Source Code for Module oort.sitebase

  1  # -*- coding: UTF-8 -*- 
  2  """This module contains everything needed to setup an Oort-based web  
  3  application. It also imports relevant parts from ``oort.display``. 
  4  """ 
  5  #======================================================================= 
  6  import urllib 
  7  import logging 
  8  from pkg_resources import EntryPoint 
  9  from rdflib import URIRef 
 10  from paste.wsgiwrappers import WSGIRequest, WSGIResponse 
 11  from paste.httpexceptions import HTTPTemporaryRedirect 
 12  from oort.display import DisplayBase, Display, SubTypeAwareDisplay 
 13  from oort.display import AspectBase, Aspect, TpltAspect, JsonAspect, RdfAspect 
 14  from oort.rdfview import RdfQuery 
 15  from oort.util.code import SlotStruct, contract, autosuper 
 16  __metaclass__ = autosuper 
 17  #======================================================================= 
 18  # FIXME: really, fix the "variant" concept.. 
 19  # TODO: option to give ignored suffix for e.g. downloading..? 
 20  # TODO: Work on SubTypeAwareDisplay (partially done; consider using "poorMansInference") 
 21  #   - or <http://dev.w3.org/cvsweb/~checkout~/2004/PythonLib-IH/RDFSClosure.py> 
 22   
 23   
 24 -class resource_viewer_meta(autosuper): 
 25 -    def __init__(cls, clsName, bases, clsDict): 
 26          autosuper.__init__(cls, clsName, bases, clsDict) 
 27          displayClasses = clsDict.setdefault('displayClasses', {}) 
 28          defaultDisplay = clsDict.get('defaultDisplay') 
 29          for member in clsDict.values(): 
 30              if isinstance(member, type) and issubclass(member, DisplayBase): 
 31                  name = getattr(member, 'name', None) 
 32                  if not name: 
 33                      continue 
 34                  displayClasses[name] = member 
 35                  if not defaultDisplay and getattr(member, 'default', False): 
 36                      defaultDisplay = name 
 37          cls.displayClasses = displayClasses 
 38          cls.defaultDisplay = defaultDisplay 
 39   
 40   
 41 -class ResourceViewerBase: 
 42      """Base class - not for direct usage.""" 
 43      __metaclass__ = resource_viewer_meta 
 44   
 45      @classmethod 
 46 -    def app_factory(cls, global_conf=None, 
 47                      graph_factory=None, **cfg): 
 48          """Factory method compatible with the app_factory feature of Paste Deploy.""" 
 49          mk_graph = EntryPoint.parse("x=%s" % graph_factory).load(False) 
 50          graph = mk_graph() 
 51          return cls(graph, cfg) 
 52   
 53      VARIANT_SEP = '-' 
 54      RESOURCE_QUERY_KEY = 'resource' 
 55   
 56      #defaultDisplay = None 
 57      langOrder = () 
 58   
 59 -    def __init__(self, graph, cfg={}): 
 60          self.graph = graph 
 61          self._logger = logging.getLogger("oort.sitebase.ResourceViewerBase <%s>" % id(self)) 
 62          configure_logging(self._logger, cfg) 
 63          self.displays = dict((name, dispCls(cfg=cfg)) 
 64                  for name, dispCls in self.displayClasses.items()) 
 65   
 66 -    def __call__(self, environ, start_response): 
 67          req = WSGIRequest(environ) 
 68   
 69          self._viewPathTemplate = req.script_name + '/%s/%s/' 
 70          args = req.path_info.split('/') 
 71          try: 
 72              args.pop(0) # remove first '' 
 73              lang = args.pop(0) 
 74              displayArg = args.pop(0) 
 75          except IndexError: 
 76              lang, displayArg = None, None 
 77          if not displayArg: 
 78              return self._default_redirect(lang, environ, start_response) 
 79   
 80          uri = req.GET.get(self.RESOURCE_QUERY_KEY) or self.resource_from(args) 
 81   
 82          get_result, contentType = self.prepared_display( 
 83                  URIRef(uri), lang, displayArg, req) 
 84   
 85          headerMap = {} 
 86          if contentType: 
 87              headerMap['Content-Type'] = contentType 
 88   
 89          start_response('200 OK', headerMap.items()) 
 90          return get_result(self.graph) 
 91   
 92 -    def _default_redirect(self, lang, environ, start_response): 
 93          redirect = HTTPTemporaryRedirect( 
 94                  self.app_url_for(lang or self.langOrder[0], self.defaultDisplay)) 
 95          return redirect(environ, start_response) 
 96   
 97      @contract.template_method 
 98 -    def resource_from(self, pathArgs): 
 99          raise NotImplementedError 
100   
101      @contract.template_method 
102 -    def resource_to_app_path(self, resource): 
103          raise NotImplementedError 
104   
105 -    def app_url_for(self, lang, displayArg, resource=None, fallback=True): 
106          urlBase = self._viewPathTemplate % (lang, displayArg) 
107          if resource: 
108              resource, success = self.resource_to_app_path(resource) 
109              if success: 
110                  return urlBase + resource.replace('#', '%23') 
111              elif fallback: 
112                  return '%s?%s=%s' % (urlBase, self.RESOURCE_QUERY_KEY, 
113                                       urllib.quote(resource)) 
114              else: 
115                  return None # TODO: raise NoAppUrlForResourceError(resource) 
116          else: 
117              return urlBase 
118   
119 -    def prepared_display(self, resource, lang, displayArg, req): 
120          args = displayArg.split(self.VARIANT_SEP, 1) 
121          name, variantArg = args[0], len(args) > 1 and args[1] 
122          display = self.displays[name] 
123          current = Current(resource, lang) 
124          appUtil = AppUtil(current, displayArg, self, req) 
125   
126          self._logger.debug("Prepared display with: %s %s %s" 
127                              % (current, appUtil, display )) 
128          # TODO: use __repr__? 
