SOAP::SOM(3) User Contributed Perl Documentation SOAP::SOM(3)NAMESOAP::SOM - provides access to the values contained in SOAP Response
DESCRIPTION
Objects from the SOAP::SOM class aren't generally instantiated directly
by an application. Rather, they are handed back by the deserialization
of a message. In other words, developers will almost never do this:
$som = SOAP::SOM->new;
SOAP::SOM objects are returned by a SOAP::Lite call in a client
context. For example:
my $client = SOAP::Lite
->readable(1)
->uri($NS)
->proxy($HOST)
$som = $client->someMethod();
METHODSnew(message)
$som = SOAP::SOM->new($message_as_xml);
As said, the need to actually create an object of this class should
be very rare. However, if the need arises, the syntax must be
followed. The single argument to new must be a valid XML document
the parser will understand as a SOAP response.
The following group of methods provide general data retrieval from the
SOAP::SOM object. The model for this is an abbreviated form of XPath.
Following this group are methods that are geared towards specific
retrieval of commonly requested elements.
match(path)
$som->match('/Envelope/Body/[1]');
This method sets the internal pointers within the data structure so
that the retrieval methods that follow will have access to the
desired data. In the example path, the match is being made against
the method entity, which is the first child tag of the body in a
SOAP response. The enumeration of container children starts at 1 in
this syntax, not 0. The returned value is dependent on the context
of the call. If the call is made in a boolean context (such as "if
($som->match($path))"), the return value is a boolean indicating
whether the requested path matched at all. Otherwise, an object
reference is returned. The returned object is also a SOAP::SOM
instance but is smaller, containing the subset of the document tree
matched by the expression.
valueof(node)
$res = $som->valueof('[1]');
When the SOAP::SOM object has matched a path internally with the
match method, this method allows retrieval of the data within any
of the matched nodes. The data comes back as native Perl data, not
a class instance (see dataof). In a scalar context, this method
returns just the first element from a matched node set. In an array
context, all elements are returned. Assuming that the earlier call
happens after the earlier call to match, it retrieves the result
entity from the method response that is contained in $som, as this
is the first child element in a method-response tag.
dataof(node)
$resobj = $som->dataof('[1]');
Performs the same operation as the earlier valueof method, except
that the data is left in its SOAP::Data form, rather than being
deserialized. This allows full access to all the attributes that
were serialized along with the data, such as namespace and
encoding.
headerof(node)
$resobj = $som->headerof('[1]');
Acts much like dataof, except that it returns an object of the
SOAP::Header class (covered later in this chapter), rather than
SOAP::Data. This is the preferred interface for manipulating the
header entities in a message.
namespaceuriof(node)
$ns = $som->namespaceof('[1]');
Retrieves the namespace URI that governs the requested node. Note
that namespaces are inherited, so this method will return the
relevant value, even if it derives from a parent or other ancestor
node.
The following methods provide more direct access to the message
envelope. All these methods return some form of a Perl value, most
often a hash reference, when called. Context is also relevant: in a
scalar context only the first matching node is returned, while in an
array context, all matching nodes are. When called as a static method
or as a regular function (such as "SOAP::SOM::envelope"), any of the
following methods returns the XPath string that is used with the match
method to retrieve the data.
root
$root = $som->root;
Returns the value of the root element as a hash reference. It
behaves exactly as "$som-"valueof('/')> does.
envelope
$envelope = $som->envelope;
Retrieves the "Envelope" element of the message, returning it and
its data as a hash reference. Keys in the hash will be Header and
Body (plus any optional elements that may be present in a SOAP 1.1
envelope), whose values will be the serialized header and body,
respectively.
header
$header = $som->header;
Retrieves the header portion of the envelope as a hash reference.
All data within it will have been deserialized. If the attributes
of the header are desired, the static form of the method can be
combined with match to fetch the header as a SOAP::Data object:
$header = $som->match(SOAP::SOM::header)->dataof;
headers
@hdrs = $som->headers;
Retrieves the node set of values with deserialized headers from
within the Header container. This is different from the earlier
header method in that it returns the whole header as a single
structure, and this returns the child elements as an array. In
other words, the following expressions yield the same data
structure:
$header = ($som->headers)[0];
$header = $som->valueof(SOAP::SOM::header.'/[1]');
body
$body = $som->body;
Retrieves the message body as a hash reference. The entity tags act
as keys, with their deserialized content providing the values.
fault
if ($som->fault) { die $som->fault->faultstring }
Acts both as a boolean test whether a fault occurred, and as a way
to retrieve the Fault entity itself from the message body as a hash
reference. If the message contains a fault, the next four methods
(faultcode, faultstring, faultactor, and faultdetail) may be used
to retrieve the respective parts of the fault (which are also
available on the hash reference as keys). If fault in a boolean
context is true, the "result", "paramsin", "paramsout", and
"method" methods all return "undef".
faultcode
$code = $som->faultcode;
Returns the faultcode element of the fault if there is a fault;
undef otherwise.
faultstring
$string = $som->faultstring;
Returns the faultstring element of the fault if there is a fault;
undef otherwise.
