xmltramp.py :  » XML » xmltramp » src » Python Open Source

"""xmltramp: Make XML documents easily accessible."""

__version__ = "2.18"
__author__ = "Aaron Swartz"
__credits__ = "Many thanks to pjz, bitsko, and DanC."
__copyright__ = "(C) 2003-2006 Aaron Swartz. GNU GPL 2."

if not hasattr(__builtins__, 'True'): True, False = 1, 0
def isstr(f): return isinstance(f, type('')) or isinstance(f, type(u''))
def islst(f): return isinstance(f, type(())) or isinstance(f, type([]))

empty = {'http://www.w3.org/1999/xhtml': ['img', 'br', 'hr', 'meta', 'link', 'base', 'param', 'input', 'col', 'area']}

def quote(x, elt=True):
  if elt and '<' in x and len(x) > 24 and x.find(']]>') == -1: return "<![CDATA["+x+"]]>"
  else: x = x.replace('&', '&amp;').replace('<', '&lt;').replace(']]>', ']]&gt;')
  if not elt: x = x.replace('"', '&quot;')
  return x

class Element:
  def __init__(self, name, attrs=None, children=None, prefixes=None):
    if islst(name) and name[0] == None: name = name[1]
    if attrs:
      na = {}
      for k in attrs.keys():
        if islst(k) and k[0] == None: na[k[1]] = attrs[k]
        else: na[k] = attrs[k]
      attrs = na
    
    self._name = name
    self._attrs = attrs or {}
    self._dir = children or []
    
    prefixes = prefixes or {}
    self._prefixes = dict(zip(prefixes.values(), prefixes.keys()))
    
    if prefixes: self._dNS = prefixes.get(None, None)
    else: self._dNS = None
  
  def __repr__(self, recursive=0, multiline=0, inprefixes=None):
    def qname(name, inprefixes): 
      if islst(name):
        if inprefixes[name[0]] is not None:
          return inprefixes[name[0]]+':'+name[1]
        else:
          return name[1]
      else:
        return name
    
    def arep(a, inprefixes, addns=1):
      out = ''

      for p in self._prefixes.keys():
        if not p in inprefixes.keys():
          if addns: out += ' xmlns'
          if addns and self._prefixes[p]: out += ':'+self._prefixes[p]
          if addns: out += '="'+quote(p, False)+'"'
          inprefixes[p] = self._prefixes[p]
      
      for k in a.keys():
        out += ' ' + qname(k, inprefixes)+ '="' + quote(a[k], False) + '"'
      
      return out
    
    inprefixes = inprefixes or {u'http://www.w3.org/XML/1998/namespace':'xml'}
    
    # need to call first to set inprefixes:
    attributes = arep(self._attrs, inprefixes, recursive) 
    out = '<' + qname(self._name, inprefixes)  + attributes 
    
    if not self._dir and (self._name[0] in empty.keys() 
      and self._name[1] in empty[self._name[0]]):
      out += ' />'
      return out
    
    out += '>'

    if recursive:
      content = 0
      for x in self._dir: 
        if isinstance(x, Element): content = 1
        
      pad = '\n' + ('\t' * recursive)
      for x in self._dir:
        if multiline and content: out +=  pad 
        if isstr(x): out += quote(x)
        elif isinstance(x, Element):
          out += x.__repr__(recursive+1, multiline, inprefixes.copy())
        else:
          raise TypeError, "I wasn't expecting "+`x`+"."
      if multiline and content: out += '\n' + ('\t' * (recursive-1))
    else:
      if self._dir: out += '...'
    
    out += '</'+qname(self._name, inprefixes)+'>'
      
    return out
  
  def __unicode__(self):
    text = ''
    for x in self._dir:
      text += unicode(x)
    return ' '.join(text.split())
    
  def __str__(self):
    return self.__unicode__().encode('utf-8')
  
  def __getattr__(self, n):
    if n[0] == '_': raise AttributeError, "Use foo['"+n+"'] to access the child element."
    if self._dNS: n = (self._dNS, n)
    for x in self._dir:
      if isinstance(x, Element) and x._name == n: return x
    raise AttributeError, 'No child element named %s' % repr(n)
    
  def __hasattr__(self, n):
    for x in self._dir:
      if isinstance(x, Element) and x._name == n: return True
    return False
    
   def __setattr__(self, n, v):
    if n[0] == '_': self.__dict__[n] = v
    else: self[n] = v
 

  def __getitem__(self, n):
    if isinstance(n, type(0)): # d[1] == d._dir[1]
      return self._dir[n]
    elif isinstance(n, slice(0).__class__):
      # numerical slices
      if isinstance(n.start, type(0)): return self._dir[n.start:n.stop]
      
