RSS feed for channels

## Issue
3779 RSS feed for channels

## Initial implementation details
- RSS only (not atom)
- Grabs latest 10 entries (Beamer have concerns)

## Credit
Referenced the community version mentioned in 3779

package.json

@@ -53,6 +53,7 @@
     "electron-notarize": "^1.0.0",
     "electron-updater": "^4.2.4",
     "express": "^4.17.1",
+    "feed": "^4.2.2",
     "if-env": "^1.0.4",
     "react-datetime-picker": "^3.2.1",
     "react-top-loading-bar": "^2.0.1",

ui/component/claimMenuList/view.jsx

@@ -7,7 +7,7 @@ import React from 'react';
 import classnames from 'classnames';
 import { Menu, MenuButton, MenuList, MenuItem } from '@reach/menu-button';
 import Icon from 'component/common/icon';
-import { generateShareUrl } from 'util/url';
+import { generateShareUrl, generateRssUrl } from 'util/url';
 import { useHistory } from 'react-router';
 import { buildURI, parseURI, COLLECTIONS_CONSTS } from 'lbry-redux';
 
@@ -103,6 +103,7 @@ function ClaimMenuList(props: Props) {
   }
 
   const shareUrl: string = generateShareUrl(SHARE_DOMAIN, uri);
+  const rssUrl: string = generateRssUrl(SHARE_DOMAIN, uri);
   const isCollectionClaim = claim && claim.value_type === 'collection';
   // $FlowFixMe
   const isPlayable =
@@ -182,6 +183,10 @@ function ClaimMenuList(props: Props) {
     }
   }
 
+  function handleCopyRssLink() {
+    navigator.clipboard.writeText(rssUrl);
+  }
+
   function handleCopyLink() {
     navigator.clipboard.writeText(shareUrl);
   }
@@ -350,7 +355,18 @@ function ClaimMenuList(props: Props) {
             )}
           </>
         )}
+
         <hr className="menu__separator" />
+
+        {isChannelPage && (
+          <MenuItem className="comment__menu-option" onSelect={handleCopyRssLink}>
+            <div className="menu__link">
+              <Icon aria-hidden icon={ICONS.SHARE} />
+              {__('Copy RSS URL')}
+            </div>
+          </MenuItem>
+        )}
+
         <MenuItem className="comment__menu-option" onSelect={handleCopyLink}>
           <div className="menu__link">
             <Icon aria-hidden icon={ICONS.SHARE} />

ui/util/url.js

@@ -147,3 +147,9 @@ export const generateShareUrl = (
   const url = `${domain}/${lbryWebUrl}` + (urlParamsString === '' ? '' : `?${urlParamsString}`);
   return url;
 };
+
+export const generateRssUrl = (domain, lbryUrl) => {
+  const { channelName, channelClaimId } = parseURI(lbryUrl);
+  const url = `${domain}/$/rss/@${channelName}/${channelClaimId}`;
+  return url;
+};

web/src/chainquery.js

@@ -9,7 +9,7 @@ const pool = mysql.createPool({
 });
 
 function queryPool(sql, params) {
-  return new Promise(resolve => {
+  return new Promise((resolve) => {
     pool.query(sql, params, (error, rows) => {
       if (error) {
         console.log('error', error); // eslint-disable-line
@@ -58,3 +58,21 @@ module.exports.getClaim = async function getClaim(claimName, claimId, channelNam
 
   return queryPool(sql, params);
 };
+
+module.exports.getChannelClaim = async function getChannelClaim(channelClaimId) {
+  const params = [];
+  const select = ['claim_id', 'name', 'title', 'thumbnail_url', 'description'].join(', ');
+
+  const sql = `SELECT ${select} FROM claim WHERE claim_id = "${channelClaimId}"`;
+  return queryPool(sql, params);
+};
+
+module.exports.getClaimsFromChannel = async function getClaimsFromChannel(channelClaimId, count = 10) {
+  const params = [];
+  const select = ['claim_id', 'name', 'title', 'thumbnail_url', 'description', 'created_at'].join(', ');
+  const sort = 'ORDER BY created_at DESC';
+  const limit = `LIMIT ${count}`;
+
+  const sql = `SELECT ${select} FROM claim WHERE publisher_id = "${channelClaimId}" ${sort} ${limit}`;
+  return queryPool(sql, params);
+};

web/src/routes.js

@@ -1,4 +1,5 @@
 const { getHtml } = require('./html');
+const { getRss } = require('./rss');
 const { generateStreamUrl } = require('../../ui/util/web');
 const fetch = require('node-fetch');
 const Router = require('@koa/router');
@@ -42,6 +43,12 @@ router.get(`/$/stream/:claimName/:claimId`, async (ctx) => {
   ctx.redirect(streamUrl);
 });
 
