Thuban/Model/save.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 Thuban for details.

"""
Functions to save a session to a file
"""

__version__ = "$Revision$"

import os

import Thuban.Lib.fileutil

from Thuban.Model.layer import Layer, RasterLayer

from Thuban.Model.classification import \
    ClassGroupDefault, ClassGroupSingleton, ClassGroupRange, ClassGroupMap
from Thuban.Model.transientdb import AutoTransientTable, TransientJoinedTable
from Thuban.Model.table import DBFTable, FIELDTYPE_STRING
from Thuban.Model.data import DerivedShapeStore, ShapefileStore

from Thuban.Model.xmlwriter import XMLWriter
from postgisdb import PostGISConnection, PostGISShapeStore

def relative_filename(dir, filename):
    """Return a filename relative to dir for the absolute file name absname.

    This is almost the same as the function in fileutil, except that dir
    can be an empty string in which case filename will be returned
    unchanged.
    """
    if dir:
        return Thuban.Lib.fileutil.relative_filename(dir, filename)
    else:
        return filename


def sort_data_stores(stores):
    """Return a topologically sorted version of the sequence of data containers

    The list is sorted so that data containers that depend on other data
    containers have higher indexes than the containers they depend on.
    """
    if not stores:
        return []
    processed = {}
    result = []
    todo = stores[:]
    while todo:
        # It doesn't really matter which if the items of todo is
        # processed next, but if we take the first one, the order is
        # preserved to some degree which makes writing some of the test
        # cases easier.
        container = todo.pop(0)
        if id(container) in processed:
            continue
        deps = [dep for dep in container.Dependencies()
                    if id(dep) not in processed]
        if deps:
            todo.append(container)
            todo.extend(deps)
        else:
            result.append(container)
            processed[id(container)] = 1
    return result


class SessionSaver(XMLWriter):

    """Class to serialize a session into an XML file.

    Applications built on top of Thuban may derive from this class and
    override or extend the methods to save additional information. This
    additional information should take the form of additional attributes
    or elements whose names are prefixed with a namespace. To define a
    namespace derived classes should extend the write_session method to
    pass the namespaces to the default implementation.
    """


    def __init__(self, session):
        XMLWriter.__init__(self)
        self.session = session
        # Map object ids to the ids used in the thuban files
        self.idmap = {}

    def get_id(self, obj):
        """Return the id used in the thuban file for the object obj"""
        return self.idmap.get(id(obj))

    def define_id(self, obj, value = None):
        if value is None:
            value = "D" + str(id(obj))
        self.idmap[id(obj)] = value
        return value

    def has_id(self, obj):
        return self.idmap.has_key(id(obj))

    def write(self, file_or_filename):
        XMLWriter.write(self, file_or_filename)

        self.write_header("session", "thuban-0.9.dtd")
        self.write_session(self.session)
        self.close()

    def write_session(self, session, attrs = None, namespaces = ()):
        """Write the session and its contents

        By default, write a session element with the title attribute and
        call write_map for each map contained in the session.

        The optional argument attrs is for additional attributes and, if
        given, should be a mapping from attribute names to attribute
        values. The values should not be XML-escaped yet.

        The optional argument namespaces, if given, should be a sequence
        of (name, URI) pairs. The namespaces are written as namespace
        attributes into the session element. This is mainly useful for
        derived classes that need to store additional information in a
        thuban session file.
        """
        if attrs is None:
            attrs = {}
        attrs["title"] = session.title
        for name, uri in namespaces:
            attrs["xmlns:" + name] = uri
        # default name space
        attrs["xmlns"] = \
               "http://thuban.intevation.org/dtds/thuban-0.9-dev.dtd"
        self.open_element("session", attrs)
        self.write_db_connections(session)
        self.write_data_containers(session)
        for map in session.Maps():
            self.write_map(map)
        self.close_element("session")

    def write_db_connections(self, session):
        for conn in session.DBConnections():
            if isinstance(conn, PostGISConnection):
                self.write_element("dbconnection",
                                   {"id": self.define_id(conn),
                                    "dbtype": "postgis",
                                    "host": conn.host,
                                    "port": conn.port,
                                    "user": conn.user,
                                    "dbname": conn.dbname})
            else:
                raise ValueError("Can't handle db connection %r" % conn)

