.js path long before * `script_loader_tag` (priority 20/30) runs, so the delay + exclusion * checks only ever see the hashed URL. A user targeting a script by * URL substring — the obvious thing to do, and what the UI invites — * would silently stop matching the moment minification was enabled. * Minifier::rewrite_script() records the original here so those * checks can test both. (FBS field report against 1.1.2) * * @var array */ private static $original_src = array(); /** * Record a script's URL as it was BEFORE minification rewrote it. * Called from Minifier::rewrite_script(). * * @param string $handle Script handle. * @param string $src Original (pre-minify) URL. */ public static function remember_original_src( string $handle, string $src ): void { if ( '' !== $handle && '' !== $src ) { self::$original_src[ $handle ] = $src; } } /** * The pre-minify URL for a handle, or '' when we never rewrote it * (external script, minification off, or a handle we didn't touch). * * @param string $handle Script handle. */ public static function original_src( string $handle ): string { return isset( self::$original_src[ $handle ] ) ? self::$original_src[ $handle ] : ''; } /** * Reset the remembered URLs. Test-only seam. */ public static function reset_original_src(): void { self::$original_src = array(); } /** * Does this tag (or attribute string) opt out of optimization? * * `data-no-optimize` / `data-no-minify` are the de-facto convention * consent managers and other plugins print so optimizers keep hands * off (Borlabs Cookie stamps both on its config script). The CSS * combine buffer has honored `data-no-optimize` from the start; the * JS paths did not, so a marked consent script was still minified * into a hashed cache file — and a stale copy of a legally relevant * consent config is a correctness problem, not a cosmetic one. (#456) * * @param string $tag A full tag, or just its attribute string. */ public static function tag_opts_out( string $tag ): bool { return (bool) preg_match( '#\sdata-no-(?:optimize|minify)\b#i', $tag ); } /** * Pristine tags as they looked before any of our transforms, keyed by * handle. See snapshot_tag() / revert_late_marked_tag(). * * @var array */ private static $pristine_tag = array(); /** * Priority for the late opt-out re-check. Past Borlabs' ScriptBlocker * at 999 — the highest stamper we have seen in the wild — so the * marker has certainly landed by the time we look. (#469) */ private const LATE_OPT_OUT_PRIORITY = 1000; /** * The priority the late opt-out re-check runs at. * * A site whose stamper hooks even later can move ours past it. */ public static function late_opt_out_priority(): int { /** * Filter the priority of xSpeed's late data-no-optimize re-check. * * @param int $priority Default 1000. */ return (int) apply_filters( 'xspeed_late_opt_out_priority', self::LATE_OPT_OUT_PRIORITY ); } /** * Filter: `script_loader_tag`, priority 9 — remember the tag before we * touch it, so a marker stamped later can still be honored. * * Our three opt-out-aware transforms run at 15/20/30. A plugin that * stamps `data-no-optimize` AFTER them is invisible to all three: * Borlabs Cookie stamps at priority 100, so its consent config was * still minified into a hashed cache file AND delayed — the script * that has to run before anything else on the page ran only on first * interaction. Snapshotting here is what lets the late pass put the * original back verbatim, rather than trying to unpick each transform * in reverse. (#469) * * @param string $tag * @param string $handle * @param string $src */ public static function snapshot_tag( $tag, $handle, $src ): string { if ( is_string( $tag ) && '' !== $tag && '' !== (string) $handle ) { self::$pristine_tag[ (string) $handle ] = $tag; } return (string) $tag; } /** * Filter: `script_loader_tag`, priority `LATE_OPT_OUT_PRIORITY` — hand * back the untouched tag when a late filter stamped an opt-out marker * after our transforms had already run. * * The priority has to clear the stamper, not merely the transforms: * Borlabs stamps at 100 and Borlabs' own script blocker at 999, so an * earlier hook reads a tag whose marker has not landed yet. PHP_INT_MAX * would be unfriendly to a site that legitimately wants the last word, * so this sits just past the highest stamper we know of and is * filterable. Reverting to the snapshot is deliberate: undoing * a delay rewrite in place would mean re-deriving `src` from * `data-xs-src` and stripping markers, and #273 is a standing reminder * that regex-editing these attributes in reverse goes wrong quietly. * * The pristine tag still carries whatever priority-10 filters did to * it, so only OUR changes are dropped. (#469) * * @param string $tag * @param string $handle * @param string $src */ public static function revert_late_marked_tag( $tag, $handle, $src ): string { if ( ! is_string( $tag ) || '' === $tag || ! self::tag_opts_out( $tag ) ) { return (string) $tag; } $handle = (string) $handle; $pristine = isset( self::$pristine_tag[ $handle ] ) ? self::$pristine_tag[ $handle ] : ''; if ( '' !