example/app.tsx

@@ -22,7 +22,12 @@ export default ()=>
         <Iso.Switch>
             <Iso.Case value="page">
                 <Iso.Switch>
-                    <Iso.Case value="about-us">About us!</Iso.Case>
+                    <Iso.Case value="about-us">
+                        <>
+                            <Iso.Meta.Metas title="About US"/>
+                            About us!
+                        </>
+                    </Iso.Case>
                     <Iso.Case default>sorry no page</Iso.Case>
                 </Iso.Switch>
             </Iso.Case>

example/deep/component.tsx

@@ -10,7 +10,7 @@ export default ()=>
     const [Data, Updating] = Iso.Fetch.Use(`https://catfact.ninja/fact`);
 
 
-    console.log("render!!")
+    console.log("component.tsx render!!")
 
     return <div class="p-4 text-red-500">
         <Iso.Meta.Metas title="Component!"/>

lib/iso.tsx

@@ -1,11 +1,14 @@
 import React from "react";
 
 type MetasInputs = { [Property in MetaKeys]?: string };
+type MetasModeArgs = {concatListed?:boolean; dropUnlisted?:boolean};
+type MetasStackItem = MetasModeArgs&MetasInputs&{id:string, depth:number}
 type Meta = {title:string, description:string, keywords:string, image:string, canonical:string }
 type MetaKeys = keyof Meta;
 
 export const Meta =
 {
+    Stack:[] as Array<MetasStackItem>,
     Meta: {
         title:"",
         description:"",
@@ -13,27 +16,98 @@ export const Meta =
         image:"",
         canonical:""
     } as Meta,
-    Context: React.createContext([{} as Meta, ()=>{}] as [Get:Meta, Set:React.StateUpdater<Meta>]),
+    Context: React.createContext([[], ()=>{}] as [Get:MetasStackItem[], Set:React.StateUpdater<MetasStackItem[]>]),
     Provider({children}:{children:Children})
     {
-        const binding = React.useState(Meta.Meta);
+        const binding = React.useState([] as MetasStackItem[]);
+        
+        React.useEffect(()=>{
+            const stack = binding[0];
+            const last = stack[stack.length-1];
+            console.log("updating page title", stack);
+            document.title = last?.title||"";
+        })
         return <Meta.Context.Provider value={binding}>{children}</Meta.Context.Provider>;
     },
-    Metas(props:{concatListed?:boolean; dropUnlisted?:boolean}&MetasInputs):null
+    Metas({concatListed=false, dropUnlisted=false, ...props}:MetasModeArgs&MetasInputs):null
     {
-        const    additive = props.concatListed ? (key:MetaKeys, value:string)=> Meta.Meta[key] += value : (key:MetaKeys, value:string)=> Meta.Meta[key] = value;
+        const id = React.useId();
-        const subtractive = props.dropUnlisted ? (key:MetaKeys)=> Meta.Meta[key] = "" : (key:MetaKeys)=> {};
+        const [, metasSet] = React.useContext(Meta.Context);
+        const {depth} = React.useContext(SwitchContext);
 
-        Object.keys(Meta).forEach((key)=>{
+        React.useEffect(()=>{
-            const metaKey = key as MetaKeys;
+            metasSet((m)=>{
-            const propValue = props[metaKey]||"";
+                console.log(`adding meta`, props, depth);
-            propValue ? additive(metaKey, propValue) : subtractive(metaKey);
+                const clone = [...m];
-        })
+                let i;
-        if(window.innerWidth)
+                for(i=clone.length-1; i>-1; i--)
-        {
+                {
-            document.title = Meta.Meta.title;
+                    if(clone[i].depth <= depth)
-        }
+                    {
                         
