https://www.tewari.info/tag/xslt/Recent content in XSLT on Ash TewariHugo -- gohugo.ioen-USFri, 21 Dec 2007 01:14:29 +0000https://www.tewari.info/2007/12/20/leveraging-xpath-axes/Fri, 21 Dec 2007 01:14:29 +0000https://www.tewari.info/2007/12/20/leveraging-xpath-axes/<p>XPATH axes come in very handy when nodes need to be selected based on (attribute&rsquo;s or child element&rsquo;s) values that must match those of other nodes elsewhere in the xml tree. Consider the following log4net configuration file :</p> <hr> <div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-fallback" data-lang="fallback"><span style="display:flex;"><span>&lt;?xml version=&#34;1.0&#34;?&gt; </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span>&lt;configuration&gt; </span></span><span style="display:flex;"><span> &lt;configSections&gt; </span></span><span style="display:flex;"><span> &lt;section name=&#34;nhibernate&#34; </span></span><span style="display:flex;"><span> type=&#34;System.Configuration.NameValueSectionHandler, System, </span></span><span style="display:flex;"><span> Version=2.0.0.0,Culture=neutral, PublicKeyToken=b77a5c561934e089&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;section name=&#34;log4net&#34; </span></span><span style="display:flex;"><span> type=&#34;log4net.Config.Log4NetConfigurationSectionHandler,log4net&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;/configSections&gt; </span></span><span style="display:flex;"><span> &lt;nhibernate&gt; </span></span><span style="display:flex;"><span> &lt;add key=&#34;hibernate.connection.provider&#34; </span></span><span style="display:flex;"><span> value=&#34;NHibernate.Connection.DriverConnectionProvider&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;add key=&#34;hibernate.connection.driver_class&#34; </span></span><span style="display:flex;"><span> value=&#34;NHibernate.Driver.SqlClientDriver&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;add key=&#34;hibernate.connection.connection_string&#34; </span></span><span style="display:flex;"><span> value=&#34;Server=servername; Database=dbname; </span></span><span style="display:flex;"><span> User=username; Password=secret;&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;add key=&#34;hibernate.connection.isolation&#34; value=&#34;ReadCommitted&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;add key=&#34;hibernate.dialect&#34; </span></span><span style="display:flex;"><span> value=&#34;NHibernate.Dialect.MsSql2000Dialect&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;/nhibernate&gt; </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span> &lt;log4net&gt; </span></span><span style="display:flex;"><span> &lt;appender name=&#34;NHibernateFileLog&#34; </span></span><span style="display:flex;"><span> type=&#34;log4net.Appender.RollingFileAppender&#34;&gt; </span></span><span style="display:flex;"><span> &lt;file value=&#34;Logs/nhibernate.txt&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;appendToFile value=&#34;true&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;rollingStyle value=&#34;Size&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;maxSizeRollBackups value=&#34;10&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;maximumFileSize value=&#34;100KB&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;staticLogFileName value=&#34;true&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;layout type=&#34;log4net.Layout.PatternLayout&#34;&gt; </span></span><span style="display:flex;"><span> &lt;conversionPattern </span></span><span style="display:flex;"><span> value=&#34;%d{HH:mm:ss.fff} [%t] %-5p %c - %m%n&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;/layout&gt; </span></span><span style="display:flex;"><span> &lt;/appender&gt; </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span> &lt;appender name=&#34;GeneralLog&#34; </span></span><span style="display:flex;"><span> type=&#34;log4net.Appender.RollingFileAppender&#34;&gt; </span></span><span style="display:flex;"><span> &lt;file value=&#34;Logs/general.txt&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;appendToFile value=&#34;true&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;maximumFileSize value=&#34;100KB&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;rollingStyle value=&#34;Size&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;maxSizeRollBackups value=&#34;5&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;layout type=&#34;log4net.Layout.PatternLayout&#34;&gt; </span></span><span style="display:flex;"><span> &lt;conversionPattern </span></span><span style="display:flex;"><span> value=&#34;%d{HH:mm:ss.fff} [%t] %-5p %c - %m%n&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;/layout&gt; </span></span><span style="display:flex;"><span> &lt;/appender&gt; </span></span><span style="display:flex;"><span> &lt;appender