| 1 |
<?php |
| 2 |
/** |
| 3 |
* CSS combining on the finished HTML. |
| 4 |
* |
| 5 |
* The enqueue-stage combiner (Asset_Combiner::combine_styles) walked |
| 6 |
* WP_Styles->queue at priority 999 and rewrote handles: point one handle at the |
| 7 |
* merged file, blank the rest. That cannot be made correct, because WordPress |
| 8 |
* keeps editing the queue after we are done. |
| 9 |
* |
| 10 |
* The reported break (#195, WooCommerce + Kadence) was not a flaw in our |
| 11 |
* bucketing or carrier choice. Traced on a live install: |
| 12 |
* |
| 13 |
* prio 998 kadence-global src='.../global.min.css' |
| 14 |
* prio 999 kadence-global src=false <- us, blanking a non-carrier |
| 15 |
* |
| 16 |
* ...and then core's `wp_maybe_inline_styles()` runs. It inlines any queued |
| 17 |
* handle carrying a `path` data key and sets `src = false` on it |
| 18 |
* (wp-includes/script-loader.php:3188). Our carrier was |
| 19 |
* `classic-theme-styles`, which core registers WITH a path — so core read that |
| 20 |
* handle's ORIGINAL file, inlined it, and discarded the combined URL we had |
| 21 |
* just written there. The merged <link> never printed and the five sheets we |
| 22 |
* had blanked were gone. Six stylesheets became one, and the site rendered |
| 23 |
* unstyled. |
| 24 |
* |
| 25 |
* No carrier-selection rule survives that: core rewrites the handle after us. |
| 26 |
* So combining moves to the finished HTML, where what we read is what shipped. |
| 27 |
* This is the layer LiteSpeed combines at, for the same reason. |
| 28 |
* |
| 29 |
* What that buys, beyond fixing the break: |
| 30 |
* |
| 31 |
* - Document order is visible, so the cascade can be preserved exactly. |
| 32 |
* - Sheets printed by plugins outside the queue are seen (they were |
| 33 |
* invisible to a queue walker, and got duplicated). |
| 34 |
* - `data-no-optimize` / `data-optimized` opt-outs work, matching what |
| 35 |
* LiteSpeed and Autoptimize already honor. |
| 36 |
* - The swap path is a pure string transform, so it is unit-testable — |
| 37 |
* the enqueue version needed a full WP bootstrap and never had a test. |
| 38 |
* |
| 39 |
* The cascade rule: only CONTIGUOUS runs of same-media local sheets merge. A |
| 40 |
* sheet we cannot combine (external, opted out, excluded) ends the run, and |
| 41 |
* everything after it starts a new one. Nothing is ever hoisted past anything |
| 42 |
* else, which is the property the old combiner could not offer. |
| 43 |
* |
| 44 |
* @package XSpeed |
| 45 |
*/ |
| 46 |
|
| 47 |
declare(strict_types=1); |
| 48 |
|
| 49 |
namespace XSpeed; |
| 50 |
|
| 51 |
defined( 'ABSPATH' ) || exit; |
| 52 |
|
| 53 |
final class Css_Combine_Buffer { |
| 54 |
|
| 55 |
/** Minimum sheets in a run before merging is worth a request. */ |
| 56 |
private const MIN_RUN = 2; |
| 57 |
|
| 58 |
/** Our own output-buffer nesting level, when we had to open one. */ |
| 59 |
private static ?int $buffer_level = null; |
| 60 |
|
| 61 |
/** Set once we have transformed a page, so we never do it twice. */ |
| 62 |
private static bool $done = false; |
| 63 |
|
| 64 |
/** |
| 65 |
* Make sure SOMETHING will hand us the finished HTML. |
| 66 |
* |
| 67 |
* `xspeed_cache_final_html` is the preferred route — the page cache |
| 68 |
* already buffers, so we transform once and the result is baked into the |
| 69 |
* cache file. But that filter fires only on a cacheable MISS. With the |
| 70 |
* page cache off, or on an excluded URL (`/cart`, `/checkout` — precisely |
| 71 |
* where a WooCommerce layout break hurts most), it never fires at all and |
| 72 |
* combining would silently stop working. |
| 73 |
* |
| 74 |
* So: open our own buffer when the cache is not going to give us one, and |
| 75 |
* no-op when it is. `$done` guarantees a page is transformed once whichever |
| 76 |
* path gets there first. |
| 77 |
*/ |
| 78 |
public static function boot(): void { |
| 79 |
add_action( |
| 80 |
'template_redirect', |
| 81 |
static function (): void { |
| 82 |
if ( is_admin() || wp_doing_ajax() || wp_doing_cron() |
| 83 |
|| ( defined( 'REST_REQUEST' ) && REST_REQUEST ) |
| 84 |
|| ( defined( 'WP_CLI' ) && WP_CLI ) |
