Discussion: How to Use RestSharp / Hammock to Automatically Parse the YouTube Response Format into POCO Objects
If you've been following me on Twitter over the past couple of weeks, you might have noticed that I've been a little frustrated with the YouTube GData API lately. Simply put: XML makes me sad. Since that frustrated Tweet I've developed a solution using LINQ-to-XML and a bunch of hard-coded namespaces which isn't how I would prefer to do it.
I would much rather use the built in object deserialization capabilities in RestSharp or HammockREST. I'll be honest - I do not have a damn clue how to use Hammock's built-in deserialization capabilities. I tried tinkering with it on my own to no avail, and there's not much documentation to speak of.
RestSharp has some more detailed documentation on its deserialization capabilities, but it doesn't answer some lingering questions I have. So without further aideu, I'd like to solicit the opinion of the developer community.
<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom" xmlns:media="http://search.yahoo.com/mrss/" xmlns:openSearch="http://a9.com/-/spec/opensearch/1.1/" xmlns:gd="http://schemas.google.com/g/2005" xmlns:yt="http://gdata.youtube.com/schemas/2007" gd:etag="W/"DkMMRn0zeSp7ImA9WxFWE0k."">
<id>tag:youtube.com,2008:user:smartdraw:uploads</id>
<updated>2010-05-31T22:21:27.381Z</updated>
<category scheme="http://schemas.google.com/g/2005#kind" term="http://gdata.youtube.com/schemas/2007#video" />
<title>Uploads by smartdraw</title>
<logo>http://www.youtube.com/img/pic_youtubelogo_123x63.gif</logo>
<link rel="related" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/users/smartdraw?v=2" />
<link rel="alternate" type="text/html" href="http://www.youtube.com/profile_videos?user=smartdraw" />
<link rel="http://schemas.google.com/g/2005#feed" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/users/smartdraw/uploads?v=2" />
<link rel="http://schemas.google.com/g/2005#batch" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/users/smartdraw/uploads/batch?v=2" />
<link rel="self" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/users/smartdraw/uploads?start-index=1&max-results=25&v=2" />
<link rel="service" type="application/atomsvc+xml" href="http://gdata.youtube.com/feeds/api/users/smartdraw/uploads?alt=atom-service&v=2" />
<link rel="next" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/users/smartdraw/uploads?start-index=26&max-results=25&v=2" />
<author>
<name>smartdraw</name>
<uri>http://gdata.youtube.com/feeds/api/users/smartdraw</uri>
</author>
<generator version="2.0" uri="http://gdata.youtube.com/">YouTube data API</generator>
<openSearch:totalResults>30</openSearch:totalResults>
<openSearch:startIndex>1</openSearch:startIndex>
<openSearch:itemsPerPage>25</openSearch:itemsPerPage>
<entry gd:etag="W/"CEIHQn47eCp7ImA9WxFWE0k."">
<id>tag:youtube.com,2008:video:NJPrllhYZrg</id>
<published>2010-02-10T23:27:38.000Z</published>
<updated>2010-05-31T21:48:53.000Z</updated>
<category scheme="http://schemas.google.com/g/2005#kind" term="http://gdata.youtube.com/schemas/2007#video" />
<category scheme="http://gdata.youtube.com/schemas/2007/categories.cat" term="People" label="People & Blogs" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="SmartDraw" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="flowcharts" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="visuals" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="communicate" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="visually" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="communication" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="powerpoint" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="presentations" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="mind" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="maps" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="software" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="Business" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="graphics" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="strategic" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="planning" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="solutions" />
<category scheme="http://gdata.youtube.com/schemas/2007/keywords.cat" term="tools" />
<title>SmartDraw 2010 Guided Tour</title>
<content type="application/x-shockwave-flash" src="http://www.youtube.com/v/NJPrllhYZrg?f=user_uploads&d=AWaEdOkfU7AZas-hLyE9s8EO88HsQjpE1a8d1GxQnGDm&app=youtube_gdata" />
