MCL/sf/adapt/qemu: comparison symbian-qemu-0.9.1-12/python-2.6.1/Doc/library/xmlrpclib.rst

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+:mod:`xmlrpclib` --- XML-RPC client access
+==========================================
+.. module:: xmlrpclib
+:synopsis: XML-RPC client access.
+.. moduleauthor:: Fredrik Lundh <fredrik@pythonware.com>
+.. sectionauthor:: Eric S. Raymond <esr@snark.thyrsus.com>
+.. note::
+The :mod:`xmlrpclib` module has been renamed to :mod:`xmlrpc.client` in
+Python 3.0.  The :term:`2to3` tool will automatically adapt imports when
+converting your sources to 3.0.
+.. XXX Not everything is documented yet.  It might be good to describe
+Marshaller, Unmarshaller, getparser, dumps, loads, and Transport.
+.. versionadded:: 2.2
+XML-RPC is a Remote Procedure Call method that uses XML passed via HTTP as a
+transport.  With it, a client can call methods with parameters on a remote
+server (the server is named by a URI) and get back structured data.  This module
+supports writing XML-RPC client code; it handles all the details of translating
+between conformable Python objects and XML on the wire.
+.. class:: ServerProxy(uri[, transport[, encoding[, verbose[,  allow_none[, use_datetime]]]]])
+A :class:`ServerProxy` instance is an object that manages communication with a
+remote XML-RPC server.  The required first argument is a URI (Uniform Resource
+Indicator), and will normally be the URL of the server.  The optional second
+argument is a transport factory instance; by default it is an internal
+:class:`SafeTransport` instance for https: URLs and an internal HTTP
+:class:`Transport` instance otherwise.  The optional third argument is an
+encoding, by default UTF-8. The optional fourth argument is a debugging flag.
+If *allow_none* is true,  the Python constant ``None`` will be translated into
+XML; the default behaviour is for ``None`` to raise a :exc:`TypeError`. This is
+a commonly-used extension to the XML-RPC specification, but isn't supported by
+all clients and servers; see http://ontosys.com/xml-rpc/extensions.php for a
+description.  The *use_datetime* flag can be used to cause date/time values to
+be presented as :class:`datetime.datetime` objects; this is false by default.
+:class:`datetime.datetime` objects may be passed to calls.
+Both the HTTP and HTTPS transports support the URL syntax extension for HTTP
+Basic Authentication: ``http://user:pass@host:port/path``.  The  ``user:pass``
+portion will be base64-encoded as an HTTP 'Authorization' header, and sent to
+the remote server as part of the connection process when invoking an XML-RPC
+method.  You only need to use this if the remote server requires a Basic
+Authentication user and password.
+The returned instance is a proxy object with methods that can be used to invoke
+corresponding RPC calls on the remote server.  If the remote server supports the
+introspection API, the proxy can also be used to query the remote server for the
+methods it supports (service discovery) and fetch other server-associated
+metadata.
