/[thuban]/branches/WIP-pyshapelib-bramz/Thuban/Model/load.py
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revision 1159 by jonathan, Thu Jun 12 12:40:27 2003 UTC revision 1970 by bh, Mon Nov 24 18:36:00 2003 UTC
# Line 24  from Thuban import _ Line 24  from Thuban import _
24  from Thuban.Model.table import FIELDTYPE_INT, FIELDTYPE_DOUBLE, \  from Thuban.Model.table import FIELDTYPE_INT, FIELDTYPE_DOUBLE, \
25       FIELDTYPE_STRING       FIELDTYPE_STRING
26    
27    from Thuban.Model.color import Color, Transparent
28    
29  from Thuban.Model.session import Session  from Thuban.Model.session import Session
30  from Thuban.Model.map import Map  from Thuban.Model.map import Map
31  from Thuban.Model.layer import Layer, RasterLayer  from Thuban.Model.layer import Layer, RasterLayer
 from Thuban.Model.color import Color  
32  from Thuban.Model.proj import Projection  from Thuban.Model.proj import Projection
33  from Thuban.Model.range import Range  from Thuban.Model.range import Range
34  from Thuban.Model.classification import Classification, \  from Thuban.Model.classification import Classification, \
35      ClassGroupDefault, ClassGroupSingleton, ClassGroupRange, ClassGroupMap, \      ClassGroupDefault, ClassGroupSingleton, ClassGroupRange, ClassGroupMap, \
36      ClassGroupProperties      ClassGroupProperties
37    from Thuban.Model.data import DerivedShapeStore, ShapefileStore
38    from Thuban.Model.table import DBFTable
39    from Thuban.Model.transientdb import TransientJoinedTable
40    
41  from Thuban.Model.xmlreader import XMLReader  from Thuban.Model.xmlreader import XMLReader
42  import resource  import resource
43    
44    import postgisdb
45    
46    class LoadError(Exception):
47    
48        """Exception raised when the thuban file is corrupted
49    
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 45  def parse_color(color): Line 65  def parse_color(color):
65      """      """
66      color = string.strip(color)      color = string.strip(color)
67      if color == "None":      if color == "None":
68          result = Color.Transparent          result = Transparent
69      elif color[0] == '#':      elif color[0] == '#':
70          if len(color) == 7:          if len(color) == 7:
71              r = string.atoi(color[1:3], 16) / 255.0              r = string.atoi(color[1:3], 16) / 255.0
# Line 59  def parse_color(color): Line 79  def parse_color(color):
79          raise ValueError(_("Invalid color specification %s") % color)          raise ValueError(_("Invalid color specification %s") % color)
80      return result      return result
81    
82    class AttrDesc:
83    
84        def __init__(self, name, required = False, default = "",
85                     conversion = None):
86            if not isinstance(name, tuple):
87                fullname = (None, name)
88            else:
89                fullname = name
90                name = name[1]
91            self.name = name
92            self.fullname = fullname
93            self.required = required
94            self.default = default
95            self.conversion = conversion
96    
97            # set by the SessionLoader's check_attrs method
98            self.value = None
99    
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
112    
113          XMLReader.AddDispatchers(self,          # Map ids used in the thuban file to the corresponding objects
114              {'session'       : ("start_session",        "end_session"),          # in the session
115               'map'           : ("start_map",            "end_map"),          self.idmap = {}
116               'projection'    : ("start_projection",     "end_projection"),  
117               'parameter'     : ("start_parameter",      None),          dispatchers = {
118               'layer'         : ("start_layer",          "end_layer"),              'session'       : ("start_session",        "end_session"),
119               'rasterlayer'   : ("start_rasterlayer",    "end_rasterlayer"),  
120               'classification': ("start_classification", "end_classification"),              'dbconnection': ("start_dbconnection", None),
121               'clnull'        : ("start_clnull",         "end_clnull"),  
122               'clpoint'       : ("start_clpoint",        "end_clpoint"),              'dbshapesource': ("start_dbshapesource", None),
123               'clrange'       : ("start_clrange",        "end_clrange"),              'fileshapesource': ("start_fileshapesource", None),
124               'cldata'        : ("start_cldata",         "end_cldata"),              'derivedshapesource': ("start_derivedshapesource", None),
125               'table'         : ("start_table",          "end_table"),              'filetable': ("start_filetable", None),
126               'labellayer'    : ("start_labellayer",     None),              'jointable': ("start_jointable", None),
127               'label'         : ("start_label",          None)})  
128                'map'           : ("start_map",            "end_map"),
129                'projection'    : ("start_projection",     "end_projection"),
130                'parameter'     : ("start_parameter",      None),
131                'layer'         : ("start_layer",          "end_layer"),
132                'rasterlayer'   : ("start_rasterlayer",    "end_rasterlayer"),
133                'classification': ("start_classification", "end_classification"),
134                'clnull'        : ("start_clnull",         "end_clnull"),
135                'clpoint'       : ("start_clpoint",        "end_clpoint"),
136                'clrange'       : ("start_clrange",        "end_clrange"),
137                'cldata'        : ("start_cldata",         "end_cldata"),
138                'table'         : ("start_table",          "end_table"),
139                'labellayer'    : ("start_labellayer",     None),
140                'label'         : ("start_label",          None)}
