/[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 2449 by frank, Mon Dec 13 13:37:40 2004 UTC
# Line 1  Line 1 
1  # Copyright (C) 2001, 2002, 2003 by Intevation GmbH  # Copyright (C) 2001, 2002, 2003, 2004 by Intevation GmbH
2  # Authors:  # Authors:
3  # Jan-Oliver Wagner <[email protected]>  # Jan-Oliver Wagner <[email protected]>
4  # Bernhard Herzog <[email protected]>  # Bernhard Herzog <[email protected]>
5  # Jonathan Coles <[email protected]>  # Jonathan Coles <[email protected]>
6    # Frank Koormann <[email protected]>
7  #  #
8  # This program is free software under the GPL (>=v2)  # This program is free software under the GPL (>=v2)
9  # Read the file COPYING coming with GRASS for details.  # Read the file COPYING coming with GRASS for details.
# Line 38  from Thuban.Model.data import DerivedSha Line 39  from Thuban.Model.data import DerivedSha
39  from Thuban.Model.table import DBFTable  from Thuban.Model.table import DBFTable
40  from Thuban.Model.transientdb import TransientJoinedTable  from Thuban.Model.transientdb import TransientJoinedTable
41    
42    from Thuban.Model.xmlreader import XMLReader
43    import resource
44    
45    import postgisdb
46    
47  class LoadError(Exception):  class LoadError(Exception):
     pass  
48    
49  from Thuban.Model.xmlreader import XMLReader      """Exception raised when the thuban file is corrupted
50  import resource  
51        Not all cases of corrupted thuban files will lead to this exception
52        but those that are found by checks in the loading code itself are.
53        """
54    
55    
56    class LoadCancelled(Exception):
57    
58        """Exception raised to indicate that loading was interrupted by the user"""
59    
60    
61  def parse_color(color):  def parse_color(color):
62      """Return the color object for the string color.      """Return the color object for the string color.
# Line 87  class AttrDesc: Line 101  class AttrDesc:
101    
102  class SessionLoader(XMLReader):  class SessionLoader(XMLReader):
103    
104      def __init__(self):      def __init__(self, db_connection_callback = None,
105                           shapefile_callback = None):
106          """Inititialize the Sax handler."""          """Inititialize the Sax handler."""
107          XMLReader.__init__(self)          XMLReader.__init__(self)
108    
109            self.db_connection_callback = db_connection_callback
110            self.shapefile_callback = shapefile_callback
111          self.theSession = None          self.theSession = None
112          self.aMap = None          self.aMap = None
113          self.aLayer = None          self.aLayer = None
# Line 101  class SessionLoader(XMLReader): Line 118  class SessionLoader(XMLReader):
118    
119          dispatchers = {          dispatchers = {
120              'session'       : ("start_session",        "end_session"),              'session'       : ("start_session",        "end_session"),
121    
122                'dbconnection': ("start_dbconnection", None),
123    
124                'dbshapesource': ("start_dbshapesource", None),
125              'fileshapesource': ("start_fileshapesource", None),              'fileshapesource': ("start_fileshapesource", None),
126              'derivedshapesource': ("start_derivedshapesource", None),              'derivedshapesource': ("start_derivedshapesource", None),
127              'filetable': ("start_filetable", None),              'filetable': ("start_filetable", None),
# Line 122  class SessionLoader(XMLReader): Line 143  class SessionLoader(XMLReader):
143    
144          # 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
145          for xmlns in ("http://thuban.intevation.org/dtds/thuban-0.8.dtd",          for xmlns in ("http://thuban.intevation.org/dtds/thuban-0.8.dtd",
146                        "http://thuban.intevation.org/dtds/thuban-0.9-dev.dtd"):                        "http://thuban.intevation.org/dtds/thuban-0.9-dev.dtd",
147                          "http://thuban.intevation.org/dtds/thuban-0.9.dtd",
148                          "http://thuban.intevation.org/dtds/thuban-1.0-dev.dtd",
149                          "http://thuban.intevation.org/dtds/thuban-1.0rc1.dtd",
150                          "http://thuban.intevation.org/dtds/thuban-1.0.0.dtd",
151                          "http://thuban.intevation.org/dtds/thuban-1.1-dev.dtd"):
152              for key, value in dispatchers.items():              for key, value in dispatchers.items():
153                  dispatchers[(xmlns, key)] = value                  dispatchers[(xmlns, key)] = value
154    
155          XMLReader.AddDispatchers(self, dispatchers)          XMLReader.AddDispatchers(self, dispatchers)
156    
157        def Destroy(self):
158            """Clear all instance variables to cut cyclic references.
