Return class for magic WordPress filter callback methods.

class-returner.php

<?php

/**
 * This class is designed to return a basic value by parsing the dynamic
 * static method name you call to determine its type and value.
 *
 * It's useful for filtering values in WordPress quickly without having
 * to create a callback function. Think of this as a continuation of the
 * callback helpers already in WordPress: __return_true(), et al.
 *
 * EXAMPLES
 * add_filter( 'twentyseventeen_front_page_sections', 'Returner::int__4' );
 * add_filter( 'site_icon_sizes', 'Returner::array__256__128__64' );
 * add_filter( 'post_class', 'Returner::featured' );
 *
 * @author  Frankie Jarrett
 * @license https://www.gnu.org/licenses/gpl-2.0.html GPL-2.0
 */
class Returner {

	/**
	 * Magic value returner method.
	 *
	 * @access public
	 * @static
	 *
	 * @param  string $name
	 * @param  array  $args (unused)
	 *
	 * @return mixed
	 */
	public static function __callStatic( $name, $args ) {

		/**
		 * Return an integer.
		 *
		 * Returner::int__6() ==> 6
		 */
		if ( 0 === strpos( $name, 'int__' ) ) {

			return (int) self::value( $name );

		}

		/**
		 * Return a negative integer.
		 *
		 * Returner::nint__6() ==> -6
		 */
		if ( 0 === strpos( $name, 'nint__' ) ) {

			return (int) self::value( $name ) * -1;

		}

		/**
		 * Return a floating point number.
		 *
		 * Returner::float__1_234() ==> 1.234
		 */
		if ( 0 === strpos( $name, 'float__' ) ) {

			return (float) str_replace( '_', '.', self::value( $name ) );

		}

		/**
		 * Return a negative floating point number.
		 *
		 * Returner::nfloat__1_234() ==> -1.234
		 */
		if ( 0 === strpos( $name, 'nfloat__' ) ) {

			return (float) str_replace( '_', '.', self::value( $name ) ) * -1;

		}

		/**
		 * Return a one-dimensional indexed array.
		 *
		 * Returner::array__foo__bar_baz() ==> [ 'foo', 'bar baz' ]
		 * Returner::array__1__foo__3() ==> [ 1, 'foo', 3 ]
		 * Returner::array__foo__FALSE__bar ==> [ 'foo', false, 'baz' ]
		 */
		if ( 0 === strpos( $name, 'array__' ) ) {

			$array = [];

			foreach ( explode( '__', self::value( $name ) ) as $value ) {

				if ( 'TRUE' === $value ) {

					$array[] = true;

					continue;

				}

				if ( 'FALSE' === $value ) {

					$array[] = false;

					continue;

				}

				$value = trim( str_replace( '_', ' ', $value ) );

				$array[] = is_numeric( $value ) ? (int) $value : $value;

			}

			return $array;

		}

		/**
		 * Return a string.
		 *
		 * Returner::foo_bar_baz() ==> 'foo bar baz'
		 */
		return trim( str_replace( '_', ' ', $name ) );

	}

	/**
	 * Return the value portion of a method name.
	 *
	 * @access public
	 * @static
	 *
	 * @param  string $name
	 *
	 * @return string
	 */
	public static function value( $name ) {

		return preg_replace( '/^[a-z]+__/', '', $name );

	}

}