name=&#34;DataLog&#34; </span></span><span style="display:flex;"><span> type=&#34;log4net.Appender.RollingFileAppender&#34;&gt; </span></span><span style="display:flex;"><span> &lt;file value=&#34;Logs/data.txt&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;appendToFile value=&#34;true&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;maximumFileSize value=&#34;100KB&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;rollingStyle value=&#34;Size&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;maxSizeRollBackups value=&#34;5&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;layout type=&#34;log4net.Layout.PatternLayout&#34;&gt; </span></span><span style="display:flex;"><span> &lt;conversionPattern </span></span><span style="display:flex;"><span> value=&#34;%d{HH:mm:ss.fff} [%t] %-5p %c - %m%n&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;/layout&gt; </span></span><span style="display:flex;"><span> &lt;/appender&gt; </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span> &lt;!-- levels: DEBUG, INFO, WARN, ERROR, FATAL --&gt; </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span> &lt;root&gt; </span></span><span style="display:flex;"><span> &lt;level value=&#34;DEBUG&#34;/&gt; </span></span><span style="display:flex;"><span> &lt;appender-ref ref=&#34;GeneralLog&#34; /&gt; </span></span><span style="display:flex;"><span> &lt;/root&gt; </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span> &lt;logger name=&#34;NHibernate&#34; additivity=&#34;false&#34;&gt; </span></span><span style="display:flex;"><span> &lt;level value=&#34;DEBUG&#34;/&gt; </span></span><span style="display:flex;"><span> &lt;appender-ref ref=&#34;NHibernateFileLog&#34;/&gt; </span></span><span style="display:flex;"><span> &lt;/logger&gt; </span></span><span style="display:flex;"><span> &lt;logger name=&#34;Pushable.Data&#34; additivity=&#34;false&#34;&gt; </span></span><span style="display:flex;"><span> &lt;level value=&#34;DEBUG&#34;/&gt; </span></span><span style="display:flex;"><span> &lt;appender-ref ref=&#34;DataLog&#34;/&gt; </span></span><span style="display:flex;"><span> &lt;/logger&gt; </span></span><span style="display:flex;"><span> &lt;/log4net&gt; </span></span><span style="display:flex;"><span>&lt;/configuration&gt; </span></span></code></pre></div><hr> <p>The <appender>s are referenced by <logger>s using &lsquo;ref&rsquo; attribute of their &lsquo;appender-ref&rsquo; child elements, using the same value as the &rsquo;name&rsquo; attribute of the <appender>. This type of linking is quite common in xml documents. Now, The first question is : How to list files that are referenced by <logger>s ? In order to solve this problem you will need to reach the <appender>s that are referenced by each <logger> and then extract the &lsquo;value&rsquo; of their <file>s.</p> <hr> <p>Solution:</p> <div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-fallback" data-lang="fallback"><span style="display:flex;"><span>&lt;?xml version=&#34;1.0&#34;?&gt; </span></span><span style="display:flex;"><span>&lt;xsl:stylesheet xmlns:xsl=&#34;http://www.w3.org/1999/XSL/Transform&#34; </span></span><span style="display:flex;"><span> version=&#34;1.0&#34;&gt; </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span> &lt;xsl:output method=&#34;text&#34;/&gt; </span></span><span style="display:flex;"><span> &lt;xsl:strip-space elements=&#34;*&#34;/&gt; </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span> &lt;xsl:template match=&#34;log4net&#34;&gt; </span></span><span style="display:flex;"><span> &lt;xsl:apply-templates </span></span><span style="display:flex;"><span> select=&#34;appender[@name=parent::log4net/logger/appender-ref/@ref]&#34;/&gt; </span></span><span style="display:flex;"><span> &lt;/xsl:template&gt; </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span> &lt;xsl:template match=&#34;appender&#34;&gt; </span></span><span style="display:flex;"><span> &lt;xsl:value-of </span></span><span style="display:flex;"><span> select=&#34;file/@value&#34;/&gt; &lt;xsl:text&gt;&amp;#10;&lt;/xsl:text&gt; </span></span><span style="display:flex;"><span> &lt;/xsl:template&gt; </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span>&lt;/xsl:stylesheet&gt; </span></span></code></pre></div><hr> <p>The second question is : How to write an xslt script to transform this xml document into an html document with a table that looks like this -</p> <table> <thead> <tr> <th>Logger</th> <th>File</th> </tr> </thead> <tbody> <tr> <td>NHibernate</td> <td>Logs/nhibernate.txt</td> </tr> <tr> <td>Pushable.Data</td> <td>Logs/data.txt</td> </tr> </tbody> </table> <hr> <p>Solution:</p> <div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-gdscript3" data-lang="gdscript3"><span style="display:flex;"><span><span style="color:#f92672">&lt;</span><span style="color:#960050;background-color:#1e0010">?