+:class:`ServerProxy` instance methods take Python basic types and objects as
+arguments and return Python basic types and classes.  Types that are conformable
+(e.g. that can be marshalled through XML), include the following (and except
+where noted, they are unmarshalled as the same Python type):
++---------------------------------+---------------------------------------------+
+| Name                            | Meaning                                     |
++=================================+=============================================+
+| :const:`boolean`                | The :const:`True` and :const:`False`        |
+|                                 | constants                                   |
++---------------------------------+---------------------------------------------+
+| :const:`integers`               | Pass in directly                            |
++---------------------------------+---------------------------------------------+
+| :const:`floating-point numbers` | Pass in directly                            |
++---------------------------------+---------------------------------------------+
+| :const:`strings`                | Pass in directly                            |
++---------------------------------+---------------------------------------------+
+| :const:`arrays`                 | Any Python sequence type containing         |
+|                                 | conformable elements. Arrays are returned   |
+|                                 | as lists                                    |
++---------------------------------+---------------------------------------------+
+| :const:`structures`             | A Python dictionary. Keys must be strings,  |
+|                                 | values may be any conformable type. Objects |
+|                                 | of user-defined classes can be passed in;   |
+|                                 | only their *__dict__* attribute is          |
+|                                 | transmitted.                                |
++---------------------------------+---------------------------------------------+
+| :const:`dates`                  | in seconds since the epoch (pass in an      |
+|                                 | instance of the :class:`DateTime` class) or |
+|                                 | a :class:`datetime.datetime` instance.      |
++---------------------------------+---------------------------------------------+
+| :const:`binary data`            | pass in an instance of the :class:`Binary`  |
+|                                 | wrapper class                               |
++---------------------------------+---------------------------------------------+
+This is the full set of data types supported by XML-RPC.  Method calls may also
+raise a special :exc:`Fault` instance, used to signal XML-RPC server errors, or
+:exc:`ProtocolError` used to signal an error in the HTTP/HTTPS transport layer.
+Both :exc:`Fault` and :exc:`ProtocolError` derive from a base class called
+:exc:`Error`.  Note that even though starting with Python 2.2 you can subclass
+builtin types, the xmlrpclib module currently does not marshal instances of such
+subclasses.
+When passing strings, characters special to XML such as ``<``, ``>``, and ``&``
+will be automatically escaped.  However, it's the caller's responsibility to
+ensure that the string is free of characters that aren't allowed in XML, such as
+the control characters with ASCII values between 0 and 31 (except, of course,
+tab, newline and carriage return); failing to do this will result in an XML-RPC
+request that isn't well-formed XML.  If you have to pass arbitrary strings via
+XML-RPC, use the :class:`Binary` wrapper class described below.
+:class:`Server` is retained as an alias for :class:`ServerProxy` for backwards
+compatibility.  New code should use :class:`ServerProxy`.
+.. versionchanged:: 2.5
+The *use_datetime* flag was added.
+.. versionchanged:: 2.6
+Instances of :term:`new-style class`\es can be passed in if they have an
+*__dict__* attribute and don't have a base class that is marshalled in a
+special way.
+.. seealso::
+`XML-RPC HOWTO <http://www.tldp.org/HOWTO/XML-RPC-HOWTO/index.html>`_
+A good description of XML-RPC operation and client software in several languages.
+Contains pretty much everything an XML-RPC client developer needs to know.
+`XML-RPC Introspection <http://xmlrpc-c.sourceforge.net/introspection.html>`_
+Describes the XML-RPC protocol extension for introspection.
+`XML-RPC Specification <http://www.xmlrpc.com/spec>`_
+The official specification.
+`Unofficial XML-RPC Errata <http://effbot.org/zone/xmlrpc-errata.htm>`_
+Fredrik Lundh's "unofficial errata, intended to clarify certain
+details in the XML-RPC specification, as well as hint at
+'best practices' to use when designing your own XML-RPC
+implementations."
+.. _serverproxy-objects:
+ServerProxy Objects
+-------------------
+A :class:`ServerProxy` instance has a method corresponding to each remote
+procedure call accepted by the XML-RPC server.  Calling the method performs an
+RPC, dispatched by both name and argument signature (e.g. the same method name
+can be overloaded with multiple argument signatures).  The RPC finishes by
+returning a value, which may be either returned data in a conformant type or a
+:class:`Fault` or :class:`ProtocolError` object indicating an error.
+Servers that support the XML introspection API support some common methods
+grouped under the reserved :attr:`system` member:
+.. method:: ServerProxy.system.listMethods()
+This method returns a list of strings, one for each (non-system) method
+supported by the XML-RPC server.
+.. method:: ServerProxy.system.methodSignature(name)
+This method takes one parameter, the name of a method implemented by the XML-RPC
+server.It returns an array of possible signatures for this method. A signature
+is an array of types. The first of these types is the return type of the method,
+the rest are parameters.
