Data Mapping Video Tutorials

This article contains a video series showcasing the features available in the XML Map Connector, the workhorse of any data transformation Flow.

Starting with the basic drag-and-drop approach and ending with custom scripting logic, this series covers everything you need to know before creating your own mapping projects in Arc. Each video will be accompanied by a brief bullet-point list of takeaways so that you can refresh your understanding at a glance.

• Video 1: Mapping Basics
• Video 2: The Expression Editor
• Video 3: Conditionals
• Video 4: Lookaheads
• Video 5: Loop Nodes
• Video 6: Custom Scripting

Video 1: Mapping Basics

The following video demonstrates the drag-and-drop basics involved in mapping one data structure onto another:

Takeaways

Key takeaways from the video:

• Drag elements from the Source onto elements in the Destination
• Parent elements create Foreach loops, which handle repeated input structures
• Leaf elements create Value-to-Value mappings, which populates the output with data from the input
• Leaf element xpaths are relative to Foreach loop xpaths that they are inside of

Video 2: The Expression Editor

The following video shows how to manipulate and transform data during the mapping:

Takeaways

Key takeaways from the video:

• The Expression Editor allows for manipulating data during the mapping
• The Dynamic Content tab allows for more granular control over the values pulled from the input file
• The Formatters tab supports formatting functions that modify the data
• Arc's formatters include string, math, date, and file operations to perform a wide range of logical tasks within a mapping element

Video 3: Conditionals

The following video demonstrates how to add simple conditional logic to a mapping:

Takeaways

Key takeaways from the video:

• Conditional filters on output nodes mean that these nodes only appear in the output if the condition is true
• Condition Nodes are logical nodes that group multiple output nodes together based on a shared condition
• If-Else logic can be implemented by making multiple copies of a single output node, and setting a different Condition filter on each

Video 4: Lookaheads

The following video walks through the purpose and process of establishing Lookahead conditions:

Takeaways

Key takeaways from the video:

• Lookaheads are a special kind of conditional logic for picking out data from within a repeated set of input
• Lookaheads check to see which instance of the repeated input contains the value that we care about
• Lookahead conditions are set in the Expression Editor in escaped square brackets:
1. First map the target value as usual
2. In the Expression Editor, add escaped square brackets after the input element to discriminate between (i.e. the parent element of the repeated set of input)
3. Inside the square brackets, specify the path to the value to check and set an equals condition

Video 5: Loop Nodes

The following video demonstrates the usefulness and behavior of Loop Nodes:

Takeaways

Key takeaways from the video:

• Loop Nodes are virtual nodes similar to regular Foreach mappings
• Loop Nodes do not show up in the output, so an entire level of XML hierarchy does not show up in the output
• Loop Nodes are useful for flattening hierarchical documents

Video 6: Custom Scripting

The following video provides examples of adding custom scripting logic to your mapping:

Takeaways

Key takeaways from the video:

• ArcScript can be written as the 'Custom Script' option for an output node, or as part of a virutal Script Node
• A Custom Script output node uses ArcScript to set the 'result.text' value that is returned in the node
• A virtual Script Node calculates a value and saves it for later
• The _map object stores variables across multiple mapping nodes
• The full list of ArcScript's keywords, formatters, and operations are available in the documentation

Next Steps

If you haven't already downloaded ArcESB, you can get started with our free 30-day trial by downloading the application.

If your mapping questions weren't answered adequately, please reach out to our support team at support@arcesb.com for additional help.