Page: http://wiki.cocoondev.org/Wiki.jsp?page=FredericGlorieux , version: 5 on Thu May 15 11:51:23 2003 by FredericGlorieux
- # [UnderstandingCocoonMounts] ? ^ + * [UnderstandingCocoonMounts] ? ^ - # [DataDebuggingTechnique] ? ^ + * [DataDebuggingTechnique] ? ^ + * [BeginnerSimpleXSLT] Page: http://wiki.cocoondev.org/Wiki.jsp?page=BeginnerSimpleXSLT , version: 1 on Thu May 15 11:48:31 2003 by FredericGlorieux New page created: + !!! XSLT, how to start ? + + I begin the page, in hope that some others will fill the holes (and correct my english). + + !!!Principles + Before, you should know a bit of what XML looks like. So let's take a very short document + {{{ + <article> + <title>BeginnerSimpleXSLT</title> + <author>FredericGlorieux</author> + <abstract>Dummy XML document</abstract> + <section> + <title>section 1</section> + <para>Some <bold>bold</bold> and <italic>italic</italic> text</para> + </section> + </article> + }}} + + This doc is nicer than HTML, especially because I can change the Schema/DTD for my specific usage (<abstract/>, <author/>). Now, how to take advantage of this? XSLT, of course. + + !!Root + This will be the root XSL document in which all snippets will now go. + {{{ + <?xml version="1.0" encoding="UTF-8"?> + <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform";> + <xsl:output method="xml" encoding="UTF-8"/> + <!-- here put your templates --> + </xsl:stylesheet> + }}} + + + {{<?xml version="1.0" encoding="UTF-8"?>}} First declaration that all xml document should have. + Note the encoding precision, UTF-8 is default for XML. + But languages other than english could have some surprise in a + browser. For an XSL, let it as UTF-8, your XML editor should know it. + + {{<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform";>}} + Root element whith a namespace declaration (XML-spec). + All elements beginning + by xsl:* is mapped as the namespace-uri "http://www.w3.org/1999/XSL/Transform";. + This is the only string identifying your tags as xslt instructions to process. + That means, you can also say + {{<myprefix:stylesheet version="1.0" xmlns:myprefix="http://www.w3.org/1999/XSL/Transform"/>}} + Could be useful when an xsl should output an xsl. + But before that, stay classic, it will be easier for copy/paste (by the way, keep also the @version attribute). + + {{<xsl:output method="xml" encoding="UTF-8"/>}} + An xsl:stylesheet is a common XML document, that will be processed. + All xsl:* will now be instructions to transform from an input to an output. + Input should be valid XML, + output could be text, xml, html (with unclosed tags, character entities like ...). + This is the reason of @method attribute. + Note @encoding, one more time, let UTF-8 for xml usages, iso-8859-1 could be useful if + strange browser display. + + !!Pull + + If I put some nice tags in my XML documents, it's probably to use them. Example, I want to extract title|author|abstract of my articles to have a short version. So let's write my first template to __pull__ what I need in the source to output it. + + + !match, select, XPath + + {{{ + <!-- this template supposed to be in a xsl:stylesheet described upper ---> + <xsl:template match="/"> + <!-- here, we are at root of the xml input, before the first element --> + <xsl:copy-of select="."/> + </xsl:template> + }}} + + {{<xsl:template match="/">}} + The xslt engine is a kind of filter, processing an xml input, + with the stylesheet instructions. Imagine a complex search/replace, except it's not working + on flat text, but on a tree of elements. + At first, the engine search for a template matching the root. + Thats what is provide here, in the @match, with the "/" value. + Unix users will fastly understand the syntax. + Now, the current node will be the root of the xml input (like after a "change directory"). + + In fact, this very complex template is doing: __nothing__. Output should be quite exactly the input in XML understanding, except encoding or some other properties specified in the xsl:output instruction (only important for text instance of an XML object). Not so unuseful... + + It's also a fast way to debug XSL, to say "Where am I?", "What's in?". The instruction ''copy-of'' output the nodes selected by the expression in @select, here: ".". The dot express current node. It's another important character of expressions, called XPath syntax. + + But don't forget what we want. From the input given upper, imagine we want this short output, with no more content. + + {{{ + <short> + <title>BeginnerSimpleXSLT</title> + <author>FredericGlorieux</author> + <abstract>Dummy XML document</abstract> + </short> + }}} + + This template should do the job + + {{{ + <xsl:template match="/article"> + <!-- here, we are after the first element --> + <short> + <xsl:copy-of select="title"/> + <xsl:copy-of select="author"/> + <xsl:copy-of select="abstract"/> + </short> + </xsl:template> + }}} + + Now, I'm matching XML input with an {{<article/>}} root element (happily, it's my input), this will change the current node inside the template for all new XPath expression (ex: @select). Note alse the <short/> element, which is not in XSLT namespace (no xsl: prefix), so the engine will understand it as an output. And now point the three copy-of, working in the article context, so the @select are respectivly catching and ouputing the {{<title/>, <author/>, <abstract/>}} nodes. + + !!Push + + Pocess for an html output. + + !!!Resources + + Links. +
