RSS

Val Town can both parse and generate RSS feeds for blogs and other updated sources.

Polling RSS

You would run this example in val town as a Scheduled val that ran on a regular interval, and it would check a blog’s feed every 15 minutes.

Polling example

import { email } from "https://esm.town/v/std/email?v=9";
import { newRSSItems } from "https://esm.town/v/stevekrouse/newRSSItems";
import { rssFeeds } from "https://esm.town/v/stevekrouse/rssFeeds";

export async function pollRSSFeeds({ lastRunAt }: Interval) {
  return Promise.all(
    Object.entries(rssFeeds).map(async ([name, url]) => {
      let items = await newRSSItems({
        url,
        lastRunAt,
      });
      if (items.length)
        await email({
          text: JSON.stringify(items, null, 2),
          subject: `New from ${name} RSS`,
        });
      return { name, items };
    }),
  );
}

Creating RSS

Creating example

import { dataToRSS } from "https://esm.town/v/stevekrouse/dataToRSS";
import { valTownBlogJSON } from "https://esm.town/v/stevekrouse/valTownBlogJSON";

export async function valTownBlogRSS() {
  const json = await valTownBlogJSON();
  return dataToRSS(
    json.map((blog) => ({
      title: blog.title,
      link: blog.url,
      pubDate: blog.date,
    })),
    {
      title: "Val Town Blog",
      link: "https://blog.val.town",
      rssLink: "https://stevekrouse-blogrss.web.val.run/",
    },
  );
}