<link rel="alternate" type="text/html" href="http://www.youtube.com/watch?v=NJPrllhYZrg&feature=youtube_gdata" />
<link rel="http://gdata.youtube.com/schemas/2007#video.responses" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/videos/NJPrllhYZrg/responses?v=2" />
<link rel="http://gdata.youtube.com/schemas/2007#video.ratings" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/videos/NJPrllhYZrg/ratings?v=2" />
<link rel="http://gdata.youtube.com/schemas/2007#video.complaints" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/videos/NJPrllhYZrg/complaints?v=2" />
<link rel="http://gdata.youtube.com/schemas/2007#video.related" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/videos/NJPrllhYZrg/related?v=2" />
<link rel="http://gdata.youtube.com/schemas/2007#mobile" type="text/html" href="http://m.youtube.com/details?v=NJPrllhYZrg" />
<link rel="self" type="application/atom+xml" href="http://gdata.youtube.com/feeds/api/users/smartdraw/uploads/NJPrllhYZrg?v=2" />
<author>
<name>smartdraw</name>
<uri>http://gdata.youtube.com/feeds/api/users/smartdraw</uri>
</author>
<yt:accessControl action="comment" permission="allowed" />
<yt:accessControl action="commentVote" permission="allowed" />
<yt:accessControl action="videoRespond" permission="moderated" />
<yt:accessControl action="rate" permission="allowed" />
<yt:accessControl action="embed" permission="allowed" />
<yt:accessControl action="syndicate" permission="allowed" />
<gd:comments>
<gd:feedLink href="http://gdata.youtube.com/feeds/api/videos/NJPrllhYZrg/comments?v=2" countHint="0" />
</gd:comments>
<media:group>
<media:credit role="uploader" scheme="urn:youtube">smartdraw</media:credit>
<media:description type="plain">Explains the features of SmartDraw, the software that allows you produce any visual, whether it's a flowchart or a floor plan, in a matter of minutes.
Download a free trial of SmartDraw here: http://www.smartdraw.com/downloads/?id=343742</media:description>
<media:keywords>SmartDraw, flowcharts, visuals, communicate, visually, communication, powerpoint, presentations, mind, maps, software, Business, graphics, strategic, planning, solutions, tools</media:keywords>
<media:player url="http://www.youtube.com/watch?v=NJPrllhYZrg&feature=youtube_gdata" />
<media:thumbnail url="http://i.ytimg.com/vi/NJPrllhYZrg/default.jpg" height="90" width="120" time="00:03:21" />
<media:thumbnail url="http://i.ytimg.com/vi/NJPrllhYZrg/2.jpg" height="90" width="120" time="00:03:21" />
<media:thumbnail url="http://i.ytimg.com/vi/NJPrllhYZrg/1.jpg" height="90" width="120" time="00:01:40.500" />
<media:thumbnail url="http://i.ytimg.com/vi/NJPrllhYZrg/3.jpg" height="90" width="120" time="00:05:01.500" />
<media:thumbnail url="http://i.ytimg.com/vi/NJPrllhYZrg/hqdefault.jpg" height="360" width="480" />
<media:title type="plain">SmartDraw 2010 Guided Tour</media:title>
<yt:duration seconds="402" />
<yt:uploaded>2010-02-10T23:27:38.000Z</yt:uploaded>
<yt:videoid>NJPrllhYZrg</yt:videoid>
</media:group>
<gd:rating average="4.4444447" max="5" min="1" numRaters="9" rel="http://schemas.google.com/g/2005#overall" />
<yt:statistics favoriteCount="9" viewCount="16206" />
<yt:rating numDislikes="1" numLikes="8" />
</entry>
</feed>
Now, here are use cases for how I might want to use this format:
- The GData API will only serve a maximum of 50 entries at any given time - one way to paginate through all of the entries in one go is to parse the link rel="next" field and query that URL until the field no longer exists. Is there a way you can use a POCO class in Hammock or RestSharp to automatically grab this field between queries against the API?
- Imagine you create a POCO class which contains the YouTube video ID, the author's username, the number of comments on the video, the keywords for the video, the number of views, and the number of the number of favorites. How would you structure this class such that RestSharp or HammockREST can automatically parse it from an ATOM response format like the one above? Bear in mind that these fields come from four of the five different XML namespaces (atom, Media RSS [media], GData [gd], and YouTube [yt]) used in this response format.
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I'm the CTO and founder of Petabridge, where I'm making distributed programming for .NET developers easy by working on Akka.NET, Phobos, and more..
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