start new router/metas

iso-router.tsx

@@ -0,0 +1,88 @@
+import * as Signal from "@preact/signals";
+import * as React from "react";
+
+///////// Metas
+type MetaFields = {title?:string, description?:string};
+type MetaRecord = MetaFields&{id:string}
+const Stack = [] as MetaRecord[];
+const StackPush =(m:MetaRecord)=> {Stack.push(m); Update();}
+const StackPop =(id:string)=> {Stack.splice(Stack.findIndex( item => item.id === id ), 1); Update();}
+const Update =()=> document.title = Stack[Stack.length-1]?.title || "---";
+Update();
+export const useMeta=(fields:MetaFields)=>
+{
+    const id = React.useId();
+    React.useEffect(()=>{
+        StackPush({...fields, id});
+        return ()=>StackPop(id);
+    }, []);
+}
+export const Meta =(props:MetaFields)=> { useMeta(props); return null; }
+
+//////// Router
+//// Create Signals
+export const pageURL = Signal.signal(new URL(globalThis.location.href || ""));
+export const pagePath = Signal.signal([] as string[]);
+Signal.effect(()=> pagePath.value = pageURL.value.pathname.split("/").filter(part=>part!=""));
+
+//// Add handlers
+globalThis.addEventListener("click", e=>
+{
+    (e.composedPath() as HTMLAnchorElement[]).find((step)=>{
+        if(step.href)
+        {
+            const url = new URL(step.href);
+            if(url.origin == document.location.origin)
+            {
+                e.preventDefault();
+                history.pushState({}, "", url);
+                pageURL.value = url;
+            }
+            return true;
+        }
+    })
+});
+globalThis.addEventListener("popstate", _=> pageURL.value = new URL(globalThis.location.href) );
+
+/// Rendering context
+type RouteContextData = {
+    /** Current nested depth of the router */ nestedDepth:number,
+    /** Index into the page path to start matching routes */ pathIndex:number,
+    /** Collection of keys from matched routes ("page/:key/") */ keys: Record<string, string>
+}
+const context = React.createContext({nestedDepth:0, pathIndex:0, keys:{}} as RouteContextData);
+export const useRoute =()=> React.useContext(context);
+export const Route =(props:{path:string[], children:React.ReactNode|React.ReactNode[]}):React.JSX.Element|null=>
+{
+    // Match the current page url, with a route.
+    const {nestedDepth, pathIndex} = React.useContext(context);
+    const pagePathRange = pagePath.value.slice(pathIndex);
+    const emptyMatch = !props.path.length && !pagePathRange.length;
+    const comparisonSize = Math.min(props.path.length, pagePath.value.length);
+
+    if(comparisonSize == 0 && emptyMatch === false) // one of the arrays is empty and one is not
+    {
+        return null;
+    }
+
+    const keys = {} as Record<string, string>; // not doing anything with this currently
+    for(let i=0; i<comparisonSize; i++)
+    {
+        const partPage = pagePathRange[i];
+        const partRoute = props.path[i];
+        if(partPage !== partRoute) // theres a mismatch
+        {
+            if(partRoute?.startsWith(":")) // mismatch because variable capture, consider it a match and capture
+            {
+                const key = partRoute?.substring(1);
+                key && (keys[key] = partPage);
+            }
+            else if(partRoute !== "*") // otherwise quit if its not a wildcard section
+            {
+                return null;
+            }
+        }
+    }
+
+    return <context.Provider value={{nestedDepth:nestedDepth+1, pathIndex:pathIndex+comparisonSize, keys}}>{props.children}</context.Provider>
+}