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| <h2>Extensions library</h2> |
| <ul> |
| <li> |
| <a href="#intro">Introduction</a> |
| </li> |
| <li> |
| <a href="#exslt">EXSLT extensions</a> |
| </li> |
| <li> |
| <a href="#xalanns">Xalan namespace</a> |
| </li> |
| <li> |
| <a href="#redirect">Redirect</a> |
| </li> |
| <li> |
| <a href="#nodeset">nodeset</a> |
| </li> |
| <li> |
| <a href="#nodeinfo">NodeInfo extension functions</a> |
| </li> |
| <li> |
| <a href="#sql">SQL library</a> |
| </li> |
| <li> |
| <a href="#pipedocument">PipeDocument</a> |
| </li> |
| <li> |
| <a href="#evaluate">evaluate</a> |
| </li> |
| <li> |
| <a href="#tokenize">tokenize</a> |
| </li> |
| <li> |
| <a href="extensions_xsltc.html">Extensions for XSLTC</a> |
| </li> |
| <li>Examples: <a href="#ex-redirect">Redirect</a>, <a href="#ex-nodeset">nodeset</a>, |
| <a href="#ex-sql">SQL library</a> |
| </li> |
| </ul> |
| |
| <table class="note"> |
| <tr> |
| <td class="noteImg"> |
| <img src="resources/note.gif" alt="note" /> |
| </td> |
| <td class="noteTxt">Unless otherwise specified, the Xalan-Java extensions library discussed in this section refers to |
| the Xalan-Java Interpretive processor. See <a href="extensions_xsltc.html">Extensions for XSLTC</a> for |
| more information.</td> |
| </tr> |
| </table> |
| <br /> |
| |
| <a name="intro"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h3>Introduction</h3> |
| <p>Extension elements and functions provide a powerful mechanism |
| for extending and simplifying what you can do with an XLST processor like |
| Xalan. With input and contributions from the XML open-source developer community, we are working on |
| placing the most useful extensions in an extensions library distributed with Xalan-Java. If you have |
| ideas and/or contributions you would like to make, please email us at |
| the <a href="mailto:dev@xalan.apache.org">Xalan Development Mailing List</a>.</p> |
| <a name="exslt"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h3>EXSLT extensions</h3> |
| <p>Xalan-Java supports the <a href="http://exslt.org/">EXSLT</a> initiative to provide a set of |
| standard extension functions and elements to XSLT users. Xalan-Java includes implementations for the |
| following EXSLT extension modules:</p> |
| <ul> |
| <li> |
| <a href="apidocs/org/apache/xalan/lib/ExsltCommon.html">EXSLT common functions</a> |
| </li> |
| <li> |
| <a href="apidocs/org/apache/xalan/lib/ExsltMath.html">EXSLT math functions</a> |
| </li> |
| <li> |
| <a href="apidocs/org/apache/xalan/lib/ExsltSets.html">EXSLT set functions</a> |
| </li> |
| <li> |
| <a href="apidocs/org/apache/xalan/lib/ExsltDatetime.html">EXSLT date-and-time functions</a> |
| </li> |
| <li> |
| <a href="apidocs/org/apache/xalan/lib/ExsltDynamic.html">EXSLT dynamic functions</a> |
| </li> |
| <li> |
| <a href="apidocs/org/apache/xalan/lib/ExsltStrings.html">EXSLT string functions</a> |
| </li> |
| <li>The EXSLT func:function and func:result elements (see |
| <a href="http://www.exslt.org/func/elements/function/index.html">EXSLT - func:function)</a> |
| </li> |
| </ul> |
| <p>All EXSLT extensions use namespaces specified in the EXSLT specification. For example, to use the |
| EXSLT math functions, specify a namespace URI as follows:</p> |
| <p> <code>xmlns:math="http://exslt.org/math"</code> |
| </p> |
| <p>Anyone who would like to help by implementating other EXSLT extensions is more than welcome. Please |
| email us at the <a href="mailto:dev@xalan.apache.org">Xalan Development Mailing List</a>.</p> |
| |
| <a name="xalanns"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h3>Xalan namespace</h3> |
| <p>The Xalan extensions are implemented in one of the classes under org.apache.xalan.lib. The main |
| extension class is <a href="apidocs/org/apache/xalan/lib/Extensions.html"> |
| org.apache.xalan.lib.Extensions</a>. Some extension |
| functions (e.g. intersection, difference, etc.) used to be in this class are now moved to the |
| corresponding <a href="#exslt">EXSLT</a> modules. All Xalan extensions use namespace URIs |
| starting with:</p> |
| <p> <code>http://xml.apache.org/xalan</code> |
| </p> |