</span>xml version<span style="color:#f92672">=</span><span style="color:#e6db74">&#34;1.0&#34;</span><span style="color:#960050;background-color:#1e0010">?</span><span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span><span style="color:#f92672">&lt;</span>xsl:stylesheet xmlns:xsl<span style="color:#f92672">=</span><span style="color:#e6db74">&#34;http://www.w3.org/1999/XSL/Transform&#34;</span> </span></span><span style="display:flex;"><span> version<span style="color:#f92672">=</span><span style="color:#e6db74">&#34;1.0&#34;</span><span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;</span>xsl:output method<span style="color:#f92672">=</span><span style="color:#e6db74">&#34;html&#34;</span><span style="color:#f92672">/&gt;</span> </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;</span>xsl:template match<span style="color:#f92672">=</span><span style="color:#e6db74">&#34;log4net&#34;</span><span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;</span>HTML<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;</span>HEAD<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;</span>TITLE<span style="color:#f92672">&gt;</span>www<span style="color:#f92672">.</span>tewari<span style="color:#f92672">.</span>info : using xpath axes<span style="color:#f92672">&lt;/</span>TITLE<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;/</span>HEAD<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;</span>BODY<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;</span>TABLE border<span style="color:#f92672">=</span><span style="color:#e6db74">&#34;1&#34;</span> width<span style="color:#f92672">=</span><span style="color:#e6db74">&#34;25%&#34;</span><span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;</span>TR<span style="color:#f92672">&gt;&lt;</span>TH<span style="color:#f92672">&gt;</span>Logger<span style="color:#f92672">&lt;/</span>TH<span style="color:#f92672">&gt;&lt;</span>TH<span style="color:#f92672">&gt;</span><span style="color:#a6e22e">File</span><span style="color:#f92672">&lt;/</span>TH<span style="color:#f92672">&gt;&lt;/</span>TR<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;</span>xsl:apply<span style="color:#f92672">-</span>templates select<span style="color:#f92672">=</span><span style="color:#e6db74">&#34;logger&#34;</span><span style="color:#f92672">/&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;/</span>TABLE<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;/</span>BODY<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;/</span>HTML<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;/</span>xsl:template<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;</span>xsl:template match<span style="color:#f92672">=</span><span style="color:#e6db74">&#34;logger&#34;</span><span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;</span>xsl:variable name<span style="color:#f92672">=</span><span style="color:#e6db74">&#34;aName&#34;</span> select<span style="color:#f92672">=</span><span style="color:#e6db74">&#34;appender-ref/@ref&#34;</span><span style="color:#f92672">/&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;</span>TR<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;</span>TD<span style="color:#f92672">&gt;&lt;</span>xsl:value<span style="color:#f92672">-</span>of select<span style="color:#f92672">=</span><span style="color:#e6db74">&#34;@name&#34;</span><span style="color:#f92672">/&gt;&lt;/</span>TD<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;</span>TD<span style="color:#f92672">&gt;&lt;</span>xsl:value<span style="color:#f92672">-</span>of </span></span><span style="display:flex;"><span> select<span style="color:#f92672">=</span><span style="color:#e6db74">&#34;parent::log4net/appender[@name=$aName]/file/@value&#34;</span><span style="color:#f92672">/&gt;&lt;/</span>TD<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;/</span>TR<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> <span style="color:#f92672">&lt;/</span>xsl:template<span style="color:#f92672">&gt;</span> </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span><span style="color:#f92672">&lt;/</span>xsl:stylesheet<span style="color:#f92672">&gt;</span> </span></span></code></pre></div><hr> <p>Credits :</p> <ul> <li> <p>xml document from <a class="link" href="http://www.hibernate.org/364.html" title="hibernate" target="_blank" rel="noopener" >hibernate</a></p> </li> <li> <p>xml converted to html using <a class="link" href="http://www.andre-simon.de/" title="Highlight" target="_blank" rel="noopener" >Highlight</a></p> </li> <li> <p><a class="link" href="http://www.sketchpath.com" title="SketchPath" target="_blank" rel="noopener" >SketchPath</a> is a brilliant tool to play with xpath. I love the &ldquo;New Context&rdquo; button : Click on a node and hit &ldquo;New Context&rdquo; to change the context for the xpath query processor !</p> </li> </ul>