class BaseHandler(tornado.web.RequestHandler):
'''
General request handler.
'''
def initialize(self, registry):
self.registry = registry
if self.registry.get_hostname() == '':
self.registry.set_hostname(self.request.protocol + '://' +
self.request.host)
def __init__(self, application, request, **kwargs):
super(BaseHandler, self).__init__(application, request, **kwargs)
# This ensures that at least one registry is loaded in case initialize
# is not called for some reason...
self.registry = NonePersistentRegistry()
if self.registry.get_hostname() == '':
self.registry.set_hostname(self.request.protocol + '://' +
self.request.host)
def extract_http_data(self):
'''
Extracts all necessary information from the HTTP envelop. Minimize the
data which is carried around inside of the service. Also ensures that
the names are always equal - When deployed in Apache the names of the
Headers change.
'''
heads = {}
headers = self.request.headers
if 'Category' in headers:
heads['Category'] = headers['Category']
if 'X-Occi-Attribute' in headers:
heads['X-OCCI-Attribute'] = headers['X-Occi-Attribute']
if 'X-Occi-Location' in headers:
heads['X-OCCI-Location'] = headers['X-Occi-Location']
if 'Link' in headers:
heads['Link'] = headers['Link']
if self.request.body is not '':
body = self.request.body.strip()
else:
body = ''
return heads, body
def get_renderer(self, content_type):
'''
Returns the proper rendering parser.
content_type -- String with either either Content-Type or Accept.
'''
try:
return self.registry.get_renderer(
self.request.headers[content_type])
except KeyError:
return self.registry.get_renderer(self.registry.get_default_type())
def response(self, status, mime_type, headers, body='OK'):
'''
Will create a response and send it to the client.
status -- The status code.
mime_type -- Sets the Content-Type of the response.
headers -- The HTTP headers.
body -- The text for the body (default: ok).
'''
self.set_header('Server', VERSION)
self.set_header('Content-Type', mime_type)
self.set_status(status)
if headers is not None:
for item in headers.keys():
self._headers[item] = headers[item]
self.write(body)
self.finish('\n')
def get_error_html(self, status_code, **kwargs):
self.set_header('Server', VERSION)
self.set_header('Content-Type', self.registry.get_default_type())
exception = sys.exc_info()[1]
msg = str(exception)
self.set_status(status_code)
return msg
def parse_action(self):
'''
Retrieves the Action which was given in the request.
'''
headers, body = self.extract_http_data()
rendering = self.get_renderer(CONTENT_TYPE)
action = rendering.to_action(headers, body)
return action
def parse_filter(self):
'''
Retrieve any attributes or categories which where provided in the
request for filtering.
'''
headers, body = self.extract_http_data()
attr = 'X-OCCI-Attribute'
if attr not in headers and 'Category' not in headers and body == '':
return [], {}
rendering = self.get_renderer(CONTENT_TYPE)
categories, attributes = rendering.get_filters(headers, body)
return categories, attributes
def parse_entity(self, def_kind=None):
'''
Retrieves the entity which was rendered within the request.
def_kind -- Indicates if the request can be incomplete (False).
'''
headers, body = self.extract_http_data()
rendering = self.get_renderer(CONTENT_TYPE)
entity = rendering.to_entity(headers, body, def_kind)
return entity
def parse_entities(self):
'''
Retrieves a set of entities which was rendered within the request.
'''
headers, body = self.extract_http_data()
rendering = self.get_renderer(CONTENT_TYPE)
entities = rendering.to_entities(headers, body)
return entities
def parse_mixins(self):
'''
Retrieves a mixin from a request.
'''
headers, body = self.extract_http_data()
rendering = self.get_renderer(CONTENT_TYPE)
mixin = rendering.to_mixins(headers, body)
return mixin
def render_entity(self, entity):
'''
Renders a single entity to the client.
entity -- The entity which should be rendered.
'''
rendering = self.get_renderer(ACCEPT)
headers, body = rendering.from_entity(entity)
self.response(200, rendering.mime_type, headers, body)
def render_entities(self, entities, key):
'''
Renders a list of entities to the client.
entities -- The entities which should be rendered.
'''
rendering = self.get_renderer(ACCEPT)
headers, body = rendering.from_entities(entities, key)
self.response(200, rendering.mime_type, headers, body)
def render_categories(self, categories):
'''
Renders a list of categories to the client.
categories -- The categories which should be rendered.
'''
rendering = self.get_renderer(ACCEPT)
headers, body = rendering.from_categories(categories)
self.response(200, rendering.mime_type, headers, body)