| <p>If you are calling Xalan-Java-supplied extensions, we recommend that you define the corresponding |
| namespace in your stylesheet, and call the extension using the namespace prefix that you have associated |
| with that namespace. That way, if we later reorganize how the Xalan-Java-supplied extensions are stored, |
| you won't have to modify your stylesheet.</p> |
| <p>For an example that uses this namespace, see <a href="#ex-nodeset">Example with the nodeset |
| extension function</a>.</p> |
| <a name="redirect"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h3>Redirect</h3> |
| <p>A standard XSL transformation involves an XSL stylesheet, an XML source tree, and the transformation |
| result tree. The transformation sends the entire result to a single |
| <a href="apidocs/javax/xml/transform/Result.html">javax.xml.transform.Result</a> object.</p> |
| <p>The namespace for the <a href="apidocs/org/apache/xalan/lib/Redirect.html">Redirect</a> |
| extension is:</p> |
| <p> <code>http://xml.apache.org/xalan/redirect</code> |
| </p> |
| <p>It supplies three extension elements that you can use to redirect portions of your transformation |
| output to multiple files: <open>, <write>, and <close>. If you use the <write> |
| element alone, the extension opens a file, writes to it, and closes the file immediately. If you want |
| explicit control over the opening and closing of files, use <write> in conjunction with |
| the <open> and <close> elements.</p> |
| <p>The <open> and <write> elements include a file attribute and/or a select attribute to |
| designate the output file. The file attribute takes a string, so you can use it to directly specify |
| the output file name. The select attribute takes an XPath expression, so you can use it to dynamically |
| generate the output file name. If you include both attributes, the Redirect extension first evaluates |
| the select attribute, and falls back to the file attribute if the select attribute expression does |
| not return a valid file name.</p> |
| <p>The <open> and <write> elements also support an append attribute. If the append attribute |
| is set to true or yes, then the result is appended to the output file.</p> |
| <a name="ex-redirect"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h4>Example with the Redirect extension</h4> |
| <p>Suppose you are outputting the bulk of your result tree to one file, but you want to output the |
| transformation of all <foo> elements and their children to another file. The following example |
| illustrates the basic structure of the XML source:</p> |
| <blockquote class="source"> |
| <pre><?xml version="1.0"?> |
| <doc> |
| <foo file="foo.out"> |
| Testing Redirect extension: |
| <bar>A foo subelement text node</bar> |
| </foo> |
| <main> |
| Everything else |
| </main> |
| </doc></pre> |
| </blockquote> |
| <p>This stylesheet redirects part of the output to a secondary file:</p> |
| <blockquote class="source"> |
| <pre> |
| <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" |
| version="1.0" |
| xmlns:redirect="http://xml.apache.org/xalan/redirect" |
| extension-element-prefixes="redirect"> |
| |
| <xsl:template match="/"> |
| <standard-out> |
| Standard output: |
| <xsl:apply-templates/> |
| </standard-out> |
| </xsl:template> |
| |
| <xsl:template match="main"> |
| <main> |
| <xsl:apply-templates/> |
| </main> |
| </xsl:template> |
| |
| <xsl:template match="/doc/foo"> |
| <redirect:write select="@file"> |
| <foo-out> |
| <xsl:apply-templates/> |
| </foo-out> |
| </redirect:write> |
| </xsl:template> |
| |
| <xsl:template match="bar"> |
| <foobar-out> |
| <xsl:apply-templates/> |
| </foobar-out> |
| </xsl:template> |
| |
| </xsl:stylesheet></pre> |
| </blockquote> |
| <p>The standard output is:</p> |
| <blockquote class="source"> |
| <pre><?xml version="1.0" encoding="UTF-8"?> |
| <standard-out> |
| Standard output: |
| <main> |
| Everything else. |
| </main> |
| <standard-out></pre> |
| </blockquote> |
| <p>The output redirected to foo.out is:</p> |
| <blockquote class="source"> |
| <pre><?xml version="1.0" encoding="UTF-8"?> |
| <foo-out> |
| Testing Redirect extension: |
| <foobar-out>foo subelement text node</foobar-out> |
| </foo-out></pre> |
| </blockquote> |
