og-images-generator/dist/plugins/connect-middleware.js

Generate OG images from a static folder and / or a middleware. Extract metadata from HTML pages. No headless browser involved. Comes as a CLI, API or plugins.

import { extractMetadataFromHtml } from '../collect.js';
import { loadUserConfig } from '../generate.js';
import { ogPathToPagePath, DEFAULT_OG_PATH_PREFIX } from '../paths.js';
import { renderOgImage } from '../render.js';
export async function connectOgImagesGenerator(options) {
    let config = options?.configReloader
        ? null
        : await loadUserConfig();
    const prefix = options?.pathPrefix ?? DEFAULT_OG_PATH_PREFIX;
    return async (request, res, next) => {
        if (options?.configReloader)
            config = await options.configReloader();
        if (!config)
            return next();
        if (!request.url)
            return next();
        if (request.url.startsWith(prefix) === false)
            return next();
        const base = 'http://' + request.rawHeaders[request.rawHeaders.indexOf('Host') + 1];
        const path = ogPathToPagePath(request.url, options?.pathPrefix, options?.trailingSlash);
        const pageUrl = new URL(path, base).href;
        const fetched = await fetch(pageUrl);
        const associatedPageHtml = await fetched.text();
        const meta = extractMetadataFromHtml(associatedPageHtml);
        const image = await renderOgImage(config, { path, meta });
        res.setHeader('Content-Type', 'image/png');
        // HACK:
        await new Promise((resolve) => setTimeout(() => {
            res.end(image);
            resolve();
        }, 0));
    };
}