129   
130          def get_result(graph): 
131              return display.get_result_generator(graph, appUtil, variantArg) 
132   
133          return get_result, display.contentType 
134   
135   
136  LOG_LEVEL_NAMES = 'DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL' 
137   
138 -def configure_logging(logger, cfg): 
139      levelName = cfg.get('logging_level', 'warning').upper() 
140      if levelName in LOG_LEVEL_NAMES: 
141          level = getattr(logging, levelName) 
142          logger.setLevel(level) 
143      # format, filename, filemode .. 
144      handler = logging.StreamHandler() 
145      logger.addHandler(handler) 
146   
147   
148 -class Current(SlotStruct): 
149      """Representation of the current *resource* request.""" 
150      __slots__ = 'resource', 'lang' 
151   
152 -class AppUtil(SlotStruct): 
153      """"An instance of this class is provided to the templates under the name  
154      'app'. It provides a controlled interface to the application and the  
155      current state (request).""" 
156   
157      __slots__ = 'current', '_displayArg', '_viewer', '_req' 
158   
159 -    def queries(self, queries): 
160          for query in queries: 
161              yield query(self._viewer.graph, self.current.resource, self.current.lang) 
162   
163 -    def link(self, resource=None, lang=None, display=None, fallback=True, displayArg=None): 
164          """Returns an URL within the current app. The following arguments  
165          can be given (all defaults to current unless provided): 
166   
167              resource 
168                  A target URI or an instance of an RdfQuery. 
169   
170              lang 
171                  The language to use. 
172   
173              display 
174                  The display name to use. 
175   
176              fallback 
177                  Revert to a GET for the resource if no app url can be made. 
178                  Defaults to True. 
179          """ 
180          if resource: 
181              if isinstance(resource, RdfQuery): 
182                  resource = resource._subject 
183          else: resource = self.current.resource 
184          lang = lang or self.current.lang 
185          displayArg = display or displayArg or self._displayArg 
186          return self._viewer.app_url_for(lang, displayArg, resource, fallback) 
187   
188 -    def safe_link(self, *args): 
189          return self.link(fallback=False) 
190   
191      @property 
192 -    def baseurl(self): 
193          """Returns the base URL of this web app.""" 
194          return self._req.script_name 
195   
196   
197 -class ResourceViewer(ResourceViewerBase): 
198      """Use for simple apps where all URIs in the graph share the same base URI  
199      (set ``resourceBase`` to that).""" 
200      resourceBase =None 
201      trailSep='/' 
202   
203 -    def __init__(self, *args): 
204          self.__super.__init__(*args) 
205          self._uriBase = self.resourceBase + "%s" 
206   
207 -    def resource_from(self, pathArgs): 
208          return self._uriBase % self.trailSep.join(pathArgs) 
209   
210 -    def resource_to_app_path(self, resource): 
211          base = self.resourceBase 
212          if resource.find(base) == 0: 
213              return str(resource)[len(base):], True 
214          else: 
215              return resource, False 
216   
217   
218 -class MultiBaseResourceViewer(ResourceViewerBase): 
219      """Use for full-fledged apps where many different base URIs will be  
220      "mounted" at different named bases (done with the dictionary  
221      ``resourceBases``).""""" 
222      resourceBases = {} 
223      defaultResource = '' 
224      # TODO: skip defaultResource and use defaultResourceBase? 
225      # TODO: if bad baseKey, raise Exception instead? 
226   
227 -    def resource_from(self, pathArgs): 
228          if not pathArgs: 
229              return self.defaultResource 
230          pathArgs = list(pathArgs) 
231          baseKey = pathArgs.pop(0) 
232          lookup = self.resourceBases.get(baseKey) 
233          if not lookup: 
234              return self.defaultResource 
235          uriBase, trailSep = lookup 
236          return uriBase + trailSep.join(pathArgs) 
237   
238 -    def resource_to_app_path(self, resource): 
239          for baseKey, (base, trailSep) in self.resourceBases.items(): 
240              if resource.find(base) == 0: 
241                  respath = str(resource)[len(base):] 
242                  if trailSep: 
243                      respath = respath.replace(trailSep, '/') 
244                  lpath = "%s/%s" % (baseKey, respath) 
245                  return lpath, True 
246          return resource, False 
247