| <p>For more information on using the Redirect extension to send output to multiple files, examine |
| the <a href="samples.html#ext1">SimpleRedirect</a> sample and see the |
| <a href="apidocs/org/apache/xalan/lib/Redirect.html">Redirect</a> class Javadoc.</p> |
| <a name="nodeset"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h3>nodeset</h3> |
| <p>Implemented in <a href="apidocs/org/apache/xalan/lib/Extensions.html"> |
| org.apache.xalan.lib.Extensions</a>,<br /> |
| <code>nodeset (result-tree-fragment)</code> casts a result tree fragment into a node-set.</p> |
| <p>To use the nodeset extension, you can either use the <code>nodeset</code> function in the |
| namespace <code>xmlns:xalan="http://xml.apache.org"</code> or the <a href="#exslt">EXSLT</a> |
| extension function <code>node-set</code> in the namespace |
| <code>xmlns:common="http://exslt.org/common"</code>.</p> |
| <table class="note"> |
| <tr> |
| <td class="noteImg"> |
| <img src="resources/note.gif" alt="note" /> |
| </td> |
| <td class="noteTxt">When you bind a variable to a template, rather than to the value generated by a select |
| expression, the data type of the variable is result tree fragment. For more information, |
| see <a href="http://www.w3.org/TR/xslt#section-Result-Tree-Fragments">Result Tree |
| Fragments</a>.</td> |
| </tr> |
| </table> |
| <a name="ex-nodeset"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h4>Example with the nodeset extension function</h4> |
| <p>The following stylesheet uses the nodeset extension function to cast a result tree fragment |
| into a node-set that can then be navigated in standard XPath manner. It uses the |
| http://xml.apache.org/xalan namespace to provide access to the nodeset() method in |
| xml.apache.xalan.lib.Extensions.</p> |
| <blockquote class="source"> |
| <pre><?xml version="1.0"?> |
| <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" |
| version="1.0" |
| xmlns:xalan="http://xml.apache.org/xalan" |
| exclude-result-prefixes="xalan"> |
| <xsl:template match="/"> |
| <out> |
| <xsl:variable name="rtf"> |
| <docelem> |
| <elem1> |
| <elem1a>ELEMENT1A</elem1a> |
| <elem1b>,ELEMENT1B</elem1b> |
| </elem1> |
| <elem2> |
| <elem2a>ELEMENT2A</elem2a> |
| </elem2> |
| </docelem> |
| </xsl:variable> |
| <xsl:for-each select="xalan:nodeset($rtf)/docelem//*"> |
| <xsl:value-of select="name(.)"/><xsl:text>,</xsl:text> |
| </xsl:for-each> |
| </out> |
| </xsl:template> |
| </xsl:stylesheet></pre> |
| </blockquote> |
| <p>The output of running this stylesheet (with any XML input source) is a comma-delimited list of |
| the element names in the node-set<br /> |
| <code><out>elem1,elem1a,elem1b,elem2,elem2a</out></code> |
| </p> |
| <table class="note"> |
| <tr> |
| <td class="noteImg"> |
| <img src="resources/note.gif" alt="note" /> |
| </td> |
| <td class="noteTxt">For illustration purposes, the preceding stylesheet pays no attention to the structure and |
| content of the XML input document. Instead, it processes the template (in the stylesheet) bound |
| to the variable named rtf.</td> |
| </tr> |
| </table> |
| |
| |
| |
| |
| <a name="nodeinfo"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h3>NodeInfo</h3> |
| <p> |
| <a href="apidocs/org/apache/xalan/lib/NodeInfo.html">org.apache.xalan.lib.NodeInfo</a> provides |
| extension elements that you can use to get information about the location of nodes in the source |
| document:</p> |
| <ul> |
| <li> |
| <a href="#systemid">systemId</a> |
| </li> |
| <li> |
| <a href="#publicid">publicId</a> (to be done)</li> |
| <li> |
| <a href="#linenumber">lineNumber</a> |
| </li> |
| <li> |
| <a href="#columnnumber">columnNumber</a> |
| </li> |
| </ul> |
| <table class="note"> |
| <tr> |
| <td class="noteImg"> |
| <img src="resources/note.gif" alt="note" /> |
| </td> |
| <td class="noteTxt">If you want to use the NodeInfo extension elements, you MUST set the TransformerFactory |
| <a href="features.html#source_location">source_location</a> attribute to true. |
| You can use the <a href="commandline.html">command-line utility</a> -L flag or the |
| <a href="apidocs/javax/xml/transform/TransformerFactory.html#setAttribute(java.lang.String, java.lang.Object)">TransformerFactory.setAttribute()</a> method to set this attribute.</td> |
