Thuban/Model/load.py

# Copyright (C) 2001, 2002, 2003 by Intevation GmbH
# Authors:
# Jan-Oliver Wagner <[email protected]>
# Bernhard Herzog <[email protected]>
# Jonathan Coles <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with GRASS for details.

"""
Parser for thuban session files.
"""

__version__ = "$Revision$"

import string, os

import xml.sax
import xml.sax.handler
from xml.sax import make_parser, ErrorHandler, SAXNotRecognizedException

from Thuban import _

from Thuban.Model.table import FIELDTYPE_INT, FIELDTYPE_DOUBLE, \
     FIELDTYPE_STRING

from Thuban.Model.color import Color, Transparent

from Thuban.Model.session import Session
from Thuban.Model.map import Map
from Thuban.Model.layer import Layer, RasterLayer
from Thuban.Model.proj import Projection
from Thuban.Model.range import Range
from Thuban.Model.classification import Classification, \
    ClassGroupDefault, ClassGroupSingleton, ClassGroupRange, ClassGroupMap, \
    ClassGroupProperties
from Thuban.Model.data import DerivedShapeStore, ShapefileStore
from Thuban.Model.table import DBFTable
from Thuban.Model.transientdb import TransientJoinedTable

class LoadError(Exception):
    pass

from Thuban.Model.xmlreader import XMLReader
import resource 

def parse_color(color):
    """Return the color object for the string color.

    Color may be either 'None' or of the form '#RRGGBB' in the usual
    HTML color notation
    """
    color = string.strip(color)
    if color == "None":
        result = Transparent
    elif color[0] == '#':
        if len(color) == 7:
            r = string.atoi(color[1:3], 16) / 255.0
            g = string.atoi(color[3:5], 16) / 255.0
            b = string.atoi(color[5:7], 16) / 255.0
            result = Color(r, g, b)
        else:
            raise ValueError(_("Invalid hexadecimal color specification %s")
                             % color)
    else:
        raise ValueError(_("Invalid color specification %s") % color)
    return result

class AttrDesc:

    def __init__(self, name, required = False, default = "",
                 conversion = None):
        if not isinstance(name, tuple):
            fullname = (None, name)
        else:
            fullname = name
            name = name[1]
        self.name = name
        self.fullname = fullname
        self.required = required
        self.default = default
        self.conversion = conversion

        # set by the SessionLoader's check_attrs method
        self.value = None


class SessionLoader(XMLReader):

    def __init__(self):
        """Inititialize the Sax handler."""
        XMLReader.__init__(self)

        self.theSession = None
        self.aMap = None
        self.aLayer = None

        # Map ids used in the thuban file to the corresponding objects
        # in the session
        self.idmap = {}

        dispatchers = {
            'session'       : ("start_session",        "end_session"),
            'fileshapesource': ("start_fileshapesource", None),
            'derivedshapesource': ("start_derivedshapesource", None),
            'filetable': ("start_filetable", None),
            'jointable': ("start_jointable", None),

            'map'           : ("start_map",            "end_map"),
            'projection'    : ("start_projection",     "end_projection"),
            'parameter'     : ("start_parameter",      None),
            'layer'         : ("start_layer",          "end_layer"),
            'rasterlayer'   : ("start_rasterlayer",    "end_rasterlayer"),
            'classification': ("start_classification", "end_classification"),
            'clnull'        : ("start_clnull",         "end_clnull"),
            'clpoint'       : ("start_clpoint",        "end_clpoint"),
            'clrange'       : ("start_clrange",        "end_clrange"),
            'cldata'        : ("start_cldata",         "end_cldata"),
            'table'         : ("start_table",          "end_table"),
            'labellayer'    : ("start_labellayer",     None),
            'label'         : ("start_label",          None)}

        # all dispatchers should be used for the 0.8 and 0.9 namespaces too
        for xmlns in ("http://thuban.intevation.org/dtds/thuban-0.8.dtd",
                      "http://thuban.intevation.org/dtds/thuban-0.9-dev.dtd"):
            for key, value in dispatchers.items():
                dispatchers[(xmlns, key)] = value

