'',
'arrow' => array(
'next' => '→',
'previous' => '←',
),
'chevron' => array(
'next' => '»',
'previous' => '«',
),
);
// If a custom label is provided, make this a link.
// `$label` is used to prepend the provided label, if we want to show the page title as well.
if ( isset( $attributes['label'] ) && ! empty( $attributes['label'] ) ) {
$label = "{$attributes['label']}";
$link = $label;
}
// If we want to also show the page title, make the page title a link and prepend the label.
if ( isset( $attributes['showTitle'] ) && $attributes['showTitle'] ) {
/*
* If the label link option is not enabled but there is a custom label,
* display the custom label as text before the linked title.
*/
if ( ! $attributes['linkLabel'] ) {
if ( $label ) {
$format = '' . wp_kses_post( $label ) . ' %link';
}
$link = '%title';
} elseif ( isset( $attributes['linkLabel'] ) && $attributes['linkLabel'] ) {
// If the label link option is enabled and there is a custom label, display it before the title.
if ( $label ) {
$link = '' . wp_kses_post( $label ) . ' %title';
} else {
/*
* If the label link option is enabled and there is no custom label,
* add a colon between the label and the post title.
*/
$label = 'next' === $navigation_type ? _x( 'Next:', 'label before the title of the next post' ) : _x( 'Previous:', 'label before the title of the previous post' );
$link = sprintf(
'%1$s %2$s',
wp_kses_post( $label ),
'%title'
);
}
}
}
// Display arrows.
if ( isset( $attributes['arrow'] ) && 'none' !== $attributes['arrow'] && isset( $arrow_map[ $attributes['arrow'] ] ) ) {
$arrow = $arrow_map[ $attributes['arrow'] ][ $navigation_type ];
if ( 'next' === $navigation_type ) {
$format = '%link' . $arrow . '';
} else {
$format = '' . $arrow . '%link';
}
}
/*
* The dynamic portion of the function name, `$navigation_type`,
* Refers to the type of adjacency, 'next' or 'previous'.
*
* @see https://developer.wordpress.org/reference/functions/get_previous_post_link/
* @see https://developer.wordpress.org/reference/functions/get_next_post_link/
*/
$get_link_function = "get_{$navigation_type}_post_link";
if ( ! empty( $attributes['taxonomy'] ) ) {
$content = $get_link_function( $format, $link, true, '', $attributes['taxonomy'] );
} else {
$content = $get_link_function( $format, $link );
}
// The `{next,previous}_post_link` filters can return null, which renders as no link.
$content = (string) $content;
/*
* Border, shadow and spacing serialization is skipped for this block so
* those styles can be withheld from the empty wrapper rendered when there is
* no adjacent post. The wrapper itself is kept for backward compatibility.
*/
$support_styles = '' === $content
? array(
'class' => '',
'style' => '',
)
: gutenberg_block_core_post_navigation_link_get_support_styles( $attributes );
if ( '' !== $support_styles['class'] ) {
$classes .= " {$support_styles['class']}";
}
$wrapper_attributes = get_block_wrapper_attributes(
array(
'class' => $classes,
'style' => $support_styles['style'],
)
);
return sprintf(
'%2$s
',
$wrapper_attributes,
$content
);
}
/**
* Generates the border, shadow and spacing class names and inline styles for
* the `core/post-navigation-link` block.
*
* Mirrors the default border, shadow and spacing block support serialization,
* which the block opts out of so the styles are only applied when a link is
* rendered.
*
* @since 7.2.0
*
* @param array $attributes The block attributes.
* @return array {
* Border, shadow and spacing class names and inline styles.
*
* @type string $class Class names generated by the style engine, or an empty string.
* @type string $style Inline styles generated by the style engine, or an empty string.
* }
*/
function gutenberg_block_core_post_navigation_link_get_support_styles( $attributes ) {
$block_styles = $attributes['style'] ?? array();
$border = $block_styles['border'] ?? array();
$border_styles = array();
// Border radius and width accept unitless numbers from the original implementation.
if ( isset( $border['radius'] ) ) {
$border_styles['radius'] = is_numeric( $border['radius'] ) ? "{$border['radius']}px" : $border['radius'];
}
if ( isset( $border['width'] ) ) {
$border_styles['width'] = is_numeric( $border['width'] ) ? "{$border['width']}px" : $border['width'];
}
if ( isset( $border['style'] ) ) {
$border_styles['style'] = $border['style'];
}
// A preset border color is stored in its own attribute rather than under `style`.
$border_styles['color'] = isset( $attributes['borderColor'] )
? "var:preset|color|{$attributes['borderColor']}"
: ( $border['color'] ?? null );
// Individual border sides e.g. top, left etc.
foreach ( array( 'top', 'right', 'bottom', 'left' ) as $side ) {
$border_styles[ $side ] = array(
'width' => $border[ $side ]['width'] ?? null,
'color' => $border[ $side ]['color'] ?? null,
'style' => $border[ $side ]['style'] ?? null,
);
}
$styles = gutenberg_style_engine_get_styles(
array(
'border' => $border_styles,
'shadow' => $block_styles['shadow'] ?? null,
'spacing' => array(
'margin' => $block_styles['spacing']['margin'] ?? null,
'padding' => $block_styles['spacing']['padding'] ?? null,
),
)
);
return array(
'class' => $styles['classnames'] ?? '',
'style' => $styles['css'] ?? '',
);
}
/**
* Registers the `core/post-navigation-link` block on the server.
*
* @since 5.9.0
*/
function gutenberg_register_block_core_post_navigation_link() {
register_block_type_from_metadata(
__DIR__ . '/post-navigation-link',
array(
'render_callback' => 'gutenberg_render_block_core_post_navigation_link',
)
);
}
add_action( 'init', 'gutenberg_register_block_core_post_navigation_link', 20 );