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a tool for shared writing and social publishing
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9.8 kB · 304 lines
TypeScript
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305import { JSDOM } from "jsdom";import { v7 } from "uuid";import { buildBlocksFromPasteHTML, type BuiltBlock,} from "src/utils/paste/htmlToBlocks";import type { FactInput } from "src/replicache/mutations";import { resolveGhostUrl } from "./parseGhostExport";
export type ImportImage = { entityID: string; url: string; // Ghost's rendered <img> carries the intrinsic size, which lets a preview // reserve the right aspect ratio before the bytes are fetched. width: number | null; height: number | null;};
export type ConvertedContent = { blocks: BuiltBlock[]; extraEntities: string[]; images: ImportImage[];};
// The paste pipeline (src/utils/paste) is written against browser globals.// Node has none, so they're installed from a jsdom window for the duration of// a synchronous conversion and removed again — leaving `document` defined on// the server would trip libraries that use it to detect a browser.let sharedDom: JSDOM | undefined;function withDomGlobals<T>(fn: () => T): T { const g = globalThis as Record<string, unknown>; if (typeof g.document !== "undefined") return fn(); sharedDom ??= new JSDOM(""); const w = sharedDom.window as unknown as Record<string, unknown>; const names = ["DOMParser", "document", "Node", "HTMLElement", "Element"]; for (const n of names) g[n] = w[n]; try { return fn(); } finally { for (const n of names) delete g[n]; }}
type Card = { type: BuiltBlock["type"]; facts: Array<{ attribute: string; data: unknown }>; image?: Omit<ImportImage, "entityID">;};type Segment = { kind: "html"; html: string } | ({ kind: "card" } & Card);
const ELEMENT_NODE = 1;const TEXT_NODE = 3;const COMMENT_NODE = 8;
const string = (attribute: string, value: string) => ({ attribute, data: { type: "string", value },});const size = (v: string | null): number | null => { const n = Number(v); return n > 0 ? n : null;};function need(el: Element, selector: string): Element { const found = el.querySelector(selector); if (!found) throw new Error(`Ghost card has no <${selector}>`); return found;}function escapeHtml(s: string) { return s.replace(/&/g, "&").replace(/</g, "<").replace(/>/g, ">");}
function imageCard(img: Element): Card { const url = img.getAttribute("src"); if (!url) throw new Error("Image without a src"); const alt = img.getAttribute("alt"); return { type: "image", facts: alt ? [string("image/alt", alt)] : [], image: { url, width: size(img.getAttribute("width")), height: size(img.getAttribute("height")), }, };}
function embedCard(iframe: Element): Card { const url = iframe.getAttribute("src"); if (!url) throw new Error("iframe without a src"); const height = size(iframe.getAttribute("height")); return { type: "embed", facts: [ string("embed/url", url), ...(height ? [ { attribute: "embed/height", data: { type: "number", value: height }, }, ] : []), ], };}
// An html card holding just an iframe is an embed; anything else is kept as// raw html.function htmlCard(container: Element): Card { const only = container.children.length === 1 ? container.firstElementChild : null; if (only?.tagName === "IFRAME") return embedCard(only); return { type: "html", facts: [string("embed/html", container.innerHTML.trim())], };}
const CARD_CLASS = /^kg-(.+)-card$/;
// Ghost "koenig" cards that map onto Leaflet blocks. Anything else tagged as a// card is refused rather than imported as something it isn't.function convertCard(el: Element): Segment[] { const kind = Array.from(el.classList) .map((c) => CARD_CLASS.exec(c)?.[1]) .find(Boolean); const cards: Segment[] = []; const card = (c: Card) => cards.push({ kind: "card", ...c }); switch (kind) { case "image": card(imageCard(need(el, "img"))); break; case "gallery": Array.from(el.querySelectorAll("img")).map(imageCard).forEach(card); break; case "embed": card(embedCard(need(el, "iframe"))); break; case "bookmark": { const url = need(el, "a[href]").getAttribute("href")!; const title = el.querySelector(".kg-bookmark-title")?.textContent?.trim(); const description = el .querySelector(".kg-bookmark-description") ?.textContent?.trim(); card({ type: "link", facts: [ string("link/url", url), ...(title ? [string("link/title", title)] : []), ...