        XMLReader.AddDispatchers(self, dispatchers)

    def start_session(self, name, qname, attrs):
        self.theSession = Session(self.encode(attrs.get((None, 'title'),
                                                        None)))

    def end_session(self, name, qname):
        pass

    def check_attrs(self, element, attrs, descr):
        """Check and convert some of the attributes of an element

        Parameters:
           element -- The element name
           attrs -- The attrs mapping as passed to the start_* methods
           descr -- Sequence of attribute descriptions (AttrDesc instances)

        Return a dictionary containig normalized versions of the
        attributes described in descr. The keys of that dictionary are
        the name attributes of the attribute descriptions. The attrs
        dictionary will not be modified.

        If the attribute is required, i.e. the 'required' attribute of
        the descrtiption is true, but it is not in attrs, raise a
        LoadError.

        If the attribute has a default value and it is not present in
        attrs, use that default value as the value in the returned dict.

        If a conversion is specified, convert the value before putting
        it into the returned dict. The following conversions are
        available:

           'filename' -- The attribute is a filename.

                         If the filename is a relative name, interpret
                         it relative to the directory containing the
                         .thuban file and make it an absolute name

           'shapestore' -- The attribute is the ID of a shapestore
                           defined earlier in the .thuban file. Look it
                           up self.idmap

           'table' -- The attribute is the ID of a table or shapestore
                      defined earlier in the .thuban file. Look it up
                      self.idmap. If it's the ID of a shapestore the
                      value will be the table of the shapestore.
        """
        normalized = {}

        for d in descr:
            if d.required and not attrs.has_key(d.fullname):
                pass
            #raise LoadError("Element %s requires an attribute %r"
            #                    % (element, d.name))
            value = attrs.get(d.fullname, d.default)

            if d.conversion == "shapesource":
                if value in self.idmap:
                    value = self.idmap[value]
                else:
                    raise LoadError("Element %s requires an already defined ID"
                                    " in attribute %r"
                                    % (element, d.name))
            elif d.conversion == "table":
                if value in self.idmap:
                    value = self.idmap[value]
                    if isinstance(value, ShapefileStore):
                        value = value.Table()
                else:
                    raise LoadError("Element %s requires an already defined ID"
                                    " in attribute %r"
                                    % (element, d.name))
            elif d.conversion == "filename":
                value = os.path.abspath(os.path.join(self.GetDirectory(),
                                                     value))

            normalized[d.name] = value
        return normalized

    def start_fileshapesource(self, name, qname, attrs):
        attrs = self.check_attrs(name, attrs,
                                  [AttrDesc("id", True),
                                   AttrDesc("filename", True,
                                            conversion = "filename"),
                                   AttrDesc("filetype", True)])
        ID = attrs["id"]
        filename = attrs["filename"]
        filetype = attrs["filetype"]
        if filetype != "shapefile":
            raise LoadError("shapesource filetype %r not supported" % filetype)
        self.idmap[ID] = self.theSession.OpenShapefile(filename)

    def start_derivedshapesource(self, name, qname, attrs):
        attrs = self.check_attrs(name, attrs,
                                 [AttrDesc("id", True),
                                  AttrDesc("shapesource", True,
                                           conversion = "shapesource"),
                                  AttrDesc("table", True, conversion="table")])
        store = DerivedShapeStore(attrs["shapesource"], attrs["table"])
        self.theSession.AddShapeStore(store)
        self.idmap[attrs["id"]] = store

    def start_filetable(self, name, qname, attrs):
        attrs = self.check_attrs(name, attrs,
                                 [AttrDesc("id", True),
                                  AttrDesc("title", True),
                                  AttrDesc("filename", True,
                                           conversion = "filename"),
                                  AttrDesc("filetype")])
        filetype = attrs["filetype"]
        if filetype != "DBF":
            raise LoadError("shapesource filetype %r not supported" % filetype)
        table = DBFTable(attrs["filename"])
        table.SetTitle(attrs["title"])
        self.idmap[attrs["id"]] = self.theSession.AddTable(table)

    def start_jointable(self, name, qname, attrs):
        attrs = self.check_attrs(name, attrs,
                                 [AttrDesc("id", True),
                                  AttrDesc("title", True),
                                  AttrDesc("left", True, conversion="table"),
                                  AttrDesc("leftcolumn", True),
                                  AttrDesc("right", True, conversion="table"),
                                  AttrDesc("rightcolumn", True),

