From 4cab83464015349317889a5453d04d27627df366 Mon Sep 17 00:00:00 2001
From: Evan Almloff <evanalmloff@gmail.com>
Date: Wed, 3 Jul 2024 00:31:18 +0200
Subject: [PATCH] switch to comments as placeholder nodes (#2579)

---
 packages/html/src/render_template.rs         |  2 +-
 packages/interpreter/src/js/core.js          |  2 +-
 packages/interpreter/src/js/hash.txt         |  2 +-
 packages/interpreter/src/ts/core.ts          | 31 +++++++++++++-------
 packages/interpreter/src/unified_bindings.rs |  4 +--
 packages/ssr/src/renderer.rs                 |  6 +---
 packages/web/Cargo.toml                      |  1 +
 packages/web/src/mutations.rs                |  5 ++--
 8 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/packages/html/src/render_template.rs b/packages/html/src/render_template.rs
index bb64ea6dd..370509538 100644
--- a/packages/html/src/render_template.rs
+++ b/packages/html/src/render_template.rs
@@ -34,7 +34,7 @@ fn render_template_node(node: &TemplateNode, out: &mut String) -> std::fmt::Resu
             write!(out, "</{tag}>")?;
         }
         TemplateNode::Text { text: t } => write!(out, "{t}")?,
-        TemplateNode::Dynamic { id: _ } => write!(out, "<pre hidden />")?,
+        TemplateNode::Dynamic { id: _ } => write!(out, "<!--placeholder-->")?,
     };
     Ok(())
 }
diff --git a/packages/interpreter/src/js/core.js b/packages/interpreter/src/js/core.js
index df21258ec..7acedae1a 100644
--- a/packages/interpreter/src/js/core.js
+++ b/packages/interpreter/src/js/core.js
@@ -1 +1 @@
-function setAttributeInner(node,field,value,ns){if(ns==="style"){node.style.setProperty(field,value);return}if(ns){node.setAttributeNS(ns,field,value);return}switch(field){case"value":if(node.value!==value)node.value=value;break;case"initial_value":node.defaultValue=value;break;case"checked":node.checked=truthy(value);break;case"initial_checked":node.defaultChecked=truthy(value);break;case"selected":node.selected=truthy(value);break;case"initial_selected":node.defaultSelected=truthy(value);break;case"dangerous_inner_html":node.innerHTML=value;break;default:if(!truthy(value)&&isBoolAttr(field))node.removeAttribute(field);else node.setAttribute(field,value)}}var truthy=function(val){return val==="true"||val===!0},isBoolAttr=function(field){switch(field){case"allowfullscreen":case"allowpaymentrequest":case"async":case"autofocus":case"autoplay":case"checked":case"controls":case"default":case"defer":case"disabled":case"formnovalidate":case"hidden":case"ismap":case"itemscope":case"loop":case"multiple":case"muted":case"nomodule":case"novalidate":case"open":case"playsinline":case"readonly":case"required":case"reversed":case"selected":case"truespeed":case"webkitdirectory":return!0;default:return!1}};class BaseInterpreter{global;local;root;handler;nodes;stack;templates;m;constructor(){}initialize(root,handler=null){if(this.global={},this.local={},this.root=root,this.nodes=[root],this.stack=[root],this.templates={},handler)this.handler=handler}createListener(event_name,element,bubbles){if(bubbles)if(this.global[event_name]===void 0)this.global[event_name]={active:1,callback:this.handler},this.root.addEventListener(event_name,this.handler);else this.global[event_name].active++;else{const id=element.getAttribute("data-dioxus-id");if(!this.local[id])this.local[id]={};element.addEventListener(event_name,this.handler)}}removeListener(element,event_name,bubbles){if(bubbles)this.removeBubblingListener(event_name);else this.removeNonBubblingListener(element,event_name)}removeBubblingListener(event_name){if(this.global[event_name].active--,this.global[event_name].active===0)this.root.removeEventListener(event_name,this.global[event_name].callback),delete this.global[event_name]}removeNonBubblingListener(element,event_name){const id=element.getAttribute("data-dioxus-id");if(delete this.local[id][event_name],Object.keys(this.local[id]).length===0)delete this.local[id];element.removeEventListener(event_name,this.handler)}removeAllNonBubblingListeners(element){const id=element.getAttribute("data-dioxus-id");delete