function validate_url( $key, $dirty, $old, &$clean ) {
		if ( isset( $dirty[ $key ] ) && $dirty[ $key ] !== '' ) {

			$submitted_url = trim( $dirty[ $key ] );
			$validated_url = filter_var( WPSEO_Utils::sanitize_url( $submitted_url ), FILTER_VALIDATE_URL );

			if ( $validated_url === false ) {
				if ( function_exists( 'add_settings_error' ) ) {
					add_settings_error(
						// Slug title of the setting.
						$this->group_name,
						// Suffix-ID for the error message box. WordPress prepends `setting-error-`.
						$key,
						// The error message.
						sprintf(
							/* translators: %s expands to an invalid URL. */
							__( '%s does not seem to be a valid url. Please correct.', 'wordpress-seo' ),
							'<strong>' . esc_url( $submitted_url ) . '</strong>'
						),
						// Message type.
						'error'
					);
				}

				// Restore the previous URL value, if any.
				if ( isset( $old[ $key ] ) && $old[ $key ] !== '' ) {
					$url = WPSEO_Utils::sanitize_url( $old[ $key ] );
					if ( $url !== '' ) {
						$clean[ $key ] = $url;
					}
				}

				Yoast_Input_Validation::add_dirty_value_to_settings_errors( $key, $submitted_url );

				return;
			}

			// The URL format is valid, let's sanitize it.
			$url = WPSEO_Utils::sanitize_url( $validated_url );

			if ( $url !== '' ) {
				$clean[ $key ] = $url;
			}
		}
	}

	/**
	 * Remove the default filters.
	 * Called from the validate() method to prevent failure to add new options.
	 *
	 * @return void
	 */
	public function remove_default_filters() {
		remove_filter( 'default_option_' . $this->option_name, [ $this, 'get_defaults' ] );
	}

	/**
	 * Get the enriched default value for an option.
	 *
	 * Checks if the concrete class contains an enrich_defaults() method and if so, runs it.
	 *
	 * {@internal The enrich_defaults method is used to set defaults for variable array keys
	 *            in an option, such as array keys depending on post_types and/or taxonomies.}}
	 *
	 * @return array
	 */
	public function get_defaults() {
		if ( method_exists( $this, 'translate_defaults' ) ) {
			$this->translate_defaults();
		}

		if ( method_exists( $this, 'enrich_defaults' ) ) {
			$this->enrich_defaults();
		}

		return apply_filters( 'wpseo_defaults', $this->defaults, $this->option_name );
	}

	/**
	 * Add filters to make sure that the option is merged with its defaults before being returned.
	 *
	 * @return void
	 */
	public function add_option_filters() {
		// Don't change, needs to check for false as could return prio 0 which would evaluate to false.
		if ( has_filter( 'option_' . $this->option_name, [ $this, 'get_option' ] ) === false ) {
			add_filter( 'option_' . $this->option_name, [ $this, 'get_option' ] );
		}
	}

	/**
	 * Remove the option filters.
	 * Called from the clean_up methods to make sure we retrieve the original old option.
	 *
	 * @return void
	 */
	public function remove_option_filters() {
		remove_filter( 'option_' . $this->option_name, [ $this, 'get_option' ] );
	}

	/**
	 * Merge an option with its default values.
	 *
	 * This method should *not* be called directly!!! It is only meant to filter the get_option() results.
	 *
	 * @param mixed $options Option value.
	 *
	 * @return mixed Option merged with the defaults for that option.
	 */
	public function get_option( $options = null ) {
		$filtered = $this->array_filter_merge( $options );

		/*
		 * If the option contains variable option keys, make sure we don't remove those settings
		 * - even if the defaults are not complete yet.
		 * Unfortunately this means we also won't be removing the settings for post types or taxonomies
		 * which are no longer in the WP install, but rather that than the other way around.
		 */
		if ( isset( $this->variable_array_key_patterns ) ) {
			$filtered = $this->retain_variable_keys( $options, $filtered );
		}

		return $filtered;
	}

	/* *********** METHODS influencing add_option(), update_option() and saving from admin pages. *********** */

