/[thuban]/branches/WIP-pyshapelib-bramz/Thuban/Model/load.py
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revision 1375 by bh, Tue Jul 8 10:53:05 2003 UTC revision 1930 by bh, Tue Nov 11 13:24:41 2003 UTC
# Line 38  from Thuban.Model.data import DerivedSha Line 38  from Thuban.Model.data import DerivedSha
38  from Thuban.Model.table import DBFTable  from Thuban.Model.table import DBFTable
39  from Thuban.Model.transientdb import TransientJoinedTable  from Thuban.Model.transientdb import TransientJoinedTable
40    
41    from Thuban.Model.xmlreader import XMLReader
42    import resource
43    
44    import postgisdb
45    
46  class LoadError(Exception):  class LoadError(Exception):
     pass  
47    
48  from Thuban.Model.xmlreader import XMLReader      """Exception raised when the thuban file is corrupted
49  import resource  
50        Not all cases of corrupted thuban files will lead to this exception
51        but those that are found by checks in the loading code itself are.
52        """
53    
54    
55    class LoadCancelled(Exception):
56    
57        """Exception raised to indicate that loading was interrupted by the user"""
58    
59    
60  def parse_color(color):  def parse_color(color):
61      """Return the color object for the string color.      """Return the color object for the string color.
# Line 87  class AttrDesc: Line 100  class AttrDesc:
100    
101  class SessionLoader(XMLReader):  class SessionLoader(XMLReader):
102    
103      def __init__(self):      def __init__(self, db_connection_callback = None):
104          """Inititialize the Sax handler."""          """Inititialize the Sax handler."""
105          XMLReader.__init__(self)          XMLReader.__init__(self)
106    
107            self.db_connection_callback = db_connection_callback
108    
109          self.theSession = None          self.theSession = None
110          self.aMap = None          self.aMap = None
111          self.aLayer = None          self.aLayer = None
# Line 101  class SessionLoader(XMLReader): Line 116  class SessionLoader(XMLReader):
116    
117          dispatchers = {          dispatchers = {
118              'session'       : ("start_session",        "end_session"),              'session'       : ("start_session",        "end_session"),
119    
120                'dbconnection': ("start_dbconnection", None),
121    
122                'dbshapesource': ("start_dbshapesource", None),
123              'fileshapesource': ("start_fileshapesource", None),              'fileshapesource': ("start_fileshapesource", None),
124              'derivedshapesource': ("start_derivedshapesource", None),              'derivedshapesource': ("start_derivedshapesource", None),
125              'filetable': ("start_filetable", None),              'filetable': ("start_filetable", None),
# Line 122  class SessionLoader(XMLReader): Line 141  class SessionLoader(XMLReader):
141    
142          # all dispatchers should be used for the 0.8 and 0.9 namespaces too          # all dispatchers should be used for the 0.8 and 0.9 namespaces too
143          for xmlns in ("http://thuban.intevation.org/dtds/thuban-0.8.dtd",          for xmlns in ("http://thuban.intevation.org/dtds/thuban-0.8.dtd",
144                        "http://thuban.intevation.org/dtds/thuban-0.9-dev.dtd"):                        "http://thuban.intevation.org/dtds/thuban-0.9-dev.dtd",
145                          "http://thuban.intevation.org/dtds/thuban-0.9.dtd",
146                          "http://thuban.intevation.org/dtds/thuban-1.0-dev.dtd"):
147              for key, value in dispatchers.items():              for key, value in dispatchers.items():
148                  dispatchers[(xmlns, key)] = value                  dispatchers[(xmlns, key)] = value
149    
150          XMLReader.AddDispatchers(self, dispatchers)          XMLReader.AddDispatchers(self, dispatchers)
151    
152        def Destroy(self):
153            """Clear all instance variables to cut cyclic references.
154    
155            The GC would have collected the loader eventually but it can
156            happen that it doesn't run at all until Thuban is closed (2.3
157            but not 2.2 tries a bit harder and forces a collection when the
158            interpreter terminates)
159            """
160            self.__dict__.clear()
161    
162      def start_session(self, name, qname, attrs):      def start_session(self, name, qname, attrs):
163          self.theSession = Session(self.encode(attrs.get((None, 'title'),          self.theSession = Session(self.encode(attrs.get((None, 'title'),
164                                                          None)))                                                          None)))
# Line 173  class SessionLoader(XMLReader): Line 204  class SessionLoader(XMLReader):
204                        defined earlier in the .thuban file. Look it up                        defined earlier in the .thuban file. Look it up
205                        self.idmap. If it's the ID of a shapestore the                        self.idmap. If it's the ID of a shapestore the
206                        value will be the table of the shapestore.                        value will be the table of the shapestore.