this.local[id]}getNode(id){return this.nodes[id]}pushRoot(node){this.stack.push(node)}appendChildren(id,many){const root=this.nodes[id],els=this.stack.splice(this.stack.length-many);for(let k=0;k<many;k++)root.appendChild(els[k])}loadChild(ptr,len){let node=this.stack[this.stack.length-1],ptr_end=ptr+len;for(;ptr<ptr_end;ptr++){let end=this.m.getUint8(ptr);for(node=node.firstChild;end>0;end--)node=node.nextSibling}return node}saveTemplate(nodes,tmpl_id){this.templates[tmpl_id]=nodes}hydrate_node(hydrateNode,ids){const split=hydrateNode.getAttribute("data-node-hydration").split(","),id=ids[parseInt(split[0])];if(this.nodes[id]=hydrateNode,split.length>1){hydrateNode.listening=split.length-1,hydrateNode.setAttribute("data-dioxus-id",id.toString());for(let j=1;j<split.length;j++){const split2=split[j].split(":"),event_name=split2[0],bubbles=split2[1]==="1";this.createListener(event_name,hydrateNode,bubbles)}}}hydrate(ids,underNodes){for(let i=0;i<underNodes.length;i++){const under=underNodes[i];if(under instanceof HTMLElement){if(under.getAttribute("data-node-hydration"))this.hydrate_node(under,ids);const hydrateNodes=under.querySelectorAll("[data-node-hydration]");for(let i2=0;i2<hydrateNodes.length;i2++)this.hydrate_node(hydrateNodes[i2],ids)}const treeWalker=document.createTreeWalker(under,NodeFilter.SHOW_COMMENT);while(treeWalker.currentNode){const currentNode=treeWalker.currentNode;if(currentNode.nodeType===Node.COMMENT_NODE){const split=currentNode.textContent.split("node-id");if(split.length>1){let next=currentNode.nextSibling;currentNode.remove();let commentAfterText,textNode;if(next.nodeType===Node.COMMENT_NODE){const newText=next.parentElement.insertBefore(document.createTextNode(""),next);commentAfterText=next,textNode=newText}else textNode=next,commentAfterText=textNode.nextSibling;treeWalker.currentNode=commentAfterText,this.nodes[ids[parseInt(split[1])]]=textNode;let exit=!treeWalker.nextNode();if(commentAfterText.remove(),exit)break}else if(!treeWalker.nextNode())break}else if(!treeWalker.nextNode())break}}}setAttributeInner(node,field,value,ns){setAttributeInner(node,field,value,ns)}}export{BaseInterpreter};
+function setAttributeInner(node,field,value,ns){if(ns==="style"){node.style.setProperty(field,value);return}if(ns){node.setAttributeNS(ns,field,value);return}switch(field){case"value":if(node.value!==value)node.value=value;break;case"initial_value":node.defaultValue=value;break;case"checked":node.checked=truthy(value);break;case"initial_checked":node.defaultChecked=truthy(value);break;case"selected":node.selected=truthy(value);break;case"initial_selected":node.defaultSelected=truthy(value);break;case"dangerous_inner_html":node.innerHTML=value;break;default:if(!truthy(value)&&isBoolAttr(field))node.removeAttribute(field);else node.setAttribute(field,value)}}var truthy=function(val){return val==="true"||val===!0},isBoolAttr=function(field){switch(field){case"allowfullscreen":case"allowpaymentrequest":case"async":case"autofocus":case"autoplay":case"checked":case"controls":case"default":case"defer":case"disabled":case"formnovalidate":case"hidden":case"ismap":case"itemscope":case"loop":case"multiple":case"muted":case"nomodule":case"novalidate":case"open":case"playsinline":case"readonly":case"required":case"reversed":case"selected":case"truespeed":case"webkitdirectory":return!0;default:return!1}};class BaseInterpreter{global;local;root;handler;nodes;stack;templates;m;constructor(){}initialize(root,handler=null){if(this.global={},this.local={},this.root=root,this.nodes=[root],this.stack=[root],this.templates={},handler)this.handler=handler}createListener(event_name,element,bubbles){if(bubbles)if(this.global[event_name]===void 0)this.global[event_name]={active:1,callback:this.handler},this.root.addEventListener(event_name,this.handler);else this.global[event_name].active++;else{const id=element.getAttribute("data-dioxus-id");if(!this.local[id])this.local[id]={};element.addEventListener(event_name,this.handler)}}removeListener(element,event_name,bubbles){if(bubbles)this.removeBubblingListener(event_name);else