| </tr> |
| </table> |
| |
| <a name="systemid"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h4>systemId</h4> |
| <p>Implemented in <a href="apidocs/org/apache/xalan/lib/NodeInfo.html"> |
| org.apache.xalan.lib.NodeInfo</a>, |
| <code>systemId()</code> returns the system ID for the current node, and |
| <code>systemId(node-set)</code> returns the system ID of the first node in the node-set.</p> |
| |
| |
| <a name="publicid"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h4>publicId</h4> |
| <p> |
| <b>To be done.</b> Implemented in <a href="apidocs/org/apache/xalan/lib/NodeInfo.html"> |
| org.apache.xalan.lib.NodeInfo</a>, |
| <code>publicId()</code> will return the public ID for the current node, and |
| <code>publicId(node-set)</code> will return the public ID of the first node in the node-set.</p> |
| |
| |
| <a name="linenumber"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h4>lineNumber</h4> |
| <p>Implemented in <a href="apidocs/org/apache/xalan/lib/NodeInfo.html"> |
| org.apache.xalan.lib.NodeInfo</a>, |
| <code>lineNumber()</code> returns the line number in the source document for the current node, and |
| <code>lineNumber(node-set)</code> returns the line number in the source document for the first node |
| in the node-set.</p> |
| <table class="note"> |
| <tr> |
| <td class="noteImg"> |
| <img src="resources/note.gif" alt="note" /> |
| </td> |
| <td class="noteTxt">This function returns -1 if the line number is not known (for example, the source is a |
| DOM Document).</td> |
| </tr> |
| </table> |
| |
| |
| <a name="columnnumber"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h4>columnNumber</h4> |
| <p>Implemented in <a href="apidocs/org/apache/xalan/lib/NodeInfo.html"> |
| org.apache.xalan.lib.NodeInfo</a>, <code>columnNumber()</code> returns the column number in the |
| source document for the current node, and <code>columnNumber(node-set)</code> returns the column |
| number in the source document for the first node in the node-set.</p> |
| <table class="note"> |
| <tr> |
| <td class="noteImg"> |
| <img src="resources/note.gif" alt="note" /> |
| </td> |
| <td class="noteTxt">This function returns -1 if the column number is not known (for example, the source is a DOM |
| Document).</td> |
| </tr> |
| </table> |
| |
| |
| |
| <a name="sql"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h3>SQL library</h3> |
| <ul> |
| <li> |
| <a href="#sqlconn">Setting up a connection</a> |
| </li> |
| <li> |
| <a href="#sqlparam">Parameterized queries</a> |
| </li> |
| <li> |
| <a href="#ex-sql">SQL library example</a> |
| </li> |
| <li> |
| <a href="samples.html#sql">SQL library sample applications</a> |
| </li> |
| </ul> |
| <p>The namespace for the SQL extension is:</p> |
| <code>http://xml.apache.org/xalan/sql</code> |
| <p> |
| The SQL extension provides extension functions for connecting to a JDBC data source, |
| executing a query, and working incrementally through a "streamable" result set. Streaming |
| (reuse of a single row node to traverse the result set) is the default mode of operation. |
| if you want unlimited access to the entire result set, you can cache the query result set |
| (1 row node for each row in the result set).</p> |
| <p> |
| <b>If you use streaming mode (the default), you can only access row elements one at a time |
| moving forward through the result set. The use of XPath expressions in your stylesheet, for |
| example, that attempt to return nodes from the result set in any other manner may produce |
| unpredictable results.</b> |
| </p> |
| <table class="note"> |
| <tr> |
| <td class="noteImg"> |
| <img src="resources/note.gif" alt="note" /> |
| </td> |
| <td class="noteTxt">Many features of the SQL library, including support for connection pools, parameterized |
| queries, caching, and added support for extracting connection information and query parameters |
| from XML source documents exist thanks to John Gentilin (johnglinux@eyecatching.com), who has |
| also added a number of <a href="samples.html#sql">SQL library samples</a>. |
| </td> |
| </tr> |
| </table> |
| <p> |
