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.color import Color 
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
from Thuban.Model.data import DerivedShapeStore, ShapefileStore

from Thuban.Model.xmlwriter import XMLWriter

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-0.8.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-0.8.dtd"
        self.open_element("session", attrs)
        self.write_data_containers(session)
        for map in session.Maps():
            self.write_map(map)
        self.close_element("session")

    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, 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})
            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 = lc.GetField()
 
        #
        # there isn't a classification of anything so do nothing
        #
        if field is None: return

        attrs["field"] = field
        attrs["field_type"] = str(lc.GetFieldType())
        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): 
                open_el  = 'clpoint label="%s" value="%s"' \
                           % (self.encode(g.GetLabel()), str(g.GetValue()))
                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.color import Color
21			from Thuban.Model.layer import Layer, RasterLayer
22
23	jonathan	876	from Thuban.Model.classification import \
24			ClassGroupDefault, ClassGroupSingleton, ClassGroupRange, ClassGroupMap
25	bh	1268	from Thuban.Model.transientdb import AutoTransientTable, TransientJoinedTable
26			from Thuban.Model.table import DBFTable
27			from Thuban.Model.data import DerivedShapeStore, ShapefileStore
28	jonathan	429
29	jonathan	1160	from Thuban.Model.xmlwriter import XMLWriter
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	1268	self.write_header("session", "thuban-0.8.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			"http://thuban.intevation.org/dtds/thuban-0.8.dtd"
137	jonathan	366	self.open_element("session", attrs)
138	bh	1268	self.write_data_containers(session)
139	bh	268	for map in session.Maps():
140			self.write_map(map)
141	jonathan	366	self.close_element("session")
142	bh	268
143	bh	1268	def write_data_containers(self, session):
144			containers = sort_data_stores(session.DataContainers())
145			for container in containers:
146			if isinstance(container, AutoTransientTable):
147			# AutoTransientTable instances are invisible in the
148			# thuban files. They're only used internally. To make
149			# sure that containers depending on AutoTransientTable
150			# instances refer to the right real containers we give
151			# the AutoTransientTable instances the same id as the
152			# source they depend on.
153			self.define_id(container,
154			self.get_id(container.Dependencies()[0]))
155			continue
156
157			idvalue = self.define_id(container)
158			if isinstance(container, ShapefileStore):
159			self.define_id(container.Table(), idvalue)
160			filename = relative_filename(self.dir, container.FileName())
161			self.write_element("fileshapesource",
162			{"id": idvalue, "filename": filename,
163			"filetype": "shapefile"})
164			elif isinstance(container, DerivedShapeStore):
165			shapesource, table = container.Dependencies()
166			self.write_element("derivedshapesource",
167			{"id": idvalue,
168			"shapesource": self.get_id(shapesource),
169			"table": self.get_id(table)})
170			elif isinstance(container, DBFTable):
171			filename = relative_filename(self.dir, container.FileName())
172			self.write_element("filetable",
173			{"id": idvalue,
174			"title": container.Title(),
175			"filename": filename,
176			"filetype": "DBF"})
177			elif isinstance(container, TransientJoinedTable):
178			left, right = container.Dependencies()
179			left_field = container.left_field
180			right_field = container.right_field
181			self.write_element("jointable",
182			{"id": idvalue,
183			"title": container.Title(),
184			"right": self.get_id(right),
185			"rightcolumn": right_field,
186			"left": self.get_id(left),
187			"leftcolumn": left_field})
188			else:
189			raise ValueError("Can't handle container %r" % container)
190
191
192	bh	268	def write_map(self, map):
193			"""Write the map and its contents.
194
195			By default, write a map element element with the title
196			attribute, call write_projection to write the projection
197			element, call write_layer for each layer contained in the map
198			and finally call write_label_layer to write the label layer.
199			"""
200	jonathan	876	self.open_element('map title="%s"' % self.encode(map.title))
201	bh	268	self.write_projection(map.projection)
202			for layer in map.Layers():
203			self.write_layer(layer)
204			self.write_label_layer(map.LabelLayer())