| 85 |
|| ( defined( 'XMLRPC_REQUEST' ) && XMLRPC_REQUEST ) |
| 86 |
// Combining a builder editor's CSS reorders the cascade the |
| 87 |
// editor's own UI depends on. (#281) |
| 88 |
|| Builder_Editor::is_active() ) { |
| 89 |
return; |
| 90 |
} |
| 91 |
// The page cache is buffering and will call us through its |
| 92 |
// filter; a second buffer would just copy the page again. |
| 93 |
if ( class_exists( '\\XSpeed\\Cache' ) && Cache::is_buffering() ) { |
| 94 |
return; |
| 95 |
} |
| 96 |
ob_start( array( __CLASS__, 'filter_buffer' ) ); |
| 97 |
self::$buffer_level = ob_get_level(); |
| 98 |
add_action( 'shutdown', array( __CLASS__, 'close_buffer' ), 0 ); |
| 99 |
}, |
| 100 |
1 |
| 101 |
); |
| 102 |
} |
| 103 |
|
| 104 |
/** ob_start() callback — transform once, pass everything else through. */ |
| 105 |
public static function filter_buffer( string $buffer ): string { |
| 106 |
return self::process( $buffer ); |
| 107 |
} |
| 108 |
|
| 109 |
/** |
| 110 |
* Clear the once-per-request guard. |
| 111 |
* |
| 112 |
* Only tests need this: a request is a fresh process, but a test run |
| 113 |
* exercises many documents through one loaded class. |
| 114 |
*/ |
| 115 |
public static function reset(): void { |
| 116 |
self::$done = false; |
| 117 |
} |
| 118 |
|
| 119 |
/** Flush only the buffer we opened. */ |
| 120 |
public static function close_buffer(): void { |
| 121 |
if ( null !== self::$buffer_level && ob_get_level() >= self::$buffer_level ) { |
| 122 |
ob_end_flush(); |
| 123 |
self::$buffer_level = null; |
| 124 |
} |
| 125 |
} |
| 126 |
|
| 127 |
/** |
| 128 |
* Combine stylesheet links in a finished HTML document. |
| 129 |
* |
| 130 |
* Returns the input unchanged when there is nothing to gain, so a caller |
| 131 |
* can hand us any page unconditionally. |
| 132 |
* |
| 133 |
* @param string $html Complete page HTML. |
| 134 |
*/ |
| 135 |
public static function process( string $html ): string { |
| 136 |
if ( '' === $html || false === stripos( $html, '<link' ) ) { |
| 137 |
return $html; |
| 138 |
} |
| 139 |
// Both entry points can fire on one request (our buffer wraps the |
| 140 |
// page, the cache filter also runs). Transforming twice would be |
| 141 |
// harmless but wasteful — and would re-parse a document whose sheets |
| 142 |
// we already marked data-optimized. |
| 143 |
if ( self::$done ) { |
| 144 |
return $html; |
| 145 |
} |
| 146 |
|
| 147 |
// Only <head> is in scope. A <link> in the body is either a late |
| 148 |
// plugin injection or markup we do not own, and moving it changes |
| 149 |
// paint order for something that already chose to be there. |
| 150 |
$head_end = stripos( $html, '</head>' ); |
| 151 |
if ( false === $head_end ) { |
| 152 |
return $html; |
| 153 |
} |
| 154 |
$head = substr( $html, 0, $head_end ); |
| 155 |
|
| 156 |
$runs = self::runs( $head ); |
| 157 |
if ( empty( $runs ) ) { |
| 158 |
return $html; |
| 159 |
} |
| 160 |
|
| 161 |
$new_head = $head; |
| 162 |
foreach ( $runs as $run ) { |
| 163 |
$merged = self::merge_run( $run ); |
| 164 |
if ( null === $merged ) { |
| 165 |
continue; |
| 166 |
} |
| 167 |
// Replace the FIRST tag of the run with the combined link and drop |
| 168 |
// the rest. Reusing the first slot is what keeps the merged CSS |
| 169 |
// exactly where the earliest sheet was, preserving the cascade. |
| 170 |
$first = true; |
| 171 |
foreach ( $run['tags'] as $tag ) { |
| 172 |
$new_head = self::replace_once( $new_head, $tag, $first ? $merged : '' ); |
| 173 |
$first = false; |
| 174 |
// Async CSS parks a <noscript> fallback immediately after each |
| 175 |
// sheet it defers. The sheet it points at is now inside the |
| 176 |
// combined file, so leaving the fallback behind would reload |
| 177 |
// every original for no-JS visitors — the combine undone for |
| 178 |
// exactly the audience least able to afford it. Drop it with |
| 179 |
// its sheet; merge_run() rebuilds one for the combined <link>. |
| 180 |
$new_head = self::drop_noscript_for( $new_head, $tag ); |
| 181 |
} |
| 182 |
} |
| 183 |
|
| 184 |
if ( $new_head === $head ) { |
| 185 |
return $html; |
| 186 |
} |
| 187 |
self::$done = true; |
