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Showing Revision 3 created 05/24/2016 by Udacity Robot.

  1. One thing I'd like to expose you really quickly is
  2. RSS, you've probably heard of RSS before. It's how you
  3. read a website that has, you know, daily content, you
  4. know, like a blog or a news site and you may
  5. have a reader that is specialized for just reading the content. RSS stands for
  6. RDF Site Summary, and, RDF stands for Resource Description Framework. Now
  7. I'm not going to quiz you on this, RDF is, is an XML format for describing just
  8. about anything. For basically representing knowledge in XML actually
  9. in my first job I dealt with a lot of
  10. RDF so, I don't want to spend any more
  11. time on it. More commonly, RSS actually refers to Really
  12. Simple Syndication and that's kind of more of more
  13. of the context of how we're going to be dealing with
  14. it. You know, RDF was kind of conceived to solve
  15. this grand data, you know, organize the world's information problems.
  16. And RSS was, you know, it uses RDF but really, its
  17. just a list of, a list of content in XML. So
  18. let me show you some more example of this in the
  19. wild. I'm at the New York Times home page right now,
  20. and if we go down to the bottom of this page,
  21. we'll see a link for RSS, so I'll click that link,
  22. and I'll choose the New York Times global home page. Now,
  23. you can see in our URL, we have GlobalHome.xml. And so
  24. we've received an XML document. And most browsers will
  25. actually display XML in a nice way. So, this
  26. is an XML document. It's actually an RSS. And
  27. so, what this basically means is there's a, a particular
  28. namespace, kind of a tag space if you will,
  29. for the items in this list. You know, just
  30. like HTML has, you know, opens with an HTML
  31. and has a body and, you know, very specific tags.
  32. An RSS document will also, has specific tags. And
  33. in XML, you can use as header area, to describe
  34. what name spacing's used. So were using the atom
  35. name space, and the RSS 2.0 name space. And that's
  36. basically what this is telling our parser, is you
  37. can download a kind of descriptions of these tags from
  38. these URLs. And then we know what tags to expect.
  39. We're not going to, I'm not going to quiz you on what
  40. RSS actually is, so if you take a, a little peak at this
  41. document, you can see it starts out with some header stuff kind of in
  42. this channel section and then when we get down to this list of items.
  43. And so I'm going to collapse these first few and we can see we've got
  44. an item and this is basically just a list of stories that are
  45. in the New York times. So I can collapse and item and we can
  46. see if there is another item. There's actually a whole bunch of items. And
  47. each item has, you know, a title, and a link, and sorts of things
  48. that you know, would power an RSS reader. You know, a little description.
  49. You know, this is, this is neat. This is for an RSS reader,
  50. or a program to download the contents of the New York Times without
  51. having to parse all the HTML. Which brings us to our next quiz.