app/lib/editor/preview-link-action.server.ts

Functions

Imports

It imports app/lib/content/slug.mjs, app/lib/editor/frontmatter.ts, app/lib/editor/github.server.ts, app/lib/error-message.mjs, app/lib/preview-links.server.ts, app/lib/preview-token.mjs. Imported by app/routes/admin.posts.$slug.edit.tsx.

Source

1import { postPath } from "~/lib/content/slug.mjs";
2import { parsePost } from "~/lib/editor/frontmatter";
3import { readFile } from "~/lib/editor/github.server";
4import { errorMessage } from "~/lib/error-message.mjs";
5import { createPreviewLink, revokePreviewLink } from "~/lib/preview-links.server";
6import { previewUrl } from "~/lib/preview-token.mjs";
7
8/**
9 * The editor's preview-link sub-router: mint a link for a draft, or revoke one.
10 *
11 * `createdBy` is a thunk because the admin session is read only in the route's action (check:policy
12 * holds it there), and only when a link is minted: a revoke never reads it.
13 */
14export async function previewLinkAction(
15  env: Env,
16  {
17    intent,
18    slug,
19    origin,
20    form,
21    createdBy,
22    headAfterProblem,
23  }: {
24    intent: "preview-link" | "revoke-preview-link";
25    slug: string;
26    origin: string;
27    form: FormData;
28    createdBy: () => string;
29    headAfterProblem: () => Promise<string>;
30  },
31) {
32  const problem = async (message: string) => ({
33    kind: "problem" as const,
34    /* These forms carry no body, so the editor keeps the loaded fields rather than an empty post. */
35    fields: undefined,
36    problem: { message, conflict: false, field: undefined, line: undefined },
37    headSha: await headAfterProblem(),
38  });
39
40  if (intent === "preview-link") {
41    /*
42     * Server side, not just the UI: minting a capability must not trust the absence of a button.
43     * The committed file is the authority, because the form is the author's unsaved draft.
44     */
45    const committed = await readFile(env, postPath(slug));
46    if (!committed) return problem(`No post file exists for "${slug}".`);
47    if (parsePost(committed.content).draft !== true) {
48      return problem(
49        "Preview links are only for drafts. This post is already public, so " +
50          "its URL is the link.",
51      );
52    }
53
54    try {
55      const link = await createPreviewLink(env, {
56        slug,
57        createdBy: createdBy(),
58      });
59      return {
60        kind: "preview-link" as const,
61        url: previewUrl(origin, link.token),
62        expiresAt: link.expiresAt,
63      };
64    } catch (error) {
65      return problem(
66        `The preview link could not be created: ${errorMessage(error)}`,
67      );
68    }
69  }
70
71  /* Revoke is not draft-gated: removing access must never be blocked by a stale page. */
72  try {
73    await revokePreviewLink(env, {
74      slug,
75      token: String(form.get("token") ?? ""),
76    });
77    return { kind: "preview-link-revoked" as const };
78  } catch (error) {
79    return problem(
80      `The preview link could not be revoked: ${errorMessage(error)}`,
81    );
82  }
83}