| 188 |
return $new_head . substr( $html, $head_end ); |
| 189 |
} |
| 190 |
|
| 191 |
/** |
| 192 |
* Split the head into contiguous runs of combinable same-media sheets. |
| 193 |
* |
| 194 |
* @return array<int,array{media:string,async:bool,tags:string[],urls:string[]}> |
| 195 |
*/ |
| 196 |
private static function runs( string $head ): array { |
| 197 |
// Blank out conditional comments and inline <style> so neither is |
| 198 |
// parsed into, and so an inline block BREAKS a run: it may carry |
| 199 |
// overrides that must keep their position between two sheets. |
| 200 |
$scan = self::mask( $head ); |
| 201 |
|
| 202 |
if ( ! preg_match_all( '#<link\b[^>]*>#i', $scan, $m, PREG_OFFSET_CAPTURE ) ) { |
| 203 |
return array(); |
| 204 |
} |
| 205 |
|
| 206 |
$excludes = self::excludes(); |
| 207 |
$runs = array(); |
| 208 |
$open = -1; // index in $runs of the run still being extended. |
| 209 |
$prev_end = null; |
| 210 |
|
| 211 |
foreach ( $m[0] as $hit ) { |
| 212 |
$offset = (int) $hit[1]; |
| 213 |
$tag = substr( $head, $offset, strlen( (string) $hit[0] ) ); |
| 214 |
|
| 215 |
if ( ! self::is_stylesheet( $tag ) ) { |
| 216 |
continue; |
| 217 |
} |
| 218 |
|
| 219 |
$url = self::attr( $tag, 'href' ); |
| 220 |
$media = self::media_of( $tag ); |
| 221 |
$async = self::is_async_style( $tag ); |
| 222 |
$local = '' !== $url ? self::local_path( $url ) : null; |
| 223 |
|
| 224 |
$combinable = null !== $local |
| 225 |
&& ! self::opted_out( $tag ) |
| 226 |
&& ! self::excluded( $url, $excludes ); |
| 227 |
|
| 228 |
// Anything of substance BETWEEN two sheets ends the run: an inline |
| 229 |
// <style> or a conditional block may carry overrides whose position |
| 230 |
// relative to these sheets is load-bearing. Masked regions are NUL |
| 231 |
// in $scan, so their presence is the test. |
| 232 |
$gap = null === $prev_end ? '' : substr( $scan, $prev_end, $offset - $prev_end ); |
| 233 |
// phpcs:ignore WordPress.WP.AlternativeFunctions.strip_tags_strip_tags -- testing whether the gap between two <link>s holds anything at all; wp_strip_all_tags() also trims and would hide a whitespace-only gap, which is exactly the case that must NOT break a run. |
| 234 |
$gap_breaks = '' !== $gap && ( false !== strpos( $gap, "\0" ) || '' !== trim( strip_tags( $gap ) ) ); |
| 235 |
|
| 236 |
$prev_end = $offset + strlen( $tag ); |
| 237 |
|
| 238 |
if ( ! $combinable ) { |
| 239 |
$open = -1; // an uncombinable sheet ends the run it sits in. |
| 240 |
continue; |
| 241 |
} |
| 242 |
|
| 243 |
// Async'd and render-blocking sheets never share a run: merging |
| 244 |
// them would either make a blocking sheet non-blocking or drag an |
| 245 |
// async'd one back onto the critical path. Grouping on the flag |
| 246 |
// keeps each combined file honest about how it loads. (#330) |
| 247 |
$extend = $open >= 0 && ! $gap_breaks |
| 248 |
&& $runs[ $open ]['media'] === $media |
| 249 |
&& $runs[ $open ]['async'] === $async; |
| 250 |
if ( $extend ) { |
| 251 |
$runs[ $open ]['tags'][] = $tag; |
| 252 |
$runs[ $open ]['urls'][] = $local; |
| 253 |
continue; |
| 254 |
} |
| 255 |
|
| 256 |
$runs[] = array( |
| 257 |
'media' => $media, |
| 258 |
'async' => $async, |
| 259 |
'tags' => array( $tag ), |
| 260 |
'urls' => array( $local ), |
| 261 |
); |
| 262 |
$open = count( $runs ) - 1; |
| 263 |
} |
| 264 |
|
| 265 |
return array_values( |
| 266 |
array_filter( |
| 267 |
$runs, |
| 268 |
static fn( $r ) => count( $r['tags'] ) >= self::MIN_RUN |
| 269 |
) |
| 270 |
); |
| 271 |
} |
| 272 |
|
| 273 |
/** |
| 274 |
* Build the combined file for one run and return its <link>, or null when |
| 275 |
* nothing could be read. |
| 276 |
* |
| 277 |
* @param array{media:string,async:bool,tags:string[],urls:string[]} $run Run to merge. |
| 278 |
*/ |
| 279 |
private static function merge_run( array $run ): ?string { |
| 280 |
$key = md5( implode( '|', array_map( static fn( $p ) => $p . ':' . (int) @filemtime( $p ), $run['urls'] ) ) ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- a missing file contributes 0 to the key; handled below. |
| 281 |
$dir = Asset_Combiner::cache_dir(); |
| 282 |