| <a href="apidocs/org/apache/xalan/lib/sql/XConnection.html">org.apache.xalan.lib.sql.XConnection</a> |
| provides a number of extension functions that you can use in your stylesheet.</p> |
| <ol> |
| <li>new() -- Use one of the XConnection constructors to connect to a data source, and return an |
| XConnection object. You can use one of the constructors creates a connection pool from which |
| stylesheets can obtain connections to a datasource. To support connection pools, SQL library |
| includes a ConnectionPool interface and a implementation: DefaultConnectionPool. You can also |
| provide your own ConnectionPool implementation.<br /> |
| <br /> |
| </li> |
| <li>query() -- Use the XConnection object query() method to return a "streamable" result set in |
| the form of a row-set node. Work your way through the row-set one row at a time. The same row |
| element is used over and over again, so you can begin "transforming" the row-set before the |
| entire result set has been returned.<br /> |
| <br /> |
| </li> |
| <li>pquery(), addParameter(), addParameterFromElement(), clearParameters() -- |
| Use the XConnection pquery() method in conjunction with these other methods to |
| set up and execute parameterized queries.<br /> |
| <br /> |
| </li> |
| <li>Use enableStreamingMode() to use a single row node to "stream" through the result set, and |
| disableStreamingMode() to cache the query result set. <br /> |
| <br /> |
| <table class="note"> |
| <tr> |
| <td class="noteImg"> |
| <img src="resources/note.gif" alt="note" /> |
| </td> |
| <td class="noteTxt"> |
| enableStreamingMode and disableStreamingMode() are depricated |
| See <a href="extensionslib.html#sql-ext-features">SQL Extension Features</a>. |
| </td> |
| </tr> |
| </table> |
| <br /> |
| </li> |
| <li>close() -- Use the XConnection object close() method to terminate the connection.</li> |
| </ol> |
| |
| <a name="sql-ext-features"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h4>SQL Extension Feature Settings</h4> |
| <p>The SQL Extension allows features of the extension to be set through the setFeature / getFeature interface.</p> |
| <p>To set a feature, use: <br /> |
| <code> |
| <xsl:value-of select="<br /> |
| sql:setFeature($db, 'feature-name', 'feature-value')"/> |
| </code> |
| <br /> |
| <br /> |
| To retrive the current value of the feature, use: <br /> |
| <code> |
| <xsl:value-of select="<br /> |
| sql:getFeature($db, 'feature-name')"/> |
| </code> |
| <br /> |
| </p> |
| <table border="1"> |
| <tr> |
| <th class="content" rowspan="1" colspan="1">Feature</th> |
| <th class="content" rowspan="1" colspan="1">Valid Values</th> |
| </tr> |
| <tr> |
| <td class="content" rowspan="1" colspan="1">streaming</td> |
| <td class="content" rowspan="1" colspan="1">true or false</td> |
| </tr> |
| </table> |
| |
| |
| <p>The query() and pquery() extension functions return a Document node that contains (as needed) |
| an array of column-header elements, a single row element that is used repeatedly, and an array |
| of col elements. Each column-header element (one per column in the row-set) contains an attribute |
| (ColumnAttribute) for each of the column descriptors in the ResultSetMetaData object. Each col |
| element contains a text node with a textual representation of the value for that column in the |
| current row.</p> |
| |
| <a name="sqlconn"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h4>Setting up a connection</h4> |
| <p>You can place connection information (JDBC driver, datasource URL, and usually user ID |
| and password) in stylesheets or in XML source documents.</p> |
| <p>The following stylesheet fragment uses stylesheet parameters to designate a JDBC driver |
| and datasource. The default parameter values can be overridden with runtime parameter values.</p> |
| <blockquote class="source"> |
| <pre> |
| <xsl:param name="driver" select="'org.apache.derby.jdbc.EmbeddedDriver'"/> |
| <xsl:param name="datasource" select="'jdbc:derby:sampleDB'"/> |
| <xsl:param name="query" select="'SELECT * FROM import1'"/> |
| </pre> |
| </blockquote> |
| <p>You can also obtain connection information from the XML source document that you use for the |
