
了解数据库技术:SQLite与MySQL的比较
wp_get_typography_value_and_unit ( $raw_value, $options = array() )
wp_get_typography_value_and_unit: 这个函数返回一个数组,包含排版选项的值和用于指定该值的单位。它需要两个参数:排版选项名称和一个默认值,如果该选项没有被设置,则返回: 该函数从数据库中检索排版选项并返回一个包含该值和单位的数组。
检查一个字符串的单位和值,并返回一个由`’值’和`’单位’组成的数组,例如数组(’42’, ‘rem’)。
function wp_get_typography_value_and_unit( $raw_value, $options = array() ) { if ( ! is_string( $raw_value ) && ! is_int( $raw_value ) && ! is_float( $raw_value ) ) { _doing_it_wrong( __FUNCTION__, __( 'Raw size value must be a string, integer, or float.' ), '6.1.0' ); return null; } if ( empty( $raw_value ) ) { return null; } // Converts numbers to pixel values by default. if ( is_numeric( $raw_value ) ) { $raw_value = $raw_value . 'px'; } $defaults = array( 'coerce_to' => '', 'root_size_value' => 16, 'acceptable_units' => array( 'rem', 'px', 'em' ), ); $options = wp_parse_args( $options, $defaults ); $acceptable_units_group = implode( '|', $options['acceptable_units'] ); $pattern = '/^(d*.?d+)(' . $acceptable_units_group . '){1,1}$/'; preg_match( $pattern, $raw_value, $matches ); // Bails out if not a number value and a px or rem unit. if ( ! isset( $matches[1] ) || ! isset( $matches[2] ) ) { return null; } $value = $matches[1]; $unit = $matches[2]; /* * Default browser font size. Later, possibly could inject some JS to * compute this `getComputedStyle( document.querySelector( "html" ) ).fontSize`. */ if ( 'px' === $options['coerce_to'] && ( 'em' === $unit || 'rem' === $unit ) ) { $value = $value * $options['root_size_value']; $unit = $options['coerce_to']; } if ( 'px' === $unit && ( 'em' === $options['coerce_to'] || 'rem' === $options['coerce_to'] ) ) { $value = $value / $options['root_size_value']; $unit = $options['coerce_to']; } /* * No calculation is required if swapping between em and rem yet, * since we assume a root size value. Later we might like to differentiate between * :root font size (rem) and parent element font size (em) relativity. */ if ( ( 'em' === $options['coerce_to'] || 'rem' === $options['coerce_to'] ) && ( 'em' === $unit || 'rem' === $unit ) ) { $unit = $options['coerce_to']; } return array( 'value' => round( $value, 3 ), 'unit' => $unit, ); }