== $pristine && $pristine !== $tag ) { // The marker is on the tag we were handed, not on the snapshot, // so carry it — and everything else the late filter set in the // same pass — over. A consumer reading the rendered HTML (or // our own buffer passes) must still see the opt-out it asked // for. $tag = self::copy_late_attributes( $tag, $pristine, $handle ); } // The snapshot was taken on `script_loader_tag`, by which point // `script_loader_src` (priority 10) had ALREADY swapped in the // hashed cache URL — so reverting the tag alone still leaves the // minified src behind, which is the half the client actually // reported. Undo that here too, using the URL rewrite_script() // recorded. (#469) return self::restore_marked_script_src( $tag, $handle, self::current_src( $tag, (string) $src ) ); } /** * The src currently on a tag, falling back to the one WordPress passed. * * After a revert the tag carries the snapshot's src, which is not * necessarily the `$src` argument this late in the chain. * * @param string $tag Tag to read. * @param string $fallback Value to use when the tag has no src. */ private static function current_src( string $tag, string $fallback ): string { $open = self::open_tag_offsets( $tag ); if ( null !== $open && preg_match( '#(?= 0; $i-- ) { $add = self::late_attribute_delta( $late_tags[ $i ]['attrs'], $to_tags[ $i ]['attrs'], $handle ); if ( '' !== $add ) { $out = substr_replace( $out, $add, $to_tags[ $i ]['attrs_end'], 0 ); } } return $out; } /** * Fallback when the late tag and the snapshot cannot be paired * positionally: copy only the attributes that protect the script from * optimizers — the opt-out markers plus `data-cfasync` — onto every * snapshot tag missing them. Values are taken as the stamper wrote * them on the late tag. (#470) * * @param string $from Tag as the late filter left it. * @param string $to Snapshot tag to stamp onto. * @param array $to_tags open_tags() result for $to. */ private static function stamp_protective_attributes( string $from, string $to, array $to_tags ): string { $protect = array(); foreach ( array( 'data-no-optimize', 'data-no-minify', 'data-cfasync' ) as $name ) { if ( preg_match( '#\s(' . preg_quote( $name, '#' ) . ')(\s*=\s*(?:"[^"]*"|\'[^\']*\'|[^\s>]*))?#i', $from, $m ) ) { $protect[ $name ] = ' ' . $name . ( isset( $m[2] ) ? $m[2] : '' ); } } if ( empty( $protect ) ) { return $to; } $out = $to; // Right to left: an earlier splice would shift every later offset. for ( $i = count( $to_tags ) - 1; $i >= 0; $i-- ) { $add = ''; foreach ( $protect as $name => $attr ) { if ( ! preg_match( '#\s' . preg_quote( $name, '#' ) . '\b#i', $to_tags[ $i ]['attrs'] ) ) { $add .= $attr; } } if ( '' !== $add ) { $out = substr_replace( $out, $add, $to_tags[ $i ]['attrs_end'], 0 ); } } return $out; } /** * The attributes present on the late tag but not the snapshot, minus * the ones OUR transforms put there for this handle. * * Only attributes recorded in $our_late_attrs are dropped — a blanket * defer/type skip threw away a defer the STAMPER set in the same pass * as its marker. Themify prints main.js with defer + data-no-optimize * together, and its config rides a deferred data: URI script printed * just before it; stripping the theme's defer made main.js * parser-blocking, so it ran ahead of its config and the theme died * with "themify_vars is not defined". `src` is still never copied: * it belongs to the snapshot, and restore_marked_script_src() owns * undoing a minified URL. * * @param string $late_attrs Attribute string from the transformed tag. * @param string $to_attrs Attribute string from the snapshot tag. * @param string $handle Script handle the tags belong to. */ private static function late_attribute_delta( string $late_attrs, string $to_attrs, string $handle ): string { $pattern = '#\s([-\w:]+)(?:\s*=\s*(?:"[^"]*"|\'[^\']*\'|[^\s>]*))?