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# Copyright (c) 2001, 2002, 2003 by Intevation GmbH |
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# Authors: |
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# Jan-Oliver Wagner <[email protected]> |
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# Bernhard Herzog <[email protected]> |
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# Jonathan Coles <[email protected]> |
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# |
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# This program is free software under the GPL (>=v2) |
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# Read the file COPYING coming with Thuban for details. |
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|
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""" |
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Functions to save a session to a file |
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""" |
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|
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__version__ = "$Revision$" |
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|
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# fix for people using python2.1 |
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from __future__ import nested_scopes |
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|
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import os |
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import string |
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|
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import Thuban.Lib.fileutil |
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|
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from Thuban.Model.color import Color |
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|
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from Thuban.Model.classification import * |
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|
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# |
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# one level of indention |
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# |
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TAB = " " |
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|
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def relative_filename(dir, filename): |
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"""Return a filename relative to dir for the absolute file name absname. |
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|
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This is almost the same as the function in fileutil, except that dir |
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can be an empty string in which case filename will be returned |
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unchanged. |
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""" |
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if dir: |
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return Thuban.Lib.fileutil.relative_filename(dir, filename) |
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else: |
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return filename |
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|
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def escape(data): |
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"""Escape &, \", ', <, and > in a string of data. |
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""" |
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data = string.replace(data, "&", "&") |
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data = string.replace(data, "<", "<") |
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data = string.replace(data, ">", ">") |
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data = string.replace(data, '"', """) |
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data = string.replace(data, "'", "'") |
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return data |
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|
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class XMLWriter: |
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"""Abstract XMLWriter. |
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|
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Should be overridden to provide specific object saving functionality. |
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""" |
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|
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def __init__(self): |
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self.filename = None |
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pass |
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|
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def write(self, file_or_filename): |
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"""Write the session to a file. |
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|
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The argument may be either a file object or a filename. If it's |
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a filename, the file will be opened for writing. Files of |
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shapefiles will be stored as filenames relative to the directory |
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the file is stored in (as given by os.path.dirname(filename)) if |
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they have a common parent directory other than the root |
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directory. |
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|
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If the argument is a file object (which is determined by the |
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presence of a write method) all filenames will be absolute |
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filenames. |
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""" |
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|
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# keep track of how many levels of indentation to write |
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self.indent_level = 0 |
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# track whether an element is currently open. see open_element(). |
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self.element_open = 0 |
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|
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if hasattr(file_or_filename, "write"): |
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# it's a file object |
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self.file = file_or_filename |
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self.dir = "" |
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else: |
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self.filename = file_or_filename |
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self.dir = os.path.dirname(self.filename) |
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self.file = open(self.filename, 'w') |
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|
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def close(self): |
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assert self.indent_level == 0 |
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if self.filename is not None: |
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self.file.close() |
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|
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def write_header(self, doctype, system): |
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"""Write the XML header""" |
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self.file.write('<?xml version="1.0" encoding="UTF-8"?>\n') |
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self.file.write('<!DOCTYPE %s SYSTEM "%s">\n' % (doctype, system)) |
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|
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def open_element(self, element, attrs = {}): |
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|
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# |
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# we note when an element is opened so that if two open_element() |
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# calls are made successively we can end the currently open |
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# tag and will later write a proper close tag. otherwise, |
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# if a close_element() call is made directly after an open_element() |
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# call we will close the tag with a /> |
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# |
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if self.element_open == 1: |
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self.file.write(">\n") |
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|
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self.element_open = 1 |
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|
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# Helper function to write an element open tag with attributes |
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self.file.write("%s<%s" % (TAB*self.indent_level, element)) |
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self.__write_attribs(attrs) |
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|
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self.indent_level += 1 |
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|
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def close_element(self, element): |
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self.indent_level -= 1 |
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assert self.indent_level >= 0 |
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|
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# see open_element() for an explanation |
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if self.element_open == 1: |
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self.element_open = 0 |
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self.file.write("/>\n") |
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else: |
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self.file.write("%s</%s>\n" % (TAB*self.indent_level, element)) |
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|
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def write_element(self, element, attrs = {}): |
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"""write an element that won't need a closing tag""" |
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self.open_element(element, attrs) |
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self.close_element(element) |
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|
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def __write_attribs(self, attrs): |
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for name, value in attrs.items(): |
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self.file.write(' %s="%s"' % (escape(name), escape(value))) |
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|
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class SessionSaver(XMLWriter): |
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"""Class to serialize a session into an XML file. |
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|
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Applications built on top of Thuban may derive from this class and |
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override or extend the methods to save additional information. This |
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additional information should take the form of additional attributes |
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or elements whose names are prefixed with a namespace. To define a |
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namespace derived classes should extend the write_session method to |
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pass the namespaces to the default implementation. |
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""" |
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|
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|
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def __init__(self, session): |
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XMLWriter.__init__(self) |
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self.session = session |
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|
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def write(self, file_or_filename): |
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XMLWriter.write(self, file_or_filename) |
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|
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self.write_header("session", "thuban.dtd") |
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self.write_session(self.session) |
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self.close() |
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|
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def write_session(self, session, attrs = None, namespaces = ()): |
