rss-finder/lib/index.js

Find rss feeds url

'use strict';

var htmlParser = require('./parser');
var extend = require('extend');
var Promise = require('pinkie-promise');
var url = require('url');
var got = require('got');

var defaults = {
  gotOptions: {
    timeout: 30000 // 30s
  },
  feedParserOptions: {}
};

function isRelativeUrl(str) {
  return /^https?:\/\//i.test(str);
}

function setError(err) {
  if (err instanceof Error) {
    return err;
  }

  return new Error(err);
}

function cleanUrl(uri) {
  if (uri[uri.length - 1] === '/') {
    return uri.substr(0, uri.length - 1);
  }

  return uri;
}

function getFaviconUrl(uri) {
  var parsedUrl = url.parse(uri);

  return url.resolve(parsedUrl.protocol + '//' + parsedUrl.host, 'favicon.ico');
}

function fixData(res, uri) {
  return new Promise(function(resolve) {
    var feedUrl;
    var favicon;
    var i = res.feedUrls.length;

    while (i--) {
      feedUrl = res.feedUrls[i];

      if (feedUrl.url) {
        if (!isRelativeUrl(feedUrl.url)) {
          feedUrl.url = url.resolve(uri, feedUrl.url);
        }
      } else {
        feedUrl.url = uri;
      }
    }

    if (!res.site.url) {
      res.site.url = cleanUrl(uri);
    }

    if (res.site.favicon) {
      if (!isRelativeUrl(res.site.favicon)) {
        res.site.favicon = url.resolve(res.site.url, res.site.favicon);
      }

      resolve(res);
    } else {
      favicon = getFaviconUrl(res.site.url);

      got(favicon, {
        retries: 0
      }).then(function() {
        res.site.favicon = favicon;
        resolve(res);
      }).catch(function() {
        resolve(res);
      });
    }
  });
}

function rssFinder(opts) {
  return new Promise(function(resolve, reject) {
    var o = extend(true, {}, defaults);

    if (typeof opts === 'string') {
      o.url = opts;
    } else if (typeof opts === 'object' && !Array.isArray(opts)) {
      o = extend(true, {}, defaults, opts);
    } else {
      reject(setError('Parameter `opts` must be a string or object.'));
      return;
    }

    if (!isRelativeUrl(o.url)) {
      reject(setError('Not HTTP URL is provided.'));
      return;
    }

    var canonicalUrl;

    got(o.url, o.gotOptions)
      .then(function(res) {
        canonicalUrl = res.url;
        return htmlParser(res.body, o.feedParserOptions);
      })
      .then(function(res) {
        return fixData(res, canonicalUrl);
      })
      .then(function(res) {
        resolve(res);
      })
      .catch(function(err) {
        reject(setError(err));
      });
  });
}

module.exports = rssFinder;