205	jonathan	366	self.close_element('map')
206	bh	6
207	bh	268	def write_projection(self, projection):
208			"""Write the projection.
209			"""
210			if projection and len(projection.params) > 0:
211	jonathan	876	self.open_element("projection", {"name": projection.GetName()})
212	bh	268	for param in projection.params:
213	jonathan	876	self.write_element('parameter value="%s"' %
214			self.encode(param))
215	jonathan	366	self.close_element("projection")
216	bh	268
217			def write_layer(self, layer, attrs = None):
218			"""Write the layer.
219
220			The optional argument attrs is for additional attributes and, if
221			given, should be a mapping from attribute names to attribute
222			values. The values should not be XML-escaped yet.
223			"""
224	jonathan	391
225	bh	268	if attrs is None:
226			attrs = {}
227	jonathan	429
228	jonathan	1251	attrs["title"] = layer.title
229			attrs["visible"] = ("false", "true")[int(layer.Visible())]
230	bh	268
231	jonathan	932	if isinstance(layer, Layer):
232	bh	1268	attrs["shapestore"] = self.get_id(layer.ShapeStore())
233	jonathan	740
234	jonathan	932	lc = layer.GetClassification()
235	bh	1268	attrs["stroke"] = lc.GetDefaultLineColor().hex()
236	jonathan	932	attrs["stroke_width"] = str(lc.GetDefaultLineWidth())
237	bh	1268	attrs["fill"] = lc.GetDefaultFill().hex()
238	jonathan	740
239	jonathan	932	self.open_element("layer", attrs)
240			self.write_projection(layer.GetProjection())
241			self.write_classification(layer)
242			self.close_element("layer")
243			elif isinstance(layer, RasterLayer):
244	bh	1219	attrs["filename"] = relative_filename(self.dir, layer.filename)
245	jonathan	932	self.open_element("rasterlayer", attrs)
246			self.write_projection(layer.GetProjection())
247			self.close_element("rasterlayer")
248
249	jonathan	366	def write_classification(self, layer, attrs = None):
250	jonathan	1251	"""Write Classification information."""
251
252	jonathan	366	if attrs is None:
253			attrs = {}
254
255	jonathan	414	lc = layer.GetClassification()
256	jonathan	366
257	jonathan	429	field = lc.GetField()
258	jonathan	366
259			#
260	jonathan	1251	# there isn't a classification of anything so do nothing
261	jonathan	366	#
262			if field is None: return
263
264			attrs["field"] = field
265	jonathan	466	attrs["field_type"] = str(lc.GetFieldType())
266	jonathan	366	self.open_element("classification", attrs)
267
268	jonathan	1251	for g in lc:
269			if isinstance(g, ClassGroupDefault):
270			open_el = 'clnull label="%s"' % self.encode(g.GetLabel())
271			close_el = 'clnull'
272			elif isinstance(g, ClassGroupSingleton):
273			open_el = 'clpoint label="%s" value="%s"' \
274			% (self.encode(g.GetLabel()), str(g.GetValue()))
275			close_el = 'clpoint'
276			elif isinstance(g, ClassGroupRange):
277			open_el = 'clrange label="%s" range="%s"' \
278			% (self.encode(g.GetLabel()), str(g.GetRange()))
279			close_el = 'clrange'
280			else:
281			assert False, _("Unsupported group type in classification")
282			continue
283	jonathan	429
284	jonathan	1251	data = g.GetProperties()
285			dict = {'stroke' : data.GetLineColor().hex(),
286			'stroke_width': str(data.GetLineWidth()),
287			'fill' : data.GetFill().hex()}
288	jonathan	429
289	jonathan	1251	self.open_element(open_el)
290			self.write_element("cldata", dict)
291			self.close_element(close_el)
292	jonathan	366
293			self.close_element("classification")
294
295	bh	268	def write_label_layer(self, layer):
296			"""Write the label layer.
297			"""
298			labels = layer.Labels()
299	bh	6	if labels:
300	jonathan	366	self.open_element('labellayer')
301	bh	6	for label in labels:
302	jonathan	366	self.write_element(('label x="%g" y="%g" text="%s"'
303			' halign="%s" valign="%s"')
304	jonathan	876	% (label.x, label.y,
305			self.encode(label.text),
306			label.halign,
307	bh	268	label.valign))
308	jonathan	366	self.close_element('labellayer')
309	bh	6
310	bh	268
311
312			def save_session(session, file, saver_class = None):
313			"""Save the session session to a file.
314
315			The file argument may either be a filename or an open file object.
316
317			The optional argument saver_class is the class to use to serialize
318			the session. By default or if it's None, the saver class will be
319	jonathan	697	SessionSaver.
320	bh	268
321			If writing the session is successful call the session's
322			UnsetModified method
323			"""
324			if saver_class is None:
325	jonathan	697	saver_class = SessionSaver
326	bh	268	saver = saver_class(session)
327			saver.write(file)
328
329	bh	6	# after a successful save consider the session unmodified.
330			session.UnsetModified()
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