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RPC::XML::Parser - Interface for parsers created by RPC::XML::ParserFactory


This class is not instantiated directly; see RPC::XML::ParserFactory.


The RPC::XML::Parser class encapsulates the interface for the parsing process. It is an empty class that is used in conjuntion with the RPC::XML::ParserFactory class.

All parser implementations that are intended to be returned by calls to RPC::XML::ParserFactory::new() should declare this as their parent class.


This class provides empty implementations for the following methods. A parser implementation must provide definitions for both of these methods. If the versions from this class are triggered they will throw exceptions (die).

The descriptions below define the interface that implementations must adhere to.


Create a new instance of the class. Any extra data passed to the constructor is taken as key/value pairs (not a hash reference) and attached to the object.

The following parameters are currently recognized:


If passed with a true value, this tells the parser that incoming Base64 data is to be spooled to a filehandle opened onto an anonymous temporary file. The file itself is unlinked after opening, though the resulting RPC::XML::base64 object can use its to_file method to save the data to a specific file at a later point. No checks on size are made; if this option is set, all Base64 data goes to filehandles.


If this argument is passed, the value is taken as the directory under which the temporary files are created. This is so that the application is not locked in to the list of directories that File::Spec defaults to with its tmpdir method. If this is not passed, the previously-mentioned method is used to derive the directory in which to create the temporary files. Only relevant if base64_to_fh is set.

The base64* parameters do not have to be implemented if the user has no plans to use the to_file method of the RPC::XML::base64 data-class.

As a special-case, to preserve backwards compatibility with pre-0.69 versions of this package, new() has special behavior when specifically called for the package RPC::XML::Parser. When called for this package, the constructor quietly loads RPC::XML::ParserFactory and uses it to construct and return an instance of a parser based on XML::Parser.

parse [ STRING | STREAM ]

Parse the XML document specified in either a string or a stream. The stream may be any file descriptor, derivative of IO::Handle, etc.

The value returned must be one of the following:

RPC::XML::request instance

When passed a valid XML-RPC request message, the return value should be an instance of the RPC::XML::request class.

RPC::XML::response instance

Likewise, when passed a valid XML-RPC response, the return value should be an instance of the RPC::XML::response class.

string containing an error message

If the message does not conform to either a request or a response, or does not properly parse, the return value must be a string containing the error message.

A non-blocking (push) parser instance

If no arguments are passed in, the return value must be a parser object that implements push-parsing (non-blocking). It does not have to be of the same class as the original object, but it must support the remaining two methods

The next two methods are only called on push-parser instances, and as such do not have to be implemented by the actual factory-compatible parser. It is enough if the non-blocking parser instance it returns from the no-argument call to parse() implements these:

parse_more STRING

Send a chunk of the current XML document to the parser for processing.


Signal the end of parsing. The return value from this should be one of the same three possibilities that the direct use of parse() (above) returns:

RPC::XML::request instance
RPC::XML::response instance
string containing an error message

parse_done() may also signal an error by throwing an exception.


Unless otherwises specified, routines return the object reference itself upon a successful operation, and an error string (which is not a blessed reference) upon error.


Please report any bugs or feature requests to bug-rpc-xml at, or through the web interface at I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.



This file and the code within are copyright (c) 2011 by Randy J. Ray.

Copying and distribution are permitted under the terms of the Artistic License 2.0 ( or the GNU LGPL 2.1 (


The XML-RPC standard is Copyright (c) 1998-2001, UserLand Software, Inc. See <> for more information about the XML-RPC specification.


RPC::XML, RPC::XML::ParserFactory, RPC::XML::Parser::XMLParser


Randy J. Ray <>