+router.get(`/$/rss/:claimName/:claimId`, async (ctx) => {
+  const xml = await getRss(ctx);
+  ctx.set('Content-Type', 'application/rss+xml');
+  ctx.body = xml;
+});
+
 router.get('*', async (ctx) => {
   const html = await getHtml(ctx);
   ctx.body = html;

web/src/rss.js

@@ -0,0 +1,64 @@
+const { URL, SITE_NAME } = require('../../config.js');
+const { getChannelClaim, getClaimsFromChannel } = require('./chainquery');
+const Feed = require('feed').Feed;
+
+async function getChannelClaimFromChainquery(claimId) {
+  const rows = await getChannelClaim(claimId);
+  if (rows && rows.length) {
+    const claim = rows[0];
+    return claim;
+  }
+
+  return undefined;
+}
+
+async function getFeed(channelClaim) {
+  const replaceLineFeeds = (str) => str.replace(/(?:\r\n|\r|\n)/g, '<br>');
+
+  const options = {
+    title: channelClaim.title + ' on ' + SITE_NAME,
+    description: channelClaim.description ? replaceLineFeeds(channelClaim.description) : '',
+    link: `${URL}/${channelClaim.name}:${channelClaim.claim_id}`,
+    favicon: URL + '/public/favicon.png',
+    generator: SITE_NAME + ' RSS Feed',
+    image: channelClaim.thumbnail_url,
+    author: {
+      name: channelClaim.name,
+      link: URL + '/' + channelClaim.name + ':' + channelClaim.claim_id,
+    },
+  };
+
+  const feed = new Feed(options);
+
+  const latestClaims = await getClaimsFromChannel(channelClaim.claim_id, 10);
+
+  latestClaims.forEach((c) => {
+    feed.addItem({
+      guid: c.claim_id,
+      id: c.claim_id,
+      title: c.title,
+      description: c.description ? replaceLineFeeds(c.description) : '',
+      image: c.thumbnail_url,
+      link: URL + '/' + c.name + ':' + c.claim_id,
+      date: new Date(c.created_at),
+    });
+  });
+
+  return feed;
+}
+
+async function getRss(ctx) {
+  if (!ctx.params.claimName || !ctx.params.claimId) {
+    return 'Invalid URL';
+  }
+
+  const channelClaim = await getChannelClaimFromChainquery(ctx.params.claimId);
+  if (channelClaim) {
+    const feed = await getFeed(channelClaim);
+    return feed.rss2();
+  }
+
+  return 'Invalid channel';
+}
+
+module.exports = { getRss };

yarn.lock

@@ -5220,6 +5220,13 @@ fd-slicer@~1.1.0:
   dependencies:
     pend "~1.2.0"
 
+feed@^4.2.2:
+  version "4.2.2"
+  resolved "https://registry.yarnpkg.com/feed/-/feed-4.2.2.tgz#865783ef6ed12579e2c44bbef3c9113bc4956a7e"
+  integrity sha512-u5/sxGfiMfZNtJ3OvQpXcvotFpYkL0n9u9mM2vkui2nGo8b4wvDkJ8gAkYqbA8QpGyFCv3RK0Z+Iv+9veCS9bQ==
+  dependencies:
+    xml-js "^1.6.11"
+
 figgy-pudding@^3.5.1:
   version "3.5.2"
   resolved "https://registry.yarnpkg.com/figgy-pudding/-/figgy-pudding-3.5.2.tgz#b4eee8148abb01dcf1d1ac34367d59e12fa61d6e"
@@ -12512,6 +12519,13 @@ xdg-basedir@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/xdg-basedir/-/xdg-basedir-4.0.0.tgz#4bc8d9984403696225ef83a1573cbbcb4e79db13"
 
+xml-js@^1.6.11:
+  version "1.6.11"
+  resolved "https://registry.yarnpkg.com/xml-js/-/xml-js-1.6.11.tgz#927d2f6947f7f1c19a316dd8eea3614e8b18f8e9"
+  integrity sha512-7rVi2KMfwfWFl+GpPg6m80IVMWXLRjO+PxTq7V2CDhoGak0wzYzFgUY2m4XJ47OGdXd8eLE8EmwfAmdjw7lC1g==
+  dependencies:
+    sax "^1.2.4"
+
 xmlbuilder@^10.0.0:
   version "10.1.1"
   resolved "https://registry.yarnpkg.com/xmlbuilder/-/xmlbuilder-10.1.1.tgz#8cae6688cc9b38d850b7c8d3c0a4161dcaf475b0"