History Manager v1.0.60

singleton

Global singleton that records the full ILocus snapshot of every locus the user has visited (including mode / DNA window / RNA identity / assembly). Keeps at most the 20 most recent entries (the MAX_HISTORY constant). Completely independent of favouriteManager.

import { historyManager } from "@rbrowser/main";

Switched to ILocus storage since v1.0.50

Older versions (≤ v1.0.49) stored a bare region string plus assembly metadata. The new version stores the full ILocus, and the attached mode field lets users distinguish the RNA / DNA / CDS ways of opening the same gene within the history.

Legacy entries in localStorage (key tbrowser_history_v1) are migrated automatically on load (string → ILocus, timestamp → ISO string), so users' bookmarks are never lost.

API aligned with favouriteManager

Since v1.0.51, historyManager's method names, signatures, and event shapes match favouriteManager—on / has / hasKey / getAll / count / remove (returns boolean) / removeKey / clear—so callers can treat both managers as the same interface. The only thing missing is toggle() ("visited" has no toggle semantics), and add() returns void.

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Method

add

method

historyManager.add(locus: ILocus): void

Records a visit and returns void. An existing entry with the same key (the mode-aware identity of ILocus) is removed first and re-inserted at the front—so visiting the same identity multiple times leaves only the latest entry. Once there are more than MAX_HISTORY (20) entries, the oldest is discarded automatically.

const locus = renderer.locusManager.getLocus();
historyManager.add(locus);

Parameter	Type	Required	Description
locus	ILocus	✓	Usually pass the return value of renderer.locusManager.getLocus() directly

Why ILocus instead of a string

ILocus carries its own mode / assembly / time / id, far more complete than "a region string plus an assembly argument alongside it." The current position can always be fetched on demand via renderer.locusManager.getLocus().

has / hasKey

method

historyManager.has(locus: ILocus): boolean
historyManager.hasKey(key: string): boolean

Checks whether the same record already exists in the history by its mode-aware identity key. Use hasKey() when you already have the key string—it saves a computation.

getAll

method

historyManager.getAll(): ILocus[]

Returns the entire history in reverse chronological order (newest first). It is already capped internally to 20 entries by MAX_HISTORY, so you can render it directly.

historyManager.getAll().forEach((locus) => {
  console.log(
    `[${locus.mode.toUpperCase()}]`,
    locus.dna.chr ? `${locus.dna.chr}:${locus.dna.start}-${locus.dna.end}` : locus.rna.trans_name,
    `@`, locus.dna.assembly || locus.rna.assembly,
    `(${locus.time})`,
  );
});

count

getter

historyManager.count: number

The current number of history entries (at most MAX_HISTORY = 20).

remove / removeKey

method

historyManager.remove(locus: ILocus): boolean
historyManager.removeKey(key: string): boolean

Removes by identity key and returns whether an entry was actually removed. Use removeKey() when you already have the key to save a computation.

clear

method

historyManager.clear(): void

Clears all history (does not affect favourites).

on

method

historyManager.on(listener: HistoryListener): () => void

Subscribes to history events and returns an unsubscribe function.

const unsubscribe = historyManager.on((event, detail) => {
  switch (event) {
    case "add":
    case "remove":
      console.log(event, detail?.key);
      // detail.locus is the full ILocus snapshot
      break;
    case "clear":
      console.log("History cleared");
      break;
  }
});
unsubscribe();

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Event

event

Event	Trigger	detail fields
"add"	Every add() (including same-key replacement)	locus, key
"remove"	remove() / removeKey() actually removed an entry	locus, key
"clear"	clear() is called	——

HistoryEvent / HistoryListener

type

type HistoryEvent = "add" | "remove" | "clear";

type HistoryListener = (
  event: HistoryEvent,
  detail?: {
    locus?: ILocus;
    key?: string;
  },
) => void;