$file = $dir . '/combined-' . $key . '.css'; |
| 283 |
$url = Asset_Combiner::cache_url() . '/combined-' . $key . '.css'; |
| 284 |
|
| 285 |
if ( ! file_exists( $file ) ) { |
| 286 |
$css = ''; |
| 287 |
foreach ( $run['urls'] as $path ) { |
| 288 |
// phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- reading a local stylesheet during page render; WP_Filesystem needs admin context. |
| 289 |
$body = (string) @file_get_contents( $path ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- unreadable sheet is skipped, not fatal. |
| 290 |
if ( '' === $body ) { |
| 291 |
continue; |
| 292 |
} |
| 293 |
$src = self::path_to_url( $path ); |
| 294 |
$body = self::strip_file_prelude( $body ); |
| 295 |
$body = Asset_Combiner::resolve_imports( $body, $src, 0 ); |
| 296 |
$body = Asset_Combiner::rewrite_url_paths( $body, $src ); |
| 297 |
// Close any comment this file left open BEFORE it can reach the |
| 298 |
// join. The `/* xspeed */` marker used to absorb this by |
| 299 |
// accident — an unterminated `/*` swallowed the marker instead |
| 300 |
// of the next stylesheet — but that made a debugging comment |
| 301 |
// load-bearing, and it stopped working the moment the join was |
| 302 |
// minified (issue #331). Neutralising it at the source is what |
| 303 |
// actually holds. |
| 304 |
$body = self::close_open_comment( $body ); |
| 305 |
// The marker stays: it is the separator that keeps a file |
| 306 |
// ending mid-declaration from fusing its last selector onto the |
| 307 |
// next file's first one. The minifier strips it from the |
| 308 |
// artifact, so it costs nothing in the shipped bytes. |
| 309 |
$css .= "/* xspeed */\n" . $body . "\n"; |
| 310 |
} |
| 311 |
if ( '' === trim( $css ) ) { |
| 312 |
return null; |
| 313 |
} |
| 314 |
$css = self::hoist_imports( $css ); |
| 315 |
|
| 316 |
// Minify AFTER hoisting: @import rules are only legal at the top |
| 317 |
// of a stylesheet, so hoist_imports() has to see the un-minified |
| 318 |
// text first. Minifying the join is what issue #331 was about — |
| 319 |
// the inputs arrive minified but the concatenation did not, and |
| 320 |
// Minifier::rewrite_style() deliberately skips anything under |
| 321 |
// /cache/xspeed/, so this file was the end of the line. One |
| 322 |
// failing file drops Lighthouse's near-binary `unminified-css` |
| 323 |
// audit to 0.5, and the only offender on the page was ours. |
| 324 |
$css = Asset_Combiner::minify_css_body( $css ); |
| 325 |
if ( ! is_dir( $dir ) ) { |
| 326 |
wp_mkdir_p( $dir ); |
| 327 |
} |
| 328 |
// phpcs:ignore WordPress.WP.AlternativeFunctions.file_put_contents_file_put_contents -- WP_Filesystem requires admin context, unavailable on the frontend. |
| 329 |
file_put_contents( $file, $css, LOCK_EX ); |
| 330 |
} |
| 331 |
|
| 332 |
// Carry Async CSS across the merge (issue #330). Every sheet in the |
| 333 |
// run was async'd — that is a condition of grouping them, enforced in |
| 334 |
// runs() — so the combined file has to be non-render-blocking too, or |
| 335 |
// combining would quietly cancel the other feature instead of the |
| 336 |
// other way round. Same media="print" + onload swap async_style_tag |
| 337 |
// emits, applied once to the one <link> that replaces them all. |
| 338 |
if ( ! empty( $run['async'] ) ) { |
| 339 |
$restore = 'all' === $run['media'] ? 'all' : $run['media']; |
| 340 |
// The <noscript> fallback is rebuilt for the combined file, so a |
| 341 |
// visitor without JS still gets the CSS — one request now instead |
| 342 |
// of one per original sheet. |
| 343 |
$async_markup = '<link rel="stylesheet" href="%1$s" data-optimized="1" media="print" onload="this.media=\'%2$s\'" data-xs-async="%2$s" />' |
| 344 |
. '<noscript><link rel="stylesheet" href="%1$s" media="%2$s" /></noscript>'; // phpcs:ignore WordPress.WP.EnqueuedResources.NonEnqueuedStylesheet -- see the note on the non-async return below; this replaces finished-HTML <link>s. |
| 345 |
return sprintf( $async_markup, esc_url( $url ), esc_attr( $restore ) ); |
| 346 |
} |
| 347 |
|
| 348 |
$media = 'all' === $run['media'] ? '' : sprintf( ' media="%s"', esc_attr( $run['media'] ) ); |
| 349 |
|