      # d['foo':] == all <foo>s
      n = n.start
      if self._dNS and not islst(n): n = (self._dNS, n)
      out = []
      for x in self._dir:
        if isinstance(x, Element) and x._name == n: out.append(x) 
      return out
    else: # d['foo'] == first <foo>
      if self._dNS and not islst(n): n = (self._dNS, n)
      for x in self._dir:
        if isinstance(x, Element) and x._name == n: return x
      raise KeyError, n
  
  def __setitem__(self, n, v):
    if isinstance(n, type(0)): # d[1]
      self._dir[n] = v
    elif isinstance(n, slice(0).__class__):
      # d['foo':] adds a new foo
      n = n.start
      if self._dNS and not islst(n): n = (self._dNS, n)

      nv = Element(n)
      self._dir.append(nv)
      
    else: # d["foo"] replaces first <foo> and dels rest
      if self._dNS and not islst(n): n = (self._dNS, n)

      nv = Element(n); nv._dir.append(v)
      replaced = False

      todel = []
      for i in range(len(self)):
        if self[i]._name == n:
          if replaced:
            todel.append(i)
          else:
            self[i] = nv
            replaced = True
      if not replaced: self._dir.append(nv)
      for i in todel: del self[i]

  def __delitem__(self, n):
    if isinstance(n, type(0)): del self._dir[n]
    elif isinstance(n, slice(0).__class__):
      # delete all <foo>s
      n = n.start
      if self._dNS and not islst(n): n = (self._dNS, n)
      
      for i in range(len(self)):
        if self[i]._name == n: del self[i]
    else:
      # delete first foo
      for i in range(len(self)):
        if self[i]._name == n: del self[i]
        break
  
  def __call__(self, *_pos, **_set): 
    if _set:
      for k in _set.keys(): self._attrs[k] = _set[k]
    if len(_pos) > 1:
      for i in range(0, len(_pos), 2):
        self._attrs[_pos[i]] = _pos[i+1]
    if len(_pos) == 1:
      return self._attrs[_pos[0]]
    if len(_pos) == 0:
      return self._attrs

  def __len__(self): return len(self._dir)

class Namespace:
  def __init__(self, uri): self.__uri = uri
  def __getattr__(self, n): return (self.__uri, n)
  def __getitem__(self, n): return (self.__uri, n)

from xml.sax.handler import EntityResolver,DTDHandler,ContentHandler,ErrorHandler

class Seeder(EntityResolver, DTDHandler, ContentHandler, ErrorHandler):
  def __init__(self):
    self.stack = []
    self.ch = ''
    self.prefixes = {}
    ContentHandler.__init__(self)
    
  def startPrefixMapping(self, prefix, uri):
    if not self.prefixes.has_key(prefix): self.prefixes[prefix] = []
    self.prefixes[prefix].append(uri)
  def endPrefixMapping(self, prefix):
    self.prefixes[prefix].pop()
  
  def startElementNS(self, name, qname, attrs):
    ch = self.ch; self.ch = ''  
    if ch and not ch.isspace(): self.stack[-1]._dir.append(ch)

    attrs = dict(attrs)
    newprefixes = {}
    for k in self.prefixes.keys(): newprefixes[k] = self.prefixes[k][-1]
    
    self.stack.append(Element(name, attrs, prefixes=newprefixes.copy()))
  
  def characters(self, ch):
    self.ch += ch
  
  def endElementNS(self, name, qname):
    ch = self.ch; self.ch = ''
    if ch and not ch.isspace(): self.stack[-1]._dir.append(ch)
  
    element = self.stack.pop()
    if self.stack:
      self.stack[-1]._dir.append(element)
    else:
      self.result = element

from xml.sax import make_parser
from xml.sax.handler import feature_namespaces

def seed(fileobj):
  seeder = Seeder()
  parser = make_parser()
  parser.setFeature(feature_namespaces, 1)
  parser.setContentHandler(seeder)
  parser.parse(fileobj)
  return seeder.result

def parse(text):
  from StringIO import StringIO
  return seed(StringIO(text))

def load(url): 
  import urllib
  return seed(urllib.urlopen(url))

def unittest():
  parse('<doc>a<baz>f<b>o</b>ob<b>a</b>r</baz>a</doc>').__repr__(1,1) == \
    '<doc>\n\ta<baz>\n\t\tf<b>o</b>ob<b>a</b>r\n\t</baz>a\n</doc>'
  
  assert str(parse("<doc />")) == ""
  assert str(parse("<doc>I <b>love</b> you.</doc>")) == "I love you."
  assert parse("<doc>\nmom\nwow\n</doc>")[0].strip() == "mom\nwow"
  assert str(parse('<bing>  <bang> <bong>center</bong> </bang>  </bing>')) == "center"
  assert str(parse('<doc>\xcf\x80</doc>')) == '\xcf\x80'
  