                                  # jointype is required for file
                                  # version 0.9 but this attribute
                                  # wasn't in the 0.8 version because of
                                  # an oversight so we assume it's
                                  # optional since we want to handle
                                  # both file format versions here.
                                  AttrDesc("jointype", False,
                                           default="INNER")])

        jointype = attrs["jointype"]
        if jointype == "LEFT OUTER":
            outer_join = True
        elif jointype == "INNER":
            outer_join = False
        else:
            raise LoadError("jointype %r not supported" % jointype )
        table = TransientJoinedTable(self.theSession.TransientDB(),
                                     attrs["left"], attrs["leftcolumn"],
                                     attrs["right"], attrs["rightcolumn"],
                                     outer_join = outer_join)
        table.SetTitle(attrs["title"])
        self.idmap[attrs["id"]] = self.theSession.AddTable(table)

    def start_map(self, name, qname, attrs):
        """Start a map."""
        self.aMap = Map(attrs.get((None, 'title'), None))

    def end_map(self, name, qname):
        self.theSession.AddMap(self.aMap)
        self.aMap = None

    def start_projection(self, name, qname, attrs):
        self.ProjectionName = self.encode(attrs.get((None, 'name'), None))
        self.ProjectionParams = [ ]

    def end_projection(self, name, qname):
        if self.aLayer is not None:
            obj = self.aLayer
        elif self.aMap is not None:
            obj = self.aMap
        else:
            assert False, "projection tag out of context"
            pass

        obj.SetProjection(
            Projection(self.ProjectionParams, self.ProjectionName))

    def start_parameter(self, name, qname, attrs):
        s = attrs.get((None, 'value'))
        s = str(s) # we can't handle unicode in proj
        self.ProjectionParams.append(s)

    def start_layer(self, name, qname, attrs, layer_class = Layer):
        """Start a layer

        Instantiate a layer of class layer_class from the attributes in
        attrs which may be a dictionary as well as the normal SAX attrs
        object and bind it to self.aLayer.
        """
        title = self.encode(attrs.get((None, 'title'), ""))
        filename = attrs.get((None, 'filename'), "")
        filename = os.path.join(self.GetDirectory(), filename)
        filename = self.encode(filename)
        visible  = self.encode(attrs.get((None, 'visible'), "true")) != "false"
        fill = parse_color(attrs.get((None, 'fill'), "None"))
        stroke = parse_color(attrs.get((None, 'stroke'), "#000000"))
        stroke_width = int(attrs.get((None, 'stroke_width'), "1"))
        if attrs.has_key((None, "shapestore")):
            store = self.idmap[attrs[(None, "shapestore")]]
        else:
            store = self.theSession.OpenShapefile(filename)
        self.aLayer = layer_class(title, store,
                                  fill = fill, stroke = stroke,
                                  lineWidth = stroke_width,
                                  visible = visible)

    def end_layer(self, name, qname):
        self.aMap.AddLayer(self.aLayer)
        self.aLayer = None

    def start_rasterlayer(self, name, qname, attrs, layer_class = RasterLayer):
        title = self.encode(attrs.get((None, 'title'), ""))
        filename = attrs.get((None, 'filename'), "")
        filename = os.path.join(self.GetDirectory(), filename)
        filename = self.encode(filename)
        visible  = self.encode(attrs.get((None, 'visible'), "true")) != "false"

        self.aLayer = layer_class(title, filename, visible = visible)

    def end_rasterlayer(self, name, qname):
        self.aMap.AddLayer(self.aLayer)
        self.aLayer = None

    def start_classification(self, name, qname, attrs):
        field = attrs.get((None, 'field'), None)

        fieldType = attrs.get((None, 'field_type'), None)
        dbFieldType = self.aLayer.GetFieldType(field)

        if fieldType != dbFieldType:
            raise ValueError(_("xml field type differs from database!"))