| 350 |
// data-optimized marks it ours, so a second pass — or another |
| 351 |
// optimizer honoring the same convention — leaves it alone. |
| 352 |
// phpcs:ignore WordPress.WP.EnqueuedResources.NonEnqueuedStylesheet -- this REPLACES already-enqueued <link>s in the finished HTML; wp_enqueue_style() cannot run here (the page is rendered) and is the layer whose late rewrites caused #195. |
| 353 |
return sprintf( |
| 354 |
'<link rel="stylesheet" href="%s" data-optimized="1"%s />', |
| 355 |
esc_url( $url ), |
| 356 |
$media |
| 357 |
); |
| 358 |
} |
| 359 |
|
| 360 |
/* ------------------------------------------------------------------ */ |
| 361 |
/* Parsing helpers */ |
| 362 |
/* ------------------------------------------------------------------ */ |
| 363 |
|
| 364 |
/** |
| 365 |
* Replace conditional comments and inline <style> with NUL padding of the |
| 366 |
* same length, so offsets still line up with the original string. |
| 367 |
*/ |
| 368 |
private static function mask( string $head ): string { |
| 369 |
return (string) preg_replace_callback( |
| 370 |
// <noscript> is masked for the same reason as the rest: the <link> |
| 371 |
// inside it is a FALLBACK, not a sheet the document loads. Async |
| 372 |
// CSS emits one after every sheet it defers, so leaving them |
| 373 |
// visible both doubled the link count and broke every run into |
| 374 |
// single sheets — which is why combining silently stopped the |
| 375 |
// moment async_css was switched on (#330). The combined <link> |
| 376 |
// gets its own fallback rebuilt in merge_run(). |
| 377 |
'#<!--\[if.*?\[endif\]-->|<style\b[^>]*>.*?</style>|<noscript\b[^>]*>.*?</noscript>|<!--.*?-->#is', |
| 378 |
static function ( $m ) { |
| 379 |
// <noscript> is padded with SPACES, not NULs. Both are hidden |
| 380 |
// from the link scanner, but the gap test below treats a NUL as |
| 381 |
// "something load-bearing sits between these two sheets" and |
| 382 |
// ends the run. An Async CSS fallback is not an override — it |
| 383 |
// is a copy of the sheet we just read — so it must not break |
| 384 |
// contiguity, or every async'd sheet ends up alone in its own |
| 385 |
// run and nothing ever merges (#330). |
| 386 |
if ( 0 === stripos( $m[0], '<noscript' ) ) { |
| 387 |
return str_repeat( ' ', strlen( $m[0] ) ); |
| 388 |
} |
| 389 |
return str_repeat( "\0", strlen( $m[0] ) ); |
| 390 |
}, |
| 391 |
$head |
| 392 |
); |
| 393 |
} |
| 394 |
|
| 395 |
private static function is_stylesheet( string $tag ): bool { |
| 396 |
return (bool) preg_match( '#\brel\s*=\s*["\']?stylesheet["\']?#i', $tag ); |
| 397 |
} |
| 398 |
|
| 399 |
private static function attr( string $tag, string $name ): string { |
| 400 |
if ( preg_match( '#\b' . preg_quote( $name, '#' ) . '\s*=\s*["\']([^"\']*)["\']#i', $tag, $m ) ) { |
| 401 |
return trim( $m[1] ); |
| 402 |
} |
| 403 |
return ''; |
| 404 |
} |
| 405 |
|
| 406 |
/** |
| 407 |
* The media this sheet really applies to. |
| 408 |
* |
| 409 |
* '' and 'screen' both mean the on-screen document. |
| 410 |
* |
| 411 |
* An async'd sheet is the special case (issue #330). Async CSS rewrites |
| 412 |
* `media="all"` to `media="print"` and restores the original from an |
| 413 |
* onload handler, parking it in `data-xs-async`. Reading the literal |
| 414 |
* `media` attribute therefore filed every async'd sheet into a `print` |
| 415 |
* bucket of its own, no run ever reached MIN_RUN, and combining silently |
| 416 |
* stopped: the reported page went from 5 stylesheets to 22 while |
| 417 |
* `get_settings` still reported `combine_css: true` — two features that |
| 418 |
* the UI presents as independent, one quietly cancelling the other. |
| 419 |
* |
| 420 |
* `data-xs-async` holds the media the sheet will have a moment after |
| 421 |
* load, which is the one that decides whether two sheets belong together. |
| 422 |
* |
| 423 |
* Two spellings, one meaning. Free's Async CSS parks the media in |
| 424 |
* `data-xs-async`; Pro's Critical CSS defers the remaining sheets itself |
| 425 |
* and parks it in `data-xspeed-async`. Reading only Free's spelling filed |
| 426 |
