The optional SOAP Header element contains header information.
----------------------------------------------------------------------------
----
The SOAP Header Element
The optional SOAP Header element contains application specific information (
like authentication, payment, etc) about the SOAP message. If the Header ele
ment is present, it must be the first child element of the Envelope element.

Note: All immediate child elements of the Header element must be namespace-q
ualified.
<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">
<soap:Header>
<m:Trans
xmlns:m="http://www.w3schools.com/transaction/"
soap:mustUnderstand="1">234</m:Trans>
</soap:Header>
...
...
</soap:Envelope>
The example above contains a header with a "Trans" element, a "mustUnderstan
d" attribute value of "1", and a value of 234.
SOAP defines three attributes in the default namespace ("http://www.w3.org/2
001/12/soap-envelope"). These attributes are: actor, mustUnderstand, and enc
odingStyle. The attributes defined in the SOAP Header defines how a recipien
t should process the SOAP message.
----------------------------------------------------------------------------
----
The actor Attribute
A SOAP message may travel from a sender to a receiver by passing different e
ndpoints along the message path. Not all parts of the SOAP message may be in
tended for the ultimate endpoint of the SOAP message but, instead, may be in
tended for one or more of the endpoints on the message path.
The SOAP actor attribute may be used to address the Header element to a part
icular endpoint.
Syntax
soap:actor="URI"
Example
<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">
<soap:Header>
<m:Trans
xmlns:m="http://www.w3schools.com/transaction/"
soap:actor="http://www.w3schools.com/appml/">
234
</m:Trans>
</soap:Header>
...
...
</soap:Envelope>
----------------------------------------------------------------------------
----
The mustUnderstand Attribute
The SOAP mustUnderstand attribute can be used to indicate whether a header e
ntry is mandatory or optional for the recipient to process.
If you add "mustUnderstand="1" to a child element of the Header element it i
ndicates that the receiver processing the Header must recognize the element.
If the receiver does not recognize the element it must fail when processing
the Header.
Syntax
soap:mustUnderstand="0|1"
Example
<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">
<soap:Header>
<m:Trans
xmlns:m="http://www.w3schools.com/transaction/"
soap:mustUnderstand="1">
234
</m:Trans>
</soap:Header>
...
...
</soap:Envelope>
----------------------------------------------------------------------------
----
The encodingStyle Attribute
The SOAP encodingStyle attribute is explained in the previous chapter
--
FROM 202.192.157.41