141    
142            # 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",
144                          "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():
148                    dispatchers[(xmlns, key)] = value
149    
150            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'), None)))          self.theSession = Session(self.encode(attrs.get((None, 'title'),
164                                                            None)))
165    
166      def end_session(self, name, qname):      def end_session(self, name, qname):
167          pass          pass
168    
169        def check_attrs(self, element, attrs, descr):
170            """Check and convert some of the attributes of an element
171    
172            Parameters:
173               element -- The element name
174               attrs -- The attrs mapping as passed to the start_* methods
175               descr -- Sequence of attribute descriptions (AttrDesc instances)
176    
177            Return a dictionary containig normalized versions of the
178            attributes described in descr. The keys of that dictionary are
179            the name attributes of the attribute descriptions. The attrs
180            dictionary will not be modified.
181    
182            If the attribute is required, i.e. the 'required' attribute of
183            the descrtiption is true, but it is not in attrs, raise a
184            LoadError.
185    
186            If the attribute has a default value and it is not present in
187            attrs, use that default value as the value in the returned dict.
188    
189            The value is converted before putting it into the returned dict.
190            The following conversions are available:
191    
192               'filename' -- The attribute is a filename.
193    
194                             If the filename is a relative name, interpret
195                             it relative to the directory containing the
196                             .thuban file and make it an absolute name
197    
198               'shapestore' -- The attribute is the ID of a shapestore
199                               defined earlier in the .thuban file. Look it
200                               up self.idmap
201    
202               'table' -- The attribute is the ID of a table or shapestore
203                          defined earlier in the .thuban file. Look it up
204                          self.idmap. If it's the ID of a shapestore the
205                          value will be the table of the shapestore.
206    
207               'idref' -- The attribute is the id of an object defined
208                          earlier in the .thuban file. Look it up self.idmap
209    
210               'ascii' -- The attribute is converted to a bytestring with
211                          ascii encoding.
212    
213               a callable -- The attribute value is passed to the callable
214                             and the return value is used as the converted
215                             value
216    
217            If no conversion is specified for an attribute it is converted
218            with self.encode.
219            """
220            normalized = {}
221    
222            for d in descr:
223                if d.required and not attrs.has_key(d.fullname):
224                    raise LoadError("Element %s requires an attribute %r"
225                                    % (element, d.name))
226                value = attrs.get(d.fullname, d.default)
227    
228                if d.conversion in ("idref", "shapesource"):
229                    if value in self.idmap:
230                        value = self.idmap[value]
231                    else:
232                        raise LoadError("Element %s requires an already defined ID"
233                                        " in attribute %r"
234                                        % (element, d.name))
235                elif d.conversion == "table":
236                    if value in self.idmap:
237                        value = self.idmap[value]
238                        if isinstance(value, ShapefileStore):
239                            value = value.Table()
240                    else:
241                        raise LoadError("Element %s requires an already defined ID"
242                                        " in attribute %r"
243                                        % (element, d.name))
244                elif d.conversion == "filename":
245                    value = os.path.abspath(os.path.join(self.GetDirectory(),
246                                                         value))
247                elif d.conversion == "ascii":
248                    value = value.encode("ascii")
249                elif d.conversion:
250                    # Assume it's a callable
251                    value = d.conversion(value)
252                else:
253                   value = self.encode(value)
254    
255                normalized[d.name] = value
256            return normalized
257    
258        def start_dbconnection(self, name, qname, attrs):
259            attrs = self.check_attrs(name, attrs,
260                                     [AttrDesc("id", True),
261                                      AttrDesc("dbtype", True),
262                                      AttrDesc("host", False, ""),
263                                      AttrDesc("port", False, ""),
264                                      AttrDesc("user", False, ""),
265                                      AttrDesc("dbname", True)])
266            ID = attrs["id"]
267            dbtype = attrs["dbtype"]
268            if dbtype != "postgis":
269                raise LoadError("dbtype %r not supported" % filetype)
270    
271            del attrs["id"]
272            del attrs["dbtype"]
273    
274            # Try to open the connection and if it fails ask the user for
275            # the correct parameters repeatedly.
