model: add onSuccess/onFailure lifecycle hooks to modelRegister

webui/static/hoover/model.js

@@ -15,7 +15,7 @@
 
 import { reactive } from './reactivity.js';
 
-/** Registered models: name → { model, subsystem, fetch } */
+/** Registered models: name → { model, subsystem, fetch, onSuccess?, onFailure? } */
 const _models = new Map();
 
 /** In-flight fetch promises for dedup: name → Promise */
@@ -29,6 +29,13 @@ const _fetchPromises = new Map();
  * @param {string} definition.subsystem - WS topic to listen for ('*' = all)
  * @param {function} definition.fetch - async (signal?, param?) => Promise<data>
  * @param {any} [definition.defaultData] - Initial data value (default: null)
+ * @param {function} [definition.onSuccess] - (name, data, param?) => void.
+ *        Called after model.data is assigned. Also fires when data === null —
+ *        only a thrown fetch error skips it. Hook errors are caught and logged
+ *        (console.warn) and never affect the fetch promise or model state.
+ * @param {function} [definition.onFailure] - (name, error) => void.
+ *        Called after model.error is assigned, only on a real throw from fetch.
+ *        Hook errors are caught and logged and never affect the fetch promise.
  * @returns {object} reactive model
  */
 export function modelRegister(name, definition) {
@@ -43,6 +50,8 @@ export function modelRegister(name, definition) {
         model,
         subsystem: definition.subsystem,
         fetch: definition.fetch,
+        onSuccess: definition.onSuccess,
+        onFailure: definition.onFailure,
     });
 
     return model;
@@ -59,9 +68,13 @@ export function getModel(name) {
     return entry.model;
 }
 
-/** Build dedup key from model name and optional param. */
+/**
+ * Build dedup key from model name and optional param.
+ * Objects (e.g. `{ action: 'refresh' }`) are JSON-serialized so distinct
+ * param objects get distinct keys; strings/undefined keep bare behavior.
+ */
 function _dedupKey(name, param) {
-    return param !== undefined ? `${name}:${String(param)}` : name;
+    return param !== undefined ? name + ':' + JSON.stringify(param) : name;
 }
 
 /**
@@ -97,8 +110,20 @@ export function modelFetch(name, signalOrParam, signal) {
         try {
             const data = await entry.fetch(actualSignal, param);
             model.data = data;
+            // Fires for any resolved result, including data === null. Hook
+            // errors must not clobber model state or the returned promise.
+            try {
+                entry.onSuccess?.(name, data, param);
+            } catch (err) {
+                console.warn('Model onSuccess hook (' + name + ') threw:', err);
+            }
         } catch (e) {
             model.error = e.message || 'Fetch failed';
+            try {
+                entry.onFailure?.(name, e);
+            } catch (err) {
+                console.warn('Model onFailure hook (' + name + ') threw:', err);
+            }
         } finally {
             model.loading = false;
             model.refreshing = false;