159    
160            The GC would have collected the loader eventually but it can
161            happen that it doesn't run at all until Thuban is closed (2.3
162            but not 2.2 tries a bit harder and forces a collection when the
163            interpreter terminates)
164            """
165            self.__dict__.clear()
166    
167      def start_session(self, name, qname, attrs):      def start_session(self, name, qname, attrs):
168          self.theSession = Session(self.encode(attrs.get((None, 'title'),          self.theSession = Session(self.encode(attrs.get((None, 'title'),
169                                                          None)))                                                          None)))
# Line 155  class SessionLoader(XMLReader): Line 191  class SessionLoader(XMLReader):
191          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
192          attrs, use that default value as the value in the returned dict.          attrs, use that default value as the value in the returned dict.
193    
194          If a conversion is specified, convert the value before putting          The value is converted before putting it into the returned dict.
195          it into the returned dict. The following conversions are          The following conversions are available:
         available:  
196    
197             'filename' -- The attribute is a filename.             'filename' -- The attribute is a filename.
198    
# Line 173  class SessionLoader(XMLReader): Line 208  class SessionLoader(XMLReader):
208                        defined earlier in the .thuban file. Look it up                        defined earlier in the .thuban file. Look it up
209                        self.idmap. If it's the ID of a shapestore the                        self.idmap. If it's the ID of a shapestore the
210                        value will be the table of the shapestore.                        value will be the table of the shapestore.
211    
212               'idref' -- The attribute is the id of an object defined
213                          earlier in the .thuban file. Look it up self.idmap
214    
215               'ascii' -- The attribute is converted to a bytestring with
216                          ascii encoding.
217    
218               a callable -- The attribute value is passed to the callable
219                             and the return value is used as the converted
220                             value
221    
222            If no conversion is specified for an attribute it is converted
223            with self.encode.
224          """          """
225          normalized = {}          normalized = {}
226    
227          for d in descr:          for d in descr:
228              if d.required and not attrs.has_key(d.fullname):              if d.required and not attrs.has_key(d.fullname):
229                  pass                  raise LoadError("Element %s requires an attribute %r"
230              #raise LoadError("Element %s requires an attribute %r"                                  % (element, d.name))
             #                    % (element, d.name))  
231              value = attrs.get(d.fullname, d.default)              value = attrs.get(d.fullname, d.default)
232    
233              if d.conversion == "shapesource":              if d.conversion in ("idref", "shapesource"):
234                  if value in self.idmap:                  if value in self.idmap:
235                      value = self.idmap[value]                      value = self.idmap[value]
236                  else:                  else:
# Line 202  class SessionLoader(XMLReader): Line 249  class SessionLoader(XMLReader):
249              elif d.conversion == "filename":              elif d.conversion == "filename":
250                  value = os.path.abspath(os.path.join(self.GetDirectory(),                  value = os.path.abspath(os.path.join(self.GetDirectory(),
251                                                       value))                                                       value))
252                elif d.conversion == "ascii":
253                    value = value.encode("ascii")
254                elif d.conversion:
255                    # Assume it's a callable
256                    value = d.conversion(value)
257                else:
258                   value = self.encode(value)
259    
260              normalized[d.name] = value              normalized[d.name] = value
261          return normalized          return normalized
262    
263        def open_shapefile(self, filename):
264            """Open shapefile, with alternative path handling.
265            
266               If a shapefile cannot be opened and an IOError is raised, check for
267               an alternative. This alternative can be specified interactively by
268               the user or taken from a list of (potential) locations, depending on
269               the callback implementation.
270                
271               The alternative is rechecked. If taken from a list the user
272               has to confirm the alternative.
273            """
274    
275            # Flag if the alternative path was specified interactively / from list.
276            from_list = 0
277            while 1:
278                try:
279                    store = self.theSession.OpenShapefile(filename)
280                    if from_list:
281                        # A valid path has been guessed from a list
282                        # Let the user confirm - or select an alternative.