276            # FIXME: it would be better not to insist on getting a
277            # connection here. We should handle this more like the raster
278            # images where the layers etc still are created but are not
279            # drawn in case Thuban can't use the data for various reasons
280            while 1:
281                try:
282                    conn = postgisdb.PostGISConnection(**attrs)
283                    break
284                except postgisdb.ConnectionError, val:
285                    if self.db_connection_callback is not None:
286                        attrs = self.db_connection_callback(attrs, str(val))
287                        if attrs is None:
288                            raise LoadCancelled
289                    else:
290                        raise
291    
292            self.idmap[ID] = conn
293            self.theSession.AddDBConnection(conn)
294    
295        def start_dbshapesource(self, name, qname, attrs):
296            attrs = self.check_attrs(name, attrs,
297                                     [AttrDesc("id", True),
298                                      AttrDesc("dbconn", True,
299                                               conversion = "idref"),
300                                      AttrDesc("tablename", True,
301                                               conversion = "ascii")])
302            ID = attrs["id"]
303            db = attrs["dbconn"]
304            tablename = attrs["tablename"]
305            self.idmap[ID] = self.theSession.OpenDBShapeStore(db, tablename)
306    
307        def start_fileshapesource(self, name, qname, attrs):
308            attrs = self.check_attrs(name, attrs,
309                                      [AttrDesc("id", True),
310                                       AttrDesc("filename", True,
311                                                conversion = "filename"),
312                                       AttrDesc("filetype", True)])
313            ID = attrs["id"]
314            filename = attrs["filename"]
315            filetype = attrs["filetype"]
316            if filetype != "shapefile":
317                raise LoadError("shapesource filetype %r not supported" % filetype)
318            self.idmap[ID] = self.theSession.OpenShapefile(filename)
319    
320        def start_derivedshapesource(self, name, qname, attrs):
321            attrs = self.check_attrs(name, attrs,
322                                     [AttrDesc("id", True),
323                                      AttrDesc("shapesource", True,
324                                               conversion = "shapesource"),
325                                      AttrDesc("table", True, conversion="table")])
326            store = DerivedShapeStore(attrs["shapesource"], attrs["table"])
327            self.theSession.AddShapeStore(store)
328            self.idmap[attrs["id"]] = store
329    
330        def start_filetable(self, name, qname, attrs):
331            attrs = self.check_attrs(name, attrs,
332                                     [AttrDesc("id", True),
333                                      AttrDesc("title", True),
334                                      AttrDesc("filename", True,
335                                               conversion = "filename"),
336                                      AttrDesc("filetype")])
337            filetype = attrs["filetype"]
338            if filetype != "DBF":
339                raise LoadError("shapesource filetype %r not supported" % filetype)
340            table = DBFTable(attrs["filename"])
341            table.SetTitle(attrs["title"])
342            self.idmap[attrs["id"]] = self.theSession.AddTable(table)
343    
344        def start_jointable(self, name, qname, attrs):
345            attrs = self.check_attrs(name, attrs,
346                                     [AttrDesc("id", True),
347                                      AttrDesc("title", True),
348                                      AttrDesc("left", True, conversion="table"),
349                                      AttrDesc("leftcolumn", True),
350                                      AttrDesc("right", True, conversion="table"),
351                                      AttrDesc("rightcolumn", True),
352    
353                                      # jointype is required for file
354                                      # version 0.9 but this attribute
355                                      # wasn't in the 0.8 version because of
356                                      # an oversight so we assume it's
357                                      # optional since we want to handle
358                                      # both file format versions here.
