XML Formatter

Overview

You can use this Snap to format the incoming document objects into XML data format.



Warning:

Breaking Change for Pipelines Using the XML Formatter Snap

After upgrading to 425patches10152, the Snap might fail when you select Map input to first repeating element in XSD checkbox with an Could not convert the document to an XML error. In such cases, ensure that you provide a complete path from the root element for an object and map the input properly to the root element.

  • Format-type Snap
  • Works in Ultra Tasks if Root element property is not selected.

Snap views

View Description Examples of upstream and downstream Snaps
Input JSON document.
Output XML document
Error

Error handling is a generic way to handle errors without losing data or failing the Snap execution. You can handle the errors that the Snap might encounter when running the pipeline by choosing one of the following options from the When errors occur list under the Views tab. The available options are:

  • Stop Pipeline Execution Stops the current pipeline execution when an error occurs.
  • Discard Error Data and Continue Ignores the error, discards that record, and continues with the remaining records.
  • Route Error Data to Error View Routes the error data to an error view without stopping the Snap execution.

Learn more about Error handling in Pipelines.

Snap settings

Legend:
  • Expression icon (): Allows using pipeline parameters to set field values dynamically (if enabled). SnapLogic Expressions are not supported. If disabled, you can provide a static value.
  • SnapGPT (): Generates SnapLogic Expressions based on natural language using SnapGPT. Learn more.
  • Suggestion icon (): Populates a list of values dynamically based on your Snap configuration. You can select only one attribute at a time using the icon. Type into the field if it supports a comma-separated list of values.
  • Upload : Uploads files. Learn more.
Learn more about the icons in the Snap settings dialog.
Field / Field set Type Description
Label String

Required. Specify a unique name for the Snap. Modify this to be more appropriate, especially if more than one of the same Snaps is in the pipeline.

Default value: XML Formatter

Example: XML Formatter
Outbound schema String/Expression Specify the XSD schema definition file URL for the outgoing data. The currently supported URL protocols are SLDB, HDFS, S3.

The Schema language supported is W3C XML Schema 1.0.

Default value: N/A

Example: sldb:///foo/bar/customer.xsd
Output Character Set String/Expression/ Suggestion

Required. Specify or select the character set encoding for the output.





Default value: UTF-8

Example: ISO860
Validate output Checkbox Select this checkbox to validate the output against the provided XSD schema definition in Outbound Schema field.
Important: If you enter an Outbound schema, then you must select Validate XML and Match data types checkboxes to get the output as per the defined schema.

Default status: Deselected
Root element String

Specify the name of the XML element under which all the incoming documents are added. If left blank, no wrapping is done and each document is written out as a separate binary.

Default value: None.

Example: DocumentRoot
Ignore empty stream Checkbox

Select this checkbox to enable the Snap to ignore when no document is received in the input view. Deselect this checkbox to enable the Snap to write an empty XML data with a header at the output view when no document has been received in the input view.

Default status: Deselected
Map input to first repeating element in XSD Checkbox Select this checkbox if you want the Snap to ignore the root element from the XSD file. See the example below for more information.
Note: This is applicable only when the Snap has the repeated element such as Array in the XSD.

If this property is selected, the root element property is ignored and the <Metadata> ... </Metadata> element does not appear at the output. If this property is not selected, the Snap writes the XML data and the input document data is always wrapped in <Data> ... </Data>. If there is no root element, map the input to the root element.

Default status: Deselected
Format as Canonical XML Checkbox Select this checkbox to transform the XML output to canonical XML.

The canonical form of an XML output (from XML Formatter Snap) is an XML representation that excludes the XML prolog and includes the start and end tag for all the XML elements. Learn more about Canonical XML Version 1.0 specifications: https://www.w3.org/TR/xml-c14n.

Default status: Deselected
Max schema levels String

Specify the max levels for schema to be processed by the Snap.

This configuration limits the number of schema levels provided by the outbound schema on the SnapLogic input view to a maximum of 10 levels. This configuration does not effect the validation capability. It serves to prevent outbound schemas from consuming too much memory and processing time.

Default value: 10

Example: 20
Snap execution Dropdown list
Choose one of the three modes in which the Snap executes. Available options are:
  • Validate & Execute: Performs limited execution of the Snap and generates a data preview during pipeline validation. Subsequently, performs full execution of the Snap (unlimited records) during pipeline runtime.
  • Execute only: Performs full execution of the Snap during pipeline execution without generating preview data.
  • Disabled: Disables the Snap and all Snaps that are downstream from it.

Default value: Validate and Execute

Example: Execute only

Additional information

The conversion from the internal JSON structure to XML follows the StAXON mapping convention. This mapping uses naming conventions to turn JSON object fields into XML nodes and attributes.

For example, using the default Snap settings, the following two documents will be processed and written out as a single chunk of XML:

The output of the formatter for these two documents is as follows.

Important: If the value associated with a key is null (a valid JSON value), then an empty string will be placed as the text in between XML elements. For example,

will be transformed into <msg attr1="0"/>.


If you want to generate a file without the wrapper elements, you can remove the "Root Element" property and the Snap produces a single binary document for every input document. The Snap also validates documents against a provided schema to ensure that the output is well-formed. Any invalid documents will be written to the error output view.

XML Formatter and XML Generator Output Differs for the Same XSD File Input

The XML Formatter and XML Generator Snaps work differently for an XSD file as the input document. To generate the same output from both the Snaps, append the following to the required schema in the Target path property of the preceding Mapper Snap:

Examples