* every Pro-deferred sheet as genuine `media="print"`, merged them into a |
| 427 |
* print-only bundle and dropped the swap — a bare, unstyled page from two |
| 428 |
* switches (#335 review, issue 1). Neither side owns the attribute name, |
| 429 |
* so both are read here. |
| 430 |
*/ |
| 431 |
private static function media_of( string $tag ): string { |
| 432 |
$async = strtolower( self::async_media( $tag ) ); |
| 433 |
if ( '' !== $async ) { |
| 434 |
return ( 'screen' === $async ) ? 'all' : $async; |
| 435 |
} |
| 436 |
$media = strtolower( self::attr( $tag, 'media' ) ); |
| 437 |
return ( '' === $media || 'screen' === $media ) ? 'all' : $media; |
| 438 |
} |
| 439 |
|
| 440 |
/** |
| 441 |
* The media parked on an async'd sheet, whichever attribute holds it. |
| 442 |
* |
| 443 |
* @return string '' when the sheet is not async'd. |
| 444 |
*/ |
| 445 |
private static function async_media( string $tag ): string { |
| 446 |
foreach ( self::async_attrs() as $attr ) { |
| 447 |
$value = self::attr( $tag, $attr ); |
| 448 |
if ( '' !== $value ) { |
| 449 |
return $value; |
| 450 |
} |
| 451 |
} |
| 452 |
|
| 453 |
// No attribute of ours, but the swap handler is the technique itself |
| 454 |
// and says the same thing: this sheet is parked under `print` and |
| 455 |
// becomes something else on load. Any plugin using the standard |
| 456 |
// print/swap idiom is read correctly rather than merged into a |
| 457 |
// print-only bundle and stripped of its handler (#335 review, issue 3). |
| 458 |
if ( preg_match( '#\bonload\s*=\s*(["\'])\s*this\.media\s*=\s*(["\'])([^"\']*)\2#i', $tag, $m ) ) { |
| 459 |
return $m[3]; |
| 460 |
} |
| 461 |
|
| 462 |
return ''; |
| 463 |
} |
| 464 |
|
| 465 |
/** |
| 466 |
* Attributes that park a sheet's real media while it loads. |
| 467 |
* |
| 468 |
* `data-xs-async` is Free's; `data-xspeed-async` is Pro's Critical CSS. |
| 469 |
* Filterable so a third deferring layer can declare itself rather than |
| 470 |
* being merged into a print-only bundle. |
| 471 |
* |
| 472 |
* @return string[] |
| 473 |
*/ |
| 474 |
private static function async_attrs(): array { |
| 475 |
$attrs = apply_filters( 'xspeed_async_css_attributes', array( 'data-xs-async', 'data-xspeed-async' ) ); |
| 476 |
return array_filter( array_map( 'strval', (array) $attrs ) ); |
| 477 |
} |
| 478 |
|
| 479 |
/** True when an async layer — Free's or Pro's — has already transformed this link. */ |
| 480 |
private static function is_async_style( string $tag ): bool { |
| 481 |
foreach ( self::async_attrs() as $attr ) { |
| 482 |
if ( preg_match( '#\b' . preg_quote( $attr, '#' ) . '\s*=#i', $tag ) ) { |
| 483 |
return true; |
| 484 |
} |
| 485 |
} |
| 486 |
return '' !== self::async_media( $tag ); |
| 487 |
} |
| 488 |
|
| 489 |
private static function opted_out( string $tag ): bool { |
| 490 |
return (bool) preg_match( '#\bdata-(no-optimize|optimized)\b#i', $tag ); |
| 491 |
} |
| 492 |
|
| 493 |
/** @return string[] */ |
| 494 |
private static function excludes(): array { |
| 495 |
/** |
| 496 |
* Filter: xspeed_combine_css_excludes |
| 497 |
* |
| 498 |
* Substrings matched against each stylesheet URL. A sheet that matches |
| 499 |
* keeps its own <link> and breaks the run around it, so the cascade |
| 500 |
* either side of it is untouched. |
| 501 |
* |
| 502 |
* @param string[] $excludes Substrings to leave alone. |
| 503 |
*/ |
| 504 |
$list = apply_filters( 'xspeed_combine_css_excludes', array() ); |
| 505 |
return is_array( $list ) ? array_filter( array_map( 'strval', $list ) ) : array(); |
| 506 |
} |
| 507 |
|
| 508 |
/** @param string[] $excludes */ |
| 509 |
private static function excluded( string $url, array $excludes ): bool { |
| 510 |
foreach ( $excludes as $needle ) { |
| 511 |
if ( '' !== $needle && false !== strpos( $url, $needle ) ) { |
| 512 |
return true; |
| 513 |
} |
| 514 |
} |
| 515 |
return false; |
| 516 |
} |
| 517 |
|
| 518 |
/** |
| 519 |
* Absolute filesystem path for a same-origin stylesheet URL, or null when |
| 520 |
* it is external, unreadable, or not a file we own. |
| 521 |
*/ |
| 522 |
private static function local_path( string $url ): ?string { |
| 523 |
