0 1 auto (CSS spec equivalent) * flex: auto -> 1 1 auto * flex: -> 1 0 (unitless number only) * flex: (unitless grow + size basis) * flex: * * Declines to custom_css for any unrecognised syntax. */ class Flex_Property_Converter extends Property_Converter_Base { const AUTO_BASIS = [ 'size' => 'auto', 'unit' => 'custom', ]; const ZERO_BASIS = [ 'size' => 0, 'unit' => 'px', ]; protected function get_supported_properties(): array { return [ 'flex' ]; } protected function do_convert( Conversion_Context $context, array $rule ): bool { $value = trim( $rule['value'] ); $parsed = $this->parse( $value ); if ( null === $parsed ) { return false; } [ $grow, $shrink, $basis ] = $parsed; $context->set_prop( 'flex', Flex_Prop_Type::generate( [ 'flexGrow' => Number_Prop_Type::generate( $grow ), 'flexShrink' => Number_Prop_Type::generate( $shrink ), 'flexBasis' => Size_Prop_Type::generate( $basis ), ] ) ); return true; } private function parse( string $value ): ?array { $lower = strtolower( $value ); if ( 'none' === $lower ) { return [ 0, 1, self::AUTO_BASIS ]; } if ( 'auto' === $lower ) { return [ 1, 1, self::AUTO_BASIS ]; } $tokens = Css_Token_Splitter::split_by_whitespace( $value ); if ( 1 === count( $tokens ) ) { $grow = $this->parse_number( $tokens[0] ); if ( null === $grow ) { return null; } return [ $grow, 1, self::ZERO_BASIS ]; } if ( 2 === count( $tokens ) ) { $grow = $this->parse_number( $tokens[0] ); if ( null === $grow ) { return null; } $basis = Size_Value_Parser::parse( $tokens[1] ); if ( null === $basis ) { return null; } return [ $grow, 1, $basis ]; } if ( 3 === count( $tokens ) ) { $grow = $this->parse_number( $tokens[0] ); $shrink = $this->parse_number( $tokens[1] ); $basis = $this->parse_basis( $tokens[2] ); if ( null === $grow || null === $shrink || null === $basis ) { return null; } return [ $grow, $shrink, $basis ]; } return null; } private function parse_number( string $token ): ?float { if ( ! is_numeric( $token ) ) { return null; } return (float) $token; } private function parse_basis( string $token ): ?array { $lower = strtolower( $token ); if ( 'auto' === $lower ) { return self::AUTO_BASIS; } return Size_Value_Parser::parse( $token ); } }