283                        filename, from_list = self.shapefile_callback(
284                                                filename, "check")
285                        if filename is None:
286                            # Selection cancelled
287                            raise LoadCancelled
288                        elif store.FileName() == filename:
289                            # Proposed file has been accepted
290                            break
291                        else:
292                            # the filename has been changed, try the new file
293                            pass
294                    else:
295                        break
296                except IOError:
297                    if self.shapefile_callback is not None:
298                        filename, from_list = self.shapefile_callback(
299                                                filename,
300                                                mode = "search",
301                                                second_try = from_list)
302                        if filename is None:
303                            raise LoadCancelled
304                        print filename
305                    else:
306                        raise
307            return store
308    
309        def start_dbconnection(self, name, qname, attrs):
310            attrs = self.check_attrs(name, attrs,
311                                     [AttrDesc("id", True),
312                                      AttrDesc("dbtype", True),
313                                      AttrDesc("host", False, ""),
314                                      AttrDesc("port", False, ""),
315                                      AttrDesc("user", False, ""),
316                                      AttrDesc("dbname", True)])
317            ID = attrs["id"]
318            dbtype = attrs["dbtype"]
319            if dbtype != "postgis":
320                raise LoadError("dbtype %r not supported" % filetype)
321    
322            del attrs["id"]
323            del attrs["dbtype"]
324    
325            # Try to open the connection and if it fails ask the user for
326            # the correct parameters repeatedly.
327            # FIXME: it would be better not to insist on getting a
328            # connection here. We should handle this more like the raster
329            # images where the layers etc still are created but are not
330            # drawn in case Thuban can't use the data for various reasons
331            while 1:
332                try:
333                    conn = postgisdb.PostGISConnection(**attrs)
334                    break
335                except postgisdb.ConnectionError, val:
336                    if self.db_connection_callback is not None:
337                        attrs = self.db_connection_callback(attrs, str(val))
338                        if attrs is None:
339                            raise LoadCancelled
340                    else:
341                        raise
342    
343            self.idmap[ID] = conn
344            self.theSession.AddDBConnection(conn)
345    
346        def start_dbshapesource(self, name, qname, attrs):
347            attrs = self.check_attrs(name, attrs,
348                                     [AttrDesc("id", True),
349                                      AttrDesc("dbconn", True,
350                                               conversion = "idref"),
351                                      AttrDesc("tablename", True,
352                                               conversion = "ascii"),
353                                      # id_column and geometry_column were
354                                      # newly introduced with thuban-1.1.dtd
355                                      # where they're required.  Since we
356                                      # support the older formats too we
357                                      # have them optional here.
358                                      AttrDesc("id_column", False, "gid",
359                                               conversion = "ascii"),
360                                      AttrDesc("geometry_column", False,
361                                               conversion = "ascii")])
362            # The default value of geometry_column to use when instantiating
363            # the db shapestore is None which we currently can't easily use
364            # in check_attrs
365            geometry_column = attrs["geometry_column"]
366            if not geometry_column:
367                geometry_column = None
368            dbopen = self.theSession.OpenDBShapeStore
369            self.idmap[attrs["id"]] = dbopen(attrs["dbconn"], attrs["tablename"],
370                                             id_column = attrs["id_column"],
371                                             geometry_column=geometry_column)
372    
373      def start_fileshapesource(self, name, qname, attrs):      def start_fileshapesource(self, name, qname, attrs):
374          attrs = self.check_attrs(name, attrs,          attrs = self.check_attrs(name, attrs,
375                                    [AttrDesc("id", True),                                    [AttrDesc("id", True),
# Line 217  class SessionLoader(XMLReader): Line 381  class SessionLoader(XMLReader):
381          filetype = attrs["filetype"]          filetype = attrs["filetype"]
382          if filetype != "shapefile":          if filetype != "shapefile":
383              raise LoadError("shapesource filetype %r not supported" % filetype)              raise LoadError("shapesource filetype %r not supported" % filetype)
384          self.idmap[ID] = self.theSession.OpenShapefile(filename)          self.idmap[ID] = self.open_shapefile(filename)
385    
386      def start_derivedshapesource(self, name, qname, attrs):      def start_derivedshapesource(self, name, qname, attrs):
387          attrs = self.check_attrs(name, attrs,          attrs = self.check_attrs(name, attrs,
# Line 277  class SessionLoader(XMLReader): Line 441  class SessionLoader(XMLReader):
441    
442      def start_map(self, name, qname, attrs):      def start_map(self, name, qname, attrs):
443          """Start a map."""          """Start a map."""
