zope.app.xmlrpcintrospection 3.4.0

What’s introspection now ?

This Zope 3 package provides an xmlrpcintrospection mechanism, as defined here:

http://xmlrpc-c.sourceforge.net/xmlrpc-howto/xmlrpc-howto-api-introspection.html

It registers three new xmlrpc methods:

• listMethods(): Lists all xmlrpc methods (ie views) registered for the current object

• methodHelp(method_name): Returns the method documentation of the given method.

• methodSignature(method_name): Returns the method documentation of the given method.

How do I use it ?

Basically, if you want to add introspection into your XMLRPCView, you just have to add a decorator for each method of the view, that specifies the return type of the method and the argument types.

The decorator is called xmlrpccallable

>>> from zope.app.xmlrpcintrospection.xmlrpcintrospection import xmlrpccallable
>>> from zope.app.publisher.xmlrpc import XMLRPCView
>>> class MySuperXMLRPCView(XMLRPCView):
...     @xmlrpccallable(str, str, str, str)
...     def myMethod(self, a, b, c):
...         """ my help """
...         return '%s %s, %s, lalalala, you and me, lalalala' % (a, b, c)

myMethod() will then be introspectable. (find a full examples below, grep for (*))

How does it works ?

It is based on introspection mechanisms provided by the apidoc package.

* ripped form xmlrpc doctests *

Let’s write a view that returns a folder listing:

>>> class FolderListing:
...     def contents(self):
...         return list(self.context.keys())

Now we’ll register it as a view:

>>> from zope.configuration import xmlconfig
>>> ignored = xmlconfig.string("""
... <configure
...     xmlns="http://namespaces.zope.org/zope"
...     xmlns:xmlrpc="http://namespaces.zope.org/xmlrpc"
...     >
...   <!-- We only need to do this include in this example,
...        Normally the include has already been done for us. -->
...   <include package="zope.app.publisher.xmlrpc" file="meta.zcml" />
...
...   <xmlrpc:view
...       for="zope.app.folder.folder.IFolder"
...       methods="contents"
...       class="zope.app.xmlrpcintrospection.README.FolderListing"
...       permission="zope.ManageContent"
...       />
... </configure>
... """)

Now, we’ll add some items to the root folder:

>>> print http(r"""
... POST /@@contents.html HTTP/1.1
... Authorization: Basic bWdyOm1ncnB3
... Content-Length: 73
... Content-Type: application/x-www-form-urlencoded
...
... type_name=BrowserAdd__zope.app.folder.folder.Folder&new_value=f1""")
HTTP/1.1 303 See Other
...

>>> print http(r"""
... POST /@@contents.html HTTP/1.1
... Authorization: Basic bWdyOm1ncnB3
... Content-Length: 73
... Content-Type: application/x-www-form-urlencoded
...
... type_name=BrowserAdd__zope.app.folder.folder.Folder&new_value=f2""")
HTTP/1.1 303 See Other
...

And call our xmlrpc method:

>>> print http(r"""
... POST / HTTP/1.0
... Authorization: Basic bWdyOm1ncnB3
... Content-Length: 102
... Content-Type: text/xml
...
... <?xml version='1.0'?>
... <methodCall>
... <methodName>contents</methodName>
... <params>
... </params>
... </methodCall>
... """)
HTTP/1.0 200 OK
...
<?xml version='1.0'?>
<methodResponse>
<params>
<param>
<value><array><data>
<value><string>f1</string></value>
<value><string>f2</string></value>
</data></array></value>
</param>
</params>
</methodResponse>
<BLANKLINE>

* end of ripped form xmlrpc doctests *

Now we want to provide to that view introspection. Let’s add three new xmlrcp methods, that published the introspection api.