#'; if ( ! preg_match_all( $pattern, $late_attrs, $late, PREG_SET_ORDER ) ) { return ''; } $have = array(); if ( preg_match_all( $pattern, $to_attrs, $existing, PREG_SET_ORDER ) ) { foreach ( $existing as $attr ) { $have[ strtolower( $attr[1] ) ] = true; } } $add = ''; foreach ( $late as $attr ) { $name = strtolower( $attr[1] ); if ( isset( $have[ $name ] ) || 'src' === $name || isset( self::$our_late_attrs[ $handle ][ $name ] ) ) { continue; } if ( 0 === strpos( $name, 'data-xs-' ) ) { continue; } $add .= $attr[0]; } return $add; } /** * Attribute names OUR transforms added in this request, keyed by * handle: defer_script_tag() records `defer`, delay_script_tag() * records `type` when it parks an inline block. Copying one of these * from the late tag back onto the snapshot would re-apply the very * transform the revert is undoing — but the same names coming from a * STAMPER are the author's intent and must survive, so the skip is * per-handle, never by name alone. `data-xs-*` is handled by prefix * separately. (#469) * * @var array> */ private static $our_late_attrs = array(); /** * Locate the opening `#is', static function ( array $m ): string { list( $whole, $attrs, $body ) = $m; if ( '' === trim( $body ) ) { return $whole; } // The tag itself asked to be left alone. (#456) if ( self::tag_opts_out( $attrs ) ) { return $whole; } // Our own replay bootstrap. Its body quotes the delay // machinery's own strings, so a pathological user target // fragment could match it — and a parked bootstrap means // nothing on the page ever replays. if ( false !== stripos( $attrs, 'xspeed-delay-bootstrap' ) ) { return $whole; } // Already marked, or a real src= — the src passes own those. // `(?' . $body . ''; }, $html ); // A PCRE failure (backtrack limit on a huge inline body) returns // null — and casting that to '' would serve AND cache a blank page. // The unrewritten original is always the safe fallback. return null === $out ? $html : $out; } /** * Inline bootstrap that flips delayed scripts on the first user * interaction. Printed once on wp_footer priority 1000. */ public static function print_delay_bootstrap(): void { if ( self::skip_in_non_frontend_context() ) { return; } if ( self::$delay_bootstrap_printed ) { return; } self::$delay_bootstrap_printed = true; // Failsafe timer for visitors who never interact. 0 disables it // entirely (interaction-only), which is what lab tools measure // best: a timer that fires inside Lighthouse's / GTmetrix's // measurement window loads the "delayed" scripts anyway and // inflates the reported TTI, so the delay looks ineffective. $opts = self::opts(); $timeout = isset( $opts['delay_js_timeout'] ) ? (int) $opts['delay_js_timeout'] : 8000; $timeout = max( 0, min( 60000, $timeout ) ); // The script is includes/js/delay-bootstrap.js, which also carries // the design notes for the lifecycle replay (#494). `npm run build` // minifies it into assets/delay-bootstrap.min.js; the timeout goes in // place of its one placeholder. // // The tag goes out through wp_print_inline_script_tag(), like Free's // other inline scripts, so a CSP plugin's wp_inline_script_attributes // filter can give it a nonce. Printed bare, a nonce CSP blocked it // and nothing was ever replayed. $js = str_replace( 'XSPEED_DELAY_TIMEOUT', (string) $timeout, self::delay_bootstrap_js() ); wp_print_inline_script_tag( $js, array( 'id' => 'xspeed-delay-bootstrap' ) ); } /** The delay bootstrap's code, read once per request. */ private static $delay_bootstrap_js = null; /** * The built delay bootstrap, without the line that records its source. * If the build is missing, the readable source is valid JS too, only * larger: printing nothing would leave every delayed script parked for * good, because the tags are already rewritten by the time this runs. */ private static function delay_bootstrap_js(): string { if ( null !== self::$delay_bootstrap_js ) { return self::$delay_bootstrap_js; } $root = dirname( __DIR__ ); $built = $root . '/assets/delay-bootstrap.min.js'; // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- a local plugin file, not a remote URL. $js = is_readable( $built ) ? (string) file_get_contents( $built ) : ''; if ( '' !== $js ) { $js = (string) preg_replace( '#\A/\*[^\n]*\*/\n#', '', $js ); } else { // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- a local plugin file, not a remote URL. $js = (string) file_get_contents( $root . '/includes/js/delay-bootstrap.js' ); } self::$delay_bootstrap_js = trim( $js ); return self::$delay_bootstrap_js; } /** * Filter: `style_loader_tag` — wrap stylesheets in the * print → onload="all" pattern so they download non-blocking. * Pairs with critical CSS workflows. Adds a

