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Docs: LazUtils/laz2_xpath. Updates content in topics including:

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* TXPathToken
 * TXPathKeyword
 * TXPathScanner
 * TXPathExpression
 * TXPathExpression.Evaluate
 * EvaluateXPathExpression
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dsiders 2023-04-13 01:13:41 +01:00
parent 3bdbedd91b
commit 958711dd67
1 changed files with 89 additions and 11 deletions
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docs/xml/lazutils/laz2_xpath.xml
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@ -47,7 +47,10 @@ This file is part of the <file>LazUtils</file> package.
<element name="TXPathToken">
<short>Identifies token types used in XPath expressions.</short>
<descr></descr>
<seealso></seealso>
<seealso>
<link id="TXPathScanner"/>
<link id="TXPathKeyword"/>
</seealso>
</element>
<!-- enumeration value Visibility: default -->
@ -145,7 +148,10 @@ Represents keywords used in XPath syntax.
TXPathKeyword is an enumeration type that represents the axis names, node
tests, operators, and standard functions available in XPath syntax.
</descr>
<seealso></seealso>
<seealso>
<link id="TXPathScanner"/>
<link id="TXPathToken"/>
</seealso>
</element>
<element name="TXPathKeyword.xkNone">
<short>No axis specified.</short>
@ -1726,12 +1732,14 @@ parse tree consists of TXPathExprNode (and descendent) class instances which
evaluate the XPath expressions and generate the result(s).
</p>
<p>
TXPathScanner is used in the implementation of the TXPathExpression class.
TXPathScanner is used in the implementation of the TXPathExpression class and
the EvaluateXPathExpression routine.
</p>
</descr>
<seealso>
<link id="TXPathExprNode"/>
<link id="TXPathExpression"/>
<link id="EvaluateXPathExpression"/>
</seealso>
</element>
@ -2817,8 +2825,25 @@ Provides indexed access to XPath variables in the XPath environment.
<short>
Evaluates an XPath expression using the specified scanner and resolver.
</short>
<descr></descr>
<seealso></seealso>
<descr>
<p>
<var>TXPathExpression</var> is a class used to evaluate an XML XPath
expression provided to an XPath scanner. It contains methods used to evaluate
the expression in the scanner and return a TXPathVariable with the node(s) or
value(s) which match the expression.
</p>
<p>
TXPathExpression instances are created and used in the EvaluateXPathExpression
routine.
</p>
</descr>
<seealso>
<link id="TXPathExpression.Evaluate"/>
<link id="TXPathScanner"/>
<link id="TXPathNSResolver"/>
<link id="TXPathVariable"/>
<link id="EvaluateXPathExpression"/>
</seealso>
</element>
<element name="TXPathExpression.FRootNode"/>
@ -2859,10 +2884,37 @@ argument is set to True.
<element name="TXPathExpression.Evaluate">
<short>
Evaluates an XPath expression using the scanner for the class instance with
the specified context node and environment.
the specified context node and XPath environment.
</short>
<descr></descr>
<seealso></seealso>
<descr>
<p>
<var>Evaluate</var> is an overloaded method in TXPathExpression used to select
node(s) or value(s) in the specified context which match an XPath expression.
It returns a TXPathVariable type which contains the node(s) or value(s) which
match the expression used in the XPath scanner for the class instance.
</p>
<p>
An overloaded variant allows the XPath environment to be provided during
expression evaluation. The TXPathEnvironment argument allows variable names,
variable values, and functions to be added to or removed from the execution
environment. It also provides an implementation of the core functions in the
XPath function library.
</p>
<p>
Evaluate iteratively calls the Evaluate method for nodes in the root context
to capture the return value for the method.
</p>
<p>
No actions are performed in the method if a root node has not been assigned in
the XPath scanner. In this situation, the return value is <b>Nil</b>.
</p>
</descr>
<seealso>
<link id="TXPathEnvironment"/>
<link id="TXPathScanner"/>
<link id="TXPathVariable"/>
<link id="TXPathExprNode.Evaluate"/>
</seealso>
</element>
<element name="TXPathExpression.Evaluate.Result">
<short>Value from the evaluated expression.</short>
@ -2886,8 +2938,24 @@ namespace resolver.
used to locate and return a node or tree of nodes that match the XPath
expression specified in <var>AExpressionString</var>. AExpressionString is
similar to a SQL query, and is used to navigate and select DOM nodes found in
the <var>AContextNode</var> argument. XPath syntax is defined in the
specification located at:
the <var>AContextNode</var> argument.
</p>
<p>
Some examples (for specific xml document content) include:
</p>
<code>
/bookstore/book
/bookstore/book[1]
/bookstore/book[last()]
/bookstore/book[price&lt;35.00]/title
//title[@lang]
//title[@lang="en"]
//title[starts-with(text(),"Introduction to")]
//book[@genre="Science Fiction"]
//*[contains(@class, "nav")]
</code>
<p>
XPath expressions and syntax are defined in the specification located at:
</p>
<p>
<url href="https://www.w3.org/TR/1999/REC-xpath-19991116/">
@ -2930,7 +2998,17 @@ application using methods like <var>AsNodeSet</var>, <var>AsBoolean</var>, or
<var>TXPathNumberVariable</var>, or <var>TXPathStringVariable</var>.
</p>
</descr>
<seealso></seealso>
<seealso>
<link id="TXPathExpression.Evaluate"/>
<link id="TXPathScanner"/>
<link id="TXPathNSResolver"/>
<link id="TXPathVariable"/>
<link id="TXPathNodeSetVariable"/>
<link id="TXPathBooleanVariable"/>
<link id="TXPathNumberVariable"/>
<link id="TXPathStringVariable"/>
<link id="#lazutils.laz2_dom.TDomNode">TDomNode</link>
</seealso>
</element>
<element name="EvaluateXPathExpression.Result">
<short>XPath variable representing the evaluated XPath expression.</short>