    def write_data_containers(self, session):
        containers = sort_data_stores(session.DataContainers())
        for container in containers:
            if isinstance(container, AutoTransientTable):
                # AutoTransientTable instances are invisible in the
                # thuban files. They're only used internally. To make
                # sure that containers depending on AutoTransientTable
                # instances refer to the right real containers we give
                # the AutoTransientTable instances the same id as the
                # source they depend on.
                self.define_id(container,
                               self.get_id(container.Dependencies()[0]))
                continue

            idvalue = self.define_id(container)
            if isinstance(container, ShapefileStore):
                self.define_id(container.Table(), idvalue)
                filename = relative_filename(self.dir, container.FileName())
                self.write_element("fileshapesource",
                                   {"id": idvalue, "filename": filename,
                                    "filetype": "shapefile"})
            elif isinstance(container, DerivedShapeStore):
                shapesource, table = container.Dependencies()
                self.write_element("derivedshapesource",
                                   {"id": idvalue,
                                    "shapesource": self.get_id(shapesource),
                                    "table": self.get_id(table)})
            elif isinstance(container, PostGISShapeStore):
                conn = container.DBConnection()
                self.write_element("dbshapesource",
                                   {"id": idvalue,
                                    "dbconn": self.get_id(conn),
                                    "tablename": container.TableName()})
            elif isinstance(container, DBFTable):
                filename = relative_filename(self.dir, container.FileName())
                self.write_element("filetable",
                                   {"id": idvalue,
                                    "title": container.Title(),
                                    "filename": filename,
                                    "filetype": "DBF"})
            elif isinstance(container, TransientJoinedTable):
                left, right = container.Dependencies()
                left_field = container.left_field
                right_field = container.right_field
                self.write_element("jointable",
                                   {"id": idvalue,
                                    "title": container.Title(),
                                    "right": self.get_id(right),
                                    "rightcolumn": right_field,
                                    "left": self.get_id(left),
                                    "leftcolumn": left_field,
                                    "jointype": container.JoinType()})
            else:
                raise ValueError("Can't handle container %r" % container)


    def write_map(self, map):
        """Write the map and its contents.

        By default, write a map element element with the title
        attribute, call write_projection to write the projection
        element, call write_layer for each layer contained in the map
        and finally call write_label_layer to write the label layer.
        """
        self.open_element('map title="%s"' % self.encode(map.title))
        self.write_projection(map.projection)
        for layer in map.Layers():
            self.write_layer(layer)
        self.write_label_layer(map.LabelLayer())
        self.close_element('map')

    def write_projection(self, projection):
        """Write the projection.
        """
        if projection and len(projection.params) > 0:
            self.open_element("projection", {"name": projection.GetName()})
            for param in projection.params:
                self.write_element('parameter value="%s"' % 
                                   self.encode(param))
            self.close_element("projection")

    def write_layer(self, layer, attrs = None):
        """Write the layer.

        The optional argument attrs is for additional attributes and, if
        given, should be a mapping from attribute names to attribute
        values. The values should not be XML-escaped yet.
        """

        if attrs is None:
            attrs = {}

        attrs["title"]   = layer.title
        attrs["visible"] = ("false", "true")[int(layer.Visible())]

        if isinstance(layer, Layer):
            attrs["shapestore"]   = self.get_id(layer.ShapeStore())

            lc = layer.GetClassification()
            attrs["stroke"] = lc.GetDefaultLineColor().hex()
            attrs["stroke_width"] = str(lc.GetDefaultLineWidth())
            attrs["fill"] = lc.GetDefaultFill().hex()

            self.open_element("layer", attrs)
            self.write_projection(layer.GetProjection())
            self.write_classification(layer)
            self.close_element("layer")
        elif isinstance(layer, RasterLayer):
            attrs["filename"] = relative_filename(self.dir, layer.filename)
            self.open_element("rasterlayer", attrs)
            self.write_projection(layer.GetProjection())
            self.close_element("rasterlayer")

    def write_classification(self, layer, attrs = None):
        """Write Classification information."""