` for * clients that never run the onload handler. * * Shared by the enqueue-path filter above and the raw-tag buffer pass * below so the two can never drift — Pro's Critical CSS recognises this * exact marker to avoid double-wrapping, and a second copy of the * pattern is how that kind of contract quietly breaks. * * Callers own every skip decision (markers, onload, non-screen media); * this helper only produces the markup. * * @param string $tag A `<link rel="stylesheet">` tag deemed safe to defer. */ private static function async_link_markup( string $tag ): string { $async = (string) preg_replace_callback( '#\bmedia\s*=\s*(["\'])([^"\']*)\1#i', static function ( $m ) { $orig = $m[2]; return 'media="print" onload="this.media=\'' . esc_attr( $orig ) . '\'" data-xs-async="' . esc_attr( $orig ) . '"'; }, $tag, 1 ); // If no media= was present (rare), inject one. if ( $async === $tag ) { $async = (string) preg_replace( '#<link\b#i', '<link media="print" onload="this.media=\'all\'" data-xs-async="all"', $tag, 1 ); } // Fallback for noscript users — re-emit the original tag inside <noscript>. return $async . '<noscript>' . $tag . '

'; } /** * Stylesheet hosts that serve FONT CSS — small, render-blocking sheets of * `@font-face` rules. The buffer pass below defers only these: a raw * cross-origin `` could carry anything, and blindly deferring an * unknown vendor's layout CSS from the buffer would reintroduce the * unstyled-flash failure async_style_tag()'s guards exist to prevent. * Font CSS is the safe subset — text renders in a fallback face and swaps, * which is exactly what `font-display: swap` does on purpose. */ private const FONT_CSS_HOSTS = array( 'fonts.googleapis.com', 'fonts.bunny.net', 'use.typekit.net', 'p.typekit.net', 'fonts.cdnfonts.com', ); /** * The font-CSS host allowlist, filtered and normalised. * * @return string[] Lowercase hostnames. */ private static function font_css_hosts(): array { /** * Hosts whose stylesheet links the async-CSS buffer pass rewrites to * the non-blocking print → onload pattern. Only font-CSS providers * belong here: every listed host's sheets are safe to load late * because they only add `@font-face` rules. * * @param string[] $hosts Hostnames (exact match, case-insensitive). */ $hosts = (array) apply_filters( 'xspeed_async_css_font_hosts', self::FONT_CSS_HOSTS ); return array_map( 'strtolower', array_map( 'strval', $hosts ) ); } /** * Media values that never apply to a screen paint. A sheet restricted to * one of these is not render-blocking for screen, so deferring it saves * nothing — and `print` in particular is either a genuine print sheet or * somebody's finished async pattern, both of which must be left alone. */ private const NON_SCREEN_MEDIA = array( 'print', 'speech', 'aural', 'braille', 'embossed', 'handheld', 'projection', 'tty', 'tv', ); /** * Filter: `xspeed_cache_final_html` — defer RAW font-CSS stylesheet links * that never passed through wp_enqueue_style. * * `async_style_tag()` hooks `style_loader_tag`, so it only ever sees * enqueued stylesheets. Themes and font plugins print Google Fonts (and * Bunny, Typekit, CDNFonts) as literal * `` * markup in the head — on the site that surfaced this, four such tags — * and each one stays render-blocking with no plugin lever. Unused CSS * skips cross-origin hrefs by design, so nothing else picks them up. * * Runs on the finished page buffer, so the rewrite is baked into the * cached HTML and replays on every static hit. Deliberately narrow: only * links whose host is on the font-CSS allowlist are touched — see * FONT_CSS_HOSTS. Same-origin links (no host, or the site's own) never * match the allowlist and are untouched. * * @param string $html Complete page HTML. */ public static function async_raw_font_css_links( $html ): string { if ( ! is_string( $html ) || '' === $html ) { return (string) $html; } if ( self::skip_in_non_frontend_context() ) { return $html; } $opts = self::opts(); if ( empty( $opts['async_css'] ) ) { return $html; } // Never rewrite inside a

(invalid; the parser closes the // outer block at the first

) and hand no-JS visitors a // media="print" sheet whose onload never runs: no stylesheet at all. // Splitting the buffer on

]*>.*?)#is', $html, -1, PREG_SPLIT_DELIM_CAPTURE ); // preg_split failed (pathological buffer / backtrack limit). Without // the split we cannot tell a fallback link from a live one, so leave // the page untouched — a few blocking font sheets beat a broken // no-JS fallback. if ( ! is_array( $parts ) ) { return $html; } foreach ( $parts as $i => $part ) { // Odd indices are the captured