/[thuban]/branches/WIP-pyshapelib-bramz/Thuban/Model/save.py
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revision 74 by bh, Mon Feb 4 19:22:08 2002 UTC revision 754 by jonathan, Fri Apr 25 14:48:15 2003 UTC
# Line 1  Line 1 
1  # Copyright (c) 2001, 2002 by Intevation GmbH  # Copyright (c) 2001, 2002, 2003 by Intevation GmbH
2  # Authors:  # Authors:
3  # Jan-Oliver Wagner <[email protected]>  # Jan-Oliver Wagner <[email protected]>
4  # Bernhard Herzog <[email protected]>  # Bernhard Herzog <[email protected]>
5    # Jonathan Coles <[email protected]>
6  #  #
7  # This program is free software under the GPL (>=v2)  # This program is free software under the GPL (>=v2)
8  # Read the file COPYING coming with Thuban for details.  # Read the file COPYING coming with Thuban for details.
# Line 12  Functions to save a session to a file Line 13  Functions to save a session to a file
13    
14  __version__ = "$Revision$"  __version__ = "$Revision$"
15    
16    # fix for people using python2.1
17    from __future__ import nested_scopes
18    
19  import os  import os
20  import string  import string
21    
22  from Thuban.Lib.fileutil import relative_filename  import Thuban.Lib.fileutil
23    
24    from Thuban.Model.color import Color
25    
26    from Thuban.Model.classification import *
27    
28    #
29    # one level of indention
30    #
31    TAB = "    "
32    
33    def relative_filename(dir, filename):
34        """Return a filename relative to dir for the absolute file name absname.
35    
36        This is almost the same as the function in fileutil, except that dir
37        can be an empty string in which case filename will be returned
38        unchanged.
39        """
40        if dir:
41            return Thuban.Lib.fileutil.relative_filename(dir, filename)
42        else:
43            return filename
44    
45  def escape(data):  def escape(data):
46      """Escape &, \", ', <, and > in a string of data.      """Escape &, \", ', <, and > in a string of data.
# Line 27  def escape(data): Line 52  def escape(data):
52      data = string.replace(data, "'", "&apos;")      data = string.replace(data, "'", "&apos;")
53      return data      return data
54    
55  def save_session(session, filename):  class XMLWriter:
56      """Save the session session to the file given by filename"""      """Abstract XMLWriter.
57      dir = os.path.dirname(filename)  
58      file = open(filename, 'w')      Should be overridden to provide specific object saving functionality.
59      write = file.write      """
60      write('<?xml version="1.0" encoding="UTF-8"?>\n')  
61      write('<!DOCTYPE session SYSTEM "thuban.dtd">\n')      def __init__(self):
62      write('<session title="%s">\n' % escape(session.title))          self.filename = None
63      for map in session.Maps():          pass
64          write('\t<map title="%s">\n' % escape(map.title))  
65          if map.projection and len(map.projection.params) > 0:      def write(self, file_or_filename):
66              write('\t\t<projection>\n')          """Write the session to a file.
67              for param in map.projection.params:  
68                  write('\t\t\t<parameter value="%s"/>\n' % escape(param))          The argument may be either a file object or a filename. If it's
69              write('\t\t</projection>\n')          a filename, the file will be opened for writing. Files of
70            shapefiles will be stored as filenames relative to the directory
71            the file is stored in (as given by os.path.dirname(filename)) if
72            they have a common parent directory other than the root
73            directory.
74    
75            If the argument is a file object (which is determined by the
76            presence of a write method) all filenames will be absolute
77            filenames.
78            """
79    
80            # keep track of how many levels of indentation to write
81            self.indent_level = 0
82            # track whether an element is currently open. see open_element().
