/[thuban]/branches/WIP-pyshapelib-bramz/Thuban/Model/load.py
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revision 1354 by jonathan, Wed Jul 2 09:37:07 2003 UTC revision 2036 by bh, Mon Dec 22 17:49:43 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 120  class SessionLoader(XMLReader): Line 139  class SessionLoader(XMLReader):
139              'labellayer'    : ("start_labellayer",     None),              'labellayer'    : ("start_labellayer",     None),
140              'label'         : ("start_label",          None)}              'label'         : ("start_label",          None)}
141    
142          # all dispatchers should be used for the 0.8 namespace          # all dispatchers should be used for the 0.8 and 0.9 namespaces too
143          xmlns = "http://thuban.intevation.org/dtds/thuban-0.8.dtd"          for xmlns in ("http://thuban.intevation.org/dtds/thuban-0.8.dtd",
144          for key, value in dispatchers.items():                        "http://thuban.intevation.org/dtds/thuban-0.9-dev.dtd",
145              dispatchers[(xmlns, key)] = value                        "http://thuban.intevation.org/dtds/thuban-0.9.dtd",
146                          "http://thuban.intevation.org/dtds/thuban-1.0-dev.dtd",
147                          "http://thuban.intevation.org/dtds/thuban-1.0rc1.dtd",
148                          "http://thuban.intevation.org/dtds/thuban-1.0.0.dtd"):
149                for key, value in dispatchers.items():
150                    dispatchers[(xmlns, key)] = value
151    
152          XMLReader.AddDispatchers(self, dispatchers)          XMLReader.AddDispatchers(self, dispatchers)
153    
154        def Destroy(self):
155            """Clear all instance variables to cut cyclic references.
156    
157            The GC would have collected the loader eventually but it can
158            happen that it doesn't run at all until Thuban is closed (2.3
159            but not 2.2 tries a bit harder and forces a collection when the
160            interpreter terminates)
161            """
162            self.__dict__.clear()
163    
164      def start_session(self, name, qname, attrs):      def start_session(self, name, qname, attrs):
165          self.theSession = Session(self.encode(attrs.get((None, 'title'),          self.theSession = Session(self.encode(attrs.get((None, 'title'),
166                                                          None)))                                                          None)))
# Line 154  class SessionLoader(XMLReader): Line 188  class SessionLoader(XMLReader):
188          If the attribute has a default value and it is not present in          If the attribute has a default value and it is not present in
189          attrs, use that default value as the value in the returned dict.          attrs, use that default value as the value in the returned dict.
190    
191          If a conversion is specified, convert the value before putting          The value is converted before putting it into the returned dict.
192          it into the returned dict. The following conversions are          The following conversions are available:
         available:  
193    
194             'filename' -- The attribute is a filename.             'filename' -- The attribute is a filename.
195    
# Line 172  class SessionLoader(XMLReader): Line 205  class SessionLoader(XMLReader):
205                        defined earlier in the .thuban file. Look it up                        defined earlier in the .thuban file. Look it up
206                        self.idmap. If it's the ID of a shapestore the                        self.idmap. If it's the ID of a shapestore the
207                        value will be the table of the shapestore.                        value will be the table of the shapestore.
208    
209               'idref' -- The attribute is the id of an object defined
210                          earlier in the .thuban file. Look it up self.idmap
211    
212               'ascii' -- The attribute is converted to a bytestring with
213                          ascii encoding.
214    
215               a callable -- The attribute value is passed to the callable
216                             and the return value is used as the converted
217                             value
218    
219            If no conversion is specified for an attribute it is converted
220            with self.encode.
