Extract publishing date

[fhamborg]

It would be great if you could additionally extract the date when an article was published. Currently, this requires parsing the web page and using tools such as newspaper3k to get that information. However, during the crawling process at least some webpages would offer this information, e.g. the time stamp within the RSS feed
<pubDate>Thu, 25 Dec 2014 02:10:00 +0900</pubDate>
or within the sitemap
<news:publication_date>2016-12-09T16:18:48Z</news:publication_date>

[sebastian-nagel]

Status update:

• <pubDate> (feeds) and <lastmod> (sitemaps) is now used to reject news articles older than 30 days.
• TODO:
  • add support for <news:publication_date>
  • pass this info from feed/sitemap forward and add it to the WARC record

[sebastian-nagel]

The project now uses crawler-commons 1.0 which brings full support for all sitemap extensions, including news sitemaps. The <news:publication_date> is now used to skip older news articles (with the current configuration older than 30 days).
Next steps to implement would be:

• make FeedParserBolt and NewsSiteMapParserBolt store the information in the metadata of the found links. This should be configurable so that also other details
• write the information from the metadata into a WARC metadata record.