XMLNillable
Define an XML element to be explicitly null and serialized with the
xsi:nil="true"
value. It specifies how a NULL value is set on an XML node when the
BDL variable is NULL but not optional. Note: The
The XMLNillable
attribute
cannot be set on a TYPE
definition. If you need to set nillable in a record defined
from a database schema with LIKE
clause, the XMLElementNillable attribute supports an implementation that sets
all elements in the record to XMLNillable
.XMLNillable
attribute is used on its own, or in combination with the XMLOptional attribute to specify conditions for the XML node
depending on how you want the BDL variable value to be serialized: - XML node optional (when null)
- XML node nillable (when null)
- Option of either XML node optional or nillable, with preference for nillable.
Example optional
The record member "val2" is defined as optional when NULL:
DEFINE rec RECORD
val1 STRING,
val2 INTEGER ATTRIBUTES(XMLOptional),
val3 FLOAT
END RECORD
When
rec.val2
is NULL, the resulting XML document is:<rec>
<val1>Hello</val1>
<val3>3.1415</val3>
</rec>
Example nillable
The record member "val2" is defined as nillable when NULL, but not
optional.
DEFINE rec RECORD
val1 STRING,
val2 INTEGER ATTRIBUTES(XMLNillable),
val3 FLOAT
END RECORD
When
rec.val2
is NULL, the resulting XML document contains the "val2" element
with the xsi:nil="true"
attribute:<rec>
<val1>Hello</val1>
<val2 xsi:nil="true"/>
<val3>3.1415</val3>
</rec>
Example optional or nillable
The record member "val2" is defined as either optional or nillable when
NULL:
DEFINE rec RECORD
val1 STRING,
val2 INTEGER ATTRIBUTES(XMLNillable,XMLOptional),
val3 FLOAT
END RECORD
When
rec.val2
is NULL, the resulting XML document does not contain the "val2"
element, as it is defined by XMLOptional (the default):<rec>
<val1>Hello</val1>
<val3>3.1415</val3>
</rec>
Or the resulting XML document can contain the "val2" element, with the
xsi:nil="true"
attribute:<rec>
<val1>Hello</val1>
<val2 xsi:nil="true"/>
<val3>3.1415</val3>
</rec>
Note: If both XMLOptional and XMLNillable are set and the BDL variable is NULL,
the serialization process from BDL to XML uses XMLOptional by default. If you prefer to serialize as
xsi:nil="true"
, you must specify the "preferred" value as a parameter of
XMLNillable. DEFINE rec RECORD
val1 STRING,
val2 INTEGER ATTRIBUTES(XMLNillable="preferred",XMLOptional),
val3 FLOAT
END RECORD
XML transformation into BDL
When getting an XML transformation into BDL, the Web Service engine will not
raise an error and the variable is set correctly whether the variable tag is
missing or has xsi:nil="true"
set. In either case, the BDL
variable is set as NULL.