x/gantt
Code Issues Proposed changes

removing controller/serializer code from wsgi.py; updating other code to use new modules

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This commit is contained in:
Brian Waldon
2011-05-18 20:33:25 -04:00
parent 194a111aca
commit 5ce221c29f
1 changed files with 2 additions and 248 deletions
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250
nova/wsgi.py
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@@ -82,36 +82,7 @@ class Server(object):
class Request(webob.Request): class Request(webob.Request):
pass
def best_match_content_type(self):
"""Determine the most acceptable content-type.
Based on the query extension then the Accept header.
"""
parts = self.path.rsplit('.', 1)
if len(parts) > 1:
format = parts[1]
if format in ['json', 'xml']:
return 'application/{0}'.format(parts[1])
ctypes = ['application/json', 'application/xml']
bm = self.accept.best_match(ctypes)
return bm or 'application/json'
def get_content_type(self):
allowed_types = ("application/xml", "application/json")
if not "Content-Type" in self.headers:
msg = _("Missing Content-Type")
LOG.debug(msg)
raise webob.exc.HTTPBadRequest(msg)
type = self.content_type
if type in allowed_types:
return type
LOG.debug(_("Wrong Content-Type: %s") % type)
raise webob.exc.HTTPBadRequest("Invalid content type")
class Application(object): class Application(object):
@@ -286,7 +257,7 @@ class Router(object):
Each route in `mapper` must specify a 'controller', which is a Each route in `mapper` must specify a 'controller', which is a
WSGI app to call. You'll probably want to specify an 'action' as WSGI app to call. You'll probably want to specify an 'action' as
well and have your controller be a wsgi.Controller, who will route well and have your controller be a controller, who will route
the request to the action method. the request to the action method.
Examples: Examples:
@@ -335,223 +306,6 @@ class Router(object):
return app return app
class Controller(object):
"""WSGI app that dispatched to methods.
WSGI app that reads routing information supplied by RoutesMiddleware
and calls the requested action method upon itself. All action methods
must, in addition to their normal parameters, accept a 'req' argument
which is the incoming wsgi.Request. They raise a webob.exc exception,
or return a dict which will be serialized by requested content type.
"""
@webob.dec.wsgify(RequestClass=Request)
def __call__(self, req):
"""Call the method specified in req.environ by RoutesMiddleware."""
arg_dict = req.environ['wsgiorg.routing_args'][1]
action = arg_dict['action']
method = getattr(self, action)
LOG.debug("%s %s" % (req.method, req.url))
del arg_dict['controller']
del arg_dict['action']
if 'format' in arg_dict:
del arg_dict['format']
arg_dict['req'] = req
result = method(**arg_dict)
if type(result) is dict:
content_type = req.best_match_content_type()
default_xmlns = self.get_default_xmlns(req)
body = self._serialize(result, content_type, default_xmlns)
response = webob.Response()
response.headers['Content-Type'] = content_type
response.body = body
msg_dict = dict(url=req.url, status=response.status_int)
msg = _("%(url)s returned with HTTP %(status)d") % msg_dict
LOG.debug(msg)
return response
else:
return result
def _serialize(self, data, content_type, default_xmlns):
"""Serialize the given dict to the provided content_type.
Uses self._serialization_metadata if it exists, which is a dict mapping
MIME types to information needed to serialize to that type.
"""
_metadata = getattr(type(self), '_serialization_metadata', {})
serializer = Serializer(_metadata, default_xmlns)
try:
return serializer.serialize(data, content_type)
except exception.InvalidContentType:
raise webob.exc.HTTPNotAcceptable()
def _deserialize(self, data, content_type):
"""Deserialize the request body to the specefied content type.
Uses self._serialization_metadata if it exists, which is a dict mapping
MIME types to information needed to serialize to that type.
"""
_metadata = getattr(type(self), '_serialization_metadata', {})
serializer = Serializer(_metadata)
return serializer.deserialize(data, content_type)
def get_default_xmlns(self, req):
"""Provide the XML namespace to use if none is otherwise specified."""
return None
class Serializer(object):
"""Serializes and deserializes dictionaries to certain MIME types."""
def __init__(self, metadata=None, default_xmlns=None):
"""Create a serializer based on the given WSGI environment.