+Because multiple signatures (ie. overloading) is permitted, this method returns
+a list of signatures rather than a singleton.
+Signatures themselves are restricted to the top level parameters expected by a
+method. For instance if a method expects one array of structs as a parameter,
+and it returns a string, its signature is simply "string, array". If it expects
+three integers and returns a string, its signature is "string, int, int, int".
+If no signature is defined for the method, a non-array value is returned. In
+Python this means that the type of the returned  value will be something other
+that list.
+.. method:: ServerProxy.system.methodHelp(name)
+This method takes one parameter, the name of a method implemented by the XML-RPC
+server.  It returns a documentation string describing the use of that method. If
+no such string is available, an empty string is returned. The documentation
+string may contain HTML markup.
+.. _boolean-objects:
+Boolean Objects
+---------------
+This class may be initialized from any Python value; the instance returned
+depends only on its truth value.  It supports various Python operators through
+:meth:`__cmp__`, :meth:`__repr__`, :meth:`__int__`, and :meth:`__nonzero__`
+methods, all implemented in the obvious ways.
+It also has the following method, supported mainly for internal use by the
+unmarshalling code:
+.. method:: Boolean.encode(out)
+Write the XML-RPC encoding of this Boolean item to the out stream object.
+A working example follows. The server code::
+import xmlrpclib
+from SimpleXMLRPCServer import SimpleXMLRPCServer
+def is_even(n):
+return n%2 == 0
+server = SimpleXMLRPCServer(("localhost", 8000))
+print "Listening on port 8000..."
+server.register_function(is_even, "is_even")
+server.serve_forever()
+The client code for the preceding server::
+import xmlrpclib
+proxy = xmlrpclib.ServerProxy("http://localhost:8000/")
+print "3 is even: %s" % str(proxy.is_even(3))
+print "100 is even: %s" % str(proxy.is_even(100))
+.. _datetime-objects:
+DateTime Objects
+----------------
+This class may be initialized with seconds since the epoch, a time
+tuple, an ISO 8601 time/date string, or a :class:`datetime.datetime`
+instance.  It has the following methods, supported mainly for internal
+use by the marshalling/unmarshalling code:
+.. method:: DateTime.decode(string)
+Accept a string as the instance's new time value.
+.. method:: DateTime.encode(out)
+Write the XML-RPC encoding of this :class:`DateTime` item to the *out* stream
+object.
+It also supports certain of Python's built-in operators through  :meth:`__cmp__`
+and :meth:`__repr__` methods.
+A working example follows. The server code::
+import datetime
+from SimpleXMLRPCServer import SimpleXMLRPCServer
+import xmlrpclib
+def today():
+today = datetime.datetime.today()
+return xmlrpclib.DateTime(today)
+server = SimpleXMLRPCServer(("localhost", 8000))
+print "Listening on port 8000..."
+server.register_function(today, "today")
+server.serve_forever()
+The client code for the preceding server::
+import xmlrpclib
+import datetime
+proxy = xmlrpclib.ServerProxy("http://localhost:8000/")
+today = proxy.today()
+# convert the ISO8601 string to a datetime object
+converted = datetime.datetime.strptime(today.value, "%Y%m%dT%H:%M:%S")
+print "Today: %s" % converted.strftime("%d.%m.%Y, %H:%M")
+.. _binary-objects:
+Binary Objects
+--------------
+This class may be initialized from string data (which may include NULs). The
+primary access to the content of a :class:`Binary` object is provided by an
+attribute:
+.. attribute:: Binary.data
+The binary data encapsulated by the :class:`Binary` instance.  The data is
+provided as an 8-bit string.
+:class:`Binary` objects have the following methods, supported mainly for
+internal use by the marshalling/unmarshalling code:
+.. method:: Binary.decode(string)
+Accept a base64 string and decode it as the instance's new data.
+.. method:: Binary.encode(out)
+Write the XML-RPC base 64 encoding of this binary item to the out stream object.