207    
208               'idref' -- The attribute is the id of an object defined
209                          earlier in the .thuban file. Look it up self.idmap
210    
211               'ascii' -- The attribute is converted to a bytestring with
212                          ascii encoding.
213    
214               a callable -- The attribute value is passed to the callable
215                             and the return value is used a as the converted
216                             value
217          """          """
218          normalized = {}          normalized = {}
219    
220          for d in descr:          for d in descr:
221              if d.required and not attrs.has_key(d.fullname):              if d.required and not attrs.has_key(d.fullname):
222                  pass                  raise LoadError("Element %s requires an attribute %r"
223              #raise LoadError("Element %s requires an attribute %r"                                  % (element, d.name))
             #                    % (element, d.name))  
224              value = attrs.get(d.fullname, d.default)              value = attrs.get(d.fullname, d.default)
225    
226              if d.conversion == "shapesource":              if d.conversion in ("idref", "shapesource"):
227                  if value in self.idmap:                  if value in self.idmap:
228                      value = self.idmap[value]                      value = self.idmap[value]
229                  else:                  else:
# Line 202  class SessionLoader(XMLReader): Line 242  class SessionLoader(XMLReader):
242              elif d.conversion == "filename":              elif d.conversion == "filename":
243                  value = os.path.abspath(os.path.join(self.GetDirectory(),                  value = os.path.abspath(os.path.join(self.GetDirectory(),
244                                                       value))                                                       value))
245                elif d.conversion == "ascii":
246                    value = value.encode("ascii")
247                elif d.conversion:
248                    # Assume it's a callable
249                    value = d.conversion(value)
250    
251              normalized[d.name] = value              normalized[d.name] = value
252          return normalized          return normalized
253    
254        def start_dbconnection(self, name, qname, attrs):
255            attrs = self.check_attrs(name, attrs,
256                                     [AttrDesc("id", True),
257                                      AttrDesc("dbtype", True),
258                                      AttrDesc("host", False, ""),
259                                      AttrDesc("port", False, ""),
260                                      AttrDesc("user", False, ""),
261                                      AttrDesc("dbname", True)])
262            ID = attrs["id"]
263            dbtype = attrs["dbtype"]
264            if dbtype != "postgis":
265                raise LoadError("dbtype %r not supported" % filetype)
266    
267            del attrs["id"]
268            del attrs["dbtype"]
269    
270            # Try to open the connection and if it fails ask the user for
271            # the correct parameters repeatedly.
272            # FIXME: it would be better not to insist on getting a
273            # connection here. We should handle this more like the raster
274            # images where the layers etc still are created but are not
275            # drawn in case Thuban can't use the data for various reasons
276            while 1:
277                try:
278                    conn = postgisdb.PostGISConnection(**attrs)
279                    break
280                except postgisdb.ConnectionError, val:
281                    if self.db_connection_callback is not None:
282                        attrs = self.db_connection_callback(attrs, str(val))
283                        if attrs is None:
284                            raise LoadCancelled
285                    else:
286                        raise
287    
288            self.idmap[ID] = conn
289            self.theSession.AddDBConnection(conn)
290    
291        def start_dbshapesource(self, name, qname, attrs):
292            attrs = self.check_attrs(name, attrs,
293                                     [AttrDesc("id", True),
294                                      AttrDesc("dbconn", True,
295                                               conversion = "idref"),
296                                      AttrDesc("tablename", True,
297                                               conversion = "ascii")])
298            ID = attrs["id"]
299            db = attrs["dbconn"]
300            tablename = attrs["tablename"]
301            self.idmap[ID] = self.theSession.OpenDBShapeStore(db, tablename)
302    
303      def start_fileshapesource(self, name, qname, attrs):      def start_fileshapesource(self, name, qname, attrs):
304          attrs = self.check_attrs(name, attrs,          attrs = self.check_attrs(name, attrs,
305                                    [AttrDesc("id", True),                                    [AttrDesc("id", True),
# Line 277  class SessionLoader(XMLReader): Line 371  class SessionLoader(XMLReader):
371    
372      def start_map(self, name, qname, attrs):      def start_map(self, name, qname, attrs):
373          """Start a map."""          """Start a map."""