        # setup conversion routines depending on the kind of data
        # we will be seeing later on
        if fieldType == FIELDTYPE_STRING:
            self.conv = str
        elif fieldType == FIELDTYPE_INT:
            self.conv = lambda p: int(float(p))
        elif fieldType == FIELDTYPE_DOUBLE:
            self.conv = float

        self.aLayer.GetClassification().SetFieldInfo(field, fieldType)

    def end_classification(self, name, qname): 
        pass

    def start_clnull(self, name, qname, attrs):
        self.cl_group = ClassGroupDefault()
        self.cl_group.SetLabel(self.encode(attrs.get((None, 'label'), "")))
        self.cl_prop = ClassGroupProperties()

    def end_clnull(self, name, qname):
        self.cl_group.SetProperties(self.cl_prop)
        self.aLayer.GetClassification().SetDefaultGroup(self.cl_group)
        del self.cl_group, self.cl_prop

    def start_clpoint(self, name, qname, attrs):
        attrib_value = attrs.get((None, 'value'), "0")

        value = self.conv(attrib_value)

        self.cl_group = ClassGroupSingleton(value)
        self.cl_group.SetLabel(self.encode(attrs.get((None, 'label'), "")))
        self.cl_prop = ClassGroupProperties()


    def end_clpoint(self, name, qname):
        self.cl_group.SetProperties(self.cl_prop)
        self.aLayer.GetClassification().AppendGroup(self.cl_group)
        del self.cl_group, self.cl_prop

    def start_clrange(self, name, qname, attrs):

        range = attrs.get((None, 'range'), None)
        # for backward compatibility (min/max are not saved)
        min   = attrs.get((None, 'min'), None)
        max   = attrs.get((None, 'max'), None)

        try:
            if range is not None:
                self.cl_group = ClassGroupRange(Range(range))
            elif min is not None and max is not None:
                self.cl_group = ClassGroupRange((self.conv(min), 
                                                 self.conv(max)))
            else:
                self.cl_group = ClassGroupRange(Range(None))

        except ValueError:
            raise ValueError(_("Classification range is not a number!"))

        self.cl_group.SetLabel(attrs.get((None, 'label'), ""))
        self.cl_prop = ClassGroupProperties()


    def end_clrange(self, name, qname):
        self.cl_group.SetProperties(self.cl_prop)
        self.aLayer.GetClassification().AppendGroup(self.cl_group)
        del self.cl_group, self.cl_prop

    def start_cldata(self, name, qname, attrs):
        self.cl_prop.SetLineColor(
            parse_color(attrs.get((None, 'stroke'), "None")))
        self.cl_prop.SetLineWidth(
            int(attrs.get((None, 'stroke_width'), "0")))
        self.cl_prop.SetFill(parse_color(attrs.get((None, 'fill'), "None")))

    def end_cldata(self, name, qname):
        pass

    def start_labellayer(self, name, qname, attrs):
        self.aLayer = self.aMap.LabelLayer()

    def start_label(self, name, qname, attrs):
        x = float(attrs[(None, 'x')])
        y = float(attrs[(None, 'y')])
        text = self.encode(attrs[(None, 'text')])
        halign = attrs[(None, 'halign')]
        valign = attrs[(None, 'valign')]
        self.aLayer.AddLabel(x, y, text, halign = halign, valign = valign)

    def characters(self, chars):
        pass


def load_session(filename):
    """Load a Thuban session from the file object file"""

    handler = SessionLoader()
    handler.read(filename)

    session = handler.theSession
    # Newly loaded session aren't modified
    session.UnsetModified()