359                                      AttrDesc("jointype", False,
360                                               default="INNER")])
361    
362            jointype = attrs["jointype"]
363            if jointype == "LEFT OUTER":
364                outer_join = True
365            elif jointype == "INNER":
366                outer_join = False
367            else:
368                raise LoadError("jointype %r not supported" % jointype )
369            table = TransientJoinedTable(self.theSession.TransientDB(),
370                                         attrs["left"], attrs["leftcolumn"],
371                                         attrs["right"], attrs["rightcolumn"],
372                                         outer_join = outer_join)
373            table.SetTitle(attrs["title"])
374            self.idmap[attrs["id"]] = self.theSession.AddTable(table)
375    
376      def start_map(self, name, qname, attrs):      def start_map(self, name, qname, attrs):
377          """Start a map."""          """Start a map."""
378          self.aMap = Map(attrs.get((None, 'title'), None))          self.aMap = Map(self.encode(attrs.get((None, 'title'), None)))
379    
380      def end_map(self, name, qname):      def end_map(self, name, qname):
381          self.theSession.AddMap(self.aMap)          self.theSession.AddMap(self.aMap)
382          self.aMap = None          self.aMap = None
383    
384      def start_projection(self, name, qname, attrs):      def start_projection(self, name, qname, attrs):
385          self.ProjectionName = self.encode(attrs.get((None, 'name'), None))          attrs = self.check_attrs(name, attrs,
386          self.ProjectionParams = [ ]                                   [AttrDesc("name", conversion=self.encode),
387                                      AttrDesc("epsg", default=None,
388                                               conversion=self.encode)])
389            self.projection_name = attrs["name"]
390            self.projection_epsg = attrs["epsg"]
391            self.projection_params = [ ]
392    
393      def end_projection(self, name, qname):      def end_projection(self, name, qname):
394          if self.aLayer is not None:          if self.aLayer is not None:
# Line 112  class SessionLoader(XMLReader): Line 399  class SessionLoader(XMLReader):
399              assert False, "projection tag out of context"              assert False, "projection tag out of context"
400              pass              pass
401    
402          obj.SetProjection(          obj.SetProjection(Projection(self.projection_params,
403              Projection(self.ProjectionParams, self.ProjectionName))                                       self.projection_name,
404                                         epsg = self.projection_epsg))
405    
406      def start_parameter(self, name, qname, attrs):      def start_parameter(self, name, qname, attrs):
407          s = attrs.get((None, 'value'))          s = attrs.get((None, 'value'))
408          s = str(s) # we can't handle unicode in proj          s = str(s) # we can't handle unicode in proj
409          self.ProjectionParams.append(s)          self.projection_params.append(s)
410    
411      def start_layer(self, name, qname, attrs, layer_class = Layer):      def start_layer(self, name, qname, attrs, layer_class = Layer):
412          """Start a layer          """Start a layer
# Line 135  class SessionLoader(XMLReader): Line 423  class SessionLoader(XMLReader):
423          fill = parse_color(attrs.get((None, 'fill'), "None"))          fill = parse_color(attrs.get((None, 'fill'), "None"))
424          stroke = parse_color(attrs.get((None, 'stroke'), "#000000"))          stroke = parse_color(attrs.get((None, 'stroke'), "#000000"))
425          stroke_width = int(attrs.get((None, 'stroke_width'), "1"))          stroke_width = int(attrs.get((None, 'stroke_width'), "1"))
426          self.aLayer = layer_class(title,          if attrs.has_key((None, "shapestore")):
427                                    self.theSession.OpenShapefile(filename),              store = self.idmap[attrs[(None, "shapestore")]]
428            else:
429                store = self.theSession.OpenShapefile(filename)
430            self.aLayer = layer_class(title, store,
431                                    fill = fill, stroke = stroke,                                    fill = fill, stroke = stroke,
432                                    lineWidth = stroke_width,                                    lineWidth = stroke_width,
433                                    visible = visible)                                    visible = visible)
# Line 159  class SessionLoader(XMLReader): Line 450  class SessionLoader(XMLReader):
450          self.aLayer = None          self.aLayer = None
451    
452      def start_classification(self, name, qname, attrs):      def start_classification(self, name, qname, attrs):
