serialization_xml.py

   1 # This file is part of jack_mixer
   2 #
   3 # Copyright (C) 2006 Nedko Arnaudov <nedko@arnaudov.name>
   4 #
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; version 2 of the License
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program; if not, write to the Free Software
  16 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17
  18 import xml.dom
  19 import xml.dom.minidom
  20
  21 from serialization import SerializationBackend
  22
  23
  24 class XmlSerializationError(Exception):
  25     pass
  26
  27
  28 class InvalidDocumentTypeError(XmlSerializationError):
  29     pass
  30
  31
  32 class XmlSerialization(SerializationBackend):
  33     def get_root_serialization_object(self, name):
  34         self.doc = xml.dom.getDOMImplementation().createDocument(
  35             xml.dom.EMPTY_NAMESPACE, name, None
  36         )
  37         return XmlSerializationObject(self.doc, self.doc.documentElement)
  38
  39     def get_root_unserialization_object(self, name):
  40         if name != self.doc.documentElement.nodeName:
  41             return None
  42         return XmlSerializationObject(self.doc, self.doc.documentElement)
  43
  44     def get_child_serialization_object(self, name, backend_object):
  45         child = self.doc.createElement(name)
  46         backend_object.element.appendChild(child)
  47         return XmlSerializationObject(self.doc, child)
  48
  49     def save(self, file):
  50         file.write(self.doc.toprettyxml())
  51
  52     def load(self, file, name):
  53         self.doc = xml.dom.minidom.parse(file)
  54
  55         document_type = self.doc.documentElement.nodeName
  56         if document_type != name:
  57             raise InvalidDocumentTypeError("Document type '%s' not supported." % document_type)
  58
  59
  60 class XmlSerializationObject:
  61     def __init__(self, doc, element):
  62         self.doc = doc
  63         self.element = element
  64
  65     def add_property(self, name, value):
  66         self.add_property_as_attribute(name, value)
  67
  68     def add_property_as_attribute(self, name, value):
  69         self.element.setAttribute(name, value)
  70
  71     # def add_property_as_child_element(self, name, value):
  72     #    child = self.doc.createElement(name)
  73     #    value = self.doc.createTextNode(value)
  74     #    child.appendChild(value)
  75     #    self.element.appendChild(child)
  76
  77     def get_childs(self):
  78         child_elements = self.element.childNodes
  79         childs = []
  80         for child in child_elements:
  81             if child.nodeType == child.ELEMENT_NODE:
  82                 childs.append(XmlSerializationObject(self.doc, child))
  83         return childs
  84
  85     def get_properties(self):
  86         properties = self.element.attributes
  87         dictionary = {}
  88         for i in range(properties.length):
  89             dictionary[properties.item(i).name] = properties.item(i).nodeValue
  90         return dictionary
  91
  92     def serialization_name(self):
  93         return self.element.nodeName