    return session

1	# Copyright (C) 2001, 2002, 2003 by Intevation GmbH
2	# Authors:
3	# Jan-Oliver Wagner <[email protected]>
4	# Bernhard Herzog <[email protected]>
5	# Jonathan Coles <[email protected]>
6	#
7	# This program is free software under the GPL (>=v2)
8	# Read the file COPYING coming with GRASS for details.
9
10	"""
11	Parser for thuban session files.
12	"""
13
14	__version__ = "$Revision$"
15
16	import string, os
17
18	import xml.sax
19	import xml.sax.handler
20	from xml.sax import make_parser, ErrorHandler, SAXNotRecognizedException
21
22	from Thuban import _
23
24	from Thuban.Model.table import FIELDTYPE_INT, FIELDTYPE_DOUBLE, \
25	FIELDTYPE_STRING
26
27	from Thuban.Model.color import Color, Transparent
28
29	from Thuban.Model.session import Session
30	from Thuban.Model.map import Map
31	from Thuban.Model.layer import Layer, RasterLayer
32	from Thuban.Model.proj import Projection
33	from Thuban.Model.range import Range
34	from Thuban.Model.classification import Classification, \
35	ClassGroupDefault, ClassGroupSingleton, ClassGroupRange, ClassGroupMap, \
36	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	class LoadError(Exception):
42	pass
43
44	from Thuban.Model.xmlreader import XMLReader
45	import resource
46
47	def parse_color(color):
48	"""Return the color object for the string color.
49
50	Color may be either 'None' or of the form '#RRGGBB' in the usual
51	HTML color notation
52	"""
53	color = string.strip(color)
54	if color == "None":
55	result = Transparent
56	elif color[0] == '#':
57	if len(color) == 7:
58	r = string.atoi(color[1:3], 16) / 255.0
59	g = string.atoi(color[3:5], 16) / 255.0
60	b = string.atoi(color[5:7], 16) / 255.0
61	result = Color(r, g, b)
62	else:
63	raise ValueError(_("Invalid hexadecimal color specification %s")
64	% color)
65	else:
66	raise ValueError(_("Invalid color specification %s") % color)
67	return result
68
69	class AttrDesc:
70
71	def __init__(self, name, required = False, default = "",
72	conversion = None):
73	if not isinstance(name, tuple):
74	fullname = (None, name)
75	else:
76	fullname = name
77	name = name[1]
78	self.name = name
79	self.fullname = fullname
80	self.required = required
81	self.default = default
82	self.conversion = conversion
83
84	# set by the SessionLoader's check_attrs method
85	self.value = None
86
87
88	class SessionLoader(XMLReader):
89
90	def __init__(self):
91	"""Inititialize the Sax handler."""
92	XMLReader.__init__(self)
93
94	self.theSession = None
95	self.aMap = None
96	self.aLayer = None
97
98	# Map ids used in the thuban file to the corresponding objects
99	# in the session
100	self.idmap = {}
101
102	dispatchers = {
103	'session' : ("start_session", "end_session"),
104	'fileshapesource': ("start_fileshapesource", None),
105	'derivedshapesource': ("start_derivedshapesource", None),
106	'filetable': ("start_filetable", None),
107	'jointable': ("start_jointable", None),
108
109	'map' : ("start_map", "end_map"),
110	'projection' : ("start_projection", "end_projection"),
111	'parameter' : ("start_parameter", None),
112	'layer' : ("start_layer", "end_layer"),
113	'rasterlayer' : ("start_rasterlayer", "end_rasterlayer"),
114	'classification': ("start_classification", "end_classification"),
115	'clnull' : ("start_clnull", "end_clnull"),
116	'clpoint' : ("start_clpoint", "end_clpoint"),
117	'clrange' : ("start_clrange", "end_clrange"),
118	'cldata' : ("start_cldata", "end_cldata"),
119	'table' : ("start_table", "end_table"),
120	'labellayer' : ("start_labellayer", None),
121	'label' : ("start_label", None)}
122
123	# all dispatchers should be used for the 0.8 and 0.9 namespaces too
124	for xmlns in ("http://thuban.intevation.org/dtds/thuban-0.8.dtd",
125	"http://thuban.intevation.org/dtds/thuban-0.9-dev.dtd"):
126	for key, value in dispatchers.items():
