Repository: facebook/react
Pull request: Escape View Transition Name Strings as base64

This is an alternative to #35059.

If the name needs escaping, then instead of escaping it, we just use a base64 name. This wouldn't allow you to match on an escaped name in your own CSS like you should be able to if browsers worked properly. But at least it would provide matching name in current browsers which is probably sufficient if you're using auto-generated names.

This also covers some cases where `CSS.escape()` isn't sufficient anyway like when the name ends in a dot.


Changed files:
filename: packages/react-dom-bindings/src/client/ReactFiberConfigDOM.js
patch: @@ -1435,8 +1435,13 @@ export function applyViewTransitionName(
   className: ?string,
 ): void {
   instance = ((instance: any): HTMLElement);
+  // If the name isn't valid CSS identifier, base64 encode the name instead.
+  // This doesn't let you select it in custom CSS selectors but it does work in current
+  // browsers.
+  const escapedName =
+    CSS.escape(name) !== name ? 'r-' + btoa(name).replace(/=/g, '') : name;
   // $FlowFixMe[prop-missing]
-  instance.style.viewTransitionName = name;
+  instance.style.viewTransitionName = escapedName;
   if (className != null) {
     // $FlowFixMe[prop-missing]
     instance.style.viewTransitionClass = className;

filename: packages/react-dom-bindings/src/server/fizz-instruction-set/ReactDOMFizzInstructionSetInlineCodeStrings.js
patch: @@ -8,7 +8,7 @@ export const clientRenderBoundary =
 export const completeBoundary =
   '$RB=[];$RV=function(a){$RT=performance.now();for(var b=0;b<a.length;b+=2){var c=a[b],e=a[b+1];null!==e.parentNode&&e.parentNode.removeChild(e);var f=c.parentNode;if(f){var g=c.previousSibling,h=0;do{if(c&&8===c.nodeType){var d=c.data;if("/$"===d||"/&"===d)if(0===h)break;else h--;else"$"!==d&&"$?"!==d&&"$~"!==d&&"$!"!==d&&"&"!==d||h++}d=c.nextSibling;f.removeChild(c);c=d}while(c);for(;e.firstChild;)f.insertBefore(e.firstChild,c);g.data="$";g._reactRetry&&requestAnimationFrame(g._reactRetry)}}a.length=0};\n$RC=function(a,b){if(b=document.getElementById(b))(a=document.getElementById(a))?(a.previousSibling.data="$~",$RB.push(a,b),2===$RB.length&&("number"!==typeof $RT?requestAnimationFrame($RV.bind(null,$RB)):(a=performance.now(),setTimeout($RV.bind(null,$RB),2300>a&&2E3<a?2300-a:$RT+300-a)))):b.parentNode.removeChild(b)};';
 export const completeBoundaryUpgradeToViewTransitions =
-  '$RV=function(A,g){function k(a,b){var e=a.getAttribute(b);e&&(b=a.style,l.push(a,b.viewTransitionName,b.viewTransitionClass),"auto"!==e&&(b.viewTransitionClass=e),(a=a.getAttribute("vt-name"))||(a="_T_"+K++ +"_"),b.viewTransitionName=a,B=!0)}var B=!1,K=0,l=[];try{var f=document.__reactViewTransition;if(f){f.finished.finally($RV.bind(null,g));return}var m=new Map;for(f=1;f<g.length;f+=2)for(var h=g[f].querySelectorAll("[vt-share]"),d=0;d<h.length;d++){var c=h[d];m.set(c.getAttribute("vt-name"),c)}var u=[];for(h=0;h<g.length;h+=2){var C=g[h],x=C.parentNode;if(x){var v=x.getBoundingClientRect();if(v.left||v.top||v.width||v.height){c=C;for(f=0;c;){if(8===c.nodeType){var r=c.data;if("/$"===r)if(0===f)break;else f--;else"$"!==r&&"$?"!