        if attrs is None:
            attrs = {}

        lc = layer.GetClassification()

        field = layer.GetClassificationColumn()

        #
        # there isn't a classification of anything so do nothing
        #
        if field is None: return

        attrs["field"] = field
        attrs["field_type"] = str(layer.GetFieldType(field))
        self.open_element("classification", attrs)

        for g in lc:
            if isinstance(g, ClassGroupDefault):
                open_el  = 'clnull label="%s"' % self.encode(g.GetLabel())
                close_el = 'clnull'
            elif isinstance(g, ClassGroupSingleton):
                if layer.GetFieldType(field) == FIELDTYPE_STRING:
                    value = self.encode(g.GetValue())
                else:
                    value = str(g.GetValue())
                open_el  = 'clpoint label="%s" value="%s"' \
                           % (self.encode(g.GetLabel()), value)
                close_el = 'clpoint'
            elif isinstance(g, ClassGroupRange):
                open_el  = 'clrange label="%s" range="%s"' \
                          % (self.encode(g.GetLabel()), str(g.GetRange()))
                close_el = 'clrange'
            else:
                assert False, _("Unsupported group type in classification")
                continue

            data = g.GetProperties()
            dict = {'stroke'      : data.GetLineColor().hex(),
                    'stroke_width': str(data.GetLineWidth()),
                    'fill'        : data.GetFill().hex()}

            self.open_element(open_el)
            self.write_element("cldata", dict)
            self.close_element(close_el)

        self.close_element("classification")

    def write_label_layer(self, layer):
        """Write the label layer.
        """
        labels = layer.Labels()
        if labels:
            self.open_element('labellayer')
            for label in labels:
                self.write_element(('label x="%g" y="%g" text="%s"'
                                    ' halign="%s" valign="%s"')
                                % (label.x, label.y, 
                                   self.encode(label.text), 
                                   label.halign,
                                   label.valign))
            self.close_element('labellayer')


def save_session(session, file, saver_class = None):
    """Save the session session to a file.

    The file argument may either be a filename or an open file object.

    The optional argument saver_class is the class to use to serialize
    the session. By default or if it's None, the saver class will be
    SessionSaver.

    If writing the session is successful call the session's
    UnsetModified method
    """
    if saver_class is None:
        saver_class = SessionSaver
    saver = saver_class(session)
    saver.write(file)