127	dispatchers[(xmlns, key)] = value
128
129	XMLReader.AddDispatchers(self, dispatchers)
130
131	def start_session(self, name, qname, attrs):
132	self.theSession = Session(self.encode(attrs.get((None, 'title'),
133	None)))
134
135	def end_session(self, name, qname):
136	pass
137
138	def check_attrs(self, element, attrs, descr):
139	"""Check and convert some of the attributes of an element
140
141	Parameters:
142	element -- The element name
143	attrs -- The attrs mapping as passed to the start_* methods
144	descr -- Sequence of attribute descriptions (AttrDesc instances)
145
146	Return a dictionary containig normalized versions of the
147	attributes described in descr. The keys of that dictionary are
148	the name attributes of the attribute descriptions. The attrs
149	dictionary will not be modified.
150
151	If the attribute is required, i.e. the 'required' attribute of
152	the descrtiption is true, but it is not in attrs, raise a
153	LoadError.
154
155	If the attribute has a default value and it is not present in
156	attrs, use that default value as the value in the returned dict.
157
158	If a conversion is specified, convert the value before putting
159	it into the returned dict. The following conversions are
160	available:
161
162	'filename' -- The attribute is a filename.
163
164	If the filename is a relative name, interpret
165	it relative to the directory containing the
166	.thuban file and make it an absolute name
167
168	'shapestore' -- The attribute is the ID of a shapestore
169	defined earlier in the .thuban file. Look it
170	up self.idmap
171
172	'table' -- The attribute is the ID of a table or shapestore
173	defined earlier in the .thuban file. Look it up
174	self.idmap. If it's the ID of a shapestore the
175	value will be the table of the shapestore.
176	"""
177	normalized = {}
178
179	for d in descr:
180	if d.required and not attrs.has_key(d.fullname):
181	pass
182	#raise LoadError("Element %s requires an attribute %r"
183	# % (element, d.name))
184	value = attrs.get(d.fullname, d.default)
185
186	if d.conversion == "shapesource":
187	if value in self.idmap:
188	value = self.idmap[value]
189	else:
190	raise LoadError("Element %s requires an already defined ID"
191	" in attribute %r"
192	% (element, d.name))
193	elif d.conversion == "table":
194	if value in self.idmap:
195	value = self.idmap[value]
196	if isinstance(value, ShapefileStore):
197	value = value.Table()
198	else:
199	raise LoadError("Element %s requires an already defined ID"
200	" in attribute %r"
201	% (element, d.name))
202	elif d.conversion == "filename":
203	value = os.path.abspath(os.path.join(self.GetDirectory(),
204	value))
205
206	normalized[d.name] = value
207	return normalized
208
209	def start_fileshapesource(self, name, qname, attrs):
210	attrs = self.check_attrs(name, attrs,
211	[AttrDesc("id", True),
212	AttrDesc("filename", True,
213	conversion = "filename"),
214	AttrDesc("filetype", True)])
215	ID = attrs["id"]
216	filename = attrs["filename"]
217	filetype = attrs["filetype"]
218	if filetype != "shapefile":
219	raise LoadError("shapesource filetype %r not supported" % filetype)
220	self.idmap[ID] = self.theSession.OpenShapefile(filename)
221
222	def start_derivedshapesource(self, name, qname, attrs):
223	attrs = self.check_attrs(name, attrs,
224	[AttrDesc("id", True),
225	AttrDesc("shapesource", True,
226	conversion = "shapesource"),
227	AttrDesc("table", True, conversion="table")])
228	store = DerivedShapeStore(attrs["shapesource"], attrs["table"])
229	self.theSession.AddShapeStore(store)
230	self.idmap[attrs["id"]] = store
231
232	def start_filetable(self, name, qname, attrs):
233	attrs = self.check_attrs(name, attrs,
234	[AttrDesc("id", True),
235	AttrDesc("title", True),
236	AttrDesc("filename", True,
237	conversion = "filename"),