+The encoded data will have newlines every 76 characters as per
+`RFC 2045 section 6.8 <http://tools.ietf.org/html/rfc2045#section-6.8>`_,
+which was the de facto standard base64 specification when the
+XML-RPC spec was written.
+It also supports certain of Python's built-in operators through a
+:meth:`__cmp__` method.
+Example usage of the binary objects.  We're going to transfer an image over
+XMLRPC::
+from SimpleXMLRPCServer import SimpleXMLRPCServer
+import xmlrpclib
+def python_logo():
+handle = open("python_logo.jpg")
+return xmlrpclib.Binary(handle.read())
+handle.close()
+server = SimpleXMLRPCServer(("localhost", 8000))
+print "Listening on port 8000..."
+server.register_function(python_logo, 'python_logo')
+server.serve_forever()
+The client gets the image and saves it to a file::
+import xmlrpclib
+proxy = xmlrpclib.ServerProxy("http://localhost:8000/")
+handle = open("fetched_python_logo.jpg", "w")
+handle.write(proxy.python_logo().data)
+handle.close()
+.. _fault-objects:
+Fault Objects
+-------------
+A :class:`Fault` object encapsulates the content of an XML-RPC fault tag. Fault
+objects have the following members:
+.. attribute:: Fault.faultCode
+A string indicating the fault type.
+.. attribute:: Fault.faultString
+A string containing a diagnostic message associated with the fault.
+In the following example we're going to intentionally cause a :exc:`Fault` by
+returning a complex type object.  The server code::
+from SimpleXMLRPCServer import SimpleXMLRPCServer
+# A marshalling error is going to occur because we're returning a
+# complex number
+def add(x,y):
+return x+y+0j
+server = SimpleXMLRPCServer(("localhost", 8000))
+print "Listening on port 8000..."
+server.register_function(add, 'add')
+server.serve_forever()
+The client code for the preceding server::
+import xmlrpclib
+proxy = xmlrpclib.ServerProxy("http://localhost:8000/")
+try:
+proxy.add(2, 5)
+except xmlrpclib.Fault, err:
+print "A fault occurred"
+print "Fault code: %d" % err.faultCode
+print "Fault string: %s" % err.faultString
+.. _protocol-error-objects:
+ProtocolError Objects
+---------------------
+A :class:`ProtocolError` object describes a protocol error in the underlying
+transport layer (such as a 404 'not found' error if the server named by the URI
+does not exist).  It has the following members:
+.. attribute:: ProtocolError.url
+The URI or URL that triggered the error.
+.. attribute:: ProtocolError.errcode
+The error code.
+.. attribute:: ProtocolError.errmsg
+The error message or diagnostic string.
+.. attribute:: ProtocolError.headers
+A string containing the headers of the HTTP/HTTPS request that triggered the
+error.
+In the following example we're going to intentionally cause a :exc:`ProtocolError`
+by providing an invalid URI::
+import xmlrpclib
+# create a ServerProxy with an invalid URI
+proxy = xmlrpclib.ServerProxy("http://invalidaddress/")
+try:
+proxy.some_method()
+except xmlrpclib.ProtocolError, err:
+print "A protocol error occurred"
+print "URL: %s" % err.url
+print "HTTP/HTTPS headers: %s" % err.headers
+print "Error code: %d" % err.errcode
+print "Error message: %s" % err.errmsg
+MultiCall Objects
+-----------------
+.. versionadded:: 2.4
+In http://www.xmlrpc.com/discuss/msgReader%241208, an approach is presented to
+encapsulate multiple calls to a remote server into a single request.
+.. class:: MultiCall(server)
+Create an object used to boxcar method calls. *server* is the eventual target of
+the call. Calls can be made to the result object, but they will immediately
+return ``None``, and only store the call name and parameters in the
+:class:`MultiCall` object. Calling the object itself causes all stored calls to
+be transmitted as a single ``system.multicall`` request. The result of this call
+is a :term:`generator`; iterating over this generator yields the individual
+results.
