davideicardi/oembed-webtask.js

## oembed-webtask.js
'use latest';

import express from 'express';
import { fromExpress } from 'webtask-tools';
import bodyParser from 'body-parser';
import request from 'request';
import cheerio from 'cheerio';
import escapeHtml from 'escape-html';

const app = express();

app.use(bodyParser.json());

app.get('/', (req, res) => {

  const renderUrl = req.query.render;
  if (renderUrl) {
    oEmbed(renderUrl, (err, data) => {
      if (err) {
        return res.status(500).send(err.message);
      }

      home(res, data);
    });
  } else {
    home(res);
  }
});


app.get('/*', (req, res) => {
  const url = getUrlToEmbed(req);

  oEmbed(url, (err, data) => {
    if (err) {
      return res.status(500).send(err.message);
    }
    res.json(data);
  });
});

module.exports = fromExpress(app);

function home(res, oEmbedPreview) {
  const HTML = renderView({
    title: 'oEmbed creator',
    body: renderHome(oEmbedPreview)
  });

  res.set('Content-Type', 'text/html');
  res.status(200).send(HTML);
}

function oEmbed(url, cb) {
  discoverOEmbed(url, (err, oEmbedUrl) => {
    if (err) {
      return res.status(500).send(err.message);
    }

    getOEmbedData(oEmbedUrl, (err, data) => {
      if (err) {
        return res.status(500).send(err.message);
      }

      cb(undefined, data);
    });
  });
}

function getOEmbedData(url, cb) {
  request.get({url, json:true}, (error, response, body) => {
    if (error) {
      return cb(error);
    }
    if (response && response.statusCode >= 300) {
      return cb(new Error(`Invalid response ${response.statusCode}`));
    }

    cb(undefined, body);
  });
}

function discoverOEmbed(url, cb) {
  request.get({url}, (error, response, body) => {
    if (error) {
      return cb(error);
    }
    if (response && response.statusCode >= 300) {
      return cb(new Error(`Invalid response ${response.statusCode}`));
    }

    const $ = cheerio.load(body);

    const oEmbedLink = $('link[type="application/json+oembed"]');
    const oEmbedUrl = oEmbedLink.attr('href');
    if (!oEmbedUrl) { // oEmbed auto discovery failed
      // TODO Here I can try to understand how to oembed based on the url
      //  something similar to https://iframely.com/
      return cb(new Error("oEmbed discovery link not found"));
    }

    cb(undefined, oEmbedUrl);
  });
}

function getUrlToEmbed(req) {
  const url = req.originalUrl;
  const slashIndex = url.indexOf('/', 1);

  return url.substr(slashIndex + 1);
}

function renderHome(oEmbedData) {
  return `
  <h1>oEmbed creator</h1>
  <form method="GET">
    <label>Url</label>
    <input name="render" value="https://www.flickr.com/photos/bees/2341623661/" />
    <button type="submit">Render</button>
  </form>
  <p>Examples:</p>
  <ul>
    <li>https://www.flickr.com/photos/bees/2341623661/</li>
    <li>https://www.youtube.com/watch?v=8SbUC-UaAxE</li>
  </ul>
  <div>
    <a href="https://oembed.com/" target="blank">More info on oEmbed</a>
  </div>
  <pre>${escapeHtml(JSON.stringify(oEmbedData || {}, null, '\t'))}</pre>
  <div>
    ${(oEmbedData && oEmbedData.html) || ""}
  </div>
  `;
}

function renderView(locals) {
  return `
    <!DOCTYPE html>
    <html>
    <head>
      <meta charset="utf-8">
      <title>${locals.title}</title>
    </head>

    <body>
      ${locals.body}
    </body>
    </html>
  `;
}
	'use latest';

	import express from 'express';
	import { fromExpress } from 'webtask-tools';
	import bodyParser from 'body-parser';
	import request from 'request';
	import cheerio from 'cheerio';
	import escapeHtml from 'escape-html';

	const app = express();

	app.use(bodyParser.json());

	app.get('/', (req, res) => {

	const renderUrl = req.query.render;
	if (renderUrl) {
	oEmbed(renderUrl, (err, data) => {
	if (err) {
	return res.status(500).send(err.message);
	}

	home(res, data);
	});
	} else {
	home(res);
	}
	});


	app.get('/*', (req, res) => {
	const url = getUrlToEmbed(req);

	oEmbed(url, (err, data) => {
	if (err) {
	return res.status(500).send(err.message);
	}
	res.json(data);
	});
	});

	module.exports = fromExpress(app);

	function home(res, oEmbedPreview) {
	const HTML = renderView({
	title: 'oEmbed creator',
	body: renderHome(oEmbedPreview)
	});

	res.set('Content-Type', 'text/html');
	res.status(200).send(HTML);
	}

	function oEmbed(url, cb) {
	discoverOEmbed(url, (err, oEmbedUrl) => {
	if (err) {
	return res.status(500).send(err.message);
	}

	getOEmbedData(oEmbedUrl, (err, data) => {
	if (err) {
	return res.status(500).send(err.message);
	}

	cb(undefined, data);
	});
	});
	}

	function getOEmbedData(url, cb) {
	request.get({url, json:true}, (error, response, body) => {
	if (error) {
	return cb(error);
	}
	if (response && response.statusCode >= 300) {
	return cb(new Error(`Invalid response ${response.statusCode}`));
	}

	cb(undefined, body);
	});
	}

	function discoverOEmbed(url, cb) {
	request.get({url}, (error, response, body) => {
	if (error) {
	return cb(error);
	}
	if (response && response.statusCode >= 300) {
	return cb(new Error(`Invalid response ${response.statusCode}`));
	}

	const $ = cheerio.load(body);

	const oEmbedLink = $('link[type="application/json+oembed"]');
	const oEmbedUrl = oEmbedLink.attr('href');
	if (!oEmbedUrl) { // oEmbed auto discovery failed
	// TODO Here I can try to understand how to oembed based on the url
	// something similar to https://iframely.com/
	return cb(new Error("oEmbed discovery link not found"));
	}

	cb(undefined, oEmbedUrl);
	});
	}

	function getUrlToEmbed(req) {
	const url = req.originalUrl;
	const slashIndex = url.indexOf('/', 1);

	return url.substr(slashIndex + 1);
	}

	function renderHome(oEmbedData) {
	return `
	<h1>oEmbed creator</h1>
	<form method="GET">
	<label>Url</label>
	<input name="render" value="https://www.flickr.com/photos/bees/2341623661/" />
	<button type="submit">Render</button>
	</form>
	<p>Examples:</p>
	<ul>
	<li>https://www.flickr.com/photos/bees/2341623661/</li>
	<li>https://www.youtube.com/watch?v=8SbUC-UaAxE</li>
	</ul>
	<div>
	<a href="https://oembed.com/" target="blank">More info on oEmbed</a>
	</div>
	<pre>${escapeHtml(JSON.stringify(oEmbedData \|\| {}, null, '\t'))}</pre>
	<div>
	${(oEmbedData && oEmbedData.html) \|\| ""}
	</div>
	`;
	}

	function renderView(locals) {
	return `
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<title>${locals.title}</title>
	</head>

	<body>
	${locals.body}
	</body>
	</html>
	`;
	}