rudeshark.net/src/mfm/html-to-mfm.ts
2018-08-19 00:20:36 +09:00

77 lines
1.5 KiB
TypeScript

const parse5 = require('parse5');
export default function(html: string): string {
if (html == null) return null;
const dom = parse5.parseFragment(html);
let text = '';
dom.childNodes.forEach((n: any) => analyze(n));
return text.trim();
function getText(node: any) {
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);
// メンション
if (txt.startsWith('@')) {
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 href = new URL(node.attrs.find((x: any) => x.name == 'href').value);
const acct = txt + '@' + href.hostname;
text += acct;
break;
//#endregion
} else if (part.length == 3) {
text += txt;
break;
}
// メンション以外
} else {
text += `[${txt}](${node.attrs.find((x: any) => x.name == 'href').value})`;
}
if (node.childNodes) {
node.childNodes.forEach((n: any) => analyze(n));
}
break;
case 'p':
text += '\n\n';
if (node.childNodes) {
node.childNodes.forEach((n: any) => analyze(n));
}
break;
default:
if (node.childNodes) {
node.childNodes.forEach((n: any) => analyze(n));
}
break;
}
}
}