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From Apache Wiki <>
Subject [Nutch Wiki] Update of "GoogleSummerOfCode/PrecisionDataExtractor" by ChrisMattmann
Date Thu, 28 Jan 2016 04:02:09 GMT
Dear Wiki user,

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The "GoogleSummerOfCode/PrecisionDataExtractor" page has been changed by ChrisMattmann:

  Nutch use parse-html plugin to parse web pages, it process the contents of the web page
by removing html tags and component like javascript and css and leaving the extracted text
to be stored on the index. Nutch by default doesn't have the capability to select certain
atomic element on an html page, like certain tags, certain content, some part of the page,
  A html page have a tree-like xml pattern with html tag as its branch and text as its node.
This branch and node could be extracted using XPath. XPath allowing us to select a certain
branch or node of an XML and therefore could be used to extract certain information and treat
it differently based on its content and the user requirements. Furthermore a web domain like
news website usually have a same html code structure for storing the information on its web
pages. This same html code structure could be parsed using the same XPath query and retrieve
the same content information element. All of the XPath query for selecting various content
could be stored on a XPath Configuration File.
  The purpose of nutch are for various web source, not all of the web page retrieved from
those various source have the same html code structure, thus have to be treated differently
using the correct XPath Configuration. The selection of the correct XPath configuration could
be done automatically using regex by matching the url of the web page with valid url pattern
for that xpath configuration. This automatic mechanism allow the user of nutch to process
various web page and get only certain information that user wants therefore making the index
more accurate and its content more flexible.
+ == Mentor Comments ==
+ * Chris Mattmann - very cool! Why not just integrate Scrapy with Nutch as a plugin? Something
like parse-scrapy?
  === Introduction ===
  To be added

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