RissRoss

Comments on CourseTools Article

Gradually I am trying to understand each part of the data transformation process.  It was helpful to read the article referred to us by Bud through Course Tools.  I liked the article's analogy relating XPath to XML as SQL is to relational databases.  Furthermore, the article made it nice and simple to understand XML and XSLT by simply stating that the data exists in XML and the structure exists in XSLT.  Through an example, the article shows you that to transfer the XML data into the format you want, you must input a reference to the XSLT stylesheet that orders the structure the way you desire.  However, I am confused as to the next step in order to get your desired output.  Does this XML document then have to flow through some server to produce the new document?  The article was not very clear on this. 

In addition to the above question, I have a few more, some of which have already been posed by Xiaohan in her blog.  First, what is CSS?  I do not recall learning about this in class.  I thought design was also taken care of by a segment of XSLT.  Furthermore, what does it mean when it associates behavior with JavaScript.  What is the article referring to by mentioning behavior?  Lastly, in the transformation example it applies, the match template equals "/" -- does that mean it wants to match everything, the whole document?

While I am a little puzzled with these questions, overall the article helped to clarify XSLT.  More importantly, the article gave an example of how to reference a XSLT stylesheet in a XML document in order to transform its structure.  To keep increasing my level of understanding I will need to do many of my own practices of this transformation because it still is confusing to me. 

The Dream Team

Ok, so over the past two weeks we have consumed a mass of information.  To categorize our learning in the most concise terms, we have learned all about the basics of the "Dream Team" plus XSQL.  XML seems to be at the center of all the information we are learning, the raw material of the data that is constantly exchanged over the Internet to multiple parties.  It is a computer language that can be read by multiple audiences, transformed to desire outputs and formats, and used to answer queries.  However, in order for this data to be useful to various people via the Internet, the other players of the Dream Team are needed- XSL, XSLT, and XPATH.  Without these other players, XML is not as functionable as you may refer back to Maulin's blog. mentioning of this XML aspect.  XSLT is necessary to transform the data from one XML format to another, and can output it in HTML language as well.  Basically, XSLT can convert XML data into any desired output.  This is an important language capability for information that is going out to multiple audiences.  The flexibility of XML allows many people to interpret the raw data through different programs and web servers.  The XSLT processor takes the raw data from the XML document, looks at the style template requests set up by the stylesheet, performs the requested transformation, and outputs the restults to a new file.  XSLT processes the XML material with the help of an XSL stylesheet.   An XSLT stylesheet is a well-formed (contains beginning tags, and ending tags for each beginning tag) XML document, which specifies the data requested in the output and notes the requested style/format of the data.  The stylesheet therefore answers two questions: 1) "What information from the original XML document do you want?, 2) "How would you like the new document structured?  What format?"  XPath answers the first question, while XSLT template rules (described in the stylesheet) answers the second questions. 

While there are many details to learn concerning the uses and formats of all the Dream Team players, I have tried to cover the big picture with my above statements.  As a short summary, XSLT processes XML documents in order to transform them into requested output forms.  As a side note, XSQL is a servlet, as I mentioned in my previous post, that processes SQL queries and displays the answers in XML. 

After summarizing the big picture, I have a few questions to pose to the class concerning the details of this major process.  First, why does it seem the same URI is used for all XSL stylesheets when the Dummies book says URIs are unique?  Second, I am confused as to what a root node is.  In the Dummies book, it says that a root node "contains all elements, including the document element."  However, I thought the document element encompassed all the information.  Therefore, what exactly is the root node?  the book says it is invisible, and therefore the concept of a root node is hard to comprehend.