summaryrefslogtreecommitdiffstats
path: root/wp-includes/blocks/post-navigation-link.php
blob: 5bbc87ef537710330355cea1209932099ffb244f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
<?php
/**
 * Server-side rendering of the `core/post-navigation-link` block.
 *
 * @package WordPress
 */

/**
 * Renders the `core/post-navigation-link` block on the server.
 *
 * @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.
 */
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' );