From b4e5f699bcae95da41010ee8464546cfad3f1aeb Mon Sep 17 00:00:00 2001
From: wmTJc9IK0Q <171362836+wmTJc9IK0Q@users.noreply.github.com>
Date: Tue, 19 Aug 2025 10:14:27 -0500
Subject: [PATCH] Cancel requests when element is removed

---
 library/src/engine/engine.ts                 | 24 ++++++++++++--------
 library/src/engine/types.ts                  |  6 ++++-
 library/src/plugins/backend/actions/fetch.ts |  1 +
 3 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/library/src/engine/engine.ts b/library/src/engine/engine.ts
index 2cf16cf1..a1cd1d07 100644
--- a/library/src/engine/engine.ts
+++ b/library/src/engine/engine.ts
@@ -4,6 +4,7 @@ import { camel, snake } from '../utils/text'
 import { DATASTAR, DSP, DSS } from './consts'
 import { initErr, runtimeErr } from './errors'
 import type {
+  ActionContext,
   ActionPlugins,
   AttributePlugin,
   Computed,
@@ -1000,19 +1001,23 @@ function applyAttributePlugin(
 
       const cleanup = plugin.onLoad(ctx)
       if (cleanup) {
-        let cleanups = removals.get(el)
-        if (cleanups) {
-          cleanups.get(rawKey)?.()
-        } else {
-          cleanups = new Map()
-          removals.set(el, cleanups)
-        }
-        cleanups.set(rawKey, cleanup)
+        setCleanup(cleanup, el, rawKey);
       }
     }
   }
 }
 
+function setCleanup(cleanup: OnRemovalFn, el: HTMLOrSVG, key: string): void {
+  let cleanups = removals.get(el)
+  if (cleanups) {
+    cleanups.get(key)?.()
+  } else {
+    cleanups = new Map()
+    removals.set(el, cleanups)
+  }
+  cleanups.set(key, cleanup)
+}
+
 // Set up a mutation observer to run plugin removal and apply functions
 function observe(mutations: MutationRecord[]) {
   const ignore = `[${aliasify('ignore')}]`
@@ -1160,6 +1165,7 @@ function generateReactiveExpression(
   const actionMatches = [...expr.matchAll(actionsRe)]
   const actionNames = new Set<string>()
   const actionFns = new Set<(...args: any[]) => any>()
+  const actionCtx: ActionContext = { ...ctx, setCleanup: (cleanup: OnRemovalFn, key: string) => setCleanup(cleanup, ctx.el, key) }
   if (actionMatches.length) {
     const actionPrefix = `${DATASTAR}Act_`
     for (const match of actionMatches) {
@@ -1175,7 +1181,7 @@ function generateReactiveExpression(
       // Add ctx to action calls
       expr = expr.replace(`@${actionName}(`, `${name}(`)
       actionNames.add(name)
-      actionFns.add((...args: any[]) => action.fn(ctx, ...args))
+      actionFns.add((...args: any[]) => action.fn(actionCtx, ...args))
     }
   }
 
diff --git a/library/src/engine/types.ts b/library/src/engine/types.ts
index 99d40e8b..023f8d26 100644
--- a/library/src/engine/types.ts
+++ b/library/src/engine/types.ts
@@ -54,7 +54,7 @@ export type WatcherPlugin = {
 }
 
 export type ActionPlugins = Record<string, ActionPlugin>
-export type ActionMethod = (ctx: RuntimeContext, ...args: any[]) => any
+export type ActionMethod = (ctx: ActionContext, ...args: any[]) => any
 
 export type ActionPlugin = {
   type: 'action'
@@ -101,6 +101,10 @@ export type RuntimeContext = InitContext & {
   runtimeErr: (reason: string, metadata?: object) => Error
 }
 
+export type ActionContext = RuntimeContext & {
+  setCleanup: (fn: OnRemovalFn, key: string) => void // sets a cleanup function for this element and key
+}
+
 export type RuntimeExpressionFunction = (
   ctx: RuntimeContext,
   ...args: any[]
diff --git a/library/src/plugins/backend/actions/fetch.ts b/library/src/plugins/backend/actions/fetch.ts
index 5c35f0e3..e50e5a52 100644
--- a/library/src/plugins/backend/actions/fetch.ts
+++ b/library/src/plugins/backend/actions/fetch.ts
@@ -48,6 +48,7 @@ export const createHttpMethod = (
 
     if (!isDisabled && !(requestCancellation instanceof AbortController)) {
       fetchAbortControllers.set(el, controller)
+      ctx.setCleanup(() => controller.abort(), `fetch`)
     }
 
     try {