$url = trim( html_entity_decode( $url, ENT_QUOTES ) ); |
| 524 |
if ( '' === $url || 0 === strpos( $url, 'data:' ) ) { |
| 525 |
return null; |
| 526 |
} |
| 527 |
$clean = strtok( $url, '?' ); |
| 528 |
if ( false === $clean ) { |
| 529 |
return null; |
| 530 |
} |
| 531 |
$info = Asset_Combiner::local_info( Asset_Combiner::to_absolute_url( $clean ) ); |
| 532 |
return is_array( $info ) && ! empty( $info['path'] ) ? (string) $info['path'] : null; |
| 533 |
} |
| 534 |
|
| 535 |
/** Inverse of local_path, for @import + url() resolution. */ |
| 536 |
private static function path_to_url( string $path ): string { |
| 537 |
$root = defined( 'ABSPATH' ) ? rtrim( ABSPATH, '/' ) : ''; |
| 538 |
if ( '' !== $root && 0 === strpos( $path, $root ) ) { |
| 539 |
return rtrim( home_url(), '/' ) . str_replace( $root, '', $path ); |
| 540 |
} |
| 541 |
return $path; |
| 542 |
} |
| 543 |
|
| 544 |
/** |
| 545 |
* Move any surviving `@import` to the top of the combined file. |
| 546 |
* |
| 547 |
* `resolve_imports()` inlines every import it can resolve, but a REMOTE |
| 548 |
* one (a Google Fonts URL, a CDN stylesheet) cannot be inlined and is |
| 549 |
* deliberately left in place. Standalone that is correct. In a combined |
| 550 |
* file it lands mid-stream, and the CSS spec only honours `@import` before |
| 551 |
* any style rule — so the browser silently drops it and that stylesheet |
| 552 |
* never loads at all. |
| 553 |
* |
| 554 |
* Hoisting keeps them working. It does change their position relative to |
| 555 |
* the merged rules, but an import that is ignored outright is strictly |
| 556 |
* worse than one that loads early: ignored means the font or vendor sheet |
| 557 |
* is simply absent. |
| 558 |
*/ |
| 559 |
private static function hoist_imports( string $css ): string { |
| 560 |
if ( false === stripos( $css, '@import' ) ) { |
| 561 |
return $css; |
| 562 |
} |
| 563 |
|
| 564 |
$imports = array(); |
| 565 |
$body = (string) preg_replace_callback( |
| 566 |
// A semicolon inside the rule does NOT end it. `[^;]+` stopped at |
| 567 |
// the first one, and a Google Fonts v2 URL puts semicolons in the |
| 568 |
// query string — `?family=Open+Sans:wght@400;500;600;700` is the |
| 569 |
// markup Google's own embed code hands you. The rule was cut in |
| 570 |
// half: a truncated @import got hoisted and the remainder was left |
| 571 |
// as loose garbage, so the browser dropped the import and the |
| 572 |
// webfont never loaded. (#277) |
| 573 |
// |
| 574 |
// So consume the parts an @import is actually made of — quoted |
| 575 |
// strings, url(...) including its own contents, and the media |
| 576 |
// query — and only then take the terminating `;`. An unterminated |
| 577 |
// @import at EOF is matched too, since browsers accept it. |
| 578 |
// The alternation covers, in order: a quoted string, a url(...) |
| 579 |
// with its contents, ANY other parenthesised group (a media |
| 580 |
// query's `(min-width:600px)`), and finally any character that is |
| 581 |
// none of those and not the terminator. |
| 582 |
'#@import\s+(?:"[^"]*"|\'[^\']*\'|url\(\s*(?:"[^"]*"|\'[^\']*\'|[^)]*)\s*\)|\([^)]*\)|[^;\'"()])+\s*;?#i', |
| 583 |
static function ( $m ) use ( &$imports ) { |
| 584 |
$rule = trim( (string) $m[0] ); |
| 585 |
// Normalise a missing terminator so the hoisted block is valid |
| 586 |
// even when the source relied on EOF to end the rule. |
| 587 |
if ( '' !== $rule && ';' !== substr( $rule, -1 ) ) { |
| 588 |
$rule .= ';'; |
| 589 |
} |
| 590 |
$imports[] = $rule; |
| 591 |
return ''; |
| 592 |
}, |
| 593 |
$css |
| 594 |
); |
| 595 |
|
| 596 |
if ( empty( $imports ) ) { |
| 597 |
return $css; |
| 598 |
} |
| 599 |
// Preserve source order, and drop duplicates — the same font import |
| 600 |
// appearing in three merged sheets should be fetched once. |
| 601 |
return implode( "\n", array_unique( $imports ) ) . "\n" . $body; |
| 602 |
} |
| 603 |
|
| 604 |
/** |
| 605 |
* Drop the bytes that are only legal at the START of a stylesheet. |
| 606 |
* |
| 607 |
* A UTF-8 BOM and an `@charset` rule are both position-sensitive: a |
| 608 |
* browser strips a LEADING BOM and honours a FIRST-LINE `@charset`, but |