| transformation. Suppose you have the following DBINFO nodeset in an XML document:</p> |
| <blockquote class="source"> |
| <pre> |
| <DBINFO> |
| <dbdriver>org.apache.derby.jdbc.EmbeddedDriver</dbdriver> |
| <dburl>jdbc:derby:sampleDB</dburl> |
| <user>jbloe</user> |
| <password>geron07moe</password> |
| </DBINFO> |
| </pre> |
| </blockquote> |
| <p>In the stylesheet, you can extract this information as follows:</p> |
| <blockquote class="source"> |
| <pre> |
| <xsl:stylesheet version 1.0 |
| xmlns:xsl="http://www.w3.org/1999/XSL/Transform" |
| xmlns:sql="http://xml.apache.org/xalan/sql" |
| extension-element-prefixes="sql"> |
| <xsl:param name="cinfo" select="//DBINFO"/> |
| <xsl:variable name="db" select="sql:new($cinfo)"/> |
| .... |
| </pre> |
| </blockquote> |
| <p>For an example of both approaches, see <a href="samples.html#basic-conn">Basic Connection</a> |
| samples.</p> |
| <p>You can also create a named connection pool that is maintained external to Xalan-Java.</p> |
| <blockquote class="source"> |
| <pre> |
| import org.apache.xalan.lib.sql.DefaultConnectionPool; |
| import org.apache.xalan.lib.sql.XConnectionPoolManager; |
| ... |
| DefaultConnectionPool cp = new DefaultConnectionPool(); |
| cp.setDriver("org.apache.derby.jdbc.EmbeddedDriver"); |
| cp.setURL("jdbc:derby:sampleDB"); |
| cp.setUser(""); |
| cp.setPassword(""); |
| // Start with 10 connections. |
| cp.setMinConnections(10); |
| cp.enablePool(); |
| // Register the connection pool so stylesheets can use it. |
| XConnectionPoolManager pm = new XConnectionPoolManager(); |
| pm.registerPool("extpool", cp); |
| </pre> |
| </blockquote> |
| <p>A stylesheet can use this connection pool as follows:</p> |
| <blockquote class="source"> |
| <pre> |
| <xsl:stylesheet version 1.0 |
| xmlns:xsl="http://www.w3.org/1999/XSL/Transform" |
| xmlns:sql="http://xml.apache.org/xalan/sql" |
| extension-element-prefixes="sql"> |
| ... |
| <xsl:variable name="db" select="sql:new($driver, 'extpool')"/> |
| </pre> |
| </blockquote> |
| <p>For an example, see the <a href="samples.html#ext-conn">ExternalConnection</a> |
| sample.</p> |
| |
| |
| <a name="sqlparam"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h4>Parameterized queries</h4> |
| <p>To define a parameterized query, use a SQL query string with a question mark (?) for each |
| parameter. You can provide the parameter values at runtime with stylesheet parameters or with |
| nodes in the XML source document. |
| For each parameter, you should also designate the SQL data type.</p> |
| <p>XConnection provides a number of addParameter() methods and an addParameterFromElement() method |
| that you can use as extension functions to pull in the parameter values (in the order the |
| parameters appear in the query). To execute the query and return the result set, call the pquery() |
| method as an extension function. There are two variations of the pquery() method. The one you |
| should ordinarily use includes as arguments the SQL query string and a string list |
| (delimited by the space, tab, or line feeds) of parameter types. For example:</p> |
| <blockquote class="source"> |
| <pre> |
| <xsl:variable name="resultset" |
| select=sql:pquery($XConnectionObj, |
| 'select * from X where Y = ? and Z = ?', |
| 'int string')"/> |
| </pre> |
| </blockquote> |
| <p> |
| For a complete example, see the <a href="samples.html#pquery">Parameterized query</a> sample. |
| </p> |
| |
| |
| <a name="ex-sql"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h4>Example with SQL library</h4> |
| <p>This example displays the result set from a table in a sample Derby database. It is also |
| available as a sample application; see <a href="samples.html#sql">SQl Extension Samples</a>.</p> |
| <blockquote class="source"> |
| <pre> |
| <?xml version="1.0"?> |
| <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" |
| version="1.0" |
| xmlns:sql="http://xml.apache.org/xalan/sql" |
| extension-element-prefixes="sql"> |
| <xsl:output method="html" indent="yes"/> |
| <xsl:param name="query" select="'SELECT * FROM import1'"/> |
| <xsl:template match="/"> |
| <!-- 1. Make the connection --> |
| <xsl:variable name="products" |