(description ? [string("link/description", description)] : []), ], }); break; } case "button": { const a = need(el, "a[href]"); const url = a.getAttribute("href")!; card({ type: "button", facts: [ string("button/text", a.textContent?.trim() || url), string("button/url", url), ], }); break; } case "callout": { const emoji = el.querySelector(".kg-callout-emoji")?.textContent?.trim(); const text = need(el, ".kg-callout-text").innerHTML; cards.push({ kind: "html", html: `<blockquote>${emoji ? emoji + " " : ""}${text}</blockquote>`, }); break; } case "signup": card({ type: "signup", facts: [] }); break; default: throw new Error(`Unsupported Ghost card "${kind ?? el.className}"`); } const caption = el.querySelector("figcaption")?.innerHTML.trim(); if (caption) cards.push({ kind: "html", html: `<p data-text-size="small">${caption}</p>`, }); return cards;}
// Split a Ghost post body into runs of ordinary HTML that the paste pipeline// understands, interleaved with cards that map to a specific Leaflet block.function segmentGhostBody(body: HTMLElement, doc: Document): Segment[] { const segments: Segment[] = []; const push = (s: Segment) => { const last = segments[segments.length - 1]; if (s.kind === "html" && last?.kind === "html") last.html += s.html; else segments.push(s); };
const nodes = Array.from(body.childNodes); for (let i = 0; i < nodes.length; i++) { const node = nodes[i]; if (node.nodeType === COMMENT_NODE) { const text = node.textContent?.trim(); // Ghost's members-only paywall card renders as a bare comment. if (text === "members-only") push({ kind: "card", type: "members-only-delimiter", facts: [] }); else if (text === "kg-card-begin: html") { const container = doc.createElement("div"); while ( ++i < nodes.length && !( nodes[i].nodeType === COMMENT_NODE && nodes[i].textContent?.trim() === "kg-card-end: html" ) ) container.appendChild(nodes[i].cloneNode(true)); push({ kind: "card", ...htmlCard(container) }); } } else if (node.nodeType === TEXT_NODE) { const text = node.textContent ?? ""; if (text.trim()) push({ kind: "html", html: `<p>${escapeHtml(text)}</p>` }); } else if (node.nodeType === ELEMENT_NODE) { const el = node as Element; if (el.tagName === "IFRAME") push({ kind: "card", ...embedCard(el) }); else if (el.tagName === "IMG") push({ kind: "card", ...imageCard(el) }); else if (el.classList.contains("kg-card")) convertCard(el).forEach(push); else push({ kind: "html", html: el.outerHTML }); } } return segments;}
export function ghostHtmlToBlocks( html: string, opts: { siteUrl: string; parent: string },): ConvertedContent { const dom = new JSDOM(`<body>${resolveGhostUrl(html, opts.siteUrl)}</body>`); const doc = dom.window.document; // Ghost leaves stray empty paragraphs behind, and keeps responsive variants // in srcset that the paste parser would otherwise pick up. for (const p of Array.from(doc.querySelectorAll("p"))) if (!p.textContent?.trim() && p.children.length === 0) p.remove(); for (const img of Array.from(doc.querySelectorAll("img"))) { img.removeAttribute("srcset"); img.removeAttribute("sizes"); // The paste pipeline only keeps images that stand as blocks of their own; // Ghost's markdown cards render each `![]()` inside a paragraph. const p = img.parentElement; if (p?.tagName !== "P") continue; if (p.textContent?.trim() || p.children.length !== 1) throw new Error(`Inline image ${img.getAttribute("src")} in a paragraph`); p.replaceWith(img); }
const content: ConvertedContent = { blocks: [], extraEntities: [], images: [], }; for (const seg of segmentGhostBody(doc.body, doc)) { if (seg.kind === "html") { const result = withDomGlobals(() => // Only the ids of extra entities are used; they join the leaflet's // entity set on insert. buildBlocksFromPasteHTML(seg.html, { parent: opts.parent, permission_set: "", }), ); content.blocks.push(...result.blocks); content.extraEntities.push( ...result.extraEntities.map((e) => e.entityID), ); content.images.push( ...result.imageTasks.map((t) => ({ entityID: t.entityID, url: t.url, width: null, height: null, })), ); } else { const entityID = v7(); content.blocks.push({ entityID, parent: opts.parent, type: seg.type, facts: [ { entity: entityID, attribute: "block/type", data: { type: "block-type-union", value: seg.type }, }, ...seg.facts.map((f) => ({ ...f, entity: entityID })), ] as FactInput[], }); if (seg.image) content.images.push({ entityID, ...seg.image }); } } return content;}