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 Thuban for details. |
9 |
|
10 |
""" |
11 |
Functions to save a session to a file |
12 |
""" |
13 |
|
14 |
__version__ = "$Revision$" |
15 |
|
16 |
# fix for people using python2.1 |
17 |
from __future__ import nested_scopes |
18 |
|
19 |
import os |
20 |
import string |
21 |
|
22 |
import Thuban.Lib.fileutil |
23 |
|
24 |
from Thuban.Model.color import Color |
25 |
|
26 |
from Thuban.Model.classification import \ |
27 |
ClassGroupDefault, ClassGroupSingleton, ClassGroupRange, ClassGroupMap |
28 |
|
29 |
# |
30 |
# one level of indention |
31 |
# |
32 |
TAB = " " |
33 |
|
34 |
def relative_filename(dir, filename): |
35 |
"""Return a filename relative to dir for the absolute file name absname. |
36 |
|
37 |
This is almost the same as the function in fileutil, except that dir |
38 |
can be an empty string in which case filename will be returned |
39 |
unchanged. |
40 |
""" |
41 |
if dir: |
42 |
return Thuban.Lib.fileutil.relative_filename(dir, filename) |
43 |
else: |
44 |
return filename |
45 |
|
46 |
def escape(data): |
47 |
"""Escape &, \", ', <, and > in a string of data. |
48 |
""" |
49 |
data = string.replace(data, "&", "&") |
50 |
data = string.replace(data, "<", "<") |
51 |
data = string.replace(data, ">", ">") |
52 |
data = string.replace(data, '"', """) |
53 |
data = string.replace(data, "'", "'") |
54 |
return data |
55 |
|
56 |
class XMLWriter: |
57 |
"""Abstract XMLWriter. |
58 |
|
59 |
Should be overridden to provide specific object saving functionality. |
60 |
""" |
61 |
|
62 |
def __init__(self): |
63 |
self.filename = None |
64 |
pass |
65 |
|
66 |
def write(self, file_or_filename): |
67 |
"""Write the session to a file. |
68 |
|
69 |
The argument may be either a file object or a filename. If it's |
70 |
a filename, the file will be opened for writing. Files of |
71 |
shapefiles will be stored as filenames relative to the directory |
72 |
the file is stored in (as given by os.path.dirname(filename)) if |
73 |
they have a common parent directory other than the root |
74 |
directory. |
75 |
|
76 |
If the argument is a file object (which is determined by the |
77 |
presence of a write method) all filenames will be absolute |
78 |
filenames. |
79 |
""" |
80 |
|
81 |
# keep track of how many levels of indentation to write |
82 |
self.indent_level = 0 |
83 |
# track whether an element is currently open. see open_element(). |
84 |
self.element_open = 0 |
85 |
|
86 |
if hasattr(file_or_filename, "write"): |
87 |
# it's a file object |
88 |
self.file = file_or_filename |
89 |
self.dir = "" |
90 |
else: |
91 |
self.filename = file_or_filename |
92 |
self.dir = os.path.dirname(self.filename) |
93 |
self.file = open(self.filename, 'w') |
94 |
|
95 |
def close(self): |
96 |
assert self.indent_level == 0 |
97 |
if self.filename is not None: |
98 |
self.file.close() |
99 |
|
100 |
def write_header(self, doctype, system): |
101 |
"""Write the XML header""" |
102 |
self.file.write('<?xml version="1.0" encoding="UTF-8"?>\n') |
103 |
self.file.write('<!DOCTYPE %s SYSTEM "%s">\n' % (doctype, system)) |
104 |
|
105 |
def open_element(self, element, attrs = {}): |
106 |
|
107 |
# |
108 |
# we note when an element is opened so that if two open_element() |
109 |
# calls are made successively we can end the currently open |
110 |
# tag and will later write a proper close tag. otherwise, |
111 |
# if a close_element() call is made directly after an open_element() |
112 |
# call we will close the tag with a /> |
113 |
# |
114 |
if self.element_open == 1: |
115 |
self.file.write(">\n") |
116 |
|
117 |
self.element_open = 1 |
118 |
|
119 |
# Helper function to write an element open tag with attributes |
120 |
self.file.write("%s<%s" % (TAB*self.indent_level, element)) |
121 |
self.__write_attribs(attrs) |
122 |
|
123 |
self.indent_level += 1 |
124 |
|
125 |
def close_element(self, element): |
126 |
self.indent_level -= 1 |
127 |
assert self.indent_level >= 0 |
128 |
