Source Code for Module ais.expandais

  1  #!/usr/bin/env python 
  2   
  3  __version__ = '$Revision: 4820 $'.split()[1] 
  4  __date__ = '$Date: 2006-09-28 12:11:51 -0400 (Thu, 28 Sep 2006) $'.split()[1] 
  5  __author__ = 'Kurt Schwehr' 
  6   
  7  __doc__=''' 
  8  Expand structs in ais xml to include-struct elements while applying name mangling 
  9   
 10  @requires: U{lxml<http://codespeak.net/lxml/>} 
 11  @requires: U{epydoc<http://epydoc.sourceforge.net/>} > 3.0alpha3 
 12   
 13  @author: '''+__author__+''' 
 14  @version: ''' + __version__ +''' 
 15  @copyright: 2006 
 16  @var __date__: Date of last svn commit 
 17  @undocumented: __version__ __author__ __doc__ parser 
 18  @since: 2006-Sep-26 
 19  @status: under development 
 20  @organization: U{CCOM<http://ccom.unh.edu/>} 
 21   
 22  @bug: WHY IS THE IMO message screwing up the day field? 
 23  @license: GPL v2 
 24  ''' 
 25   
 26  import sys 
 27  from lxml import etree  
 28   
 29 -def getPos(parent,child): 
 30      ''' 
 31      Return the position number of the child node.  It seems like this 
 32      really should be a part of the element tree interface.  Perhaps 
 33      I overlooked it. 
 34      ''' 
 35      for i in range(len(parent)): 
 36          if parent[i]==child: return i 
 37      return None 
 38   
 39   
 40 -def expandAis(inET,verbose=False): 
 41      ''' 
 42      Replace each include-struct with the structure.  This code is not 
 43      pretty, but it seems to work.  The include-struct name is 
 44      prepended to each field name within the struct.  The 
 45      include-struct description is also added to before the fields 
 46      description. 
 47   
 48      @param inET: lxml element tree to expand 
 49      @return: lxml element tree with expanded structures 
 50      ''' 
 51      inET.xinclude() 
 52      import copy 
 53      outET = copy.deepcopy(inET) 
 54      #outET.xinclude() 
 55   
 56      root = outET.getroot() 
 57      includeStructs = root.xpath('message/include-struct') 
 58      for inc in includeStructs: 
 59   
 60          if verbose: print 'inc:',inc.attrib['name'], 'parent:',inc.getparent().tag 
 61          parent = inc.getparent() 
 62          nodePosition = getPos(parent,inc) 
 63          #if verbose: print 'pos:',nodePosition 
 64   
 65          structName = inc.attrib['struct'] 
 66          baseName = inc.attrib['name']+'_' 
 67   
 68          if len(inc.xpath('do_not_mangle_name'))>0: 
 69              if verbose: print 'Not mangling',structName,baseName[:-1] 
 70              baseName = '' 
 71          #if verbose: print 'baseName:',baseName, 'structName=',structName 
 72   
 73          # // means find all struct tags at all levels 
 74          structDef = root.xpath("//struct[@name='"+structName+"']") 
 75   
 76          # Put in a comment where the include-struct was. 
 77          inc.getparent().replace(inc,etree.Comment('Struct include of '+inc.attrib['name']+' was here')) 
 78   
 79          replacement=copy.deepcopy(structDef[0]) 
 80   
 81          postgis=False # Does this structure have an associated postgis data structure? 
 82          postgisName=None 
 83          postgisType=None 
 84          if 'postgis_type' in replacement.attrib: 
 85              postgis=True 
 86              postgisType=replacement.attrib['postgis_type'] 
 87              postgisName=inc.attrib['name'] #baseName 
 88              if verbose: print 'Found PostGIS datatype for structure:',postgisName,postgisType 
 89               
 90   
 91          # FIX: what happens when the include is at the beginning or end of the list? 
 92   
 93          for subfield in replacement.xpath('field'): 
 94              subfield.attrib['name']=baseName+subfield.attrib['name'] 
 95              desc = subfield.xpath('description') 
 96   
 97              if postgis: 
 98                  if verbose: print 'Annotating',subfield.attrib['name'], 'with postgis info' 
 99                  subfield.attrib['postgisType']=postgisType 
100                  subfield.attrib['postgisName']=postgisName 
101   
102              if len(desc)==1: 
103                  txt = inc.xpath('description')[0].text 
104                  if None == txt: 
105                      if verbose: 'WARNING: are you sure you want no text in this description?' 
106                      txt = '' 
107                  else: txt +='  '  # FIX: was \n\t which cause trouble with word export 
108                  desc[0].text=  txt+desc[0].text  
109              else: 
110                  print 'WARNING: no description for subfield!!!!  Must have exactly one description field' 
111              # Now that the node is ready, jam it in there after the replaced comment 
112   
113              #print "FIX: make sure these end up in the right place!!!!" 
114   
115              newPos = nodePosition+getPos(replacement,subfield) #+1 
116              nodePosition+=1 
117              parent.insert(newPos,subfield) 
118          #if verbose: print 'New parent:',etree.tostring(parent) 
119   
120      return outET 
121   
122 -def nukeStructs(inET,verbose=False): 
123      ''' 
124      Replace each include-struct with the structure.  This code is not 
125      pretty, but it seems to work.  The include-struct name is 
126      prepended to each field name within the struct.  The 
127      include-struct description is also added to before the fields 
128      description. 
129   
130      @param inET: lxml element tree to expand 
131      @return: lxml element tree with expanded structures 
132      ''' 
133      import copy 
134      outET = copy.deepcopy(inET) 
135   
136      root = outET.getroot() 
137      structs = root.xpath('struct') 
138      for struct in structs: 
139          if verbose: print 'nuking struct:',struct.attrib['name'] 
140          struct.getparent().replace(struct,etree.Comment('Struct '+struct.attrib['name']+' was here')) 
141   
142      return outET 
143   
144  if __name__ == '__main__': 
145      from optparse import OptionParser 
146      parser = OptionParser(usage="%prog [options]", 
147                              version="%prog "+__version__) 
148      parser.add_option('-i','--input-file',dest='inFilename',default=None, 
149                          help='AIS to read from')     
150      parser.add_option('-o','--output-file',dest='outFilename',default='out-ais.xml', 
151                          help='New AIS file that has structures expanded')     
152      parser.add_option('-v','--verbose',dest='verbose',default=False,action='store_true', 
153                          help='Verbose mode') 
154   
155      parser.add_option('-k','--keep-structs',dest='keepStructs',default=False,action='store_true', 
156                          help='Keep the structure definitions at the beginning of the file') 
157      (options,args) = parser.parse_args() 
158   
159      tree = etree.parse(options.inFilename) 
160      #tree.xinclude() 
161      newET = expandAis(tree,options.verbose) 
162      if not options.keepStructs:  
163          newET = nukeStructs(newET,options.verbose) 
164      newET.write(options.outFilename) 
165   
166      #if options.verbose: print etree.tostring(newET) 
167