Overview

Use an XML action to process XML data, and convert it into specific data objects that can be used by PhixFlow for processing. The XML Node extracts one or more records from the provided XML document using the XPath specified.

Properties Tab

Basic Settings

Field Description Example Value

Name Name given to the XML Node. This will be displayed on the actionflow canvas. MyXMLReader

Input Expression

This field is mandatory.

The input expression provides the source of the XML data to be operated upon. Typically, this will be a simple expression pointing at an incoming attribute, such as, the body from a HTTP Node.

// Consists of the pipe name and the name of a mapped attribute

in.body

XPath

The XPath expression is evaluated against the XML document provided by the Input Expression and returns a list of XML elements. It determines which elements are extracted from the XML.

Note that the XPath determines the number of elements that are processed, which directly correlates to the number of records returned by the XML Node. For example, if the path returns the route element of the XML Document only one record will be returned. Whereas a path that returns children nodes will return one record for each child element.

// XML XPath

/root/main/title

XPath Syntax

Expression	Description
`/`	symbol used to traverse down into the XML structure. It is the child operator, used to denote a child element of the current element. All elements are delimited using this notation e.g. `/rss/Item/Date`, will return the value held in the Date element.
..	is used to traverse up 1 element in the hierarchy from child to parent.
`[ ]`	is used to select a child element of the current element (by name or index number).
@	is used to select all attributes with the specified name e.g. //`@foo` will return all attributes named foo in the XML document. See Attributes vs Elements for details.
`//`	Selects elements, from within the current element, that match the selection regardless of their location e.g. `/root/item//bar` will return all bar elements from within item.
`*`	a wildcard, returning all elements regardless of their name.

Attribute Expression Syntax

Expression Description

.

symbol is used to traverse down into the XML structure. It is the child operator, used to denote a child element of the current element.

All elements are delimited using this notation e.g. _result.Feed.Tilte, will return the value held in Title element.

^ symbol is used to traverse up 1 element in the hierarchy from child to parent.

[ ] is used to select a child element of the current element (by name or index number).

Worked examples are provided at the end of this page.

Output Attributes

Contains a list of attributes returned by the node. In this node XML is converted into data objects that can be used by PhixFlow, this information is accessed using the Attribute Expression syntax in an output attribute. To add an output attribute click the button and complete the appropriate details. For example:

Namespaces

XML documents containing namespaces are supported.

The Namespace grid contains a list of expected namespaces defined in an XML response.

Add a Namespace

To add a namespace to the list, click Create New. PhixFlow opens a new XML Namespace property pane.

Remove Namespace

To remove a namespace, use the Delete in the toolbar.

Example

See Worked Example below.

Advanced

Field	Description
Prioritise Throughput Over Ordering	When enabled, records are processed in parallel to optimise performance. This means the order records are processed is nondeterministic. When disabled (default), records are processed in the order they are provided.

Worked Example

<root xmlns:h="http://example.com/schema"> 
	<main page="PF Main Page"> 
		<title name="PF Title">PF Title Text
			<datarow> 
				<data initials="AA">Alistair Andrews</data>
				<data initials="BB">Bert Brown</data> 
			</datarow> 
		</title> 
	</main> 
</root>

XPath

/root/main/title

A record is created for each element returned by the path. Therefore we do not recommend returning the root as this only returns a single record.

Results

The following examples show how to reference the returned xpaths xml data structure in an Output Attribute:

Xpath value: _result → returns the elements from the path.
Xpath element attributes: _result.name → returns 'PF Title'
Xpath parent attributes: _result.^.page -> returns 'PF Main Page'
Xpath child attributes: listToString(_result.datarow.data.initials) → returns 'AA,BB'
Xpath child attribute text values: listToString(_result.datarow.data) → returns 'Alistair Andrews,Bert Brown'

Note the use of

^ to traverse to the immediate parent element.
. to traverse to the immediate child element.
the listToString function is used to handle multiple matching child values.

Namespace Example

<root xmlns:h="http://example.com/schema"> 
	<main page="PF Main Page"> 
		<h:title name="PF Title">PF Title Text
			<h:datarow> 
				<h:data h:initials="AA">Alistair Andrews</data>
				<h:data h:initials="BB">Bert Brown</data> 
			</h:datarow> 
		</h:title> 
	</main> 
</root>

Within the XPath expression they are referred to using semicolons

/root/main/h:title

A record is created for each element returned by the path. Therefore we do not recommend returning the root as this only returns a single record.

Within Attribute Expressions a $ is used instead of the normal : namespace notation

Xpath element attibutes: _result.h$name → returns 'PF Title'
Xpath child attributes: listToString(_result.h$datarow.h$data.h$initials) → returns 'AA,BB'
Xpath child attribute text values: listToString(_result.h$datarow.h$data.value) -> returns 'Alistair Andrews,Bert Brown'

The namespace prefix used here 'h' must be configured in the XML Namespace.

Learn More

For links to all pages in this topic, see Understanding Actionflows.