collapseContexts in XI Message Mappings

Use

collapseContexts()copies the first value from all contexts to one context. Empty contexts are replaced with an empty string.

This can be useful if an upper-level node is to be created each time a lower-level node exists, for example. The function is useful in combination with the function SplitByValue().

Example

In the following example, a separate upper-level element is to be created in the target structure for each occurrence of element :

Source Structure (Left) and Target Structure (Right)

Field Name	minOccurs	maxOccurs	Field Name	minOccurs	maxOccurs
srcRoot	1	1	destRoot	1	1
srcSub	0	unbounded	destSub	0	unbounded
srcItem	0	unbounded	destItem	0	unbounded

This is achieved by using a combination of the functions SplitByValue() and collapseContexts(). To create a queue for in which a context change is performed after each value, use removeContexts() and SplitByValue(). To create a queue with exactly as many context changes, but with empty values (the aim is to create the same number of upper-level tags without values), apply collapseContexts() to the same nesting of functions:

Message Mapping with collapseContexts() and SplitByValue()

Target Field Mapping	Value of SplitByValue()
/destRoot=/srcRoot
/destRoot/destSub= collapseContexts( SplitByValue( removeContexts(/srcRoot/srcSub/SrcItem)))	Each Value
/destRoot/destSub/destItem= SplitByValue( removeContexts(/srcRoot/srcSub/SrcItem)))	Each Value

Example

Source Instance	Result
encoding="UTF-8"?> PID001 PID002 PID003 PID004 PID005 PID006 PID007	xmlns:ns0="workshopDemo"> PID001 PID002 PID003 PID004 PID005 PID006 PID007