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What is an XML Action?

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

Creating XML Actions

Click and drag the
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icon from the toolbar onto the canvas
Enter a name for the XML action, then select Create Action
In the XML action
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on the right, populate the following details:

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 is used to navigate through elements and attributes in an XML document and determines which elements are extracted from the XML.

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 XPath returns the root element of the XML document, only one record will be returned. Whereas if the XPath returns children elements, one record will be returned for each child element.

// XML XPath

/root/main/title

4.

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all settings

XPath Syntax

Expression	Description
`/`	Traverses 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.
..	Traverses up 1 element in the hierarchy from child to parent.
`[ ]`	Selects a child element of the current element (by name or index number).
@	Selects 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.
`*`	Is a wildcard, returning all elements regardless of their name.

See XML and XPath and XPath Syntax for examples of how different XPath expressions provide different results.

Output Attributes

Add a list of attributes to be returned by the XML action, using the value _result. followed by the Attribute Expression Syntax (see below) and the name of the element/attribute required. To add an Output Attribute, click the

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button and complete the appropriate details. For example:

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Attribute Expression Syntax

Expression	Description
.	Traverses 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.Ttlte`, will return the value held in Title element.
^	Traverses up 1 element in the hierarchy from child to parent.
`[ ]`	Selects a child element of the current element (by name or index number).
`*`	Is a wildcard, returning all elements regardless of their name.
@	Selects all attributes with the specified name, e.g. //`@foo` will return all attributes named foo in the XML document.

XML Namespaces

XML Namespaces provide a method to avoid element name conflicts by ensuring they are unique. XML documents containing namespaces are supported.

For more information on XML Namespaces, see https://www.w3schools.com/xml/xml_namespaces.asp and XML Namespace. Also, see Namespaces in the Example XML below.

Example XML

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title	See Example

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language	xml

<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>

XPath

/root/main/title

Results

The following examples show how to reference the returned XPath's XML data structure in an Output Attribute:

XML Data	Expression	Returns
XPath value	`_result`	PF Title Text
XPath element attributes	`_result.name`	PF Title
XPath parent attributes	`_result.^.page`	PF Main Page
XPath child attributes	`listToString(_result.datarow.data.initials)`	AA,BB
XPath child attribute text values	`listToString(_result.datarow.data)`	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 to handle multiple matching child elements/attributes

Namespaces

XPath

Within path expressions, namespaces 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.

Results

Within attribute expressions, a $ is used instead of the normal : namespace notation.

XML Data	Expression	Returns
XPath element attributes	`_result.h$name`	PF Title
XPath child attributes	`listToString(_result.h$datarow.h$data.h$initials)`	AA,BB
XPath child attribute text values	`listToString(_result.h$datarow.h$data.value)`	Alistair Andrews,Bert Brown

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

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Worked Example

Here is a worked example using an XML file from BBC News (https://feeds.bbci.co.uk/news/technology/rss.xml).

In this example, we are using:

A Shop News screen containing a blank grid and a button - this screen was created using the Multi-tile template

Tip
If you are completing this chapter as part of the Actionflow course and using a training instance, the data and screens have already been pre-loaded into the Actionflow Intermediate Application. For these example, we'll be working on the Shop News screen.

Create an RSS Feed using XML Data

In this example, we'll create a table containing BBC News from an XML file.

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Table Setup

Create a new
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on your
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to save the news data to, and ensure it contains the following attributes:
1. Name: UID
  1. Type: Integer
  2. Expression: _NULL
2. Name: Title
  1. Type: String
  2. Expression: _NULL
3. Name: Description
  1. Type: Bigstring
  2. Expression: _NULL
4. Name: Link
  1. Type: String
  2. Expression: _NULL
5. Name: Date
  1. Type: Datetime
  2. Expression: _NULL
6. Name: Source
  1. Type: String
  2. Expression: _NULL

Actionflow Setup

On the Shop News screen, add an Actionflow on the Start RSS Feed button
Select Click to Connect and choose On Click
Drag a
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action onto the canvas and give it a suitable name - this will be used to retrieve the news from the XML document
Drag the
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connection point node onto the
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action
Click on the
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action to open its Properties
1. HTTP Method: GET
2. URL: https://feeds.bbci.co.uk/news/technology/rss.xml
Drag a
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action onto the canvas and give it a suitable name - this will be used to convert the XML data into data suitable for PhixFlow to process
Connect the out connector from the
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to the
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action
1. Map across the attribute, body
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XML Action Setup

Click on the
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action to open its Properties and populate the following:
1. Input Expression: in.body
2. Path: /rss/channel/item
3. Output Attributes:
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  title Name: Title, Type: String
  _result.title
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  title Name: Description, Type: Bigstring
  _result.description
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  title Name: Link, Type: String
  _result.link
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  title Name: ID, Type: String
  _NULL
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  title Name: Date, Type: Datetime
  do( $dater = replaceAll(_result.pubDate, " GMT", ""), $dater = substring($dater, 6), toDate($dater, "dd MMM yyyy HH:mm:ss") )
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  title Name: Source, Type: String
  _result.^.title
Hover over the XML action and select out
Create a
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action
1. Primary Table: The News table you created earlier
2. Map across the XML attributes to their relevant attributes on the Save action
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Screen Setup

Open the Shop News screen
Click on
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in the toolbar, then select the News table you created earlier
In the Available Attributes selector, select all attributes and drag them onto the screen, then choose to display the data as a
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Testing

On the Shop News screen,
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the screen and click the Start RSS Feed button
If the Actionflow is working, the News grid should contain all of the BBC News data

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What is an XML Action?