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"""Write the session and its contents |
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|
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By default, write a session element with the title attribute and |
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call write_map for each map contained in the session. |
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|
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The optional argument attrs is for additional attributes and, if |
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given, should be a mapping from attribute names to attribute |
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values. The values should not be XML-escaped yet. |
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|
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The optional argument namespaces, if given, should be a sequence |
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of (name, URI) pairs. The namespaces are written as namespace |
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attributes into the session element. This is mainly useful for |
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derived classes that need to store additional information in a |
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thuban session file. |
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""" |
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if attrs is None: |
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attrs = {} |
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attrs["title"] = session.title |
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for name, uri in namespaces: |
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attrs["xmlns:" + name] = uri |
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self.open_element("session", attrs) |
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for map in session.Maps(): |
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self.write_map(map) |
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self.close_element("session") |
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|
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def write_map(self, map): |
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"""Write the map and its contents. |
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|
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By default, write a map element element with the title |
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attribute, call write_projection to write the projection |
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element, call write_layer for each layer contained in the map |
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and finally call write_label_layer to write the label layer. |
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""" |
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self.open_element('map title="%s"' % escape(map.title)) |
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self.write_projection(map.projection) |
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for layer in map.Layers(): |
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self.write_layer(layer) |
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self.write_label_layer(map.LabelLayer()) |
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self.close_element('map') |
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|
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def write_projection(self, projection): |
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"""Write the projection. |
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""" |
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if projection and len(projection.params) > 0: |
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self.open_element("projection") |
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for param in projection.params: |
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self.write_element('parameter value="%s"' % escape(param)) |
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self.close_element("projection") |
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|
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def write_layer(self, layer, attrs = None): |
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"""Write the layer. |
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|
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The optional argument attrs is for additional attributes and, if |
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given, should be a mapping from attribute names to attribute |
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values. The values should not be XML-escaped yet. |
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""" |
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lc = layer.GetClassification() |
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|
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if attrs is None: |
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attrs = {} |
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|
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attrs["title"] = layer.title |
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attrs["filename"] = relative_filename(self.dir, layer.filename) |
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attrs["stroke"] = lc.GetDefaultLineColor().hex() |
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attrs["stroke_width"] = str(lc.GetDefaultLineWidth()) |
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attrs["fill"] = lc.GetDefaultFill().hex() |
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|
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self.open_element("layer", attrs) |
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|
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proj = layer.GetProjection() |
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if proj is not None: |
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self.write_projection(proj) |
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|
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self.write_classification(layer) |
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|
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self.close_element("layer") |
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|
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def write_classification(self, layer, attrs = None): |
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if attrs is None: |
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attrs = {} |
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|
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lc = layer.GetClassification() |
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|
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field = lc.GetField() |
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|
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# |
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# there isn't a classification of anything |
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# so don't do anything |
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# |
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if field is None: return |
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|
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attrs["field"] = field |
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attrs["field_type"] = str(lc.GetFieldType()) |
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self.open_element("classification", attrs) |
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|
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|
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types = [[lambda p: 'clnull label="%s"' % p.GetLabel(), |
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lambda p: 'clnull'], |
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[lambda p: 'clpoint label="%s" value="%s"' % |
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(p.GetLabel(), str(p.GetValue())), |
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lambda p: 'clpoint'], |
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[lambda p: 'clrange label="%s" min="%s" max="%s"' % |
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(p.GetLabel(), |
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str(p.GetMin()), (str(p.GetMax()))), |
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lambda p: 'clrange']] |
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|
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def write_class_group(group): |
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type = -1 |
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if isinstance(group, ClassGroupDefault): type = 0 |
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elif isinstance(group, ClassGroupSingleton): type = 1 |
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elif isinstance(group, ClassGroupRange): type = 2 |
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elif isinstance(group, ClassGroupMap): type = 3 |
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assert type >= 0 |
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|
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if type <= 2: |
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data = group.GetProperties() |
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dict = {'stroke' : data.GetLineColor().hex(), |
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'stroke_width': str(data.GetLineWidth()), |
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'fill' : data.GetFill().hex()} |
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|
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self.open_element(types[type][0](group)) |
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self.write_element("cldata", dict) |
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self.close_element(types[type][1](group)) |
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else: pass # XXX: we need to handle maps |
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|
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for i in lc: |
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write_class_group(i) |
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|
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self.close_element("classification") |
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|
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def write_label_layer(self, layer): |
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"""Write the label layer. |
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""" |
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labels = layer.Labels() |
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if labels: |
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self.open_element('labellayer') |
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for label in labels: |
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self.write_element(('label x="%g" y="%g" text="%s"' |
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' halign="%s" valign="%s"') |
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% (label.x, label.y, label.text, label.halign, |
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label.valign)) |
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self.close_element('labellayer') |
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|
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|
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|
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def save_session(session, file, saver_class = None): |
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"""Save the session session to a file. |
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|
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The file argument may either be a filename or an open file object. |
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|
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The optional argument saver_class is the class to use to serialize |
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the session. By default or if it's None, the saver class will be |
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SessionSaver. |
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|
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If writing the session is successful call the session's |
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UnsetModified method |
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""" |
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if saver_class is None: |
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saver_class = SessionSaver |
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saver = saver_class(session) |
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saver.write(file) |
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|
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# after a successful save consider the session unmodified. |
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session.UnsetModified() |
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