+                        break;
+                    }
+                }
+                clone.splice(i+1, 0, {id, depth, concatListed, dropUnlisted, ...props});
+                return clone;
+            });
+            return ()=>
+            {
+                metasSet((m)=>{
+                    const clone = [...m];
+                    const ind = clone.findIndex(i=>i.id === id);      
+                    if(ind > -1)
+                    {
+                        console.log(`removing meta`, props, depth);
+                        clone.splice(ind, 1);
+                    } 
+                    return clone;
+                });
+
+            };
+        }, []);
+
+        React.useEffect(()=>{
+            metasSet((m)=>{
+                const clone = [...m];
+                const ind = clone.findIndex(i=>i.id === id);      
+                if(ind > -1)
+                {
+                    console.log(`updating meta`, props, depth);
+                    clone[ind] = {...clone[ind], ...props};
+                } 
+                return clone;
+            });
+        }, Object.keys(props).map( (key) => props[key as MetaKeys] ));
+
+        /*
+        React.useEffect(()=>{
+
+            metasSet((m)=>
+            {
+                const metas = {...m};
+
+                const    additive = concatListed ? (key:MetaKeys, value:string)=> metas[key] += value : (key:MetaKeys, value:string)=> metas[key] = value;
+                const subtractive = dropUnlisted ? (key:MetaKeys)=> metas[key] = "" : (key:MetaKeys)=> {};
+            
+                Object.keys(metas).forEach((key)=>{
+                    const metaKey = key as MetaKeys;
+                    const propValue = props[metaKey]||"";
+                    propValue ? additive(metaKey, propValue) : subtractive(metaKey);
+                });
+
+                Meta.Meta = metas;
+                console.log(Meta.Meta);
+
+                if(window.innerWidth)
+                {
+                    document.title = metas.title;
+                }
+
+                return metas;
+            });
+        }, [props]);
+        */
         return null;
     }
 };
@@ -163,7 +237,7 @@ export const Switch =({children}:{children:Children})=>
             }
             if(childCase?.props?.default && !fallback)
             {
-                console.log(routeSegment);
+                //console.log(routeSegment);
                 fallback = childCaseChildren;
             }
         } 
@@ -202,7 +276,7 @@ export const Fetch = {
             inCheck.Promise = fetch(URL, Init?Init:undefined).then(resp=>resp.json()).then((json)=>{
                 inCheck.JSON = json;
                 inCheck.CachedAt = new Date().getTime();
-                console.log(`...cached!`);
+                //console.log(`...cached!`);
                 return inCheck;
             });
             return inCheck;
@@ -213,7 +287,7 @@ export const Fetch = {
             // not in the cache
             // - listen
 
-            console.log(`making new cache record...`);
+            //console.log(`making new cache record...`);
             return [load({URL, CacheFor, CachedAt:0, CacheOnServer, DelaySSR, Seed}), false, true];
         }
         else if(check.CachedAt == 0)
@@ -222,26 +296,26 @@ export const Fetch = {
             // - listen
             // - possibly init if there is something in JSON
 
-            console.log(`currently being cached...`);
+            //console.log(`currently being cached...`);
             return [check, check.JSON ? true : false, true];
         }
         else
         {
-            console.log(`found in cache...`);
+            //console.log(`found in cache...`);
             let secondsAge = (new Date().getTime() - check.CachedAt)/1000;
             if(secondsAge > check.CacheFor)
             {
                 // cached but expired
                 // - listen
                 // - init
-                console.log(`...outdated...`);
+                //console.log(`...outdated...`);
                 return [load(check), true, true];
             }
             else
             {
                 // cached and ready
                 // - init
-                console.log(`...retrieved!`);
+                //console.log(`...retrieved!`);
                 return [check, true, false];
             }
 

server.tsx

@@ -267,7 +267,7 @@ FileListen("${url.pathname}", reloadHandler);`;
             import {hydrate, createElement as H} from "react";
             import * as Twind from "https://esm.sh/v115/@twind/core@1.1.3/es2022/core.mjs";
             import {default as App, CSS} from "@eno/app";
-            import {Router, Fetch} from "@eno/iso";
+            import {Router, Fetch, Meta} from "@eno/iso";
             Twind.install(CSS);
             Fetch.Seed(${JSON.stringify(seed)});
             const hmrWrap = H( ()=>H(App) );