'metadata' is an optional dict mapping MIME types to information
needed to serialize a dictionary to that type.
"""
self.metadata = metadata or {}
self.default_xmlns = default_xmlns
def _get_serialize_handler(self, content_type):
handlers = {
'application/json': self._to_json,
'application/xml': self._to_xml,
}
try:
return handlers[content_type]
except Exception:
raise exception.InvalidContentType(content_type=content_type)
def serialize(self, data, content_type):
"""Serialize a dictionary into the specified content type."""
return self._get_serialize_handler(content_type)(data)
def deserialize(self, datastring, content_type):
"""Deserialize a string to a dictionary.
The string must be in the format of a supported MIME type.
"""
return self.get_deserialize_handler(content_type)(datastring)
def get_deserialize_handler(self, content_type):
handlers = {
'application/json': self._from_json,
'application/xml': self._from_xml,
}
try:
return handlers[content_type]
except Exception:
raise exception.InvalidContentType(content_type=content_type)
def _from_json(self, datastring):
return utils.loads(datastring)
def _from_xml(self, datastring):
xmldata = self.metadata.get('application/xml', {})
plurals = set(xmldata.get('plurals', {}))
node = minidom.parseString(datastring).childNodes[0]
return {node.nodeName: self._from_xml_node(node, plurals)}
def _from_xml_node(self, node, listnames):
"""Convert a minidom node to a simple Python type.
listnames is a collection of names of XML nodes whose subnodes should
be considered list items.
"""
if len(node.childNodes) == 1 and node.childNodes[0].nodeType == 3:
return node.childNodes[0].nodeValue
elif node.nodeName in listnames:
return [self._from_xml_node(n, listnames) for n in node.childNodes]
else:
result = dict()
for attr in node.attributes.keys():
result[attr] = node.attributes[attr].nodeValue
for child in node.childNodes:
if child.nodeType != node.TEXT_NODE:
result[child.nodeName] = self._from_xml_node(child,
listnames)
return result
def _to_json(self, data):
return utils.dumps(data)
def _to_xml(self, data):
metadata = self.metadata.get('application/xml', {})
# We expect data to contain a single key which is the XML root.
root_key = data.keys()[0]
doc = minidom.Document()
node = self._to_xml_node(doc, metadata, root_key, data[root_key])
xmlns = node.getAttribute('xmlns')
if not xmlns and self.default_xmlns:
node.setAttribute('xmlns', self.default_xmlns)
return node.toprettyxml(indent=' ')
def _to_xml_node(self, doc, metadata, nodename, data):
"""Recursive method to convert data members to XML nodes."""
result = doc.createElement(nodename)
# Set the xml namespace if one is specified
# TODO(justinsb): We could also use prefixes on the keys
xmlns = metadata.get('xmlns', None)
if xmlns:
result.setAttribute('xmlns', xmlns)
if type(data) is list:
collections = metadata.get('list_collections', {})
if nodename in collections:
metadata = collections[nodename]
for item in data:
node = doc.createElement(metadata['item_name'])
node.setAttribute(metadata['item_key'], str(item))
result.appendChild(node)
return result
singular = metadata.get('plurals', {}).get(nodename, None)
if singular is None:
if nodename.endswith('s'):
singular = nodename[:-1]
else:
singular = 'item'
for item in data:
node = self._to_xml_node(doc, metadata, singular, item)
result.appendChild(node)
elif type(data) is dict:
collections = metadata.get('dict_collections', {})
if nodename in collections:
metadata = collections[nodename]
for k, v in data.items():
node = doc.createElement(metadata['item_name'])
node.setAttribute(metadata['item_key'], str(k))
text = doc.createTextNode(str(v))
node.appendChild(text)
result.appendChild(node)
return result
attrs = metadata.get('attributes', {}).get(nodename, {})
for k, v in data.items():
if k in attrs:
result.setAttribute(k, str(v))
else:
node = self._to_xml_node(doc, metadata, k, v)
result.appendChild(node)
else:
# Type is atom
node = doc.createTextNode(str(data))
result.appendChild(node)
return result
def paste_config_file(basename): def paste_config_file(basename):
"""Find the best location in the system for a paste config file. """Find the best location in the system for a paste config file.