|
129 |
# see open_element() for an explanation |
130 |
if self.element_open == 1: |
131 |
self.element_open = 0 |
132 |
self.file.write("/>\n") |
133 |
else: |
134 |
self.file.write("%s</%s>\n" % (TAB*self.indent_level, element)) |
135 |
|
136 |
def write_element(self, element, attrs = {}): |
137 |
"""write an element that won't need a closing tag""" |
138 |
self.open_element(element, attrs) |
139 |
self.close_element(element) |
140 |
|
141 |
def __write_attribs(self, attrs): |
142 |
for name, value in attrs.items(): |
143 |
self.file.write(' %s="%s"' % (self.encode(name), |
144 |
self.encode(value))) |
145 |
|
146 |
def encode(self, str): |
147 |
"""Assume that str is in Latin1, escape it, and encode it in UTF-8. |
148 |
|
149 |
If str is None, return None |
150 |
""" |
151 |
|
152 |
if str is not None: |
153 |
return unicode(escape(str),'latin1').encode("utf8") |
154 |
#return escape(str).encode("utf8") |
155 |
else: |
156 |
return None |
157 |
|
158 |
class SessionSaver(XMLWriter): |
159 |
|
160 |
"""Class to serialize a session into an XML file. |
161 |
|
162 |
Applications built on top of Thuban may derive from this class and |
163 |
override or extend the methods to save additional information. This |
164 |
additional information should take the form of additional attributes |
165 |
or elements whose names are prefixed with a namespace. To define a |
166 |
namespace derived classes should extend the write_session method to |
167 |
pass the namespaces to the default implementation. |
168 |
""" |
169 |
|
170 |
|
171 |
def __init__(self, session): |
172 |
XMLWriter.__init__(self) |
173 |
self.session = session |
174 |
|
175 |
def write(self, file_or_filename): |
176 |
XMLWriter.write(self, file_or_filename) |
177 |
|
178 |
self.write_header("session", "thuban.dtd") |
179 |
self.write_session(self.session) |
180 |
self.close() |
181 |
|
182 |
def write_session(self, session, attrs = None, namespaces = ()): |
183 |
"""Write the session and its contents |
184 |
|
185 |
By default, write a session element with the title attribute and |
186 |
call write_map for each map contained in the session. |
187 |
|
188 |
The optional argument attrs is for additional attributes and, if |
189 |
given, should be a mapping from attribute names to attribute |
190 |
values. The values should not be XML-escaped yet. |
191 |
|
192 |
The optional argument namespaces, if given, should be a sequence |
193 |
of (name, URI) pairs. The namespaces are written as namespace |
194 |
attributes into the session element. This is mainly useful for |
195 |
derived classes that need to store additional information in a |
196 |
thuban session file. |
197 |
""" |
198 |
if attrs is None: |
199 |
attrs = {} |
200 |
attrs["title"] = session.title |
201 |
for name, uri in namespaces: |
202 |
attrs["xmlns:" + name] = uri |
203 |
self.open_element("session", attrs) |
204 |
for map in session.Maps(): |
205 |
self.write_map(map) |
206 |
self.close_element("session") |
207 |
|
208 |
def write_map(self, map): |
209 |
"""Write the map and its contents. |
210 |
|
211 |
By default, write a map element element with the title |
212 |
attribute, call write_projection to write the projection |
213 |
element, call write_layer for each layer contained in the map |
214 |
and finally call write_label_layer to write the label layer. |
215 |
""" |
216 |
self.open_element('map title="%s"' % self.encode(map.title)) |
217 |
self.write_projection(map.projection) |
218 |
for layer in map.Layers(): |
219 |
self.write_layer(layer) |
220 |
self.write_label_layer(map.LabelLayer()) |
221 |
self.close_element('map') |
222 |
|
223 |
def write_projection(self, projection): |
224 |
"""Write the projection. |
225 |
""" |
226 |
if projection and len(projection.params) > 0: |
227 |
self.open_element("projection", {"name": projection.GetName()}) |
228 |
for param in projection.params: |
229 |
self.write_element('parameter value="%s"' % |
230 |
self.encode(param)) |
231 |