>>> ignored = xmlconfig.string("""
... <configure
...     xmlns="http://namespaces.zope.org/zope"
...     xmlns:xmlrpc="http://namespaces.zope.org/xmlrpc"
...     >
...   <!-- We only need to do this include in this example,
...        Normally the include has already been done for us. -->
...   <include package="zope.app.publisher.xmlrpc" file="meta.zcml" />
...   <xmlrpc:view
...     for="zope.interface.Interface"
...     methods="listMethods  methodHelp methodSignature"
...     class="zope.app.xmlrpcintrospection.xmlrpcintrospection.XMLRPCIntrospection"
...     permission="zope.Public"
...     />
... </configure>
... """)

They are linked to XMLRPCIntrospection class, that actually

knows how to lookup to all interfaces

And call our xmlrpc method, that should list the content method:

>>> print http(r"""
... POST / HTTP/1.0
... Content-Type: text/xml
...
... <?xml version='1.0'?>
... <methodCall>
... <methodName>listMethods</methodName>
... <params>
... </params>
... </methodCall>
... """, handle_errors=False)
HTTP/1.0 200 OK
...
<?xml version='1.0'?>
<methodResponse>
...
<value><string>contents</string></value>
...
</methodResponse>
<BLANKLINE>

Let’s try to add another method, to se if it gets listed…

>>> class FolderListing2:
...     def contents2(self):
...         return list(self.context.keys())
>>> from zope.configuration import xmlconfig
>>> ignored = xmlconfig.string("""
... <configure
...     xmlns="http://namespaces.zope.org/zope"
...     xmlns:xmlrpc="http://namespaces.zope.org/xmlrpc"
...     >
...   <!-- We only need to do this include in this example,
...        Normally the include has already been done for us. -->
...   <include package="zope.app.publisher.xmlrpc" file="meta.zcml" />
...
...   <xmlrpc:view
...       for="zope.app.folder.folder.IFolder"
...       methods="contents2"
...       class="zope.app.xmlrpcintrospection.README.FolderListing2"
...       permission="zope.ManageContent"
...       />
... </configure>
... """)
>>> print http(r"""
... POST / HTTP/1.0
... Content-Type: text/xml
...
... <?xml version='1.0'?>
... <methodCall>
... <methodName>listMethods</methodName>
... <params>
... </params>
... </methodCall>
... """, handle_errors=False)
HTTP/1.0 200 OK
...
<?xml version='1.0'?>
<methodResponse>
...
<value><string>contents</string></value>
<value><string>contents2</string></value>
...
</methodResponse>
<BLANKLINE>

No we want to test methodHelp and methodSignature, to check that it returns,

• The method doc

• The list of attributes

In RPC, the list of attributes has to be return in an array of type:

[return type, param1 type, param2 type]

Since in Python we cannot have a static type for the method return type, we introduce here a new mechanism based on a decorator, that let the xmlrpcview developer add his own signature.

If the signature is not given, a defaut list is returned:

[None, None, None…]

The decorator append to the function objet two new parameters, to get back the signature.

>>> from zope.app.xmlrpcintrospection.xmlrpcintrospection import xmlrpccallable
>>> class JacksonFiveRPC:
...     @xmlrpccallable(str, str, str, str)
...     def says(self, a, b, c):
...         return '%s %s, %s, lalalala, you and me, lalalala' % (a, b, c)

Let’s try to get back the signature:

>>> JacksonFiveRPC().says.return_type
<type 'str'>
>>> JacksonFiveRPC().says.parameters_types
(<type 'str'>, <type 'str'>, <type 'str'>)

The method is still callable as needed:

>>> JacksonFiveRPC().says('a', 'b', 'c')
'a b, c, lalalala, you and me, lalalala'

Let’s try out decorated and not decorated methods signatures (*):

>>> class JacksonFiveRPC:
...     @xmlrpccallable(str, str, str, str)
...     def says(self, a, b, c):
...         return '%s %s, %s, lalalala, you and me, lalalala' % (a, b, c)
...     def says_not_decorated(self, a, b, c):
...         return '%s %s, %s, lalalala, you and me, lalalala' % (a, b, c)
>>> from zope.configuration import xmlconfig
>>> ignored = xmlconfig.string("""
... <configure
...     xmlns="http://namespaces.zope.org/zope"
...     xmlns:xmlrpc="http://namespaces.zope.org/xmlrpc"
...     >
...   <!-- We only need to do this include in this example,
...        Normally the include has already been done for us. -->
...   <include package="zope.app.publisher.xmlrpc" file="meta.zcml" />
...
...   <xmlrpc:view
...       for="zope.app.folder.folder.IFolder"
...       methods="says says_not_decorated"
...       class="zope.app.xmlrpcintrospection.README.JacksonFiveRPC"
...       permission="zope.ManageContent"
...       />
... </configure>
... """)