238	AttrDesc("filetype")])
239	filetype = attrs["filetype"]
240	if filetype != "DBF":
241	raise LoadError("shapesource filetype %r not supported" % filetype)
242	table = DBFTable(attrs["filename"])
243	table.SetTitle(attrs["title"])
244	self.idmap[attrs["id"]] = self.theSession.AddTable(table)
245
246	def start_jointable(self, name, qname, attrs):
247	attrs = self.check_attrs(name, attrs,
248	[AttrDesc("id", True),
249	AttrDesc("title", True),
250	AttrDesc("left", True, conversion="table"),
251	AttrDesc("leftcolumn", True),
252	AttrDesc("right", True, conversion="table"),
253	AttrDesc("rightcolumn", True),
254
255	# jointype is required for file
256	# version 0.9 but this attribute
257	# wasn't in the 0.8 version because of
258	# an oversight so we assume it's
259	# optional since we want to handle
260	# both file format versions here.
261	AttrDesc("jointype", False,
262	default="INNER")])
263
264	jointype = attrs["jointype"]
265	if jointype == "LEFT OUTER":
266	outer_join = True
267	elif jointype == "INNER":
268	outer_join = False
269	else:
270	raise LoadError("jointype %r not supported" % jointype )
271	table = TransientJoinedTable(self.theSession.TransientDB(),
272	attrs["left"], attrs["leftcolumn"],
273	attrs["right"], attrs["rightcolumn"],
274	outer_join = outer_join)
275	table.SetTitle(attrs["title"])
276	self.idmap[attrs["id"]] = self.theSession.AddTable(table)
277
278	def start_map(self, name, qname, attrs):
279	"""Start a map."""
280	self.aMap = Map(attrs.get((None, 'title'), None))
281
282	def end_map(self, name, qname):
283	self.theSession.AddMap(self.aMap)
284	self.aMap = None
285
286	def start_projection(self, name, qname, attrs):
287	self.ProjectionName = self.encode(attrs.get((None, 'name'), None))
288	self.ProjectionParams = [ ]
289
290	def end_projection(self, name, qname):
291	if self.aLayer is not None:
292	obj = self.aLayer
293	elif self.aMap is not None:
294	obj = self.aMap
295	else:
296	assert False, "projection tag out of context"
297	pass
298
299	obj.SetProjection(
300	Projection(self.ProjectionParams, self.ProjectionName))
301
302	def start_parameter(self, name, qname, attrs):
303	s = attrs.get((None, 'value'))
304	s = str(s) # we can't handle unicode in proj
305	self.ProjectionParams.append(s)
306
307	def start_layer(self, name, qname, attrs, layer_class = Layer):
308	"""Start a layer
309
310	Instantiate a layer of class layer_class from the attributes in
311	attrs which may be a dictionary as well as the normal SAX attrs
312	object and bind it to self.aLayer.
313	"""
314	title = self.encode(attrs.get((None, 'title'), ""))
315	filename = attrs.get((None, 'filename'), "")
316	filename = os.path.join(self.GetDirectory(), filename)
317	filename = self.encode(filename)
318	visible = self.encode(attrs.get((None, 'visible'), "true")) != "false"
319	fill = parse_color(attrs.get((None, 'fill'), "None"))
320	stroke = parse_color(attrs.get((None, 'stroke'), "#000000"))
321	stroke_width = int(attrs.get((None, 'stroke_width'), "1"))
322	if attrs.has_key((None, "shapestore")):
323	store = self.idmap[attrs[(None, "shapestore")]]
324	else:
325	store = self.theSession.OpenShapefile(filename)
326	self.aLayer = layer_class(title, store,
327	fill = fill, stroke = stroke,
328	lineWidth = stroke_width,
329	visible = visible)
330
331	def end_layer(self, name, qname):
332	self.aMap.AddLayer(self.aLayer)
333	self.aLayer = None
334
335	def start_rasterlayer(self, name, qname, attrs, layer_class = RasterLayer):
336	title = self.encode(attrs.get((None, 'title'), ""))
337	filename = attrs.get((None, 'filename'), "")
338	filename = os.path.join(self.GetDirectory(), filename)
339	filename = self.encode(filename)
340	visible = self.encode(attrs.get((None, 'visible'), "true")) != "false"
341
342	self.aLayer = layer_class(title, filename, visible = visible)