this.removeNonBubblingListener(element,event_name)}removeBubblingListener(event_name){if(this.global[event_name].active--,this.global[event_name].active===0)this.root.removeEventListener(event_name,this.global[event_name].callback),delete this.global[event_name]}removeNonBubblingListener(element,event_name){const id=element.getAttribute("data-dioxus-id");if(delete this.local[id][event_name],Object.keys(this.local[id]).length===0)delete this.local[id];element.removeEventListener(event_name,this.handler)}removeAllNonBubblingListeners(element){const id=element.getAttribute("data-dioxus-id");delete this.local[id]}getNode(id){return this.nodes[id]}pushRoot(node){this.stack.push(node)}appendChildren(id,many){const root=this.nodes[id],els=this.stack.splice(this.stack.length-many);for(let k=0;k<many;k++)root.appendChild(els[k])}loadChild(ptr,len){let node=this.stack[this.stack.length-1],ptr_end=ptr+len;for(;ptr<ptr_end;ptr++){let end=this.m.getUint8(ptr);for(node=node.firstChild;end>0;end--)node=node.nextSibling}return node}saveTemplate(nodes,tmpl_id){this.templates[tmpl_id]=nodes}hydrate_node(hydrateNode,ids){const split=hydrateNode.getAttribute("data-node-hydration").split(","),id=ids[parseInt(split[0])];if(this.nodes[id]=hydrateNode,split.length>1){hydrateNode.listening=split.length-1,hydrateNode.setAttribute("data-dioxus-id",id.toString());for(let j=1;j<split.length;j++){const split2=split[j].split(":"),event_name=split2[0],bubbles=split2[1]==="1";this.createListener(event_name,hydrateNode,bubbles)}}}hydrate(ids,underNodes){for(let i=0;i<underNodes.length;i++){const under=underNodes[i];if(under instanceof HTMLElement){if(under.getAttribute("data-node-hydration"))this.hydrate_node(under,ids);const hydrateNodes=under.querySelectorAll("[data-node-hydration]");for(let i2=0;i2<hydrateNodes.length;i2++)this.hydrate_node(hydrateNodes[i2],ids)}const treeWalker=document.createTreeWalker(under,NodeFilter.SHOW_COMMENT);while(treeWalker.currentNode){const currentNode=treeWalker.currentNode;if(currentNode.nodeType===Node.COMMENT_NODE){const id=currentNode.textContent,placeholderSplit=id.split("placeholder");if(placeholderSplit.length>1){if(this.nodes[ids[parseInt(placeholderSplit[1])]]=currentNode,!treeWalker.nextNode())break;continue}const textNodeSplit=id.split("node-id");if(textNodeSplit.length>1){let next=currentNode.nextSibling;currentNode.remove();let commentAfterText,textNode;if(next.nodeType===Node.COMMENT_NODE){const newText=next.parentElement.insertBefore(document.createTextNode(""),next);commentAfterText=next,textNode=newText}else textNode=next,commentAfterText=textNode.nextSibling;treeWalker.currentNode=commentAfterText,this.nodes[ids[parseInt(textNodeSplit[1])]]=textNode;let exit=!treeWalker.nextNode();if(commentAfterText.remove(),exit)break;continue}}if(!treeWalker.nextNode())break}}}setAttributeInner(node,field,value,ns){setAttributeInner(node,field,value,ns)}}export{BaseInterpreter};
diff --git a/packages/interpreter/src/js/hash.txt b/packages/interpreter/src/js/hash.txt
index 019943e7a..cbfbc11f6 100644
--- a/packages/interpreter/src/js/hash.txt
+++ b/packages/interpreter/src/js/hash.txt
@@ -1 +1 @@
-2622553468088460837
\ No newline at end of file
+6628058622237003340
\ No newline at end of file
diff --git a/packages/interpreter/src/ts/core.ts b/packages/interpreter/src/ts/core.ts
index e0aa939bc..63b2854de 100644
--- a/packages/interpreter/src/ts/core.ts
+++ b/packages/interpreter/src/ts/core.ts
@@ -173,9 +173,22 @@ export class BaseInterpreter {
         const currentNode = treeWalker.currentNode as ChildNode;
         if (currentNode.nodeType === Node.COMMENT_NODE) {
           const id = currentNode.textContent!;
-          const split = id.split("node-id");
 
-          if (split.length > 1) {
+          // First try to hydrate the comment node as a placeholder
+          const placeholderSplit = id.split("placeholder");
+
+          if (placeholderSplit.length > 1) {
+            this.nodes[ids[parseInt(placeholderSplit[1])]] = currentNode;
+            if (!treeWalker.nextNode()) {
