XMLExecuteXPath (Function)

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Syntax 2: Executing an XPATH query on an XML document: Reading the query result
Limitations
XML functions and threads

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XMLExecuteXPath (Function)

Executes an XPATH query:

in a variable of type xmlDocument.
Not available.
in an XML document.
Not available.

Only the calculation queries performed in an XML document are supported in PHP.

Ejemplo

clDoc is xmlDocument = XMLOpen(n, fromString)
c is xpathResult = XMLExecuteXPath(clDoc, "/root/text()")
IF c.IsValue THEN
	Trace(c.Value)
ELSE
	FOR EACH ANode OF c.Node
		Trace("Node: " + UnNode..Text)
	END
	FOR EACH attrib OF c.Attribute
		Trace("Node: " + attrib.Name)
	END
END

// Load the XML file
MyDoc is string
MyDoc = fLoadText("example.xml")
// Query text: Search for the Index tag
XPATHQuery is string = "Help/Function/Index"
// Create the document
XMLDocument("Example", MyDoc)
IF ErrorOccurred = True THEN
	Error("The file is not in XML format.")
	RETURN
END
b is boolean
b = XMLExecuteXPath("Example", XPATHQuery)
// Is it a calculation query?
IF b = True AND XMLOut("Example") = True THEN
	 // The calculation result is as follows
	 Trace("XMLResult=" + XMLResult("Example"))
END
// Is it a selection XPath query?
IF XMLFound("Example") = True THEN
	// Browse the result selection
	WHILE XMLFound("Example") = True
		Trace(XMLPath("Example"))
		XMLNext("Example")
	END
	// Browse completed, end the query
	XMLCancelSearch("Example")
END

Sintaxis

Syntax not available in PHP and browser code

Executing an XPATH query on an xmlDocument variable Ocultar los detalles

<Result> = XMLExecuteXPath(<XML document> , <Text of XPath query>)

<Result>: xpathResult variable

xpathResult variable containing the result of the XPATH query.
Reading the result:
The IsValue property allows you to know if the result is a value.
For a selection query (the result is not a value), the xpathResult variable must be browsed.
For a calculation query (the result is a value), the Value property reads the result.

<XML document>: xmlDocument variable

Name of the xmlDocument variable containing the XML code to analyze.

<Text of XPath query>: Character string

Text of the XPath query to execute.

Syntax not available in Android and Android Widget

Executing an XPATH query on an XML document (syntax kept for backward compatibility) Ocultar los detalles

<Result> = XMLExecuteXPath(<Name of the XML document> , <Text of XPath query>)

<Result>: Boolean

True if the query was executed,
False otherwise or if no element corresponds to the query.
Reading the result:
For a selection query, if the XPATH query has been executed, the XML search functions are used to browse the result of the XPATH query.
For a calculation query, XMLResult is used to read the result.

<Name of the XML document>: Character string

Name of the XML document used. This document contains the XML code to study and it was created by XMLDocument.

<Text of XPath query>: Character string

Text of the XPath query to execute.

Observaciones

Syntax 2: Executing an XPATH query on an XML document: Reading the query result

If XMLExecuteXPath returns True, the query has been successfully executed.. The result of the query can be read as follows:

Calculation request function XMLFound returns False.
The result can be read by XMLResult.
Some examples of calculation queries:


Counting the number of tags whose name is "ITEM", which means the number of different items found in the order.	count(//ITEM)
Number of tags containing a subelement named <PRICE>	count(//*[PRICE])
Total of the invoice	sum(//ITEM[PRICE])- sum(//COUPON[PRICE])

Record selection request function XMLFound returns True.
In a selection query, XMLExecuteXPath changes the current position in the XML document to set the position on the first element of the selection result. Then, XMLNext allows you to browse the selection.
Some examples of selection queries:
Browse all the elements with a "unit" attribute. //*[@unit]
Browse all the tags whose name is "ITEM". //ITEM

To cancel the query and to browse the entire document again, use XMLCancelSearch.

Limitations

Several XPath browse queries cannot be nested.
Syntax 1: Execute an XPATH request on a variable of type xmlDocument:
- The list of nodes is not sorted.
- The standard used for the XPath query is XPath 1.0.
Syntax 2: Executing an XPATH query on an XML document:
XMLSavePosition and XMLRestorePosition cannot be used to save/restore a position when browsing the result of a select XPath query.

XML functions and threads

If your application uses threads, the XML document is shared between all these threads. For more details on threads, see Managing threads.

If the current position in an XML document is modified in a thread, the current position in this XML document is modified for all the threads.

Clasificación Lógica de negocio / UI: Lógica de negocio

Componente: wd300xml.dll

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Versión mínima requerida

Versión 9

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Última modificación: 28/03/2025

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