gutenberg / lib / experimental / interactivity-api / class-wp-directive-processor.php

class-wp-directive-processor.php in Gutenberg 16.2.1, at lib/experimental/interactivity-api/class-wp-directive-processor.php

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1	<?php
2	/**
3	* WP_Directive_Processor class
4	*
5	* @package Gutenberg
6	* @subpackage Interactivity API
7	*/
8
9	/**
10	* This processor is built on top of the HTML Tag Processor and augments its
11	* capabilities to process the Interactivity API directives.
12	*
13	* IMPORTANT DISCLAIMER: This code is highly experimental and its only purpose
14	* is to provide a way to test the server-side rendering of the Interactivity
15	* API. Most of this code will be discarded once the HTML Processor is
16	* available. Please restrain from investing unnecessary time and effort trying
17	* to improve this code.
18	*/
19	class WP_Directive_Processor extends WP_HTML_Tag_Processor {
20
21	/**
22	* An array of root blocks.
23	*
24	* @var array
25	*/
26	static $root_blocks = array();
27
28	/**
29	* Add a root block to the list.
30	*
31	* @param array $block The block to add.
32	*
33	* @return void
34	*/
35	public static function add_root_block( $block ) {
36	self::$root_blocks[] = md5( serialize( $block ) );
37	}
38
39	/**
40	* Check if block is a root block.
41	*
42	* @param array $block The block to check.
43	*
44	* @return bool True if block is a root block, false otherwise.
45	*/
46	public static function is_root_block( $block ) {
47	return in_array( md5( serialize( $block ) ), self::$root_blocks, true );
48	}
49
50
51	/**
52	* Find the matching closing tag for an opening tag.
53	*
54	* When called while on an open tag, traverse the HTML until we find the
55	* matching closing tag, respecting any in-between content, including nested
56	* tags of the same name. Return false when called on a closing or void tag,
57	* or if no matching closing tag was found.
58	*
59	* @return bool Whether a matching closing tag was found.
60	*/
61	public function next_balanced_closer() {
62	$depth = 0;
63
64	$tag_name = $this->get_tag();
65
66	if ( self::is_html_void_element( $tag_name ) ) {
67	return false;
68	}
69
70	while ( $this->next_tag(
71	array(
72	'tag_name' => $tag_name,
73	'tag_closers' => 'visit',
74	)
75	) ) {
76	if ( ! $this->is_tag_closer() ) {
77	$depth++;
78	continue;
79	}
80
81	if ( 0 === $depth ) {
82	return true;
83	}
84
85	$depth--;
86	}
87
88	return false;
89	}
90
91	/**
92	* Return the content between two balanced tags.
93	*
94	* When called on an opening tag, return the HTML content found between that
95	* opening tag and its matching closing tag.
96	*
97	* @return string The content between the current opening and its matching
98	* closing tag.
99	*/
100	public function get_inner_html() {
101	$bookmarks = $this->get_balanced_tag_bookmarks();
102	if ( ! $bookmarks ) {
103	return false;
104	}
105	list( $start_name, $end_name ) = $bookmarks;
106
107	$start = $this->bookmarks[ $start_name ]->end + 1;
108	$end = $this->bookmarks[ $end_name ]->start;
109
110	$this->seek( $start_name ); // Return to original position.
111	$this->release_bookmark( $start_name );
112	$this->release_bookmark( $end_name );
113
114	return substr( $this->html, $start, $end - $start );
115	}
116
117	/**
118	* Set the content between two balanced tags.
119	*
120	* When called on an opening tag, set the HTML content found between that
121	* opening tag and its matching closing tag.
122	*
123	* @param string $new_html The string to replace the content between the
124	* matching tags with.
125	*
126	* @return bool Whether the content was successfully replaced.
127	*/
128	public function set_inner_html( $new_html ) {
129	$this->get_updated_html(); // Apply potential previous updates.
130
131	$bookmarks = $this->get_balanced_tag_bookmarks();
132	if ( ! $bookmarks ) {
133	return false;
134	}
135	list( $start_name, $end_name ) = $bookmarks;
136
137	$start = $this->bookmarks[ $start_name ]->end + 1;
138	$end = $this->bookmarks[ $end_name ]->start;
139
140	$this->seek( $start_name ); // Return to original position.
141	$this->release_bookmark( $start_name );
142	$this->release_bookmark( $end_name );
143
144	$this->lexical_updates[] = new WP_HTML_Text_Replacement( $start, $end, $new_html );
145	return true;
146	}
147
148	/**
149	* Return a pair of bookmarks for the current opening tag and the matching
150	* closing tag.
151	*
152	* @return array\|false A pair of bookmarks, or false if there's no matching
153	* closing tag.
154	*/
155	public function get_balanced_tag_bookmarks() {
156	$i = 0;
157	while ( array_key_exists( 'start' . $i, $this->bookmarks ) ) {
158	++$i;
159	}
160	$start_name = 'start' . $i;
161
162	$this->set_bookmark( $start_name );
163	if ( ! $this->next_balanced_closer() ) {
164	$this->release_bookmark( $start_name );
165	return false;
166	}
167
168	$i = 0;
169	while ( array_key_exists( 'end' . $i, $this->bookmarks ) ) {
170	++$i;
171	}
172	$end_name = 'end' . $i;
173	$this->set_bookmark( $end_name );
174
175	return array( $start_name, $end_name );
176	}
177
178	/**
179	* Whether a given HTML element is void (e.g. <br>).
180	*
181	* @param string $tag_name The element in question.
182	* @return bool True if the element is void.
183	*
184	* @see https://html.spec.whatwg.org/#elements-2
185	*/
186	public static function is_html_void_element( $tag_name ) {
187	switch ( $tag_name ) {
188	case 'AREA':
189	case 'BASE':
190	case 'BR':
191	case 'COL':
192	case 'EMBED':
193	case 'HR':
194	case 'IMG':
195	case 'INPUT':
196	case 'LINK':
197	case 'META':
198	case 'SOURCE':
199	case 'TRACK':
200	case 'WBR':
201	return true;
202
203	default:
204	return false;
205	}
206	}
207
208	/**
209	* Extract and return the directive type and the the part after the double
210	* hyphen from an attribute name (if present), in an array format.
211	*
212	* Examples:
213	*
214	* 'wp-island' => array( 'wp-island', null )
215	* 'wp-bind--src' => array( 'wp-bind', 'src' )
216	* 'wp-thing--and--thang' => array( 'wp-thing', 'and--thang' )
217	*
218	* @param string $name The attribute name.
219	* @return array The resulting array
220	*/
221	public static function parse_attribute_name( $name ) {
222	return explode( '--', $name, 2 );
223	}
224	}
225