    # after a successful save consider the session unmodified.
    session.UnsetModified()
1	bh	454	# Copyright (c) 2001, 2002, 2003 by Intevation GmbH
2	bh	6	# Authors:
3			# Jan-Oliver Wagner <[email protected]>
4			# Bernhard Herzog <[email protected]>
5	jonathan	414	# Jonathan Coles <[email protected]>
6	bh	6	#
7			# This program is free software under the GPL (>=v2)
8			# Read the file COPYING coming with Thuban for details.
9
10			"""
11			Functions to save a session to a file
12			"""
13
14			__version__ = "$Revision$"
15
16			import os
17
18	bh	201	import Thuban.Lib.fileutil
19	bh	6
20	jonathan	932	from Thuban.Model.layer import Layer, RasterLayer
21
22	jonathan	876	from Thuban.Model.classification import \
23			ClassGroupDefault, ClassGroupSingleton, ClassGroupRange, ClassGroupMap
24	bh	1268	from Thuban.Model.transientdb import AutoTransientTable, TransientJoinedTable
25	bh	1417	from Thuban.Model.table import DBFTable, FIELDTYPE_STRING
26	bh	1268	from Thuban.Model.data import DerivedShapeStore, ShapefileStore
27	jonathan	429
28	jonathan	1160	from Thuban.Model.xmlwriter import XMLWriter
29	bh	1638	from postgisdb import PostGISConnection, PostGISShapeStore
30	jonathan	366
31	bh	201	def relative_filename(dir, filename):
32			"""Return a filename relative to dir for the absolute file name absname.
33
34			This is almost the same as the function in fileutil, except that dir
35			can be an empty string in which case filename will be returned
36			unchanged.
37			"""
38			if dir:
39			return Thuban.Lib.fileutil.relative_filename(dir, filename)
40			else:
41			return filename
42
43	bh	1268
44			def sort_data_stores(stores):
45			"""Return a topologically sorted version of the sequence of data containers
46
47			The list is sorted so that data containers that depend on other data
48			containers have higher indexes than the containers they depend on.
49			"""
50			if not stores:
51			return []
52			processed = {}
53			result = []
54			todo = stores[:]
55			while todo:
56			# It doesn't really matter which if the items of todo is
57			# processed next, but if we take the first one, the order is
58			# preserved to some degree which makes writing some of the test
59			# cases easier.
60			container = todo.pop(0)
61			if id(container) in processed:
62			continue
63			deps = [dep for dep in container.Dependencies()
64			if id(dep) not in processed]
65			if deps:
66			todo.append(container)
67			todo.extend(deps)
68			else:
69			result.append(container)
70			processed[id(container)] = 1
71			return result
72
73
74	jonathan	710	class SessionSaver(XMLWriter):
75	bh	268
76	jonathan	697	"""Class to serialize a session into an XML file.
77
78			Applications built on top of Thuban may derive from this class and
79			override or extend the methods to save additional information. This
80			additional information should take the form of additional attributes
81			or elements whose names are prefixed with a namespace. To define a
82			namespace derived classes should extend the write_session method to
83			pass the namespaces to the default implementation.
84			"""
85
86
87			def __init__(self, session):
88	jonathan	710	XMLWriter.__init__(self)
89	jonathan	697	self.session = session
90	bh	1268	# Map object ids to the ids used in the thuban files
91			self.idmap = {}
92	jonathan	697
93	bh	1268	def get_id(self, obj):
94			"""Return the id used in the thuban file for the object obj"""
95			return self.idmap.get(id(obj))
96
97			def define_id(self, obj, value = None):
98			if value is None:
99			value = "D" + str(id(obj))
100			self.idmap[id(obj)] = value
101			return value
102
103			def has_id(self, obj):
104			return self.idmap.has_key(id(obj))
105
106	jonathan	697	def write(self, file_or_filename):
107	jonathan	710	XMLWriter.write(self, file_or_filename)
108	jonathan	697
109	bh	1375	self.write_header("session", "thuban-0.9.dtd")
110	jonathan	697	self.write_session(self.session)
111			self.close()
112
113	bh	268	def write_session(self, session, attrs = None, namespaces = ()):
114			"""Write the session and its contents
115
116			By default, write a session element with the title attribute and
117			call write_map for each map contained in the session.
118
119			The optional argument attrs is for additional attributes and, if
120			given, should be a mapping from attribute names to attribute
121			values. The values should not be XML-escaped yet.
122
123			The optional argument namespaces, if given, should be a sequence
