Source Code for Module concurrent_tree_crawler.xml_tree_serialization

 1  import xml.parsers.expat 
 2  from concurrent_tree_crawler.abstract_node import AbstractNode, NodeState 
 3   
 4 -class XMLTreeWriter: 
 5 -        def __init__(self, file_): 
 6                  self.__f = file_ 
 7   
 8 -        def write(self, sentinel): 
 9                  """ 
10                  @type sentinel: L{AbstractNode} 
11                  """ 
12                  root = sentinel.get_child("root") 
13                  self.__print(0, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>") 
14                  self.__print(0, "<tree>") 
15                  self.__print_node(1, root) 
16                  self.__print(0, "</tree>") 
17           
18 -        def __print_node(self, level, node): 
19                  prefix_str = "<node name=\"{}\" state=\"{}\"".format( 
20                          node.get_name(), NodeState.to_str(node.get_state())) 
21                  children = node.get_children() 
22                  if children: 
23                          self.__print(level, "{}>".format(prefix_str)) 
24                          for child in node.get_children(): 
25                                  self.__print_node(level+1, child) 
26                          self.__print(level, "</node>") 
27                  else: 
28                          self.__print(level, "{}/>".format(prefix_str)) 
29           
30 -        def __print(self, level, text): 
31                  print >>self.__f, "{}{}".format("\t"*level, text) 
32   
33 -class XMLTreeReader: 
34 -        def __init__(self, file_): 
35                  self.__file = file_ 
36                  self.__curr_node = None 
37                  self.__parser = xml.parsers.expat.ParserCreate() 
38           
39                  self.__parser.StartElementHandler = self.__start_element 
40                  self.__parser.EndElementHandler = self.__end_element 
41                  self.__parser.CharacterDataHandler = self.__char_data 
42           
43 -        def __start_element(self, name, attrs): 
44                  if name == "tree": 
45                          return 
46                  if name == "node": 
47                          state = NodeState.from_str(attrs["state"]) 
48                          node_name = attrs["name"] 
49                          self.__curr_node = self.__curr_node.add_child(node_name, state) 
50           
51 -        def __end_element(self, name): 
52                  if name == "tree": 
53                          return 
54                  if name == "node": 
55                          self.__curr_node = self.__curr_node.get_parent() 
56           
57 -        def __char_data(self, data): 
58                  pass 
59           
60 -        def read(self, sentinel): 
61                  """ 
62                  @param sentinel: a node that will be treated as sentinel in the 
63                          newly created tree, it shouldn't have any children. 
64                  @type sentinel: L{AbstractNode} 
65                  """  
66                  assert not sentinel.get_children(), \ 
67                          "The sentinel should be a single node, without children" 
68                  self.__curr_node = sentinel 
69                  self.__parser.ParseFile(self.__file) 
70