221          """          """
222          normalized = {}          normalized = {}
223    
224          for d in descr:          for d in descr:
225              if d.required and not attrs.has_key(d.fullname):              if d.required and not attrs.has_key(d.fullname):
226                  pass                  raise LoadError("Element %s requires an attribute %r"
227              #raise LoadError("Element %s requires an attribute %r"                                  % (element, d.name))
             #                    % (element, d.name))  
228              value = attrs.get(d.fullname, d.default)              value = attrs.get(d.fullname, d.default)
229    
230              if d.conversion == "shapesource":              if d.conversion in ("idref", "shapesource"):
231                  if value in self.idmap:                  if value in self.idmap:
232                      value = self.idmap[value]                      value = self.idmap[value]
233                  else:                  else:
# Line 201  class SessionLoader(XMLReader): Line 246  class SessionLoader(XMLReader):
246              elif d.conversion == "filename":              elif d.conversion == "filename":
247                  value = os.path.abspath(os.path.join(self.GetDirectory(),                  value = os.path.abspath(os.path.join(self.GetDirectory(),
248                                                       value))                                                       value))
249                elif d.conversion == "ascii":
250                    value = value.encode("ascii")
251                elif d.conversion:
252                    # Assume it's a callable
253                    value = d.conversion(value)
254                else:
255                   value = self.encode(value)
256    
257              normalized[d.name] = value              normalized[d.name] = value
258          return normalized          return normalized
259    
260        def start_dbconnection(self, name, qname, attrs):
261            attrs = self.check_attrs(name, attrs,
262                                     [AttrDesc("id", True),
263                                      AttrDesc("dbtype", True),
264                                      AttrDesc("host", False, ""),
265                                      AttrDesc("port", False, ""),
266                                      AttrDesc("user", False, ""),
267                                      AttrDesc("dbname", True)])
268            ID = attrs["id"]
269            dbtype = attrs["dbtype"]
270            if dbtype != "postgis":
271                raise LoadError("dbtype %r not supported" % filetype)
272    
273            del attrs["id"]
274            del attrs["dbtype"]
275    
276            # Try to open the connection and if it fails ask the user for
277            # the correct parameters repeatedly.
278            # FIXME: it would be better not to insist on getting a
279            # connection here. We should handle this more like the raster
280            # images where the layers etc still are created but are not
281            # drawn in case Thuban can't use the data for various reasons
282            while 1:
283                try:
284                    conn = postgisdb.PostGISConnection(**attrs)
285                    break
286                except postgisdb.ConnectionError, val:
287                    if self.db_connection_callback is not None:
288                        attrs = self.db_connection_callback(attrs, str(val))
289                        if attrs is None:
290                            raise LoadCancelled
291                    else:
292                        raise
293    
294            self.idmap[ID] = conn
295            self.theSession.AddDBConnection(conn)
296    
297        def start_dbshapesource(self, name, qname, attrs):
298            attrs = self.check_attrs(name, attrs,
299                                     [AttrDesc("id", True),
300                                      AttrDesc("dbconn", True,
301                                               conversion = "idref"),
302                                      AttrDesc("tablename", True,
303                                               conversion = "ascii")])
304            ID = attrs["id"]
305            db = attrs["dbconn"]
306            tablename = attrs["tablename"]
307            self.idmap[ID] = self.theSession.OpenDBShapeStore(db, tablename)
308    
309      def start_fileshapesource(self, name, qname, attrs):      def start_fileshapesource(self, name, qname, attrs):
310          attrs = self.check_attrs(name, attrs,          attrs = self.check_attrs(name, attrs,
311                                    [AttrDesc("id", True),                                    [AttrDesc("id", True),
# Line 249  class SessionLoader(XMLReader): Line 350  class SessionLoader(XMLReader):
350                                    AttrDesc("left", True, conversion="table"),                                    AttrDesc("left", True, conversion="table"),
351                                    AttrDesc("leftcolumn", True),                                    AttrDesc("leftcolumn", True),
352                                    AttrDesc("right", True, conversion="table"),                                    AttrDesc("right", True, conversion="table"),
353                                    AttrDesc("rightcolumn")])                                    AttrDesc("rightcolumn", True),
354    
355                                      # jointype is required for file
356                                      # version 0.9 but this attribute
357                                      # wasn't in the 0.8 version because of
358                                      # an oversight so we assume it's
359                                      # optional since we want to handle
360                                      # both file format versions here.