444          self.aMap = Map(attrs.get((None, 'title'), None))          self.aMap = Map(self.encode(attrs.get((None, 'title'), None)))
445    
446      def end_map(self, name, qname):      def end_map(self, name, qname):
447          self.theSession.AddMap(self.aMap)          self.theSession.AddMap(self.aMap)
448          self.aMap = None          self.aMap = None
449    
450      def start_projection(self, name, qname, attrs):      def start_projection(self, name, qname, attrs):
451          self.ProjectionName = self.encode(attrs.get((None, 'name'), None))          attrs = self.check_attrs(name, attrs,
452          self.ProjectionParams = [ ]                                   [AttrDesc("name", conversion=self.encode),
453                                      AttrDesc("epsg", default=None,
454                                               conversion=self.encode)])
455            self.projection_name = attrs["name"]
456            self.projection_epsg = attrs["epsg"]
457            self.projection_params = [ ]
458    
459      def end_projection(self, name, qname):      def end_projection(self, name, qname):
460          if self.aLayer is not None:          if self.aLayer is not None:
# Line 296  class SessionLoader(XMLReader): Line 465  class SessionLoader(XMLReader):
465              assert False, "projection tag out of context"              assert False, "projection tag out of context"
466              pass              pass
467    
468          obj.SetProjection(          obj.SetProjection(Projection(self.projection_params,
469              Projection(self.ProjectionParams, self.ProjectionName))                                       self.projection_name,
470                                         epsg = self.projection_epsg))
471    
472      def start_parameter(self, name, qname, attrs):      def start_parameter(self, name, qname, attrs):
473          s = attrs.get((None, 'value'))          s = attrs.get((None, 'value'))
474          s = str(s) # we can't handle unicode in proj          s = str(s) # we can't handle unicode in proj
475          self.ProjectionParams.append(s)          self.projection_params.append(s)
476    
477      def start_layer(self, name, qname, attrs, layer_class = Layer):      def start_layer(self, name, qname, attrs, layer_class = Layer):
478          """Start a layer          """Start a layer
# Line 322  class SessionLoader(XMLReader): Line 492  class SessionLoader(XMLReader):
492          if attrs.has_key((None, "shapestore")):          if attrs.has_key((None, "shapestore")):
493              store = self.idmap[attrs[(None, "shapestore")]]              store = self.idmap[attrs[(None, "shapestore")]]
494          else:          else:
495              store = self.theSession.OpenShapefile(filename)              store = self.open_shapefile(filename)
496    
497          self.aLayer = layer_class(title, store,          self.aLayer = layer_class(title, store,
498                                    fill = fill, stroke = stroke,                                    fill = fill, stroke = stroke,
499                                    lineWidth = stroke_width,                                    lineWidth = stroke_width,
# Line 346  class SessionLoader(XMLReader): Line 517  class SessionLoader(XMLReader):
517          self.aLayer = None          self.aLayer = None
518    
519      def start_classification(self, name, qname, attrs):      def start_classification(self, name, qname, attrs):
520          field = attrs.get((None, 'field'), None)          attrs = self.check_attrs(name, attrs,
521                                     [AttrDesc("field", True),
522                                      AttrDesc("field_type", True)])
523            field = attrs["field"]
524            fieldType = attrs["field_type"]
525    
         fieldType = attrs.get((None, 'field_type'), None)  
526          dbFieldType = self.aLayer.GetFieldType(field)          dbFieldType = self.aLayer.GetFieldType(field)
527    
528          if fieldType != dbFieldType:          if fieldType != dbFieldType:
# Line 363  class SessionLoader(XMLReader): Line 537  class SessionLoader(XMLReader):
537          elif fieldType == FIELDTYPE_DOUBLE:          elif fieldType == FIELDTYPE_DOUBLE:
538              self.conv = float              self.conv = float
539    
540          self.aLayer.GetClassification().SetFieldInfo(field, fieldType)          self.aLayer.SetClassificationColumn(field)
541    
542      def end_classification(self, name, qname):      def end_classification(self, name, qname):
543          pass          pass
# Line 381  class SessionLoader(XMLReader): Line 555  class SessionLoader(XMLReader):
555      def start_clpoint(self, name, qname, attrs):      def start_clpoint(self, name, qname, attrs):
