server-php-xml-class-xquery-lite-class-xquery-lite.htm / htm
<html>
<head>
<title>XQuery Lite (class_xquery_lite.php)</title>
<link rel="stylesheet" href="main.css" type="text/css">
</head>
<body>
<div align="center">
<table border="0" width="80%" cellpadding="0" cellspacing="0">
<tr>
<td bgcolor="#aaaaee" class="text" align="center"><a href="http://phpxmlclasses.sourceforge.net/">PHP XML Classes</a></td>
</tr>
</table>
<table border="0" width="80%" cellpadding="0" cellspacing="0">
<tr>
<td bgcolor="#aaaaee" class="textblbl" align="center">XqueryLite (class_xquery_lite.php)</td>
</tr>
</table>
<br/>
<table border="0" width="80%">
<tr>
<td bgcolor="#eeeeff" class="text">Description: This is a PHP implementation of the <a href="xquery_lite.html">Xquery Lite</a>
language for XML query. This implementation is based on the PHP DOM extension (it uses Xpath). It is 100% compatible with
Xquery Lite.
</td>
</tr>
</table>
<br/>
<table border="0" bgcolor="ddddff" width="80%">
<tr>
<td valign="top" class="text" width="50%"><b>NEWS:</b>
<ul>
<li>First release of this class
</ul>
</td>
<td valign="top" width="50%" class="text">
This class code as well as documentation are hosted at <a href="http://www.sourceforge.net">SourceForge</a>
please visit our <a href="http://www.sourceforge.net/projects/phpxmlclasses/">SourceForge page</a> for releases, documentation, bug-tracking, support
forums and mailing lists.
</td>
</tr>
</table>
<br/>
<table border="0" width="80%" cellpadding="0" cellspacing="0">
<tr>
<td class="textbl" bgcolor="aaaaee" width="50%">Resources</td>
<td class="textbl" bgcolor="aaaaee" width="50%">Requirements</td>
</tr>
</table>
<table border="1" width="80%" cellpadding="0" cellspacing="0">
<tr>
<td valign="top" bgcolor="eeeeff" class="text" width="50%">
<ul>
<li><a class="textbl" href="http://www.sourceforge.net/projects/phpxmlclasses">Downloads</a>
<li><a class="textbl" href="http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/phpxmlclasses/xquery_lite/">Browse CVS</a>
<li><a class="textbl" href="http://sourceforge.net/tracker/?atid=470965&group_id=53613&func=browse">Report Bugs</a>
<li><a class="textbl" href="http://phpxmlclasses.sourceforge.net/xquery_lite.html">Xquery Lite Tutorial</a> (<a class="textbl" href="http://phpxmlclasses.sourceforge.net/xquery_lite_1.0.pdf">pdf</a>)
<li><a class="textbl" href="http://research.salutia.com/xquery_lite/demo.php">Demo Site</a>
</ul>
</td>
<td valign="top" bgcolor="eeeeff" class="text" width="50%">
<ul>
<li>PHP 4.2.1+
<li>DOM extension compiled
</ul>
</td>
</tr>
</table>
<br/>
<table border="0" width="80%" cellpadding="0" cellspacing="0">
<tr>
<td class="textbl" bgcolor="aaaaee" width="50%">Features</td>
<td class="textbl" bgcolor="aaaaee" width="50%">To-dos</td>
</tr>
</table>
<table border="1" width="80%" cellpadding="0" cellspacing="0">
<tr>
<td valign="top" bgcolor="eeeeff" class="text" width="50%">
<ul>
<li>Xquery Lite 1.0 supported.
</ul>
</td>
<td valign="top" bgcolor="ddddff" class="text" width="50%">
<ul>
<li>Support the new release of the Xquery Lite language adding if statements, sortby statements and others.
<li>Queries may be "unsafe" if the user may enter a query, so a small security check is needed in order to
allow user-entered queries without a problem.