124			of (name, URI) pairs. The namespaces are written as namespace
125			attributes into the session element. This is mainly useful for
126			derived classes that need to store additional information in a
127			thuban session file.
128			"""
129			if attrs is None:
130			attrs = {}
131			attrs["title"] = session.title
132			for name, uri in namespaces:
133			attrs["xmlns:" + name] = uri
134	bh	1268	# default name space
135			attrs["xmlns"] = \
136	bh	1375	"http://thuban.intevation.org/dtds/thuban-0.9-dev.dtd"
137	jonathan	366	self.open_element("session", attrs)
138	bh	1638	self.write_db_connections(session)
139	bh	1268	self.write_data_containers(session)
140	bh	268	for map in session.Maps():
141			self.write_map(map)
142	jonathan	366	self.close_element("session")
143	bh	268
144	bh	1638	def write_db_connections(self, session):
145			for conn in session.DBConnections():
146			if isinstance(conn, PostGISConnection):
147			self.write_element("dbconnection",
148			{"id": self.define_id(conn),
149			"dbtype": "postgis",
150			"host": conn.host,
151			"port": conn.port,
152			"user": conn.user,
153			"dbname": conn.dbname})
154			else:
155			raise ValueError("Can't handle db connection %r" % conn)
156
157	bh	1268	def write_data_containers(self, session):
158			containers = sort_data_stores(session.DataContainers())
159			for container in containers:
160			if isinstance(container, AutoTransientTable):
161			# AutoTransientTable instances are invisible in the
162			# thuban files. They're only used internally. To make
163			# sure that containers depending on AutoTransientTable
164			# instances refer to the right real containers we give
165			# the AutoTransientTable instances the same id as the
166			# source they depend on.
167			self.define_id(container,
168			self.get_id(container.Dependencies()[0]))
169			continue
170
171			idvalue = self.define_id(container)
172			if isinstance(container, ShapefileStore):
173			self.define_id(container.Table(), idvalue)
174			filename = relative_filename(self.dir, container.FileName())
175			self.write_element("fileshapesource",
176			{"id": idvalue, "filename": filename,
177			"filetype": "shapefile"})
178			elif isinstance(container, DerivedShapeStore):
179			shapesource, table = container.Dependencies()
180			self.write_element("derivedshapesource",
181			{"id": idvalue,
182			"shapesource": self.get_id(shapesource),
183			"table": self.get_id(table)})
184	bh	1638	elif isinstance(container, PostGISShapeStore):
185			conn = container.DBConnection()
186			self.write_element("dbshapesource",
187			{"id": idvalue,
188			"dbconn": self.get_id(conn),
189			"tablename": container.TableName()})
190	bh	1268	elif isinstance(container, DBFTable):
191			filename = relative_filename(self.dir, container.FileName())
192			self.write_element("filetable",
193			{"id": idvalue,
194			"title": container.Title(),
195			"filename": filename,
196			"filetype": "DBF"})
197			elif isinstance(container, TransientJoinedTable):
198			left, right = container.Dependencies()
199			left_field = container.left_field
200			right_field = container.right_field
201			self.write_element("jointable",
202			{"id": idvalue,
203			"title": container.Title(),
204			"right": self.get_id(right),
205			"rightcolumn": right_field,
206			"left": self.get_id(left),
207	bh	1375	"leftcolumn": left_field,
208			"jointype": container.JoinType()})
209	bh	1268	else:
210			raise ValueError("Can't handle container %r" % container)
211
212
213	bh	268	def write_map(self, map):
214			"""Write the map and its contents.
215
216			By default, write a map element element with the title
217			attribute, call write_projection to write the projection
218			element, call write_layer for each layer contained in the map
219			and finally call write_label_layer to write the label layer.
220			"""
221	jonathan	876	self.open_element('map title="%s"' % self.encode(map.title))
222	bh	268	self.write_projection(map.projection)
223			for layer in map.Layers():
224			self.write_layer(layer)
225			self.write_label_layer(map.LabelLayer())
226	jonathan	366	self.close_element('map')
227	bh	6
228	bh	268	def write_projection(self, projection):
229			"""Write the projection.
230			"""
231			if projection and len(projection.params) > 0:
232	jonathan	876	self.open_element("projection", {"name": projection.GetName()})
233	bh	268	for param in projection.params:
234	jonathan	876	self.write_element('parameter value="%s"' %
