MRM XML physical format: NULL handling

The purpose of null handling is to specify how messages deal with null values; that is, the absence of a meaningful value for an element.

Null properties for the MRM XML physical format are set for the message set only, and apply to all the defined objects within the message set, by using the four properties Encoding Null Num, Encoding Null Non-Num, Encoding Null Num Val and Encoding Null Non-Num Val.

Null handling takes place only if the logical Nillable property of the element is set.

The purpose of these parameters is to specify how messages deal with null values. In an XML message there are several options. Most obviously an element could omit a value, for example:

<element1></element1>

Or, the element could include a distinctive value that means that no real value is present, for example.

<element1>null</element1>

Or, the element could follow XML Schema instance rules:

<element1 xsi:nil="true"/>

The properties Encoding Null Num and Encoding Null Non-Num specify the style of null handling, for example, that null is represented by an empty element.

The properties Encoding Null Num Val and Encoding Null Non-Num Val provide a value (if needed) to represent a null value. For an element of type string, this might be null or unspecified while for a number it might be 0 or 0.0.