</ul>
</td>
</tr>
</table>
<br/>
<table border="0" bgcolor="ddddff" width="80%">
<tr>
<!--
<td valign="top" class="text" width="50%"><b>To-do/future releases:</b>
<ul>
<li>Class
<li>Class
<li>Class
</ul>
</td> -->
<td valign="top" width="100%" class="text">
Contact: Luis Argerich (<a href="mailto:lrargerich@yahoo.com">;lrargerich@yahoo.com</a>)
</td>
</tr>
</table>
<br/>
<table border="0" bgcolor="ddddff" width="80%">
<tr>
<!--
<td valign="top" class="text" width="50%"><b>To-do/future releases:</b>
<ul>
<li>Class
<li>Class
<li>Class
</ul>
</td> -->
<td valign="top" width="100%" class="text">
Detailed description and usage: The usage of this class is easy, basically you just create an object
and then use init to initialize the object and the evaluate_xqueryl method to process a qery:
<pre>xq->init();
xq->evaluate_xqueryl(</pre>
If you need to process a second query call the init method to reset object internal state to the
initial state. In order to learn more about Xquery Lite and how to write a query please visit the
<a href="xquery_lite.html">Xquery Lite home page</a>
<br/>
</div>
<h3>Documentation</h3>
<h2>Classes</h2>
<ul>
<li><a href="#class27">XqueryLite</a></li>
</ul>
<a name="class27"></a>
<h3>XqueryLite</h3>
Extends: None
Description: This class implements the Xquery Lite 1.0 language, a querying language for XML based on Xquery 1.0 using Xpath and FLWR expressions as the foundations.
<br>
<!-- METHOD SUMMARY -->
<A NAME="pDomNode_method_summary"><!-- --></A>
<TABLE BORDER="1" CELLPADDING="3" CELLSPACING="0" WIDTH="100%">
<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
<TD COLSPAN=2><FONT SIZE="+2">
<B>Method Summary</B></FONT></TD>
</TR>
<!-- A ROW -->
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> void</CODE></FONT></TD>
<TD><CODE><B><A HREF="#class27method1">XqueryLite</A></B>()</CODE>
<BR>
Constructor</TD>
</TR>
<!-- A ROW -->
<!-- A ROW -->
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> void</CODE></FONT></TD>
<TD><CODE><B><A HREF="#class27method2">init</A></B>()</CODE>
<BR>
Initializes the object internal state to the initial state</TD>
</TR>
<!-- A ROW -->
<!-- A ROW -->
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> string</CODE></FONT></TD>
<TD><CODE><B><A HREF="#class27method3">evaluate_xqueryl</A></B>(string query)</CODE>
<BR>
Evaluates an Xquery Lite 1.0 query</TD>
</TR>
<!-- A ROW -->
<!-- A ROW -->
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> array</CODE></FONT></TD>
<TD><CODE><B><A HREF="#class27method4">_tokenize</A></B>(string node)</CODE>
<BR>
(PRIVATE) Returns the root tagname from a node</TD>
</TR>
<!-- A ROW -->
<!-- A ROW -->
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> string</CODE></FONT></TD>
<TD><CODE><B><A HREF="#class27method6">_parse_for</A></B>(string nodeset)</CODE>
<BR>
(PRIVATE) Filters a nodeset returning a nodeset without duplicate nodes</TD>
</TR>
<!-- A ROW -->
<!-- A ROW -->
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> string</CODE></FONT></TD>
<TD><CODE><B><A HREF="#class27method8">_normalize_elements</A></B>(object expr, boolean a/xpath_expr expression</TD>
</TR>
<!-- A ROW -->
<!-- A ROW -->
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> int</CODE></FONT></TD>
<TD><CODE><B><A HREF="#class27method10">_count_var</A></B>(string a/xpath_expr expression</TD>
</TR>
<!-- A ROW -->