==r&&"$~"!==r&&"$!"!==r||f++}else if(1===c.nodeType){d=c;var D=d.getAttribute("vt-name"),y=m.get(D);k(d,y?"vt-share":"vt-exit");y&&(k(y,"vt-share"),m.set(D,null));var E=d.querySelectorAll("[vt-share]");for(d=0;d<E.length;d++){var F=E[d],G=F.getAttribute("vt-name"),\nH=m.get(G);H&&(k(F,"vt-share"),k(H,"vt-share"),m.set(G,null))}}c=c.nextSibling}for(var I=g[h+1],t=I.firstElementChild;t;)null!==m.get(t.getAttribute("vt-name"))&&k(t,"vt-enter"),t=t.nextElementSibling;c=x;do for(var n=c.firstElementChild;n;){var J=n.getAttribute("vt-update");J&&"none"!==J&&!l.includes(n)&&k(n,"vt-update");n=n.nextElementSibling}while((c=c.parentNode)&&1===c.nodeType&&"none"!==c.getAttribute("vt-update"));u.push.apply(u,I.querySelectorAll(\'img[src]:not([loading="lazy"])\'))}}}if(B){var z=\ndocument.__reactViewTransition=document.startViewTransition({update:function(){A(g);for(var a=[document.documentElement.clientHeight,document.fonts.ready],b={},e=0;e<u.length;b={g:b.g},e++)if(b.g=u[e],!b.g.complete){var p=b.g.getBoundingClientRect();0<p.bottom&&0<p.right&&p.top<window.innerHeight&&p.left<window.innerWidth&&(p=new Promise(function(w){return function(q){w.g.addEventListener("load",q);w.g.addEventListener("error",q)}}(b)),a.push(p))}return Promise.race([Promise.all(a),new Promise(function(w){var q=\nperformance.now();setTimeout(w,2300>q&&2E3<q?2300-q:500)})])},types:[]});z.ready.finally(function(){for(var a=l.length-3;0<=a;a-=3){var b=l[a],e=b.style;e.viewTransitionName=l[a+1];e.viewTransitionClass=l[a+1];""===b.getAttribute("style")&&b.removeAttribute("style")}});z.finished.finally(function(){document.__reactViewTransition===z&&(document.__reactViewTransition=null)});$RB=[];return}}catch(a){}A(g)}.bind(null,$RV);';
+  '$RV=function(A,g){function k(a,b){var e=a.getAttribute(b);e&&(b=a.style,l.push(a,b.viewTransitionName,b.viewTransitionClass),"auto"!==e&&(b.viewTransitionClass=e),(a=a.getAttribute("vt-name"))||(a="_T_"+K++ +"_"),a=CSS.escape(a)!==a?"r-"+btoa(a).replace(/=/g,""):a,b.viewTransitionName=a,B=!0)}var B=!1,K=0,l=[];try{var f=document.__reactViewTransition;if(f){f.finished.finally($RV.bind(null,g));return}var m=new Map;for(f=1;f<g.length;f+=2)for(var h=g[f].querySelectorAll("[vt-share]"),d=0;d<h.length;d++){var c=h[d];m.set(c.getAttribute("vt-name"),c)}var u=[];for(h=0;h<g.length;h+=2){var C=g[h],x=C.parentNode;if(x){var v=x.getBoundingClientRect();if(v.left||v.top||v.width||v.height){c=C;for(f=0;c;){if(8===c.nodeType){var r=c.data;if("/$"===r)if(0===f)break;else f--;else"$"!==r&&"$?"!==r&&"$~"!==r&&"$!"!==r||f++}else if(1===c.nodeType){d=c;var D=d.getAttribute("vt-name"),y=m.get(D);k(d,y?"vt-share":"vt-exit");y&&(k(y,"vt-share"),m.set(D,null));var E=d.querySelectorAll("[vt-share]");\nfor(d=0;d<E.length;d++){var F=E[d],G=F.getAttribute("vt-name"),H=m.get(G);H&&(k(F,"vt-share"),k(H,"vt-share"),m.set(G,null))}}c=c.nextSibling}for(var I=g[h+1],t=I.firstElementChild;t;)null!==m.get(t.getAttribute("vt-name"))&&k(t,"vt-enter"),t=t.nextElementSibling;c=x;do for(var n=c.firstElementChild;n;){var J=n.getAttribute("vt-update");J&&"none"!==J&&!l.includes(n)&&k(n,"vt-update");n=n.nextElementSibling}while((c=c.parentNode)&&1===c.nodeType&&"none"!