rss-finder/lib/parser.js

Find rss feeds url

'use strict';

var htmlparser = require('htmlparser2');
var FeedParser = require('feedparser');
var Promise = require('pinkie-promise');

var rssTypes = [
  'application/rss+xml',
  'application/atom+xml',
  'application/rdf+xml',
  'application/rss',
  'application/atom',
  'application/rdf',
  'text/rss+xml',
  'text/atom+xml',
  'text/rdf+xml',
  'text/rss',
  'text/atom',
  'text/rdf'
];

var iconRels = [
  'icon',
  'shortcut icon'
];

function htmlParser(htmlBody, feedParserOptions) {
  return new Promise(function(resolve, reject) {
    var rs = {};
    var feeds = [];
    var parser;
    var isFeeds;
    var favicon;
    var isSiteTitle;
    var siteTitle;
    var feedParser;

    parser = new htmlparser.Parser({
      onopentag: function(name, attr) {
        if (/(feed)|(atom)|(rdf)|(rss)/.test(name)) {
          isFeeds = true;
        }

        if (name === 'link' && rssTypes.indexOf(attr.type) !== -1 && attr.href) {
          feeds.push({
            title: attr.title || null,
            url: attr.href
          });
        }

        if (name === 'link' && (iconRels.indexOf(attr.rel) !== -1 || attr.type === 'image/x-icon')) {
          favicon = attr.href;
        }

        if (name === 'title') {
          isSiteTitle = true;
        }
      },
      ontext: function(text) {
        if (isSiteTitle) {
          siteTitle = text;
        }
      },
      onclosetag: function(name) {
        if (name === 'title') {
          isSiteTitle = false;
        }
      }
    }, {
      recognizeCDATA: true
    });

    parser.write(htmlBody);
    parser.end();

    if (isFeeds) {
      feedParser = new FeedParser(feedParserOptions);

      feeds = [];

      feedParser.on('error', function(err) {
        reject(err);
      });

      feedParser.on('readable', function() {
        var data;

        if (feeds.length === 0) {
          data = this.meta;
          feeds.push(data);
        }
      });

      feedParser.write(htmlBody);

      feedParser.end(function() {
        if (feeds.length !== 0) {
          rs.site = {
            title: feeds[0].title || null,
            favicon: feeds[0].favicon || null,
            url: feeds[0].link || null
          };

          rs.feedUrls = [{
            title: feeds[0].title || null,
            url: feeds[0].xmlUrl || null
          }];
        }

        resolve(rs);
      });
    } else {
      rs.site = {
        title: siteTitle || null,
        favicon: favicon || null
      };

      rs.feedUrls = feeds;

      resolve(rs);
    }
  });
}

module.exports = htmlParser;