83            self.element_open = 0
84    
85            if hasattr(file_or_filename, "write"):
86                # it's a file object
87                self.file = file_or_filename
88                self.dir = ""
89            else:
90                self.filename = file_or_filename
91                self.dir = os.path.dirname(self.filename)
92                self.file = open(self.filename, 'w')
93    
94        def close(self):
95            assert self.indent_level == 0
96            if self.filename is not None:
97                self.file.close()
98    
99        def write_header(self, doctype, system):
100            """Write the XML header"""
101            self.file.write('<?xml version="1.0" encoding="UTF-8"?>\n')
102            self.file.write('<!DOCTYPE %s SYSTEM "%s">\n' % (doctype, system))
103    
104        def open_element(self, element, attrs = {}):
105    
106            #
107            # we note when an element is opened so that if two open_element()
108            # calls are made successively we can end the currently open
109            # tag and will later write a proper close tag. otherwise,
110            # if a close_element() call is made directly after an open_element()
111            # call we will close the tag with a />
112            #
113            if self.element_open == 1:
114                self.file.write(">\n")
115    
116            self.element_open = 1
117    
118            # Helper function to write an element open tag with attributes
119            self.file.write("%s<%s" % (TAB*self.indent_level, element))
120            self.__write_attribs(attrs)
121    
122            self.indent_level += 1
123    
124        def close_element(self, element):
125            self.indent_level -= 1
126            assert self.indent_level >= 0
127    
128            # see open_element() for an explanation
129            if self.element_open == 1:
130                self.element_open = 0
131                self.file.write("/>\n")
132            else:
133                self.file.write("%s</%s>\n" % (TAB*self.indent_level, element))
134    
135        def write_element(self, element, attrs = {}):
136            """write an element that won't need a closing tag"""
137            self.open_element(element, attrs)
138            self.close_element(element)
139    
140        def __write_attribs(self, attrs):
141            for name, value in attrs.items():
142                self.file.write(' %s="%s"' % (escape(name), escape(value)))
143        
144    class SessionSaver(XMLWriter):
145    
146        """Class to serialize a session into an XML file.
147    
148        Applications built on top of Thuban may derive from this class and
149        override or extend the methods to save additional information. This
150        additional information should take the form of additional attributes
151        or elements whose names are prefixed with a namespace. To define a
152        namespace derived classes should extend the write_session method to
153        pass the namespaces to the default implementation.
154        """
155    
156    
157        def __init__(self, session):
158            XMLWriter.__init__(self)
159            self.session = session
160    
161        def write(self, file_or_filename):
162            XMLWriter.write(self, file_or_filename)
163    
164            self.write_header("session", "thuban.dtd")
165            self.write_session(self.session)
166            self.close()
167    
168        def write_session(self, session, attrs = None, namespaces = ()):
169            """Write the session and its contents
170    
171            By default, write a session element with the title attribute and
172            call write_map for each map contained in the session.
173    
174            The optional argument attrs is for additional attributes and, if
175            given, should be a mapping from attribute names to attribute
176            values. The values should not be XML-escaped yet.
177    
178            The optional argument namespaces, if given, should be a sequence
179            of (name, URI) pairs. The namespaces are written as namespace
180            attributes into the session element. This is mainly useful for
181            derived classes that need to store additional information in a
182            thuban session file.
183            """
184            if attrs is None:
185                attrs = {}
186            attrs["title"] = session.title
187            for name, uri in namespaces:
188                attrs["xmlns:" + name] = uri
189            self.open_element("session", attrs)
190            for map in session.Maps():
191                self.write_map(map)
192            self.close_element("session")
193    
194        def write_map(self, map):
195            """Write the map and its contents.
196    
197            By default, write a map element element with the title
198            attribute, call write_projection to write the projection
199            element, call write_layer for each layer contained in the map
200            and finally call write_label_layer to write the label layer.
201            """
202            self.open_element('map title="%s"' % escape(map.title))
203            self.write_projection(map.projection)
204          for layer in map.Layers():          for layer in map.Layers():
205              fill = layer.fill              self.write_layer(layer)
206              if fill is None:          self.write_label_layer(map.LabelLayer())
207                  fill = "None"          self.close_element('map')
208              else:  
209                  fill = fill.hex()      def write_projection(self, projection):
210              stroke = layer.stroke          """Write the projection.
211              if stroke is None:          """
212                  stroke = "None"          if projection and len(projection.params) > 0:
213              else:              self.open_element("projection",
214                  stroke = stroke.hex()                                {"name": escape(projection.GetName())})
215              write(('\t\t<layer title="%s" filename="%s"'              for param in projection.params:
216                     ' fill="%s" stroke="%s" stroke_width="%d"/>\n') %                  self.write_element('parameter value="%s"' % escape(param))
217                    (escape(layer.title),              self.close_element("projection")
218                     escape(relative_filename(dir, layer.filename)),  
219                     fill, stroke, layer.stroke_width))      def write_layer(self, layer, attrs = None):
220          labels = map.LabelLayer().Labels()          """Write the layer.