235			self.encode(param))
236	jonathan	366	self.close_element("projection")
237	bh	268
238			def write_layer(self, layer, attrs = None):
239			"""Write the layer.
240
241			The optional argument attrs is for additional attributes and, if
242			given, should be a mapping from attribute names to attribute
243			values. The values should not be XML-escaped yet.
244			"""
245	jonathan	391
246	bh	268	if attrs is None:
247			attrs = {}
248	jonathan	429
249	jonathan	1251	attrs["title"] = layer.title
250			attrs["visible"] = ("false", "true")[int(layer.Visible())]
251	bh	268
252	jonathan	932	if isinstance(layer, Layer):
253	bh	1268	attrs["shapestore"] = self.get_id(layer.ShapeStore())
254	jonathan	740
255	jonathan	932	lc = layer.GetClassification()
256	bh	1268	attrs["stroke"] = lc.GetDefaultLineColor().hex()
257	jonathan	932	attrs["stroke_width"] = str(lc.GetDefaultLineWidth())
258	bh	1268	attrs["fill"] = lc.GetDefaultFill().hex()
259	jonathan	740
260	jonathan	932	self.open_element("layer", attrs)
261			self.write_projection(layer.GetProjection())
262			self.write_classification(layer)
263			self.close_element("layer")
264			elif isinstance(layer, RasterLayer):
265	bh	1219	attrs["filename"] = relative_filename(self.dir, layer.filename)
266	jonathan	932	self.open_element("rasterlayer", attrs)
267			self.write_projection(layer.GetProjection())
268			self.close_element("rasterlayer")
269
270	jonathan	366	def write_classification(self, layer, attrs = None):
271	jonathan	1251	"""Write Classification information."""
272
273	jonathan	366	if attrs is None:
274			attrs = {}
275
276	jonathan	414	lc = layer.GetClassification()
277	jonathan	366
278	bh	1452	field = layer.GetClassificationColumn()
279
280	jonathan	366	#
281	jonathan	1251	# there isn't a classification of anything so do nothing
282	jonathan	366	#
283			if field is None: return
284
285			attrs["field"] = field
286	jonathan	1430	attrs["field_type"] = str(layer.GetFieldType(field))
287	jonathan	366	self.open_element("classification", attrs)
288
289	jonathan	1251	for g in lc:
290			if isinstance(g, ClassGroupDefault):
291			open_el = 'clnull label="%s"' % self.encode(g.GetLabel())
292			close_el = 'clnull'
293	bh	1417	elif isinstance(g, ClassGroupSingleton):
294	jonathan	1430	if layer.GetFieldType(field) == FIELDTYPE_STRING:
295	bh	1417	value = self.encode(g.GetValue())
296			else:
297			value = str(g.GetValue())
298	jonathan	1251	open_el = 'clpoint label="%s" value="%s"' \
299	bh	1417	% (self.encode(g.GetLabel()), value)
300	jonathan	1251	close_el = 'clpoint'
301			elif isinstance(g, ClassGroupRange):
302			open_el = 'clrange label="%s" range="%s"' \
303			% (self.encode(g.GetLabel()), str(g.GetRange()))
304			close_el = 'clrange'
305			else:
306			assert False, _("Unsupported group type in classification")
307			continue
308	jonathan	429
309	jonathan	1251	data = g.GetProperties()
310			dict = {'stroke' : data.GetLineColor().hex(),
311			'stroke_width': str(data.GetLineWidth()),
312			'fill' : data.GetFill().hex()}
313	jonathan	429
314	jonathan	1251	self.open_element(open_el)
315			self.write_element("cldata", dict)
316			self.close_element(close_el)
317	jonathan	366
318			self.close_element("classification")
319
320	bh	268	def write_label_layer(self, layer):
321			"""Write the label layer.
322			"""
323			labels = layer.Labels()
324	bh	6	if labels:
325	jonathan	366	self.open_element('labellayer')
326	bh	6	for label in labels:
327	jonathan	366	self.write_element(('label x="%g" y="%g" text="%s"'
328			' halign="%s" valign="%s"')
329	jonathan	876	% (label.x, label.y,
330			self.encode(label.text),
331			label.halign,
332	bh	268	label.valign))
333	jonathan	366	self.close_element('labellayer')
334	bh	6
335	bh	268
336
337			def save_session(session, file, saver_class = None):
338			"""Save the session session to a file.
339
340			The file argument may either be a filename or an open file object.
341
342			The optional argument saver_class is the class to use to serialize
343			the session. By default or if it's None, the saver class will be
344	jonathan	697	SessionSaver.
345	bh	268
346			If writing the session is successful call the session's
347			UnsetModified method
348			"""
349			if saver_class is None:
350	jonathan	697	saver_class = SessionSaver
351	bh	268	saver = saver_class(session)
352			saver.write(file)
353
354	bh	6	# after a successful save consider the session unmodified.
355			session.UnsetModified()
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