343
344	def end_rasterlayer(self, name, qname):
345	self.aMap.AddLayer(self.aLayer)
346	self.aLayer = None
347
348	def start_classification(self, name, qname, attrs):
349	field = attrs.get((None, 'field'), None)
350
351	fieldType = attrs.get((None, 'field_type'), None)
352	dbFieldType = self.aLayer.GetFieldType(field)
353
354	if fieldType != dbFieldType:
355	raise ValueError(_("xml field type differs from database!"))
356
357	# setup conversion routines depending on the kind of data
358	# we will be seeing later on
359	if fieldType == FIELDTYPE_STRING:
360	self.conv = str
361	elif fieldType == FIELDTYPE_INT:
362	self.conv = lambda p: int(float(p))
363	elif fieldType == FIELDTYPE_DOUBLE:
364	self.conv = float
365
366	self.aLayer.GetClassification().SetFieldInfo(field, fieldType)
367
368	def end_classification(self, name, qname):
369	pass
370
371	def start_clnull(self, name, qname, attrs):
372	self.cl_group = ClassGroupDefault()
373	self.cl_group.SetLabel(self.encode(attrs.get((None, 'label'), "")))
374	self.cl_prop = ClassGroupProperties()
375
376	def end_clnull(self, name, qname):
377	self.cl_group.SetProperties(self.cl_prop)
378	self.aLayer.GetClassification().SetDefaultGroup(self.cl_group)
379	del self.cl_group, self.cl_prop
380
381	def start_clpoint(self, name, qname, attrs):
382	attrib_value = attrs.get((None, 'value'), "0")
383
384	value = self.conv(attrib_value)
385
386	self.cl_group = ClassGroupSingleton(value)
387	self.cl_group.SetLabel(self.encode(attrs.get((None, 'label'), "")))
388	self.cl_prop = ClassGroupProperties()
389
390
391	def end_clpoint(self, name, qname):
392	self.cl_group.SetProperties(self.cl_prop)
393	self.aLayer.GetClassification().AppendGroup(self.cl_group)
394	del self.cl_group, self.cl_prop
395
396	def start_clrange(self, name, qname, attrs):
397
398	range = attrs.get((None, 'range'), None)
399	# for backward compatibility (min/max are not saved)
400	min = attrs.get((None, 'min'), None)
401	max = attrs.get((None, 'max'), None)
402
403	try:
404	if range is not None:
405	self.cl_group = ClassGroupRange(Range(range))
406	elif min is not None and max is not None:
407	self.cl_group = ClassGroupRange((self.conv(min),
408	self.conv(max)))
409	else:
410	self.cl_group = ClassGroupRange(Range(None))
411
412	except ValueError:
413	raise ValueError(_("Classification range is not a number!"))
414
415	self.cl_group.SetLabel(attrs.get((None, 'label'), ""))
416	self.cl_prop = ClassGroupProperties()
417
418
419	def end_clrange(self, name, qname):
420	self.cl_group.SetProperties(self.cl_prop)
421	self.aLayer.GetClassification().AppendGroup(self.cl_group)
422	del self.cl_group, self.cl_prop
423
424	def start_cldata(self, name, qname, attrs):
425	self.cl_prop.SetLineColor(
426	parse_color(attrs.get((None, 'stroke'), "None")))
427	self.cl_prop.SetLineWidth(
428	int(attrs.get((None, 'stroke_width'), "0")))
429	self.cl_prop.SetFill(parse_color(attrs.get((None, 'fill'), "None")))
430
431	def end_cldata(self, name, qname):
432	pass
433
434	def start_labellayer(self, name, qname, attrs):
435	self.aLayer = self.aMap.LabelLayer()
436
437	def start_label(self, name, qname, attrs):
438	x = float(attrs[(None, 'x')])
439	y = float(attrs[(None, 'y')])
440	text = self.encode(attrs[(None, 'text')])
441	halign = attrs[(None, 'halign')]
442	valign = attrs[(None, 'valign')]
443	self.aLayer.AddLabel(x, y, text, halign = halign, valign = valign)
444
445	def characters(self, chars):
446	pass
447
448
449	def load_session(filename):
450	"""Load a Thuban session from the file object file"""
451
452	handler = SessionLoader()
453	handler.read(filename)
454
455	session = handler.theSession
456	# Newly loaded session aren't modified
457	session.UnsetModified()
458
459	return session
460
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