374          self.aMap = Map(attrs.get((None, 'title'), None))          self.aMap = Map(self.encode(attrs.get((None, 'title'), None)))
375    
376      def end_map(self, name, qname):      def end_map(self, name, qname):
377          self.theSession.AddMap(self.aMap)          self.theSession.AddMap(self.aMap)
378          self.aMap = None          self.aMap = None
379    
380      def start_projection(self, name, qname, attrs):      def start_projection(self, name, qname, attrs):
381          self.ProjectionName = self.encode(attrs.get((None, 'name'), None))          attrs = self.check_attrs(name, attrs,
382          self.ProjectionParams = [ ]                                   [AttrDesc("name", conversion=self.encode),
383                                      AttrDesc("epsg", default=None,
384                                               conversion=self.encode)])
385            self.projection_name = attrs["name"]
386            self.projection_epsg = attrs["epsg"]
387            self.projection_params = [ ]
388    
389      def end_projection(self, name, qname):      def end_projection(self, name, qname):
390          if self.aLayer is not None:          if self.aLayer is not None:
# Line 296  class SessionLoader(XMLReader): Line 395  class SessionLoader(XMLReader):
395              assert False, "projection tag out of context"              assert False, "projection tag out of context"
396              pass              pass
397    
398          obj.SetProjection(          obj.SetProjection(Projection(self.projection_params,
399              Projection(self.ProjectionParams, self.ProjectionName))                                       self.projection_name,
400                                         epsg = self.projection_epsg))
401    
402      def start_parameter(self, name, qname, attrs):      def start_parameter(self, name, qname, attrs):
403          s = attrs.get((None, 'value'))          s = attrs.get((None, 'value'))
404          s = str(s) # we can't handle unicode in proj          s = str(s) # we can't handle unicode in proj
405          self.ProjectionParams.append(s)          self.projection_params.append(s)
406    
407      def start_layer(self, name, qname, attrs, layer_class = Layer):      def start_layer(self, name, qname, attrs, layer_class = Layer):
408          """Start a layer          """Start a layer
# Line 363  class SessionLoader(XMLReader): Line 463  class SessionLoader(XMLReader):
463          elif fieldType == FIELDTYPE_DOUBLE:          elif fieldType == FIELDTYPE_DOUBLE:
464              self.conv = float              self.conv = float
465    
466          self.aLayer.GetClassification().SetFieldInfo(field, fieldType)          self.aLayer.SetClassificationColumn(field)
467    
468      def end_classification(self, name, qname):      def end_classification(self, name, qname):
469          pass          pass
# Line 381  class SessionLoader(XMLReader): Line 481  class SessionLoader(XMLReader):
481      def start_clpoint(self, name, qname, attrs):      def start_clpoint(self, name, qname, attrs):
482          attrib_value = attrs.get((None, 'value'), "0")          attrib_value = attrs.get((None, 'value'), "0")
483    
484          value = self.conv(attrib_value)          field = self.aLayer.GetClassificationColumn()
485            if self.aLayer.GetFieldType(field) == FIELDTYPE_STRING:
486                value = self.encode(attrib_value)
487            else:
488                value = self.conv(attrib_value)
489          self.cl_group = ClassGroupSingleton(value)          self.cl_group = ClassGroupSingleton(value)
490          self.cl_group.SetLabel(self.encode(attrs.get((None, 'label'), "")))          self.cl_group.SetLabel(self.encode(attrs.get((None, 'label'), "")))
491          self.cl_prop = ClassGroupProperties()          self.cl_prop = ClassGroupProperties()
# Line 446  class SessionLoader(XMLReader): Line 549  class SessionLoader(XMLReader):
549          pass          pass
550    
551    
552  def load_session(filename):  def load_session(filename, db_connection_callback = None):
553      """Load a Thuban session from the file object file"""      """Load a Thuban session from the file object file
554    
555      handler = SessionLoader()      The db_connection_callback, if given should be a callable object
556        that can be called like this:
557           db_connection_callback(params, message)
558    
559        where params is a dictionary containing the known connection
560        parameters and message is a string with a message why the connection
561        failed. db_connection_callback should return a new dictionary with
562        corrected and perhaps additional parameters like a password or None
563        to indicate that the user cancelled.
564        """
565        handler = SessionLoader(db_connection_callback)
566      handler.read(filename)      handler.read(filename)
567    
568      session = handler.theSession      session = handler.theSession
569      # Newly loaded session aren't modified      # Newly loaded session aren't modified
570      session.UnsetModified()      session.UnsetModified()
571    
572        handler.Destroy()
573    
574      return session      return session
575    
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