From 04e978cc353b44e73f71811943da6c3e69a4b9c5 Mon Sep 17 00:00:00 2001
From: SethTrowbridge <seth111@gmail.com>
Date: Wed, 16 Jul 2025 16:42:38 -0400
Subject: [PATCH] add hmr.js

---
 src/hmr.js | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 src/hmr.js

diff --git a/src/hmr.js b/src/hmr.js
new file mode 100644
index 0000000..38b93c4
--- /dev/null
+++ b/src/hmr.js
@@ -0,0 +1,92 @@
+//@ts-check
+// hmr
+const HMR = globalThis.HMR = {
+    Time: 0,
+    /** @type {Record<string, string>} */
+    Temp:{},
+    Tick()
+    {
+        for(const k in HMR.Temp)
+        {
+            sessionStorage.setItem(k, HMR.Temp[k]);
+        } 
+        HMR.Temp = {};
+        HMR.Time = 0;
+    },
+    /** @type {(key:string, value:string)=>void} */
+    Save(key, value)
+    {
+        this.Temp[key] = value;
+        if(!this.Time)
+        {
+            this.Time = setTimeout(this.Tick, 500);
+        }
+        console.log("SAVE", key, value);
+    },
+    /** @type {(key:string)=>string|null} */
+    Load(key)
+    {
+        const value = sessionStorage.getItem(key);
+        console.log("LOAD", key, value);
+        return value;
+    },
+
+    /** @type {string|undefined} */
+    _ID: undefined,
+    _index: 0,
+    /** @type {(id:string|undefined = undefined)=>void} */
+    StartID(id)
+    {
+        this._index = 0;
+        this._ID = id;
+    },
+    NextID()
+    {
+        return this._ID ? this._ID + "_" + (this._index++) + "_" : "";
+    },
+
+    BindVan()
+    {
+        //bind Van
+        const origninalState = globalThis.van.state;
+        globalThis.van.state =(value, key="")=>
+        {
+            const type = typeof value;
+            let reader =d=>d;
+            let writer =d=>d?.toString() || null;
+
+            switch(type)
+            {
+                case "boolean" :
+                    reader =(data)=> data === "true"; break;
+                case "number" :
+                    reader = parseFloat; break;
+                case "object" :
+                    reader = JSON.parse;
+                    writer = JSON.stringify;
+                    break;
+            }
+
+            const fullKey = "HMR_" + HMR.NextID() + key;
+            const stringValue = HMR.Load(fullKey);
+            const signal = origninalState((stringValue ? reader(stringValue) : value));
+            van.derive(()=>HMR.Save(fullKey, writer(signal.val)));
+
+            return signal;
+        };
+    },
+
+    BindVanX()
+    {
+        //bind VanX
+        const originalReactive = globalThis.vanX.reactive;
+        globalThis.vanX.reactive =(obj, id)=>
+        {
+            HMR.StartID(id);
+            const state = originalReactive(obj);
+            HMR.StartID();
+            return state;
+        }
+    }
+
+}