+A usage example of this class follows.  The server code ::
+from SimpleXMLRPCServer import SimpleXMLRPCServer
+def add(x,y):
+return x+y
+def subtract(x, y):
+return x-y
+def multiply(x, y):
+return x*y
+def divide(x, y):
+return x/y
+# A simple server with simple arithmetic functions
+server = SimpleXMLRPCServer(("localhost", 8000))
+print "Listening on port 8000..."
+server.register_multicall_functions()
+server.register_function(add, 'add')
+server.register_function(subtract, 'subtract')
+server.register_function(multiply, 'multiply')
+server.register_function(divide, 'divide')
+server.serve_forever()
+The client code for the preceding server::
+import xmlrpclib
+proxy = xmlrpclib.ServerProxy("http://localhost:8000/")
+multicall = xmlrpclib.MultiCall(proxy)
+multicall.add(7,3)
+multicall.subtract(7,3)
+multicall.multiply(7,3)
+multicall.divide(7,3)
+result = multicall()
+print "7+3=%d, 7-3=%d, 7*3=%d, 7/3=%d" % tuple(result)
+Convenience Functions
+---------------------
+.. function:: boolean(value)
+Convert any Python value to one of the XML-RPC Boolean constants, ``True`` or
+``False``.
+.. function:: dumps(params[, methodname[,  methodresponse[, encoding[, allow_none]]]])
+Convert *params* into an XML-RPC request. or into a response if *methodresponse*
+is true. *params* can be either a tuple of arguments or an instance of the
+:exc:`Fault` exception class.  If *methodresponse* is true, only a single value
+can be returned, meaning that *params* must be of length 1. *encoding*, if
+supplied, is the encoding to use in the generated XML; the default is UTF-8.
+Python's :const:`None` value cannot be used in standard XML-RPC; to allow using
+it via an extension,  provide a true value for *allow_none*.
+.. function:: loads(data[, use_datetime])
+Convert an XML-RPC request or response into Python objects, a ``(params,
+methodname)``.  *params* is a tuple of argument; *methodname* is a string, or
+``None`` if no method name is present in the packet. If the XML-RPC packet
+represents a fault condition, this function will raise a :exc:`Fault` exception.
+The *use_datetime* flag can be used to cause date/time values to be presented as
+:class:`datetime.datetime` objects; this is false by default.
+.. versionchanged:: 2.5
+The *use_datetime* flag was added.
+.. _xmlrpc-client-example:
+Example of Client Usage
+-----------------------
+::
+# simple test program (from the XML-RPC specification)
+from xmlrpclib import ServerProxy, Error
+# server = ServerProxy("http://localhost:8000") # local server
+server = ServerProxy("http://betty.userland.com")
+print server
+try:
+print server.examples.getStateName(41)
+except Error, v:
+print "ERROR", v
+To access an XML-RPC server through a proxy, you need to define  a custom
+transport.  The following example shows how:
+.. Example taken from http://lowlife.jp/nobonobo/wiki/xmlrpcwithproxy.html
+::
+import xmlrpclib, httplib
+class ProxiedTransport(xmlrpclib.Transport):
+def set_proxy(self, proxy):
+self.proxy = proxy
+def make_connection(self, host):
+self.realhost = host
+	h = httplib.HTTP(self.proxy)
+	return h
+def send_request(self, connection, handler, request_body):
+connection.putrequest("POST", 'http://%s%s' % (self.realhost, handler))
+def send_host(self, connection, host):
+connection.putheader('Host', self.realhost)
+p = ProxiedTransport()
+p.set_proxy('proxy-server:8080')
+server = xmlrpclib.Server('http://time.xmlrpc.com/RPC2', transport=p)
+print server.currentTime.getCurrentTime()
+Example of Client and Server Usage
+----------------------------------
+See :ref:`simplexmlrpcserver-example`.