| 609 |
* either one appearing mid-file is just a stray token — and it invalidates |
| 610 |
* the rule immediately after it. |
| 611 |
* |
| 612 |
* Kadence ships `woocommerce.min.css` with a BOM (`ef bb bf`). Standalone |
| 613 |
* that is fine. Concatenated third into a combined file it killed the rule |
| 614 |
* that followed — `.kadence-shop-top-row`, the flex container for the |
| 615 |
* WooCommerce shop toolbar — so "Showing all 4 results", the sorting |
| 616 |
* dropdown and the grid/list toggles collapsed into three stacked rows on |
| 617 |
* /shop, while every other page looked fine. (QA on #195) |
| 618 |
* |
| 619 |
* The combined file needs no `@charset` of its own: it is served with a |
| 620 |
* `Content-Type: text/css` charset from the webserver, which outranks an |
| 621 |
* in-file rule. |
| 622 |
*/ |
| 623 |
/** |
| 624 |
* Close a comment the stylesheet left open. |
| 625 |
* |
| 626 |
* A `/*` with no closing `*/` comments out everything after it. In a |
| 627 |
* combined file that is every subsequent stylesheet — one malformed vendor |
| 628 |
* file silently blanks the rest of the page's CSS. |
| 629 |
* |
| 630 |
* String literals are skipped, so `content: "/*"` is not mistaken for an |
| 631 |
* opener. Pure — unit-tested. |
| 632 |
*/ |
| 633 |
public static function close_open_comment( string $css ): string { |
| 634 |
$len = strlen( $css ); |
| 635 |
$in_string = ''; |
| 636 |
$i = 0; |
| 637 |
|
| 638 |
while ( $i < $len ) { |
| 639 |
$ch = $css[ $i ]; |
| 640 |
|
| 641 |
if ( '' !== $in_string ) { |
| 642 |
if ( '\\' === $ch ) { |
| 643 |
$i += 2; |
| 644 |
continue; |
| 645 |
} |
| 646 |
if ( $ch === $in_string ) { |
| 647 |
$in_string = ''; |
| 648 |
} |
| 649 |
++$i; |
| 650 |
continue; |
| 651 |
} |
| 652 |
|
| 653 |
if ( '"' === $ch || "'" === $ch ) { |
| 654 |
$in_string = $ch; |
| 655 |
++$i; |
| 656 |
continue; |
| 657 |
} |
| 658 |
|
| 659 |
if ( '/' === $ch && $i + 1 < $len && '*' === $css[ $i + 1 ] ) { |
| 660 |
$close = strpos( $css, '*/', $i + 2 ); |
| 661 |
if ( false === $close ) { |
| 662 |
// Unterminated: close it at the end of this file so the |
| 663 |
// next one in the bundle is still parsed. |
| 664 |
return $css . '*/'; |
| 665 |
} |
| 666 |
$i = $close + 2; |
| 667 |
continue; |
| 668 |
} |
| 669 |
|
| 670 |
++$i; |
| 671 |
} |
| 672 |
|
| 673 |
return $css; |
| 674 |
} |
| 675 |
|
| 676 |
private static function strip_file_prelude( string $css ): string { |
| 677 |
// BOM first — an @charset can sit behind one. |
| 678 |
if ( 0 === strncmp( $css, "\xEF\xBB\xBF", 3 ) ) { |
| 679 |
$css = substr( $css, 3 ); |
| 680 |
} |
| 681 |
// Only a LEADING @charset is meaningful, so only that one is dropped; |
| 682 |
// the string "@charset" inside a rule or comment is left alone. |
| 683 |
return (string) preg_replace( '/^\s*@charset\s+["\'][^"\']*["\']\s*;/i', '', $css ); |
| 684 |
} |
| 685 |
|
| 686 |
/** str_replace, but only the first occurrence. */ |
| 687 |
/** |
| 688 |
* Remove the `<noscript>` fallback that Async CSS emitted for one sheet. |
| 689 |
* |
| 690 |
* Matched by the sheet's own href so only its fallback goes — a page can |
| 691 |
* carry many, and an unrelated one must survive. Whitespace between the |
| 692 |
* link and its noscript is tolerated; anything else means this is not the |
| 693 |
* pair we think it is, and nothing is removed. |
| 694 |
*/ |
| 695 |
private static function drop_noscript_for( string $head, string $tag ): string { |
| 696 |
$href = self::attr( $tag, 'href' ); |
| 697 |
if ( '' === $href ) { |
| 698 |
return $head; |
| 699 |
} |
| 700 |
return (string) preg_replace( |
| 701 |
'#<noscript\b[^>]*>\s*<link\b[^>]*' . preg_quote( $href, '#' ) . '[^>]*>\s*</noscript>#i', |
| 702 |
'', |
| 703 |
$head, |
| 704 |
1 |
| 705 |
); |
| 706 |
} |
| 707 |
|
| 708 |
private static function replace_once( string $haystack, string $needle, string $replace ): string { |
| 709 |
$pos = strpos( $haystack, $needle ); |
| 710 |
if ( false === $pos ) { |
| 711 |
return $haystack; |
| 712 |
} |
| 713 |
return substr_replace( $haystack, $replace, $pos, strlen( $needle ) ); |
| 714 |
} |
| 715 |
} |
| 716 |
|