Now let’s try to get the signature for says():

>>> print http(r"""
... POST / HTTP/1.0
... Content-Type: text/xml
...
... <?xml version='1.0'?>
... <methodCall>
... <methodName>methodSignature</methodName>
... <params>
... <param>
... <value>says</value>
... </param>
... </params>
... </methodCall>
... """, handle_errors=False)
HTTP/1.0 200 OK
...
<?xml version='1.0'?>
<methodResponse>
<params>
<param>
<value><array><data>
<value><array><data>
<value><string>str</string></value>
<value><string>str</string></value>
<value><string>str</string></value>
<value><string>str</string></value>
</data></array></value>
</data></array></value>
</param>
</params>
</methodResponse>
<BLANKLINE>

Now let’s try to get the signature for says_not_decorated()`:

>>> print http(r"""
... POST / HTTP/1.0
... Content-Type: text/xml
...
... <?xml version='1.0'?>
... <methodCall>
... <methodName>methodSignature</methodName>
... <params>
... <param>
... <value>says_not_decorated</value>
... </param>
... </params>
... </methodCall>
... """, handle_errors=False)
HTTP/1.0 200 OK
...
<?xml version='1.0'?>
<methodResponse>
<params>
<param>
<value><array><data>
<value><array><data>
<value><string>undef</string></value>
<value><string>undef</string></value>
<value><string>undef</string></value>
<value><string>undef</string></value>
</data></array></value>
</data></array></value>
</param>
</params>
</methodResponse>
<BLANKLINE>

Last, but not least, the method help:

>>> class JacksonFiveRPCDocumented:
...     @xmlrpccallable(str, str, str, str)
...     def says(self, a, b, c):
...         """ this is the help for
...             says()
...         """
...         return '%s %s, %s, lalalala, you and me, lalalala' % (a, b, c)
...     def says_not_documented(self, a, b, c):
...         return '%s %s, %s, lalalala, you and me, lalalala' % (a, b, c)
>>> from zope.configuration import xmlconfig
>>> ignored = xmlconfig.string("""
... <configure
...     xmlns="http://namespaces.zope.org/zope"
...     xmlns:xmlrpc="http://namespaces.zope.org/xmlrpc"
...     >
...   <!-- We only need to do this include in this example,
...        Normally the include has already been done for us. -->
...   <include package="zope.app.publisher.xmlrpc" file="meta.zcml" />
...
...   <xmlrpc:view
...       for="zope.app.folder.folder.IFolder"
...       methods="says says_not_documented"
...       class="zope.app.xmlrpcintrospection.README.JacksonFiveRPCDocumented"
...       permission="zope.ManageContent"
...       />
... </configure>
... """)
>>> print http(r"""
... POST / HTTP/1.0
... Content-Type: text/xml
...
... <?xml version='1.0'?>
... <methodCall>
... <methodName>methodHelp</methodName>
... <params>
... <param>
... <value>says</value>
... </param>
... </params>
... </methodCall>
... """, handle_errors=False)
HTTP/1.0 200 OK
...
<?xml version='1.0'?>
<methodResponse>
<params>
<param>
<value><string> this is the help for
             says()
         </string></value>
</param>
</params>
</methodResponse>
<BLANKLINE>
>>> print http(r"""
... POST / HTTP/1.0
... Content-Type: text/xml
...
... <?xml version='1.0'?>
... <methodCall>
... <methodName>methodHelp</methodName>
... <params>
... <param>
... <value>says_not_documented</value>
... </param>
... </params>
... </methodCall>
... """, handle_errors=False)
HTTP/1.0 200 OK
...
<?xml version='1.0'?>
<methodResponse>
<params>
<param>
<value><string>undef</string></value>
</param>
</params>
</methodResponse>
<BLANKLINE>