+              break;
+            }
+            continue;
+          }
+
+          // Then try to hydrate the comment node as a marker for the next text node
+          const textNodeSplit = id.split("node-id");
+
+          if (textNodeSplit.length > 1) {
             // For most text nodes, this should be text
             let next = currentNode.nextSibling;
             // remove the comment node
@@ -198,23 +211,19 @@ export class BaseInterpreter {
               commentAfterText = textNode.nextSibling;
             }
             treeWalker.currentNode = commentAfterText;
-            this.nodes[ids[parseInt(split[1])]] = textNode;
+            this.nodes[ids[parseInt(textNodeSplit[1])]] = textNode;
             let exit = !treeWalker.nextNode();
             // remove the comment node after the text node
             commentAfterText.remove();
             if (exit) {
               break;
             }
-          } else {
-            if (!treeWalker.nextNode()) {
-              break;
-            }
-          }
-        } else {
-          if (!treeWalker.nextNode()) {
-            break;
+            continue;
           }
         }
+        if (!treeWalker.nextNode()) {
+          break;
+        }
       }
     }
   }
diff --git a/packages/interpreter/src/unified_bindings.rs b/packages/interpreter/src/unified_bindings.rs
index 151fec9f1..81ae00b51 100644
--- a/packages/interpreter/src/unified_bindings.rs
+++ b/packages/interpreter/src/unified_bindings.rs
@@ -75,7 +75,7 @@ mod js {
         "{let node = document.createTextNode($text$); this.nodes[$id$] = node; this.stack.push(node);}"
     }
     fn create_placeholder(id: u32) {
-        "{let node = document.createElement('pre'); node.hidden = true; this.stack.push(node); this.nodes[$id$] = node;}"
+        "{let node = document.createComment('placeholder'); this.stack.push(node); this.nodes[$id$] = node;}"
     }
     fn new_event_listener(event_name: &str<u8, evt>, id: u32, bubbles: u8) {
         r#"
@@ -164,7 +164,7 @@ mod js {
 
     #[cfg(feature = "binary-protocol")]
     fn add_placeholder() {
-        "{let node = document.createElement('pre'); node.hidden = true; this.stack.push(node);}"
+        "{let node = document.createComment('placeholder'); this.stack.push(node);}"
     }
 
     #[cfg(feature = "binary-protocol")]
diff --git a/packages/ssr/src/renderer.rs b/packages/ssr/src/renderer.rs
index 1f3140778..70d387b23 100644
--- a/packages/ssr/src/renderer.rs
+++ b/packages/ssr/src/renderer.rs
@@ -174,11 +174,7 @@ impl Renderer {
 
                     DynamicNode::Placeholder(_) => {
                         if self.pre_render {
-                            write!(
-                                buf,
-                                "<pre data-node-hydration={} hidden></pre>",
-                                self.dynamic_node_id
-                            )?;
+                            write!(buf, "<!--placeholder{}-->", self.dynamic_node_id)?;
                             self.dynamic_node_id += 1;
                         }
                     }
diff --git a/packages/web/Cargo.toml b/packages/web/Cargo.toml
index f4f2154ad..de6dc3e20 100644
--- a/packages/web/Cargo.toml
+++ b/packages/web/Cargo.toml
@@ -46,6 +46,7 @@ features = [
     "HtmlTextAreaElement",
     "HtmlFormElement",
     "Text",
+    "Comment",
     "Window",
     "DataTransfer",
     "console",
diff --git a/packages/web/src/mutations.rs b/packages/web/src/mutations.rs
index e0899de03..b06d10d38 100644
--- a/packages/web/src/mutations.rs
+++ b/packages/web/src/mutations.rs
@@ -44,9 +44,8 @@ impl WebsysDom {
             }
             Text { text } => self.document.create_text_node(text).dyn_into().unwrap(),
             Dynamic { .. } => {
-                let el = self.document.create_element("pre").unwrap();
-                let _ = el.toggle_attribute("hidden");
-                el.dyn_into().unwrap()
+                let placeholder = self.document.create_comment("placeholder");
+                placeholder.dyn_into().unwrap()
             }
         }
     }