221    
222            The optional argument attrs is for additional attributes and, if
223            given, should be a mapping from attribute names to attribute
224            values. The values should not be XML-escaped yet.
225            """
226            lc = layer.GetClassification()
227    
228            if attrs is None:
229                attrs = {}
230    
231            attrs["title"]        = layer.title
232            attrs["filename"]     = relative_filename(self.dir, layer.filename)
233            attrs["stroke"]       = lc.GetDefaultLineColor().hex()
234            attrs["stroke_width"] = str(lc.GetDefaultLineWidth())
235            attrs["fill"]         = lc.GetDefaultFill().hex()
236    
237            self.open_element("layer", attrs)
238    
239            proj = layer.GetProjection()
240            if proj is not None:
241                self.write_projection(proj)
242    
243            self.write_classification(layer)
244    
245            self.close_element("layer")
246    
247        def write_classification(self, layer, attrs = None):
248            if attrs is None:
249                attrs = {}
250    
251            lc = layer.GetClassification()
252    
253            field = lc.GetField()
254    
255            #
256            # there isn't a classification of anything
257            # so don't do anything
258            #
259            if field is None: return
260    
261            attrs["field"] = field
262            attrs["field_type"] = str(lc.GetFieldType())
263            self.open_element("classification", attrs)
264    
265    
266            types = [[lambda p: 'clnull label="%s"' % p.GetLabel(),
267                      lambda p: 'clnull'],
268                     [lambda p: 'clpoint label="%s" value="%s"' %
269                                 (p.GetLabel(), str(p.GetValue())),
270                      lambda p: 'clpoint'],
271                     [lambda p: 'clrange label="%s" min="%s" max="%s"' %
272                                 (p.GetLabel(),
273                                  str(p.GetMin()), (str(p.GetMax()))),
274                      lambda p: 'clrange']]
275    
276            def write_class_group(group):
277                type = -1
278                if isinstance(group, ClassGroupDefault): type = 0
279                elif isinstance(group, ClassGroupSingleton): type = 1
280                elif isinstance(group, ClassGroupRange): type = 2
281                elif isinstance(group, ClassGroupMap):   type = 3
282                assert type >= 0
283    
284                if type <= 2:
285                    data = group.GetProperties()
286                    dict = {'stroke'      : data.GetLineColor().hex(),
287                            'stroke_width': str(data.GetLineWidth()),
288                            'fill'        : data.GetFill().hex()}
289    
290                    self.open_element(types[type][0](group))
291                    self.write_element("cldata", dict)
292                    self.close_element(types[type][1](group))
293                else: pass # XXX: we need to handle maps
294    
295            for i in lc:
296                write_class_group(i)
297    
298            self.close_element("classification")
299    
300        def write_label_layer(self, layer):
301            """Write the label layer.
302            """
303            labels = layer.Labels()
304          if labels:          if labels:
305              write('\t\t<labellayer>\n')              self.open_element('labellayer')
306              for label in labels:              for label in labels:
307                  write(('\t\t\t<label x="%g" y="%g" text="%s"'                  self.write_element(('label x="%g" y="%g" text="%s"'
308                         ' halign="%s" valign="%s"/>\n')                                      ' halign="%s" valign="%s"')
309                        % (label.x, label.y, label.text, label.halign,                                  % (label.x, label.y, label.text, label.halign,
310                           label.valign))                                     label.valign))
311              write('\t\t</labellayer>\n')              self.close_element('labellayer')
312          write('\t</map>\n')  
313      write('</session>\n')  
314    
315    def save_session(session, file, saver_class = None):
316        """Save the session session to a file.
317    
318        The file argument may either be a filename or an open file object.
319    
320        The optional argument saver_class is the class to use to serialize
321        the session. By default or if it's None, the saver class will be
322        SessionSaver.
323    
324        If writing the session is successful call the session's
325        UnsetModified method
326        """
327        if saver_class is None:
328            saver_class = SessionSaver
329        saver = saver_class(session)
330        saver.write(file)
331    
332      # after a successful save consider the session unmodified.      # after a successful save consider the session unmodified.
333      session.UnsetModified()      session.UnsetModified()

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