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