| select="sql:new('org.apache.derby.jdbc.EmbeddedDriver', |
| 'jdbc:derby:sampleDB')"/> |
| <HTML> |
| <HEAD> |
| </HEAD> |
| <BODY> |
| <TABLE border="1"> |
| <!--2. Execute the query --> |
| <xsl:variable name="table" select='sql:query($products, $query)'/> |
| <TR> |
| <!-- Get column-label attribute from each column-header--> |
| <xsl:for-each select="$table/sql/metadata/column-header"> |
| <TH><xsl:value-of select="@column-label"/></TH> |
| </xsl:for-each> |
| </TR> |
| <xsl:apply-templates select="$table/sql/row-set/row"/> |
| <xsl:text>&#10;</xsl:text> |
| </TABLE> |
| </BODY> |
| </HTML> |
| <!-- 3. Close the connection --> |
| <xsl:value-of select="sql:close($products)"/> |
| </xsl:template> |
| |
| <xsl:template match="row"> |
| <TR> |
| <xsl:apply-templates select="col"/> |
| </TR> |
| </xsl:template> |
| |
| <xsl:template match="col"> |
| <TD> |
| <!-- Here is the column data --> |
| <xsl:value-of select="text()"/> |
| </TD> |
| </xsl:template> |
| |
| </xsl:stylesheet> |
| </pre> |
| </blockquote> |
| |
| |
| |
| <a name="pipedocument"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h3>pipeDocument</h3> |
| <p>Implemented in <a href="apidocs/org/apache/xalan/lib/PipeDocument.html"> |
| org.apache.xalan.lib.PipeDocument</a>,<br /> |
| the pipeDocument extension element pipes an XML document through a series of one or more |
| transformations. The output of each transformation is piped to the next transformation. The |
| final transformation creates a target file.</p> |
| <p>The namespace for the pipeDocument extension is:</p> |
| <p> <code>http://xml.apache.org/xalan/PipeDocument</code> |
| </p> |
| <p>Suppose, for example,you have a stylesheet that is processing a "book" document with elements |
| designating the documents to be transformed. This primary stylesheet generates a table of |
| contents for the book. For each source document it uses a pipeDocument extension element to pipe |
| the document through a series of one or more transformations.</p> |
| |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h4>Sample: generating a table of contents and an HTML "book"</h4> |
| <p>An XML "book" document contains a number of doc elements like the following:<br /> |
| <code><doc source="sources/intro.xml" id="intro" label="Introduction"></code> |
| </p> |
| <p>The source attribute identifies the document to be transformed, the id is the output file name, |
| and the primary stylesheet places the label in the table-of-contents link.</p> |
| <p>The stylesheet declares the pipeDocument namespace, designates the namespace prefix as an |
| extension element prefix, and contains a parameter designating where the output files are to |
| be placed:</p> |
| <blockquote class="source"> |
| <pre><xsl:stylesheet version="1.0" |
| xmlns:xsl="http://www.w3.org/1999/XSL/Transform" |
| xmlns:pipe="http://xml.apache.org/xalan/PipeDocument" |
| extension-element-prefixes="pipe"> |
| |
| <xsl:param name="destdir" value="html/output"> |
| ...</pre> |
| </blockquote> |
| <p>This stylesheet contains a template where each doc element is processed. For each doc element, the |
| stylesheet adds an entry to the table-of-contents document. The extension element pipes the specified |
| document through a series of two transformations, with an stylesheet input parameter for the first |
| transformation. The pipeDocument target attribute designates the output from the second |
| transformation.</p> |
| |
| <blockquote class="source"> |
| <pre><xsl:template match="doc"> |
| <p> |
| <a href={$destdir}><xsl:value-of select="@label"/><a> |
| </p> |
| |
| <pipe:pipeDocument source="{@source}" target="{$destdir/@id}"> |
| <stylesheet href="ss1.xsl"> |
| <param name="doc-id" value="@id"/> |
| </stylesheet> |
| <stylesheet href="ss2.xsl"/> |
| </pipe:pipeDocument> |
| |
| </xsl:template></pre> |
| </blockquote> |
| |
| <p>Notes:</p> |
| <ul> |
| <li>The base URI for the source attribute is the XML "book" document.</li> |
| <li>The target attribute is taken as is (the base is the current user directory from which this |
| transformation is being run).</li> |
| <li>The stylsheet containg the extension element is the base URI for the stylesheet hrefs.</li> |
| </ul> |
| |
