metasync / media-optimization / class-dimension-injector.php

class-dimension-injector.php in Search Atlas SEO – OTTO AI SEO Automation for WordPress 2.6.13, at media-optimization/class-dimension-injector.php

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1	<?php
2	/**
3	* Metasync_Dimension_Injector
4	* Scans HTML for <img> tags missing width/height and injects them
5	* based on file metadata to prevent Cumulative Layout Shift (CLS).
6	*
7	* @package Search Atlas SEO
8	* @copyright Copyright (C) 2021-2025, Search Atlas Group - support@searchatlas.com
9	* @since 2.6.0
10	*/
11
12	if (!defined('ABSPATH')) {
13	exit;
14	}
15
16	class Metasync_Dimension_Injector {
17
18	/** In-memory cache to avoid repeated file lookups within a request. */
19	private array $cache = [];
20
21	public function __construct() {
22	add_filter('the_content', [$this, 'inject_dimensions'], 30);
23	add_filter('post_thumbnail_html', [$this, 'inject_dimensions'], 30);
24	add_filter('widget_text', [$this, 'inject_dimensions'], 30);
25	}
26
27	/**
28	* Find <img> tags missing width or height and inject dimensions.
29	*/
30	public function inject_dimensions(string $content): string {
31	if (empty($content) \|\| is_admin()) {
32	return $content;
33	}
34
35	return preg_replace_callback('/<img\s[^>]+>/i', function ($matches) {
36	$tag = $matches[0];
37
38	$has_width = preg_match('/\swidth\s*=/i', $tag);
39	$has_height = preg_match('/\sheight\s*=/i', $tag);
40
41	// Both already present - nothing to do
42	if ($has_width && $has_height) {
43	return $tag;
44	}
45
46	$dims = $this->get_dimensions($tag);
47	if (!$dims) {
48	return $tag;
49	}
50
51	if (!$has_width) {
52	$tag = $this->add_attribute($tag, 'width', (string) $dims['width']);
53	}
54	if (!$has_height) {
55	$tag = $this->add_attribute($tag, 'height', (string) $dims['height']);
56	}
57
58	return $tag;
59	}, $content);
60	}
61
62	/**
63	* Try to determine image dimensions from multiple sources.
64	*/
65	private function get_dimensions(string $img_tag): ?array {
66	if (!preg_match('/src=["\']([^"\']+)["\']/i', $img_tag, $m)) {
67	return null;
68	}
69	$src = $m[1];
70
71	if (isset($this->cache[$src])) {
72	return $this->cache[$src];
73	}
74
75	$dims = null;
76
77	// Strategy 1: Try to find WordPress attachment by URL
78	$dims = $this->get_dims_from_attachment($src);
79
80	// Strategy 2: Try to read the local file directly
81	if (!$dims) {
82	$dims = $this->get_dims_from_local_file($src);
83	}
84
85	// Strategy 3: For external images, try getimagesize with URL (slower)
86	if (!$dims) {
87	$dims = $this->get_dims_from_remote($src);
88	}
89
90	if ($dims) {
91	$this->cache[$src] = $dims;
92	}
93
94	return $dims;
95	}
96
97	/**
98	* Look up dimensions from WP attachment metadata.
99	*/
100	private function get_dims_from_attachment(string $url): ?array {
101	$attachment_id = attachment_url_to_postid($url);
102
103	if (!$attachment_id) {
104	// Try without size suffix (e.g., image-300x200.jpg -> image.jpg)
105	$clean_url = preg_replace('/-\d+x\d+(\.\w+)$/', '$1', $url);
106	$attachment_id = attachment_url_to_postid($clean_url);
107	}
108
109	if (!$attachment_id) {
110	return null;
111	}
112
113	$meta = wp_get_attachment_metadata($attachment_id);
114	if (!$meta) {
115	return null;
116	}
117
118	// Check sub-sizes first
119	if (!empty($meta['sizes'])) {
120	$filename = wp_basename($url);
121	foreach ($meta['sizes'] as $size_data) {
122	if ($size_data['file'] === $filename) {
123	return [
124	'width' => (int) $size_data['width'],
125	'height' => (int) $size_data['height'],
126	];
127	}
128	}
129	}
130
131	// Fall back to full size
132	if (!empty($meta['width']) && !empty($meta['height'])) {
133	return [
134	'width' => (int) $meta['width'],
135	'height' => (int) $meta['height'],
136	];
137	}
138
139	return null;
140	}
141
142	/**
143	* Convert URL to local path and use getimagesize().
144	*/
145	private function get_dims_from_local_file(string $url): ?array {
146	$upload_dir = wp_get_upload_dir();
147
148	if (strpos($url, $upload_dir['baseurl']) === false) {
149	return null;
150	}
151
152	$relative = str_replace($upload_dir['baseurl'], '', $url);
153	$file = $upload_dir['basedir'] . $relative;
154
155	if (!file_exists($file)) {
156	return null;
157	}
158
159	$info = @getimagesize($file);
160	if ($info && $info[0] > 0 && $info[1] > 0) {
161	return ['width' => $info[0], 'height' => $info[1]];
162	}
163
164	return null;
165	}
166
167	/**
168	* Fetch dimensions from a remote URL.
169	* Downloads just enough bytes to read image headers.
170	*/
171	private function get_dims_from_remote(string $url): ?array {
172	if (strpos($url, 'http') !== 0) {
173	return null;
174	}
175
176	$response = wp_remote_get($url, [
177	'timeout' => 3,
178	'headers' => ['Range' => 'bytes=0-32767'],
179	]);
180
181	if (is_wp_error($response)) {
182	return null;
183	}
184
185	$body = wp_remote_retrieve_body($response);
186	if (empty($body)) {
187	return null;
188	}
189
190	if (!function_exists('wp_tempnam')) {
191	require_once ABSPATH . 'wp-admin/includes/file.php';
192	}
193
194	$tmp = wp_tempnam($url);
195	file_put_contents($tmp, $body);
196	$info = @getimagesize($tmp);
197	@unlink($tmp);
198
199	if ($info && $info[0] > 0 && $info[1] > 0) {
200	return ['width' => $info[0], 'height' => $info[1]];
201	}
202
203	return null;
204	}
205
206	/**
207	* Insert an attribute into an <img> tag.
208	*/
209	private function add_attribute(string $tag, string $name, string $value): string {
210	return preg_replace(
211	'/(<img\s)/i',
212	sprintf('$1%s="%s" ', esc_attr($name), esc_attr($value)),
213	$tag,
214	1
215	);
216	}
217	}
218