==c.getAttribute("vt-update"));u.push.apply(u,\nI.querySelectorAll(\'img[src]:not([loading="lazy"])\'))}}}if(B){var z=document.__reactViewTransition=document.startViewTransition({update:function(){A(g);for(var a=[document.documentElement.clientHeight,document.fonts.ready],b={},e=0;e<u.length;b={g:b.g},e++)if(b.g=u[e],!b.g.complete){var p=b.g.getBoundingClientRect();0<p.bottom&&0<p.right&&p.top<window.innerHeight&&p.left<window.innerWidth&&(p=new Promise(function(w){return function(q){w.g.addEventListener("load",q);w.g.addEventListener("error",q)}}(b)),\na.push(p))}return Promise.race([Promise.all(a),new Promise(function(w){var q=performance.now();setTimeout(w,2300>q&&2E3<q?2300-q:500)})])},types:[]});z.ready.finally(function(){for(var a=l.length-3;0<=a;a-=3){var b=l[a],e=b.style;e.viewTransitionName=l[a+1];e.viewTransitionClass=l[a+1];""===b.getAttribute("style")&&b.removeAttribute("style")}});z.finished.finally(function(){document.__reactViewTransition===z&&(document.__reactViewTransition=null)});$RB=[];return}}catch(a){}A(g)}.bind(null,\n$RV);';
 export const completeBoundaryWithStyles =
   '$RM=new Map;$RR=function(n,w,p){function u(q){this._p=null;q()}for(var r=new Map,t=document,h,b,e=t.querySelectorAll("link[data-precedence],style[data-precedence]"),v=[],k=0;b=e[k++];)"not all"===b.getAttribute("media")?v.push(b):("LINK"===b.tagName&&$RM.set(b.getAttribute("href"),b),r.set(b.dataset.precedence,h=b));e=0;b=[];var l,a;for(k=!0;;){if(k){var f=p[e++];if(!f){k=!1;e=0;continue}var c=!1,m=0;var d=f[m++];if(a=$RM.get(d)){var g=a._p;c=!0}else{a=t.createElement("link");a.href=d;a.rel=\n"stylesheet";for(a.dataset.precedence=l=f[m++];g=f[m++];)a.setAttribute(g,f[m++]);g=a._p=new Promise(function(q,x){a.onload=u.bind(a,q);a.onerror=u.bind(a,x)});$RM.set(d,a)}d=a.getAttribute("media");!g||d&&!matchMedia(d).matches||b.push(g);if(c)continue}else{a=v[e++];if(!a)break;l=a.getAttribute("data-precedence");a.removeAttribute("media")}c=r.get(l)||h;c===h&&(h=a);r.set(l,a);c?c.parentNode.insertBefore(a,c.nextSibling):(c=t.head,c.insertBefore(a,c.firstChild))}if(p=document.getElementById(n))p.previousSibling.data=\n"$~";Promise.all(b).then($RC.bind(null,n,w),$RX.bind(null,n,"CSS failed to load"))};';
 export const completeSegment =

filename: packages/react-dom-bindings/src/server/fizz-instruction-set/ReactDOMFizzInstructionSetShared.js
patch: @@ -130,7 +130,12 @@ export function revealCompletedBoundariesWithViewTransitions(
       const idPrefix = '';
       name = '_' + idPrefix + 'T_' + autoNameIdx++ + '_';
     }
-    elementStyle['viewTransitionName'] = name;
+    // If the name isn't valid CSS identifier, base64 encode the name instead.
+    // This doesn't let you select it in custom CSS selectors but it does work in current
+    // browsers.
+    const escapedName =
+      CSS.escape(name) !== name ? 'r-' + btoa(name).replace(/=/g, '') : name;
+    elementStyle['viewTransitionName'] = escapedName;
     shouldStartViewTransition = true;
   }
   try {

filename: scripts/flow/environment.js
patch: @@ -644,3 +644,7 @@ declare module 'rbush' {
     fromJSON(data: any): RBush<T>;
   }
 }
+
+declare class CSS {
+  static escape(str: string): string;
+}