	/**
	 * Register (whitelist) the option for the configuration pages.
	 * The validation callback is already registered separately on the sanitize_option hook,
	 * so no need to double register.
	 *
	 * @return void
	 */
	public function register_setting() {
		if ( ! WPSEO_Capability_Utils::current_user_can( 'wpseo_manage_options' ) ) {
			return;
		}

		if ( $this->multisite_only === true ) {
			$network_settings_api = Yoast_Network_Settings_API::get();
			if ( $network_settings_api->meets_requirements() ) {
				$network_settings_api->register_setting( $this->group_name, $this->option_name );
			}
			return;
		}

		register_setting( $this->group_name, $this->option_name );
	}

	/**
	 * Validate the option.
	 *
	 * @param mixed $option_value The unvalidated new value for the option.
	 *
	 * @return array Validated new value for the option.
	 */
	public function validate( $option_value ) {
		$clean = $this->get_defaults();

		/* Return the defaults if the new value is empty. */
		if ( ! is_array( $option_value ) || $option_value === [] ) {
			return $clean;
		}

		$option_value = array_map( [ 'WPSEO_Utils', 'trim_recursive' ], $option_value );

		$old = $this->get_original_option();
		if ( ! is_array( $old ) ) {
			$old = [];
		}
		$old = array_merge( $clean, $old );

		$clean = $this->validate_option( $option_value, $clean, $old );

		// Prevent updates to variables that are disabled via the override option.
		$clean = $this->prevent_disabled_options_update( $clean, $old );

		/* Retain the values for variable array keys even when the post type/taxonomy is not yet registered. */
		if ( isset( $this->variable_array_key_patterns ) ) {
			$clean = $this->retain_variable_keys( $option_value, $clean );
		}

		$this->remove_default_filters();

		return $clean;
	}

	/**
	 * Checks whether a specific option key is disabled.
	 *
	 * This is determined by whether an override option is available with a key that equals the given key prefixed
	 * with 'allow_'.
	 *
	 * @param string $key Option key.
	 *
	 * @return bool True if option key is disabled, false otherwise.
	 */
	public function is_disabled( $key ) {
		$override_option = $this->get_override_option();
		if ( empty( $override_option ) ) {
			return false;
		}

		return isset( $override_option[ self::ALLOW_KEY_PREFIX . $key ] ) && ! $override_option[ self::ALLOW_KEY_PREFIX . $key ];
	}

	/**
	 * All concrete classes must contain a validate_option() method which validates all
	 * values within the option.
	 *
	 * @param array $dirty New value for the option.
	 * @param array $clean Clean value for the option, normally the defaults.
	 * @param array $old   Old value of the option.
	 */
	abstract protected function validate_option( $dirty, $clean, $old );

	/* *********** METHODS for ADDING/UPDATING/UPGRADING the option. *********** */

	/**
	 * Retrieve the real old value (unmerged with defaults).
	 *
	 * @return array|bool The original option value (which can be false if the option doesn't exist).
	 */
	protected function get_original_option() {
		$this->remove_default_filters();
		$this->remove_option_filters();

		// Get (unvalidated) array, NOT merged with defaults.
		if ( $this->multisite_only !== true ) {
			$option_value = get_option( $this->option_name );
		}
		else {
			$option_value = get_site_option( $this->option_name );
		}

		$this->add_option_filters();
		$this->add_default_filters();

		return $option_value;
	}

	/**
	 * Add the option if it doesn't exist for some strange reason.
	 *
	 * @uses WPSEO_Option::get_original_option()
	 *
	 * @return void
	 */
	public function maybe_add_option() {
		if ( $this->get_original_option() === false ) {
			if ( $this->multisite_only !== true ) {
				update_option( $this->option_name, $this->get_defaults() );
			}
			else {
				$this->update_site_option( $this->get_defaults() );
			}
		}
	}