<!-- A ROW -->
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> boolean</CODE></FONT></TD>
<TD><CODE><B><A HREF="#class27method11">_parse_where</A></B>(string expr)</CODE>
<BR>
(PRIVATE) Parses a return statement</TD>
</TR>
<!-- A ROW -->
<!-- A ROW -->
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> void</CODE></FONT></TD>
<TD><CODE><B><A HREF="#class27method13">_parse_let</A></B>(string exprs)</CODE>
<BR>
(PRIVATE) Split a for statement in several if it has to</TD>
</TR>
<!-- A ROW -->
<!-- A ROW -->
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> string</CODE></FONT></TD>
<TD><CODE><B><A HREF="#class27method15">_parse_query</A></B>(string query)</PRE>
<DL>
<DD>This method is used to evaluate an Xquery Lite 1.0 query, just pass the query as an argument and receive the result.<DD>
<DL>
<DT><B>Parameters:</B><DD>
<br><DT><B>Returns:</B><DD>The result of the query whatever it is<DT><B>Throws:</B><DD><CODE>Several exceptions can be reaised as warnings if an error occurs when parsing the query, tipically the query has a syntax error or the XML source can't be located.</CODE>
</DL>
</DD>
</DL>
<HR>
<!-- a method -->
<!-- method -->
<A NAME="class27method4"><!-- --></A>
<H3>_tokenize</H3>
<PRE>
array <B>_tokenize</B>(string exp)</PRE>
<DL>
<DD>This private method receives a Xquery Lite expression (whatever is found between curly brackets) and returns an array of statements, for example v[0]=a for statament, v[1]=a let statement, v[2]=a where statement, v[3]=return statement.<DD>
<DL>
<DT><B>Parameters:</B><DD>
<br><DT><B>Returns:</B><DD>An array where each array position contains an statement<DT><B>Throws:</B><DD><CODE>None</CODE>
</DL>
</DD>
</DL>
<HR>
<!-- a method -->
<!-- method -->
<A NAME="class27method5"><!-- --></A>
<H3>_get_root_name</H3>
<PRE>
string <B>_get_root_name</B>(object node)</PRE>
<DL>
<DD>This method returns the name of the root element from an XML fragment passed as a node.<DD>
<DL>
<DT><B>Parameters:</B><DD>
<br><DT><B>Returns:</B><DD>The name of the root element<DT><B>Throws:</B><DD><CODE>None</CODE>
</DL>
</DD>
</DL>
<HR>
<!-- a method -->
<!-- method -->
<A NAME="class27method6"><!-- --></A>
<H3>_parse_for</H3>
<PRE>
string <B>_parse_for</B>(string expr)</PRE>
<DL>
<DD>This method parses a for statement and puts the nodeset resulting from the for statement in the object result_sets member.<DD>
<DL>
<DT><B>Parameters:</B><DD>
<br><DT><B>Returns:</B><DD>The name of the Xquery variable corresponding to the for statement.<DT><B>Throws:</B><DD><CODE>It can raise an error if the XML source is not found, if it is not well formed or if the Xpath expression in the for statement is wrong</CODE>
</DL>
</DD>
</DL>
<HR>
<!-- a method -->
<!-- method -->
<A NAME="class27method7"><!-- --></A>
<H3>_distinct</H3>
<PRE>
array <B>_distinct</B>(array nodeset)</PRE>
<DL>
<DD>Filters a nodeset returning a nodeset without duplicate nodes, the normalize_elements function is used in order to compare nodes and find duplicate nodes in the nodeset.<DD>
<DL>
<DT><B>Parameters:</B><DD>
<br><DT><B>Returns:</B><DD>An array of nodes (another nodeset) without duplicate nodes<DT><B>Throws:</B><DD><CODE>None</CODE>
</DL>
</DD>
</DL>
<HR>
<!-- a method -->
<!-- method -->
<A NAME="class27method8"><!-- --></A>
<H3>_normalize_elements</H3>
<PRE>
string <B>_normalize_elements</B>(object node)</PRE>
