File size: 3,422 Bytes
0815e01 66fd359 0815e01 66fd359 0815e01 66fd359 b6f5bc4 66fd359 0815e01 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 | import { track } from "./busy.js";
import { onSignOut, token } from "./session.js";
export class ApiError extends Error {
constructor(status, message) { super(message); this.status = status; }
}
const MESSAGES = { 503: "砖讬专讜转 讛讛转讞讘专讜转 诇讗 讝诪讬谉 讻专讙注, 谞住讜 砖讜讘 讘注讜讚 专讙注", 403: "讗讬谉 讛专砖讗讛 诇驻注讜诇讛 讛讝讜" };
const remembered = new Map(); // GET path -> the last answer
let changes = 0; // counts changes, so an answer to a read that began before one is not kept
onSignOut(() => { remembered.clear(); changes++; });
async function request(path, { method = "GET", body } = {}) {
const started = changes;
if (method !== "GET") { remembered.clear(); changes++; } // after a change of theirs, no old answer is ever shown
const headers = { Authorization: "Bearer " + await token() };
if (body !== undefined) headers["Content-Type"] = "application/json";
const response = await fetch(path, { method, headers, body: body === undefined ? undefined : JSON.stringify(body) });
if (response.ok) {
const data = response.status === 204 ? null : await response.json();
if (method === "GET") { if (started === changes) remembered.set(path, data); }
else { remembered.clear(); changes++; }
return data;
}
let detail = "";
try { detail = (await response.json()).detail; } catch { /* no body */ }
if (detail && typeof detail === "object" && typeof detail.message === "string") { // {message, problems}: a refusal with its list
const error = new ApiError(response.status, detail.message);
error.problems = Array.isArray(detail.problems) ? detail.problems : [];
throw error;
}
throw new ApiError(response.status, typeof detail === "string" && detail ? detail : (MESSAGES[response.status] || "诪砖讛讜 讛砖转讘砖, 谞住讜 砖讜讘"));
}
/** A request to the server. The button that was just pressed shows it is working if the answer takes a moment (busy.js). */
export const api = (path, options) => track(request(path, options));
/** The last answer for this GET path, or undefined (nothing yet, or something was changed since). */
export const lastAnswer = path => remembered.get(path);
let screen = 0;
const busyNow = () => {
const here = document.activeElement;
return !!(here && here.matches?.("input, textarea, select, [contenteditable]")) || !!document.querySelector("main details[open], .sheet, dialog[open]");
};
/** Shows a screen: draws `render(data)` at once from the last answer if there is one, then draws again when the fresh answer
* differs, unless the person has moved on, is typing, or has something open. Without a last answer it waits, as before.
* `path` may be a list: then `render` gets the answers as a list. */
export async function swr(path, render) {
const paths = Array.isArray(path) ? path : [path], one = !Array.isArray(path);
const give = list => render(one ? list[0] : list);
const mine = ++screen, hash = location.hash, before = paths.map(p => remembered.get(p));
if (before.some(x => x === undefined)) return give(await Promise.all(paths.map(p => api(p))));
give(before);
Promise.all(paths.map(p => api(p))).then(fresh => {
if (mine === screen && hash === location.hash && JSON.stringify(fresh) !== JSON.stringify(before) && !busyNow()) give(fresh);
}).catch(() => { /* the screen already shows what it knew */ });
}
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