self.close_element("projection") |
232 |
|
233 |
def write_layer(self, layer, attrs = None): |
234 |
"""Write the layer. |
235 |
|
236 |
The optional argument attrs is for additional attributes and, if |
237 |
given, should be a mapping from attribute names to attribute |
238 |
values. The values should not be XML-escaped yet. |
239 |
""" |
240 |
lc = layer.GetClassification() |
241 |
|
242 |
if attrs is None: |
243 |
attrs = {} |
244 |
|
245 |
attrs["title"] = layer.title |
246 |
attrs["filename"] = relative_filename(self.dir, layer.filename) |
247 |
attrs["stroke"] = lc.GetDefaultLineColor().hex() |
248 |
attrs["stroke_width"] = str(lc.GetDefaultLineWidth()) |
249 |
attrs["fill"] = lc.GetDefaultFill().hex() |
250 |
attrs["visible"] = ("false", "true")[int(layer.Visible())] |
251 |
|
252 |
self.open_element("layer", attrs) |
253 |
|
254 |
proj = layer.GetProjection() |
255 |
if proj is not None: |
256 |
self.write_projection(proj) |
257 |
|
258 |
self.write_classification(layer) |
259 |
|
260 |
self.close_element("layer") |
261 |
|
262 |
def write_classification(self, layer, attrs = None): |
263 |
if attrs is None: |
264 |
attrs = {} |
265 |
|
266 |
lc = layer.GetClassification() |
267 |
|
268 |
field = lc.GetField() |
269 |
|
270 |
# |
271 |
# there isn't a classification of anything |
272 |
# so don't do anything |
273 |
# |
274 |
if field is None: return |
275 |
|
276 |
attrs["field"] = field |
277 |
attrs["field_type"] = str(lc.GetFieldType()) |
278 |
self.open_element("classification", attrs) |
279 |
|
280 |
|
281 |
types = [[lambda p: 'clnull label="%s"' % self.encode(p.GetLabel()), |
282 |
lambda p: 'clnull'], |
283 |
[lambda p: 'clpoint label="%s" value="%s"' % |
284 |
(self.encode(p.GetLabel()), str(p.GetValue())), |
285 |
lambda p: 'clpoint'], |
286 |
[lambda p: 'clrange label="%s" range="%s"' % |
287 |
(self.encode(p.GetLabel()), |
288 |
str(p.GetRange())), |
289 |
lambda p: 'clrange']] |
290 |
|
291 |
def write_class_group(group): |
292 |
type = -1 |
293 |
if isinstance(group, ClassGroupDefault): type = 0 |
294 |
elif isinstance(group, ClassGroupSingleton): type = 1 |
295 |
elif isinstance(group, ClassGroupRange): type = 2 |
296 |
elif isinstance(group, ClassGroupMap): type = 3 |
297 |
assert type >= 0 |
298 |
|
299 |
if type <= 2: |
300 |
data = group.GetProperties() |
301 |
dict = {'stroke' : data.GetLineColor().hex(), |
302 |
'stroke_width': str(data.GetLineWidth()), |
303 |
'fill' : data.GetFill().hex()} |
304 |
|
305 |
self.open_element(types[type][0](group)) |
306 |
self.write_element("cldata", dict) |
307 |
self.close_element(types[type][1](group)) |
308 |
else: pass # XXX: we need to handle maps |
309 |
|
310 |
for i in lc: |
311 |
write_class_group(i) |
312 |
|
313 |
self.close_element("classification") |
314 |
|
315 |
def write_label_layer(self, layer): |
316 |
"""Write the label layer. |
317 |
""" |
318 |
labels = layer.Labels() |
319 |
if labels: |
320 |
self.open_element('labellayer') |
321 |
for label in labels: |
322 |
self.write_element(('label x="%g" y="%g" text="%s"' |
323 |
' halign="%s" valign="%s"') |
324 |
% (label.x, label.y, |
325 |
self.encode(label.text), |
326 |
label.halign, |
327 |
label.valign)) |
328 |
self.close_element('labellayer') |
329 |
|
330 |
|
331 |
|
332 |
def save_session(session, file, saver_class = None): |
333 |
"""Save the session session to a file. |
334 |
|
335 |
The file argument may either be a filename or an open file object. |
336 |
|
337 |
The optional argument saver_class is the class to use to serialize |
338 |
the session. By default or if it's None, the saver class will be |
339 |
SessionSaver. |
340 |
|
341 |
If writing the session is successful call the session's |
342 |
UnsetModified method |
343 |
""" |
344 |
if saver_class is None: |
345 |
saver_class = SessionSaver |
346 |
saver = saver_class(session) |
347 |
saver.write(file) |
348 |
|
349 |
# after a successful save consider the session unmodified. |
350 |
session.UnsetModified() |