	/**
	 * Update a site_option.
	 *
	 * {@internal This special method is only needed for multisite options, but very needed indeed there.
	 *            The order in which certain functions and hooks are run is different between
	 *            get_option() and get_site_option() which means in practice that the removing
	 *            of the default filters would be done too late and the re-adding of the default
	 *            filters might not be done at all.
	 *            Aka: use the WPSEO_Options::update_site_option() method (which calls this method)
	 *            for safely adding/updating multisite options.}}
	 *
	 * @param mixed $value The new value for the option.
	 *
	 * @return bool Whether the update was successful.
	 */
	public function update_site_option( $value ) {
		if ( $this->multisite_only === true && is_multisite() ) {
			$this->remove_default_filters();
			$result = update_site_option( $this->option_name, $value );
			$this->add_default_filters();

			return $result;
		}
		else {
			return false;
		}
	}

	/**
	 * Retrieve the real old value (unmerged with defaults), clean and re-save the option.
	 *
	 * @uses WPSEO_Option::get_original_option()
	 * @uses WPSEO_Option::import()
	 *
	 * @param string|null $current_version Optional. Version from which to upgrade, if not set,
	 *                                     version-specific upgrades will be disregarded.
	 *
	 * @return void
	 */
	public function clean( $current_version = null ) {
		$option_value = $this->get_original_option();
		$this->import( $option_value, $current_version );
	}

	/**
	 * Clean and re-save the option.
	 *
	 * @uses clean_option() method from concrete class if it exists.
	 *
	 * @todo [JRF/whomever] Figure out a way to show settings error during/after the upgrade - maybe
	 * something along the lines of:
	 * -> add them to a property in this class
	 * -> if that property isset at the end of the routine and add_settings_error function does not exist,
	 *    save as transient (or update the transient if one already exists)
	 * -> next time an admin is in the WP back-end, show the errors and delete the transient or only delete it
	 *    once the admin has dismissed the message (add ajax function)
	 * Important: all validation routines which add_settings_errors would need to be changed for this to work
	 *
	 * @param array       $option_value          Option value to be imported.
	 * @param string|null $current_version       Optional. Version from which to upgrade, if not set,
	 *                                           version-specific upgrades will be disregarded.
	 * @param array|null  $all_old_option_values Optional. Only used when importing old options to
	 *                                           have access to the real old values, in contrast to
	 *                                           the saved ones.
	 *
	 * @return void
	 */
	public function import( $option_value, $current_version = null, $all_old_option_values = null ) {
		if ( $option_value === false ) {
			$option_value = $this->get_defaults();
		}
		elseif ( is_array( $option_value ) && method_exists( $this, 'clean_option' ) ) {
			$option_value = $this->clean_option( $option_value, $current_version, $all_old_option_values );
		}

		/*
		 * Save the cleaned value - validation will take care of cleaning out array keys which
		 * should no longer be there.
		 */
		if ( $this->multisite_only !== true ) {
			update_option( $this->option_name, $option_value );
		}
		else {
			$this->update_site_option( $this->option_name, $option_value );
		}
	}

	/**
	 * Returns the variable array key patterns for an options class.
	 *
	 * @return array
	 */
	public function get_patterns() {
		return (array) $this->variable_array_key_patterns;
	}

	/**
	 * Retrieves the option name.
	 *
	 * @return string The set option name.
	 */
	public function get_option_name() {
		return $this->option_name;
	}

	/*
	 * Concrete classes *may* contain a clean_option method which will clean out old/renamed
	 * values within the option.
	 *
	 * ```
	 * abstract public function clean_option( $option_value, $current_version = null, $all_old_option_values = null );
	 * ```
	 */

	/* *********** HELPER METHODS for internal use. *********** */

	/**
	 * Helper method - Combines a fixed array of default values with an options array
	 * while filtering out any keys which are not in the defaults array.
	 *
	 * @todo [JRF] - shouldn't this be a straight array merge ? at the end of the day, the validation
	 * removes any invalid keys on save.
	 *
	 * @param array|null $options Optional. Current options. If not set, the option defaults
	 *                            for the $option_key will be returned.
	 *
	 * @return array Combined and filtered options array.
	 */
	protected function array_filter_merge( $options = null ) {