faultactor
$actor = $som->faultactor;
Returns the faultactor element of the fault, if there is a fault
and if the actor was specified within it. The faultactor element is
optional in the serialization of a fault, so it may not always be
present. This element is usually a string.
faultdetail
$detail = $som->faultdetail;
Returns the content of the detail element of the fault, if there is
a fault and if the detail element was provided. Note that the name
of the element isn't the same as the method, due to the possibility
for confusion had the method been called simply, detail. As with
the faultactor element, this isn't always a required component of a
fault, so it isn't guaranteed to be present. The specification for
the detail portion of a fault calls for it to contain a series of
element tags, so the application may expect a hash reference as a
return value when detail information is available (and undef
otherwise).
method
$method = $som->method
Retrieves the "method" element of the message, as a hash reference.
This includes all input parameters when called on a request message
or all result/output parameters when called on a response message.
If there is a fault present in the message, it returns undef.
result
$value = $som->result;
Returns the value that is the result of a SOAP response. The value
will be already deserialized into a native Perl datatype.
paramsin
@list = $som->paramsin;
Retrieves the parameters being passed in on a SOAP request. If
called in a scalar context, the first parameter is returned. When
called in a list context, the full list of all parameters is
returned. Each parameter is a hash reference, following the
established structure for such return values.
paramsout
@list = $som->paramsout;
Returns the output parameters from a SOAP response. These are the
named parameters that are returned in addition to the explicit
response entity itself. It shares the same scalar/list context
behavior as the paramsin method.
paramsall
@list = $som->paramsall;
Returns all parameters from a SOAP response, including the result
entity itself, as one array.
parts()
Return an array of "MIME::Entity"'s if the current payload contains
attachments, or returns undefined if payload is not MIME multipart.
is_multipart()
Returns true if payload is MIME multipart, false otherwise.
EXAMPLES
ACCESSING ELEMENT VALUES
Suppose for the following SOAP Envelope:
<Envelope>
<Body>
<fooResponse>
<bar>abcd</bar>
</fooResponse>
</Body>
</Envelope>
And suppose you wanted to access the value of the bar element, then use
the following code:
my $soap = SOAP::Lite
->uri($SOME_NS)
->proxy($SOME_HOST);
my $som = $soap->foo();
print $som->valueof('//fooResponse/bar');
ACCESSING ATTRIBUTE VALUES
Suppose the following SOAP Envelope:
<Envelope>
<Body>
<c2fResponse>
<convertedTemp test="foo">98.6</convertedTemp>
</c2fResponse>
</Body>
</Envelope>
Then to print the attribute 'test' use the following code:
print "The attribute is: " .
$som->dataof('//c2fResponse/convertedTemp')->attr->{'test'};
ITERATING OVER AN ARRAY
Suppose for the following SOAP Envelope:
<Envelope>
<Body>
<catalog>
<product>
<title>Programming Web Service with Perl</title>
<price>$29.95</price>
</product>
<product>
<title>Perl Cookbook</title>
<price>$49.95</price>
</product>
</catalog>
</Body>
</Envelope>
If the SOAP Envelope returned contained an array, use the following
code to iterate over the array:
for my $t ($som->valueof('//catalog/product')) {
print $t->{title} . " - " . $t->{price} . "\n";
}
DETECTING A SOAP FAULT
A SOAP::SOM object is returned by a SOAP::Lite client regardless of
whether the call succeeded or not. Therefore, a SOAP Client is
responsible for determining if the returned value is a fault or not. To
do so, use the fault() method which returns 1 if the SOAP::SOM object
is a fault and 0 otherwise.
my $som = $client->someMethod(@parameters);
if ($som->fault) {
print $som->faultdetail;
} else {
# do something
}
PARSING ARRAYS OF ARRAYS
The most efficient way To parse and to extract data out of an array
containing another array encoded in a SOAP::SOM object is the
following:
$xml = <<END_XML;
<foo>
<person>
<foo>123</foo>
<foo>456</foo>
</person>
<person>
<foo>789</foo>
<foo>012</foo>
</person>
</foo>
END_XML
my $som = SOAP::Deserializer->deserialize($xml);
my $i = 0;
foreach my $a ($som->dataof("//person/*")) {
$i++;
my $j = 0;
foreach my $b ($som->dataof("//person/[$i]/*")) {
$j++;
# do something
}
}
SEE ALSO
SOAP::Data, SOAP::Serializer
ACKNOWLEDGEMENTS
Special thanks to O'Reilly publishing which has graciously allowed
SOAP::Lite to republish and redistribute large excerpts from
Programming Web Services with Perl, mainly the SOAP::Lite reference
found in Appendix B.
COPYRIGHT
Copyright (C) 2000-2004 Paul Kulchenko. All rights reserved.
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
AUTHORS
Paul Kulchenko (paulclinger@yahoo.com)
Randy J. Ray (rjray@blackperl.com)
Byrne Reese (byrne@majordojo.com)
perl v5.14.1 2010-06-03 SOAP::SOM(3)