556          attrib_value = attrs.get((None, 'value'), "0")          attrib_value = attrs.get((None, 'value'), "0")
557    
558          value = self.conv(attrib_value)          field = self.aLayer.GetClassificationColumn()
559            if self.aLayer.GetFieldType(field) == FIELDTYPE_STRING:
560                value = self.encode(attrib_value)
561            else:
562                value = self.conv(attrib_value)
563          self.cl_group = ClassGroupSingleton(value)          self.cl_group = ClassGroupSingleton(value)
564          self.cl_group.SetLabel(self.encode(attrs.get((None, 'label'), "")))          self.cl_group.SetLabel(self.encode(attrs.get((None, 'label'), "")))
565          self.cl_prop = ClassGroupProperties()          self.cl_prop = ClassGroupProperties()
# Line 426  class SessionLoader(XMLReader): Line 603  class SessionLoader(XMLReader):
603              parse_color(attrs.get((None, 'stroke'), "None")))              parse_color(attrs.get((None, 'stroke'), "None")))
604          self.cl_prop.SetLineWidth(          self.cl_prop.SetLineWidth(
605              int(attrs.get((None, 'stroke_width'), "0")))              int(attrs.get((None, 'stroke_width'), "0")))
606            self.cl_prop.SetSize(int(attrs.get((None, 'size'), "5")))
607          self.cl_prop.SetFill(parse_color(attrs.get((None, 'fill'), "None")))          self.cl_prop.SetFill(parse_color(attrs.get((None, 'fill'), "None")))
608    
609      def end_cldata(self, name, qname):      def end_cldata(self, name, qname):
# Line 435  class SessionLoader(XMLReader): Line 613  class SessionLoader(XMLReader):
613          self.aLayer = self.aMap.LabelLayer()          self.aLayer = self.aMap.LabelLayer()
614    
615      def start_label(self, name, qname, attrs):      def start_label(self, name, qname, attrs):
616          x = float(attrs[(None, 'x')])          attrs = self.check_attrs(name, attrs,
617          y = float(attrs[(None, 'y')])                                   [AttrDesc("x", True, conversion = float),
618          text = self.encode(attrs[(None, 'text')])                                    AttrDesc("y", True, conversion = float),
619          halign = attrs[(None, 'halign')]                                    AttrDesc("text", True),
620          valign = attrs[(None, 'valign')]                                    AttrDesc("halign", True,
621                                               conversion = "ascii"),
622                                      AttrDesc("valign", True,
623                                               conversion = "ascii")])
624            x = attrs['x']
625            y = attrs['y']
626            text = attrs['text']
627            halign = attrs['halign']
628            valign = attrs['valign']
629            if halign not in ("left", "center", "right"):
630                raise LoadError("Unsupported halign value %r" % halign)
631            if valign not in ("top", "center", "bottom"):
632                raise LoadError("Unsupported valign value %r" % valign)
633          self.aLayer.AddLabel(x, y, text, halign = halign, valign = valign)          self.aLayer.AddLabel(x, y, text, halign = halign, valign = valign)
634    
635      def characters(self, chars):      def characters(self, chars):
636          pass          pass
637    
638    
639  def load_session(filename):  def load_session(filename, db_connection_callback = None,
640      """Load a Thuban session from the file object file"""                             shapefile_callback = None):
641        """Load a Thuban session from the file object file
642      handler = SessionLoader()  
643        The db_connection_callback, if given should be a callable object
644        that can be called like this:
645           db_connection_callback(params, message)
646    
647        where params is a dictionary containing the known connection
648        parameters and message is a string with a message why the connection
649        failed. db_connection_callback should return a new dictionary with
650        corrected and perhaps additional parameters like a password or None
651        to indicate that the user cancelled.
652        """
653        handler = SessionLoader(db_connection_callback, shapefile_callback)
654      handler.read(filename)      handler.read(filename)
655    
656      session = handler.theSession      session = handler.theSession
657      # Newly loaded session aren't modified      # Newly loaded session aren't modified
658      session.UnsetModified()      session.UnsetModified()
659    
660        handler.Destroy()
661    
662      return session      return session
663    
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