Hello! Dave Winer of UserLand software (my boss) has generously allowed me
to add XML-RPC support to Zope. Since I'm lazy--and Fredrik Lundh has
already written a wonderful XML-RPC module for Python--my code simply
hooks Fredrik's routines into Zope's server architecture. The hard work
was done by the following people:
* Jim Fulton of Digital Creations, who added XML-RPC hooks to ZPublisher
and answering my stupid questions.
* Fredrik Lundh of PythonWare, who wrote an excellent Python XML-RPC module.
* Dave Winer of UserLand Software, who wrote the XML-RPC spec (and who
pays my salary).
Please give all your thanks to these folks; they really *did* do all of the
work. However, I may have plugged their components together incorrectly, so
send all the blame and hate mail to me. :-)
What is XML-RPC?
----------------
XML-RPC is a very simple RPC protocol that runs over HTTP. The function
name and arguments are encoded as XML. XML-RPC isn't the fastest way to
call a function on remote server, but it might be one of the easier to
understand. (See http://www.xmlrpc.com/ for details.)
An XML-RPC request looks like this:
POST /z2/ 1.0
Content-Type: text/xml
Content-Length: 170
<?xml version='1.0'?>
<methodCall>
<methodName>test.string_length</methodName>
<params>
<param>
<value><string>foo</string></value>
</param>
</params>
</methodCall>
The response looks like this:
HTTP/1.1 200 OK
Content-Length: 122
Content-Type: text/xml
<?xml version='1.0'?>
<methodResponse>
<params>
<param>
<value><int>3</int></value>
</param>
</params>
</methodResponse>
Fredrik Lundh of PythonWare wrote a very nice XML-RPC library for
Python. (See http://www.pythonware.com/products/xmlrpc/ to get a copy.)
Using his code, I could call the above function as:
>>> import xmlrpclib
>>> s = xmlrpclib.Server("http://localhost/z2/")
>>> s.test.string_length("foo")
3
In other words, XML-RPC lets you treat a remote object almost like a local
Python object. Think of it as a super-simple cousin to CORBA and DCOM, and
you'll get the right idea.
XML-RPC for Zope
----------------
Writing XML-RPC methods is just as easy, thanks to Zope. Simply load a
Python function as an External Method, and you're ready to go:
def string_length(string):
return len(string)
Easy, huh? To use XML-RPC for Zope, you'll need to get the latest version
of Zope from CVS and read the release notes on UserLand's site:
http://linux.userland.com/stories/storyReader$18
Future Directions
-----------------
Zope XML-RPC still has a few rough edges. If you discover any bugs which
aren't mentioned on the site, or have any ideas for improvement, drop me a
line.
Thank you to all the people who helped out!
Cheers,
Eric Kidd
UserLand Software
to add XML-RPC support to Zope. Since I'm lazy--and Fredrik Lundh has
already written a wonderful XML-RPC module for Python--my code simply
hooks Fredrik's routines into Zope's server architecture. The hard work
was done by the following people:
* Jim Fulton of Digital Creations, who added XML-RPC hooks to ZPublisher
and answering my stupid questions.
* Fredrik Lundh of PythonWare, who wrote an excellent Python XML-RPC module.
* Dave Winer of UserLand Software, who wrote the XML-RPC spec (and who
pays my salary).
Please give all your thanks to these folks; they really *did* do all of the
work. However, I may have plugged their components together incorrectly, so
send all the blame and hate mail to me. :-)
What is XML-RPC?
----------------
XML-RPC is a very simple RPC protocol that runs over HTTP. The function
name and arguments are encoded as XML. XML-RPC isn't the fastest way to
call a function on remote server, but it might be one of the easier to
understand. (See http://www.xmlrpc.com/ for details.)
An XML-RPC request looks like this:
POST /z2/ 1.0
Content-Type: text/xml
Content-Length: 170
<?xml version='1.0'?>
<methodCall>
<methodName>test.string_length</methodName>
<params>
<param>
<value><string>foo</string></value>
</param>
</params>
</methodCall>
The response looks like this:
HTTP/1.1 200 OK
Content-Length: 122
Content-Type: text/xml
<?xml version='1.0'?>
<methodResponse>
<params>
<param>
<value><int>3</int></value>
</param>
</params>
</methodResponse>
Fredrik Lundh of PythonWare wrote a very nice XML-RPC library for
Python. (See http://www.pythonware.com/products/xmlrpc/ to get a copy.)
Using his code, I could call the above function as:
>>> import xmlrpclib
>>> s = xmlrpclib.Server("http://localhost/z2/")
>>> s.test.string_length("foo")
3
In other words, XML-RPC lets you treat a remote object almost like a local
Python object. Think of it as a super-simple cousin to CORBA and DCOM, and
you'll get the right idea.
XML-RPC for Zope
----------------
Writing XML-RPC methods is just as easy, thanks to Zope. Simply load a
Python function as an External Method, and you're ready to go:
def string_length(string):
return len(string)
Easy, huh? To use XML-RPC for Zope, you'll need to get the latest version
of Zope from CVS and read the release notes on UserLand's site:
http://linux.userland.com/stories/storyReader$18
Future Directions
-----------------
Zope XML-RPC still has a few rough edges. If you discover any bugs which
aren't mentioned on the site, or have any ideas for improvement, drop me a
line.
Thank you to all the people who helped out!
Cheers,
Eric Kidd
UserLand Software