egirlskey/src/mfm/fromHtml.ts
2020-04-04 08:46:54 +09:00

79 lines
1.8 KiB
TypeScript

import { parseFragment, DefaultTreeDocumentFragment } from 'parse5';
import { urlRegex } from './prelude';
export function fromHtml(html: string, hashtagNames?: string[]): string {
const dom = parseFragment(html) as DefaultTreeDocumentFragment;
let text = '';
for (const n of dom.childNodes) {
analyze(n);
}
return text.trim();
function getText(node: any): string {
if (node.nodeName === '#text') return node.value;
if (node.childNodes) {
return node.childNodes.map((n: any) => getText(n)).join('');
}
return '';
}
function analyze(node: any) {
switch (node.nodeName) {
case '#text':
text += node.value;
break;
case 'br':
text += '\n';
break;
case 'a':
const txt = getText(node);
const rel = node.attrs.find((x: any) => x.name === 'rel');
const href = node.attrs.find((x: any) => x.name === 'href');
// ハッシュタグ
if (hashtagNames && href && hashtagNames.map(x => x.toLowerCase()).includes(txt.toLowerCase())) {
text += txt;
// メンション
} else if (txt.startsWith('@') && !(rel && rel.value.match(/^me /))) {
const part = txt.split('@');
if (part.length === 2) {
//#region ホスト名部分が省略されているので復元する
const acct = `${txt}@${(new URL(href.value)).hostname}`;
text += acct;
//#endregion
} else if (part.length === 3) {
text += txt;
}
// その他
} else {
text += (!href || (txt === href.value && txt.match(urlRegex))) ? txt : `[${txt}](${href.value})`;
}
break;
case 'p':
text += '\n\n';
if (node.childNodes) {
for (const n of node.childNodes) {
analyze(n);
}
}
break;
default:
if (node.childNodes) {
for (const n of node.childNodes) {
analyze(n);
}
}
break;
}
}
}