<?php
/**
* Server-side rendering of the `core/post-navigation-link` block.
*
* @package WordPress
*/
/**
* Renders the `core/post-navigation-link` block on the server.
*
* @since 5.9.0
*
* @param array $attributes Block attributes.
* @param string $content Block default content.
*
* @return string Returns the next or previous post link that is adjacent to the current post.
*/
function render_block_core_post_navigation_link( $attributes, $content ) {
if ( ! is_singular() ) {
return '';
}
// Get the navigation type to show the proper link. Available options are `next|previous`.
$navigation_type = isset( $attributes['type'] ) ? $attributes['type'] : 'next';
// Allow only `next` and `previous` in `$navigation_type`.
if ( ! in_array( $navigation_type, array( 'next', 'previous' ), true ) ) {
return '';
}
$classes = "post-navigation-link-$navigation_type";
if ( isset( $attributes['textAlign'] ) ) {
$classes .= " has-text-align-{$attributes['textAlign']}";
}
$wrapper_attributes = get_block_wrapper_attributes(
array(
'class' => $classes,
)
);
// Set default values.
$format = '%link';
$link = 'next' === $navigation_type ? _x( 'Next', 'label for next post link' ) : _x( 'Previous', 'label for previous post link' );
$label = '';
// Only use hardcoded values here, otherwise we need to add escaping where these values are used.
$arrow_map = array(
'none' => '',
'arrow' => array(
'next' => '→',
'previous' => '←',
),
'chevron' => array(
'next' => '»',
'previous' => '«',
),
);
// If a custom label is provided, make this a link.
// `$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 = '<span class="post-navigation-link__label">' . wp_kses_post( $label ) . '</span> %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 = '<span class="post-navigation-link__label">' . wp_kses_post( $label ) . '</span> <span class="post-navigation-link__title">%title</span>';
} 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' );
$link = sprintf(
'<span class="post-navigation-link__label">%1$s</span> <span class="post-navigation-link__title">%2$s</span>',
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<span class="wp-block-post-navigation-link__arrow-next is-arrow-' . $attributes['arrow'] . '" aria-hidden="true">' . $arrow . '</span>';
} else {
$format = '<span class="wp-block-post-navigation-link__arrow-previous is-arrow-' . $attributes['arrow'] . '" aria-hidden="true">' . $arrow . '</span>%link';
}
}
/*
* The dynamic portion of the function name, `$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, $link );
}
return sprintf(
'<div %1$s>%2$s</div>',
$wrapper_attributes,
$content
);
}
/**
* Registers the `core/post-navigation-link` block on the server.
*
* @since 5.9.0
*/
function register_block_core_post_navigation_link() {
register_block_type_from_metadata(
__DIR__ . '/post-navigation-link',
array(
'render_callback' => 'render_block_core_post_navigation_link',
)
);
}
add_action( 'init', 'register_block_core_post_navigation_link' );