| |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h4>Variation: using pipeDocument in an empty stylesheet</h4> |
| <p>Suppose you want to pipe a document through a series of transformations. You can use the pipeDocument |
| extension element to perform this operation by placing the extension element in an otherwise empty |
| stylesheet.</p> |
| <p>The following stylesheet is used to merge the Xalan documents into a book (the first transformation), |
| and transform the book into a tree of formatting objects, which can then be used to generate a PDF file. |
| This transformation is invoked as follows:</p> |
| <p> |
| <code>java org.apache.xalan.xslt.Process -in printbook.xml</code> |
| <br /> |
| <code> -param source printbook.xml</code> |
| <br /> |
| <code> -param target xalanbook.fo</code> |
| </p> |
| <p>There is no XML input document or output document for the primary transformation, which does no more |
| than invoke the extension element.</p> |
| <blockquote class="source"> |
| <pre><?xml version='1.0'?> |
| |
| <xsl:stylesheet version="1.0" |
| xmlns:xsl="http://www.w3.org/1999/XSL/Transform" |
| xmlns:pipe="http://xml.apache.org/xalan/PipeDocument" |
| extension-element-prefixes="pipe"> |
| |
| <xsl:param name="source"/> |
| <xsl:param name="target"/> |
| |
| <xsl:template match="/"> |
| |
| <pipe:pipeDocument |
| source="{$source}" |
| target="{$target}"> |
| <stylesheet href="printbook_assemble.xsl"/> |
| <stylesheet href="bkbook8x11_xalan.xsl"/> |
| </pipe:pipeDocument> |
| |
| </xsl:template> |
| |
| </xsl:stylesheet></pre> |
| </blockquote> |
| |
| |
| |
| |
| <a name="evaluate"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h3>evaluate</h3> |
| <p>Implemented in <a href="apidocs/org/apache/xalan/lib/Extensions.html"> |
| org.apache.xalan.lib.Extensions</a>,<br /> |
| <code>evaluate (xpath-expression)</code> function returns the result of evaluating the xpath-expression |
| in the current XPath expression context (automatically passed in by the extension mechanism).</p> |
| <p>Use the evaluation extension function when the value of the expression is not known until run time.</p> |
| <table class="note"> |
| <tr> |
| <td class="noteImg"> |
| <img src="resources/note.gif" alt="note" /> |
| </td> |
| <td class="noteTxt">Although you can still use the evaluate extension function in the main Extensions class, the |
| preferred solution is to use the same function in the EXSLT dynamic package. This will make your |
| stylesheet more portable across XSLT processors that support EXSLT extensions.</td> |
| </tr> |
| </table> |
| |
| |
| <a name="tokenize"></a> |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| <h3>tokenize</h3> |
| <p>Implemented in <a href="apidocs/org/apache/xalan/lib/Extensions.html"> |
| org.apache.xalan.lib.Extensions</a>,<br /> |
| <code>tokenize (tokenize-string, delimiters)</code> |
| <br /> |
| or<br /> |
| <code>tokenize (tokenize-string)</code> function returns a node-set containing one text node for each |
| token in the tokenize-string.</p> |
| <p>The delimiters determine which characters are used to divide the tokenize-string into individual |
| tokens. If you do not include the delimiters argument, the function uses tab (&#x09), linefeed |
| (&#x0A), return (&#x0D), and space (&#x20) as delimiters. if tokenize-string is an empty |
| string or contains only delimiters, the result is an empty node-set.</p> |
| <table class="note"> |
| <tr> |
| <td class="noteImg"> |
| <img src="resources/note.gif" alt="note" /> |
| </td> |
| <td class="noteTxt">Although you can still use the tokenize extension function in the main Extensions class, the |
| preferred solution is to use the same function in the EXSLT strings package. This will make your |
| stylesheet more portable across XSLT processors that support EXSLT extensions.</td> |
| </tr> |
| </table> |
| |
| <p align="right" size="2"> |
| <a href="#content">(top)</a> |
| </p> |
| </div> |
| <div id="footer">Copyright © 1999-2014 The Apache Software Foundation<br />Apache, Xalan, and the Feather logo are trademarks of The Apache Software Foundation<div class="small">Web Page created on - Thu 2014-05-15</div> |
| </div> |
| </body> |
| </html> |