453          field = attrs.get((None, 'field'), None)          attrs = self.check_attrs(name, attrs,
454                                     [AttrDesc("field", True),
455                                      AttrDesc("field_type", True)])
456            field = attrs["field"]
457            fieldType = attrs["field_type"]
458    
         fieldType = attrs.get((None, 'field_type'), None)  
459          dbFieldType = self.aLayer.GetFieldType(field)          dbFieldType = self.aLayer.GetFieldType(field)
460    
461          if fieldType != dbFieldType:          if fieldType != dbFieldType:
# Line 176  class SessionLoader(XMLReader): Line 470  class SessionLoader(XMLReader):
470          elif fieldType == FIELDTYPE_DOUBLE:          elif fieldType == FIELDTYPE_DOUBLE:
471              self.conv = float              self.conv = float
472    
473          self.aLayer.GetClassification().SetField(field)          self.aLayer.SetClassificationColumn(field)
474    
475      def end_classification(self, name, qname):      def end_classification(self, name, qname):
476          pass          pass
# Line 194  class SessionLoader(XMLReader): Line 488  class SessionLoader(XMLReader):
488      def start_clpoint(self, name, qname, attrs):      def start_clpoint(self, name, qname, attrs):
489          attrib_value = attrs.get((None, 'value'), "0")          attrib_value = attrs.get((None, 'value'), "0")
490    
491          value = self.conv(attrib_value)          field = self.aLayer.GetClassificationColumn()
492            if self.aLayer.GetFieldType(field) == FIELDTYPE_STRING:
493                value = self.encode(attrib_value)
494            else:
495                value = self.conv(attrib_value)
496          self.cl_group = ClassGroupSingleton(value)          self.cl_group = ClassGroupSingleton(value)
497          self.cl_group.SetLabel(self.encode(attrs.get((None, 'label'), "")))          self.cl_group.SetLabel(self.encode(attrs.get((None, 'label'), "")))
498          self.cl_prop = ClassGroupProperties()          self.cl_prop = ClassGroupProperties()
# Line 217  class SessionLoader(XMLReader): Line 514  class SessionLoader(XMLReader):
514              if range is not None:              if range is not None:
515                  self.cl_group = ClassGroupRange(Range(range))                  self.cl_group = ClassGroupRange(Range(range))
516              elif min is not None and max is not None:              elif min is not None and max is not None:
517                  self.cl_group = ClassGroupRange(self.conv(min), self.conv(max))                  self.cl_group = ClassGroupRange((self.conv(min),
518                                                     self.conv(max)))
519              else:              else:
520                  self.cl_group = ClassGroupRange(Range(None))                  self.cl_group = ClassGroupRange(Range(None))
521    
# Line 243  class SessionLoader(XMLReader): Line 541  class SessionLoader(XMLReader):
541      def end_cldata(self, name, qname):      def end_cldata(self, name, qname):
542          pass          pass
543    
     def start_table(self, name, qname, attrs):  
         #print "table title: %s" % attrs.get('title', None)  
         pass  
   
     def end_table(self, name, qname):  
         pass  
   
544      def start_labellayer(self, name, qname, attrs):      def start_labellayer(self, name, qname, attrs):
545          self.aLayer = self.aMap.LabelLayer()          self.aLayer = self.aMap.LabelLayer()
546    
# Line 265  class SessionLoader(XMLReader): Line 556  class SessionLoader(XMLReader):
556          pass          pass
557    
558    
559  def load_session(filename):  def load_session(filename, db_connection_callback = None):
560      """Load a Thuban session from the file object file"""      """Load a Thuban session from the file object file
561    
562      handler = SessionLoader()      The db_connection_callback, if given should be a callable object
563        that can be called like this:
564           db_connection_callback(params, message)
565    
566        where params is a dictionary containing the known connection
567        parameters and message is a string with a message why the connection
568        failed. db_connection_callback should return a new dictionary with
569        corrected and perhaps additional parameters like a password or None
570        to indicate that the user cancelled.
571        """
572        handler = SessionLoader(db_connection_callback)
573      handler.read(filename)      handler.read(filename)
574    
575      session = handler.theSession      session = handler.theSession
576      # Newly loaded session aren't modified      # Newly loaded session aren't modified
577      session.UnsetModified()      session.UnsetModified()
578    
579        handler.Destroy()
580    
581      return session      return session
582    
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