Async Workflows and Source Panels

Callback Router Panel

Use a typed callback map to route work while replay keeps the panel in order.

callback router A callback map keeps branch logic explicit and lets replay show which handler updated the result.

Callback Router Panel

mode
callback_router.ts
Replay: real traced execution (multi-file project)
type Mode = "status" | "refresh" | "archive";
type Handler = (mode: Mode) => string;

const mode: Mode = "status";
let access: string = "";
let handled: string = "";

const handlers: Record<Mode, Handler> = {
    status: (current: Mode) => `handled:${current}`,
    refresh: (current: Mode) => `cache:${current}`,
    archive: (current: Mode) => `queue:${current}`
};

function checkAccess(current: Mode): void {
    if (current === "archive") {
        access = "review";
    } else {
        access = "ok";
    }
}

checkAccess(mode);
handled = handlers[mode](mode);

console.log(`mode=${mode}`);
console.log(`access=${access}`);
console.log(handled);

type Mode = "status" | "refresh" | "archive";
type Handler = (mode: Mode) => string;

const mode: Mode = "refresh";
let access: string = "";
let handled: string = "";

const handlers: Record<Mode, Handler> = {
    status: (current: Mode) => `handled:${current}`,
    refresh: (current: Mode) => `cache:${current}`,
    archive: (current: Mode) => `queue:${current}`
};

function checkAccess(current: Mode): void {
    if (current === "archive") {
        access = "review";
    } else {
        access = "ok";
    }
}

checkAccess(mode);
handled = handlers[mode](mode);

console.log(`mode=${mode}`);
console.log(`access=${access}`);
console.log(handled);

type Mode = "status" | "refresh" | "archive";
type Handler = (mode: Mode) => string;

const mode: Mode = "archive";
let access: string = "";
let handled: string = "";

const handlers: Record<Mode, Handler> = {
    status: (current: Mode) => `handled:${current}`,
    refresh: (current: Mode) => `cache:${current}`,
    archive: (current: Mode) => `queue:${current}`
};

function checkAccess(current: Mode): void {
    if (current === "archive") {
        access = "review";
    } else {
        access = "ok";
    }
}

checkAccess(mode);
handled = handlers[mode](mode);

console.log(`mode=${mode}`);
console.log(`access=${access}`);
console.log(handled);

  1. mode ← status, access ← (empty), handled ← (empty), handlers ← [object Object]

    1type Mode = "status" | "refresh" | "archive";2type Handler = (mode: Mode) => string;34const mode→ status: Mode = "status";  //@mode="refresh", "archive"5let access→ (empty): string = "";6let handled→ (empty): string = "";78const handlers→ [object Object]: Record<Mode, Handler> = {9    status: (current: Mode) => `handled:${current}`,10    refresh: (current: Mode) => `cache:${current}`,11    archive: (current: Mode) => `queue:${current}`12};1314function checkAccess(current: Mode): void {15    if (current === "archive") {16        access = "review";17    } else {18        access = "ok";19    }20}2122checkAccess(modestatus);23handled = handlers[mode](mode);

  2. function checkAccess(current: Mode): void

    11    archive: (current: Mode) => `queue:${current}`12};1314function checkAccess(currentstatus: Mode): void {15    if (current === "archive") {

  3. handled ← handled:status

    19    }20}2122checkAccess(modestatus);23handled = handlers[object Object][modestatus](mode);2425console.log(`mode=${modestatus}`);26console.log(`access=${accessok}`);27console.log(handledhandled:status);
    outputmode=status
access=ok
handled:status

  1. mode ← refresh, access ← (empty), handled ← (empty), handlers ← [object Object]

    1type Mode = "status" | "refresh" | "archive";2type Handler = (mode: Mode) => string;34const mode→ refresh: Mode = "refresh";5let access→ (empty): string = "";6let handled→ (empty): string = "";78const handlers→ [object Object]: Record<Mode, Handler> = {9    status: (current: Mode) => `handled:${current}`,10    refresh: (current: Mode) => `cache:${current}`,11    archive: (current: Mode) => `queue:${current}`12};1314function checkAccess(current: Mode): void {15    if (current === "archive") {16        access = "review";17    } else {18        access = "ok";19    }20}2122checkAccess(moderefresh);23handled = handlers[mode](mode);

  2. function checkAccess(current: Mode): void

    11    archive: (current: Mode) => `queue:${current}`12};1314function checkAccess(currentrefresh: Mode): void {15    if (current === "archive") {

  3. handled ← cache:refresh

    19    }20}2122checkAccess(moderefresh);23handled = handlers[object Object][moderefresh](mode);2425console.log(`mode=${moderefresh}`);26console.log(`access=${accessok}`);27console.log(handledcache:refresh);
    outputmode=refresh
access=ok
cache:refresh

  1. mode ← archive, access ← (empty), handled ← (empty), handlers ← [object Object]

    1type Mode = "status" | "refresh" | "archive";2type Handler = (mode: Mode) => string;34const mode→ archive: Mode = "archive";5let access→ (empty): string = "";6let handled→ (empty): string = "";78const handlers→ [object Object]: Record<Mode, Handler> = {9    status: (current: Mode) => `handled:${current}`,10    refresh: (current: Mode) => `cache:${current}`,11    archive: (current: Mode) => `queue:${current}`12};1314function checkAccess(current: Mode): void {15    if (current === "archive") {16        access = "review";17    } else {18        access = "ok";19    }20}2122checkAccess(modearchive);23handled = handlers[mode](mode);

  2. function checkAccess(current: Mode): void

    11    archive: (current: Mode) => `queue:${current}`12};1314function checkAccess(currentarchive: Mode): void {15    if (current === "archive") {

  3. if (current === "archive")

    14function checkAccess(current: Mode): void {15    if (currentarchive === "archive") {16        access = "review";17    } else {

  4. handled ← queue:archive

    19    }20}2122checkAccess(modearchive);23handled = handlers[object Object][modearchive](mode);2425console.log(`mode=${modearchive}`);26console.log(`access=${accessreview}`);27console.log(handledqueue:archive);
    outputmode=archive
access=review
queue:archive