361                                      AttrDesc("jointype", False,
362                                               default="INNER")])
363    
364            jointype = attrs["jointype"]
365            if jointype == "LEFT OUTER":
366                outer_join = True
367            elif jointype == "INNER":
368                outer_join = False
369            else:
370                raise LoadError("jointype %r not supported" % jointype )
371          table = TransientJoinedTable(self.theSession.TransientDB(),          table = TransientJoinedTable(self.theSession.TransientDB(),
372                                       attrs["left"], attrs["leftcolumn"],                                       attrs["left"], attrs["leftcolumn"],
373                                       attrs["right"], attrs["rightcolumn"])                                       attrs["right"], attrs["rightcolumn"],
374                                         outer_join = outer_join)
375          table.SetTitle(attrs["title"])          table.SetTitle(attrs["title"])
376          self.idmap[attrs["id"]] = self.theSession.AddTable(table)          self.idmap[attrs["id"]] = self.theSession.AddTable(table)
377    
378      def start_map(self, name, qname, attrs):      def start_map(self, name, qname, attrs):
379          """Start a map."""          """Start a map."""
380          self.aMap = Map(attrs.get((None, 'title'), None))          self.aMap = Map(self.encode(attrs.get((None, 'title'), None)))
381    
382      def end_map(self, name, qname):      def end_map(self, name, qname):
383          self.theSession.AddMap(self.aMap)          self.theSession.AddMap(self.aMap)
384          self.aMap = None          self.aMap = None
385    
386      def start_projection(self, name, qname, attrs):      def start_projection(self, name, qname, attrs):
387          self.ProjectionName = self.encode(attrs.get((None, 'name'), None))          attrs = self.check_attrs(name, attrs,
388          self.ProjectionParams = [ ]                                   [AttrDesc("name", conversion=self.encode),
389                                      AttrDesc("epsg", default=None,
390                                               conversion=self.encode)])
391            self.projection_name = attrs["name"]
392            self.projection_epsg = attrs["epsg"]
393            self.projection_params = [ ]
394    
395      def end_projection(self, name, qname):      def end_projection(self, name, qname):
396          if self.aLayer is not None:          if self.aLayer is not None:
# Line 277  class SessionLoader(XMLReader): Line 401  class SessionLoader(XMLReader):
401              assert False, "projection tag out of context"              assert False, "projection tag out of context"
402              pass              pass
403    
404          obj.SetProjection(          obj.SetProjection(Projection(self.projection_params,
405              Projection(self.ProjectionParams, self.ProjectionName))                                       self.projection_name,
406                                         epsg = self.projection_epsg))
407    
408      def start_parameter(self, name, qname, attrs):      def start_parameter(self, name, qname, attrs):
409          s = attrs.get((None, 'value'))          s = attrs.get((None, 'value'))
410          s = str(s) # we can't handle unicode in proj          s = str(s) # we can't handle unicode in proj
411          self.ProjectionParams.append(s)          self.projection_params.append(s)
412    
413      def start_layer(self, name, qname, attrs, layer_class = Layer):      def start_layer(self, name, qname, attrs, layer_class = Layer):
414          """Start a layer          """Start a layer
# Line 327  class SessionLoader(XMLReader): Line 452  class SessionLoader(XMLReader):
452          self.aLayer = None          self.aLayer = None
453    
454      def start_classification(self, name, qname, attrs):      def start_classification(self, name, qname, attrs):
455          field = attrs.get((None, 'field'), None)          attrs = self.check_attrs(name, attrs,
456                                     [AttrDesc("field", True),
457                                      AttrDesc("field_type", True)])
458            field = attrs["field"]
459            fieldType = attrs["field_type"]
460    
         fieldType = attrs.get((None, 'field_type'), None)  
461          dbFieldType = self.aLayer.GetFieldType(field)          dbFieldType = self.aLayer.GetFieldType(field)
462    
463          if fieldType != dbFieldType:          if fieldType != dbFieldType:
# Line 344  class SessionLoader(XMLReader): Line 472  class SessionLoader(XMLReader):
472          elif fieldType == FIELDTYPE_DOUBLE:          elif fieldType == FIELDTYPE_DOUBLE:
473              self.conv = float              self.conv = float
474    
475          self.aLayer.GetClassification().SetFieldInfo(field, fieldType)          self.aLayer.SetClassificationColumn(field)
476    
477      def end_classification(self, name, qname):      def end_classification(self, name, qname):
478          pass          pass
# Line 362  class SessionLoader(XMLReader): Line 490  class SessionLoader(XMLReader):
490      def start_clpoint(self, name, qname, attrs):      def start_clpoint(self, name, qname, attrs):
491          attrib_value = attrs.get((None, 'value'), "0")          attrib_value = attrs.get((None, 'value'), "0")
492    
493          value = self.conv(attrib_value)          field = self.aLayer.GetClassificationColumn()
494            if self.aLayer.GetFieldType(field) == FIELDTYPE_STRING:
495                value = self.encode(attrib_value)
496            else:
497                value = self.conv(attrib_value)
498          self.cl_group = ClassGroupSingleton(value)          self.cl_group = ClassGroupSingleton(value)
499          self.cl_group.SetLabel(self.encode(attrs.get((None, 'label'), "")))          self.cl_group.SetLabel(self.encode(attrs.get((None, 'label'), "")))
500          self.cl_prop = ClassGroupProperties()          self.cl_prop = ClassGroupProperties()
# Line 416  class SessionLoader(XMLReader): Line 547  class SessionLoader(XMLReader):
547          self.aLayer = self.aMap.LabelLayer()          self.aLayer = self.aMap.LabelLayer()
548    
549      def start_label(self, name, qname, attrs):      def start_label(self, name, qname, attrs):
550          x = float(attrs[(None, 'x')])          attrs = self.check_attrs(name, attrs,
551          y = float(attrs[(None, 'y')])                                   [AttrDesc("x", True, conversion = float),
552          text = self.encode(attrs[(None, 'text')])                                    AttrDesc("y", True, conversion = float),
553          halign = attrs[(None, 'halign')]                                    AttrDesc("text", True),
554          valign = attrs[(None, 'valign')]                                    AttrDesc("halign", True,
555                                               conversion = "ascii"),
556                                      AttrDesc("valign", True,
557                                               conversion = "ascii")])
558            x = attrs['x']
559            y = attrs['y']
560            text = attrs['text']
561            halign = attrs['halign']
562            valign = attrs['valign']
563            if halign not in ("left", "center", "right"):
564                raise LoadError("Unsupported halign value %r" % halign)
565            if valign not in ("top", "center", "bottom"):
566                raise LoadError("Unsupported valign value %r" % valign)
567          self.aLayer.AddLabel(x, y, text, halign = halign, valign = valign)          self.aLayer.AddLabel(x, y, text, halign = halign, valign = valign)
568    
569      def characters(self, chars):      def characters(self, chars):
570          pass          pass
571    
572    
573  def load_session(filename):  def load_session(filename, db_connection_callback = None):
574      """Load a Thuban session from the file object file"""      """Load a Thuban session from the file object file
575    
576      handler = SessionLoader()      The db_connection_callback, if given should be a callable object
577        that can be called like this:
578           db_connection_callback(params, message)
579    
580        where params is a dictionary containing the known connection
581        parameters and message is a string with a message why the connection
582        failed. db_connection_callback should return a new dictionary with
583        corrected and perhaps additional parameters like a password or None
584        to indicate that the user cancelled.
585        """
586        handler = SessionLoader(db_connection_callback)
587      handler.read(filename)      handler.read(filename)
588    
589      session = handler.theSession      session = handler.theSession
590      # Newly loaded session aren't modified      # Newly loaded session aren't modified
591      session.UnsetModified()      session.UnsetModified()
592    
593        handler.Destroy()
594    
595      return session      return session
596    
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