<DL>
<DD>This function normalizes a dom subtree removing all whitespace elements thus producing a normalized representation of the subtree that can be used in comparisons.<DD>
<DL>
<DT><B>Parameters:</B><DD>
<br><DT><B>Returns:</B><DD>An string containing a normalized dump of the subtree<DT><B>Throws:</B><DD><CODE>None</CODE>
</DL>
</DD>
</DL>
<HR>
<!-- a method -->
<!-- method -->
<A NAME="class27method9"><!-- --></A>
<H3>_parse_var</H3>
<PRE>
string <B>_parse_var</B>(string expr, boolean a/xpath_expr where expr - The expression to be parsed<br><br><DT><B>Returns:</B><DD>A string representing the result, if the result is a nodeset then all nodes are concatenated one after the other.<DT><B>Throws:</B><DD><CODE>It can raise an exception if the xpath expression has an error or if the variable is not well formed XML</CODE>
</DL>
</DD>
</DL>
<HR>
<!-- a method -->
<!-- method -->
<A NAME="class27method10"><!-- --></A>
<H3>_count_var</H3>
<PRE>
int <B>_count_var</B>(string expr)</PRE>
<DL>
<DD>This method parses a expr - The expression<br><DT><B>Returns:</B><DD>The number of elements in the nodeset if no xpath expression is passed returns 1 if the variable exists if the nodeset is empty returns 0<DT><B>Throws:</B><DD><CODE>It can raise an error if the variable is not XML if it doesn't exist or it the Xpath expression is wrong.</CODE>
</DL>
</DD>
</DL>
<HR>
<!-- a method -->
<!-- method -->
<A NAME="class27method11"><!-- --></A>
<H3>_parse_where</H3>
<PRE>
boolean <B>_parse_where</B>(string expr - The where statement<br><DT><B>Returns:</B><DD>The result of the where expression<DT><B>Throws:</B><DD><CODE>If there's an error in the expression it raises an error</CODE>
</DL>
</DD>
</DL>
<HR>
<!-- a method -->
<!-- method -->
<A NAME="class27method12"><!-- --></A>
<H3>_parse_return</H3>
<PRE>
string <B>_parse_return</B>(string expr - The return statement, everything found from the return word to the end of the query, including the return word.<br><DT><B>Returns:</B><DD>The result of the return statement<DT><B>Throws:</B><DD><CODE>Several errors can be raised since this can potentially call evaluate_xqueryl</CODE>
</DL>
</DD>
</DL>
<HR>
<!-- a method -->
<!-- method -->
<A NAME="class27method13"><!-- --></A>
<H3>_parse_let</H3>
<PRE>
void <B>_parse_let</B>(string expr - The let statement<br><DT><B>Returns:</B><DD>nothing<DT><B>Throws:</B><DD><CODE>None</CODE>
</DL>
</DD>
</DL>
<HR>
<!-- a method -->
<!-- method -->
<A NAME="class27method14"><!-- --></A>
<H3>_split_fors</H3>
<PRE>
array <B>_split_fors</B>(string exprs - A for statement in compact or extended notation<br><DT><B>Returns:</B><DD>An array where each element is a for statement<DT><B>Throws:</B><DD><CODE>None</CODE>
</DL>
</DD>
</DL>
<HR>
<!-- a method -->
<!-- method -->
<A NAME="class27method15"><!-- --></A>
<H3>_parse_query</H3>
<PRE>
string <B>_parse_query</B>(string query - The Xquery Lite expression to be parsed<br><DT><B>Returns:</B><DD>The result of the query<DT><B>Throws:</B><DD><CODE>If there's an error when parsing the query</CODE>
</DL>
</DD>
</DL>
<HR>
<!-- a method -->
<!-- ============ METHOD DETAIL ========== -->
</td>
</tr>
</table>
</body>
</html>
(C) Æliens 20/2/2008
You may not copy or print any of this material without explicit permission of the author or the publisher. In case of other copyright issues, contact the author.