		$defaults = $this->get_defaults();

		if ( ! isset( $options ) || $options === false || $options === [] ) {
			return $defaults;
		}

		$options = (array) $options;

		/*
			$filtered = array();

			if ( $defaults !== array() ) {
				foreach ( $defaults as $key => $default_value ) {
					// @todo should this walk through array subkeys ?
					$filtered[ $key ] = ( isset( $options[ $key ] ) ? $options[ $key ] : $default_value );
				}
			}
		*/
		$filtered = array_merge( $defaults, $options );

		return $filtered;
	}

	/**
	 * Sets updated values for variables that are disabled via the override option back to their previous values.
	 *
	 * @param array $updated Updated option value.
	 * @param array $old     Old option value.
	 *
	 * @return array Updated option value, with all disabled variables set to their old values.
	 */
	protected function prevent_disabled_options_update( $updated, $old ) {
		$override_option = $this->get_override_option();
		if ( empty( $override_option ) ) {
			return $updated;
		}

		/*
		 * This loop could as well call `is_disabled( $key )` for each iteration,
		 * however this would be worse performance-wise.
		 */
		foreach ( $old as $key => $value ) {
			if ( isset( $override_option[ self::ALLOW_KEY_PREFIX . $key ] ) && ! $override_option[ self::ALLOW_KEY_PREFIX . $key ] ) {
				$updated[ $key ] = $old[ $key ];
			}
		}

		return $updated;
	}

	/**
	 * Retrieves the value of the override option, if available.
	 *
	 * An override option contains values that may determine access to certain sub-variables
	 * of this option.
	 *
	 * Only regular options in multisite can have override options, which in that case
	 * would be network options.
	 *
	 * @return array Override option value, or empty array if unavailable.
	 */
	protected function get_override_option() {
		if ( empty( $this->override_option_name ) || $this->multisite_only === true || ! is_multisite() ) {
			return [];
		}

		return get_site_option( $this->override_option_name, [] );
	}

	/**
	 * Make sure that any set option values relating to post_types and/or taxonomies are retained,
	 * even when that post_type or taxonomy may not yet have been registered.
	 *
	 * {@internal The wpseo_titles concrete class overrules this method. Make sure that any
	 *            changes applied here, also get ported to that version.}}
	 *
	 * @param array $dirty Original option as retrieved from the database.
	 * @param array $clean Filtered option where any options which shouldn't be in our option
	 *                     have already been removed and any options which weren't set
	 *                     have been set to their defaults.
	 *
	 * @return array
	 */
	protected function retain_variable_keys( $dirty, $clean ) {
		if ( ( is_array( $this->variable_array_key_patterns ) && $this->variable_array_key_patterns !== [] ) && ( is_array( $dirty ) && $dirty !== [] ) ) {
			foreach ( $dirty as $key => $value ) {

				// Do nothing if already in filtered options.
				if ( isset( $clean[ $key ] ) ) {
					continue;
				}

				foreach ( $this->variable_array_key_patterns as $pattern ) {

					if ( strpos( $key, $pattern ) === 0 ) {
						$clean[ $key ] = $value;
						break;
					}
				}
			}
		}

		return $clean;
	}

	/**
	 * Check whether a given array key conforms to one of the variable array key patterns for this option.
	 *
	 * @used-by validate_option() methods for options with variable array keys.
	 *
	 * @param string $key Array key to check.
	 *
	 * @return string Pattern if it conforms, original array key if it doesn't or if the option
	 *                does not have variable array keys.
	 */
	protected function get_switch_key( $key ) {
		if ( ! isset( $this->variable_array_key_patterns ) || ( ! is_array( $this->variable_array_key_patterns ) || $this->variable_array_key_patterns === [] ) ) {
			return $key;
		}

		foreach ( $this->variable_array_key_patterns as $pattern ) {
			if ( strpos( $key, $pattern ) === 0 ) {
				return $pattern;
			}
		}

		return $key;
	}
}