app/lib/editor/draft-buffer.ts

Functions

Imports

It imports no other module of this repo. Imported by app/components/admin/post-editor.tsx, app/components/admin/use-draft-buffer.ts.

Source

1// Local only: save equals commit, so a server autosave would write git history every few seconds.
2// The key carries the base commit so a buffer written over commit A is never restored over B.
3
4export type DraftBuffer = {
5  at: string;
6  fields: Record<string, string>;
7};
8
9/** Session fields, never restored: a stale headSha would be a precondition from a page load that is over. */
10const NOT_AUTHORED = new Set(["headSha", "isNew", "firstPublished", "intent"]);
11
12export function draftKey(slug: string, headSha: string) {
13  return `post-draft:${slug || "new"}:${headSha || "detached"}`;
14}
15
16export function readForm(form: HTMLFormElement): Record<string, string> {
17  const out: Record<string, string> = {};
18  for (const [key, value] of new FormData(form).entries()) {
19    if (typeof value === "string" && !NOT_AUTHORED.has(key)) out[key] = value;
20  }
21  return out;
22}
23
24export function writeBuffer(key: string, fields: Record<string, string>): string | null {
25  try {
26    const at = new Date().toISOString();
27    window.localStorage.setItem(key, JSON.stringify({ at, fields } satisfies DraftBuffer));
28    return at;
29  } catch {
30    // Private mode, quota, or storage disabled: the editor works without a crash net.
31    return null;
32  }
33}
34
35export function readBuffer(key: string): DraftBuffer | null {
36  try {
37    const raw = window.localStorage.getItem(key);
38    if (!raw) return null;
39    const parsed = JSON.parse(raw) as DraftBuffer;
40    return parsed && typeof parsed.at === "string" && parsed.fields ? parsed : null;
41  } catch {
42    return null;
43  }
44}
45
46export function clearAllBuffersFor(slug: string) {
47  try {
48    const prefix = `post-draft:${slug || "new"}:`;
49    const doomed: string[] = [];
50    for (let i = 0; i < window.localStorage.length; i += 1) {
51      const key = window.localStorage.key(i);
52      if (key && key.startsWith(prefix)) doomed.push(key);
53    }
54    for (const key of doomed) window.localStorage.removeItem(key);
55  } catch {
56    // Storage unavailable: nothing to clear.
57  }
58}
59
60/** A slug cannot contain a colon, so a two-segment key is the legacy scheme that carried no base commit. */
61export function purgeLegacyBuffers() {
62  try {
63    const doomed: string[] = [];
64    for (let i = 0; i < window.localStorage.length; i += 1) {
65      const key = window.localStorage.key(i);
66      if (!key || !key.startsWith("post-draft:")) continue;
67      if (key.split(":").length === 2) doomed.push(key);
68    }
69    for (const key of doomed) window.localStorage.removeItem(key);
70    return doomed.length;
71  } catch {
72    return 0;
73  }
74}
75
76/** A buffer matching the committed file is noise, and offering it would train the author to dismiss the banner. */
77export function bufferDiffers(
78  buffer: DraftBuffer,
79  current: Record<string, string>,
80): boolean {
81  const keys = new Set([...Object.keys(buffer.fields), ...Object.keys(current)]);
82  for (const key of keys) {
83    if ((buffer.fields[key] ?? "") !== (current[key] ?? "")) return true;
84  }
85  return false;
86}