  d = Element('foo', attrs={'foo':'bar'}, children=['hit with a', Element('bar'), Element('bar')])
  
  try: 
    d._doesnotexist
    raise "ExpectedError", "but found success. Damn."
  except AttributeError: pass
  assert d.bar._name == 'bar'
  try:
    d.doesnotexist
    raise "ExpectedError", "but found success. Damn."
  except AttributeError: pass
  
  assert hasattr(d, 'bar') == True
  
  assert d('foo') == 'bar'
  d(silly='yes')
  assert d('silly') == 'yes'
  assert d() == d._attrs
  
  assert d[0] == 'hit with a'
  d[0] = 'ice cream'
  assert d[0] == 'ice cream'
  del d[0]
  assert d[0]._name == "bar"
  assert len(d[:]) == len(d._dir)
  assert len(d[1:]) == len(d._dir) - 1
  assert len(d['bar':]) == 2
  d['bar':] = 'baz'
  assert len(d['bar':]) == 3
  assert d['bar']._name == 'bar'
  
  d = Element('foo')
  
  doc = Namespace("http://example.org/bar")
  bbc = Namespace("http://example.org/bbc")
  dc = Namespace("http://purl.org/dc/elements/1.1/")
  d = parse("""<doc version="2.7182818284590451"
    xmlns="http://example.org/bar" 
    xmlns:dc="http://purl.org/dc/elements/1.1/"
    xmlns:bbc="http://example.org/bbc">
    <author>John Polk and John Palfrey</author>
    <dc:creator>John Polk</dc:creator>
    <dc:creator>John Palfrey</dc:creator>
    <bbc:show bbc:station="4">Buffy</bbc:show>
  </doc>""")

  assert repr(d) == '<doc version="2.7182818284590451">...</doc>'
  assert d.__repr__(1) == '<doc xmlns:bbc="http://example.org/bbc" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns="http://example.org/bar" version="2.7182818284590451"><author>John Polk and John Palfrey</author><dc:creator>John Polk</dc:creator><dc:creator>John Palfrey</dc:creator><bbc:show bbc:station="4">Buffy</bbc:show></doc>'
  assert d.__repr__(1,1) == '<doc xmlns:bbc="http://example.org/bbc" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns="http://example.org/bar" version="2.7182818284590451">\n\t<author>John Polk and John Palfrey</author>\n\t<dc:creator>John Polk</dc:creator>\n\t<dc:creator>John Palfrey</dc:creator>\n\t<bbc:show bbc:station="4">Buffy</bbc:show>\n</doc>'

  assert repr(parse("<doc xml:lang='en' />")) == '<doc xml:lang="en"></doc>'

  assert str(d.author) == str(d['author']) == "John Polk and John Palfrey"
  assert d.author._name == doc.author
  assert str(d[dc.creator]) == "John Polk"
  assert d[dc.creator]._name == dc.creator
  assert str(d[dc.creator:][1]) == "John Palfrey"
  d[dc.creator] = "Me!!!"
  assert str(d[dc.creator]) == "Me!!!"
  assert len(d[dc.creator:]) == 1
  d[dc.creator:] = "You!!!"
  assert len(d[dc.creator:]) == 2
  
  assert d[bbc.show](bbc.station) == "4"
  d[bbc.show](bbc.station, "5")
  assert d[bbc.show](bbc.station) == "5"

  e = Element('e')
  e.c = '<img src="foo">'
  assert e.__repr__(1) == '<e><c>&lt;img src="foo"></c></e>'
  e.c = '2 > 4'
  assert e.__repr__(1) == '<e><c>2 > 4</c></e>'
  e.c = 'CDATA sections are <em>closed</em> with ]]>.'
  assert e.__repr__(1) == '<e><c>CDATA sections are &lt;em>closed&lt;/em> with ]]&gt;.</c></e>'
  e.c = parse('<div xmlns="http://www.w3.org/1999/xhtml">i<br /><span></span>love<br />you</div>')
  assert e.__repr__(1) == '<e><c><div xmlns="http://www.w3.org/1999/xhtml">i<br /><span></span>love<br />you</div></c></e>'  
  
  e = Element('e')
  e('c', 'that "sucks"')
  assert e.__repr__(1) == '<e c="that &quot;sucks&quot;"></e>'

  
  assert quote("]]>") == "]]&gt;"
  assert quote('< dkdkdsd dkd sksdksdfsd fsdfdsf]]> kfdfkg >') == '&lt; dkdkdsd dkd sksdksdfsd fsdfdsf]]&gt; kfdfkg >'
  
  assert parse('<x a="&lt;"></x>').__repr__(1) == '<x a="&lt;"></x>'
  assert parse('<a xmlns="http://a"><b xmlns="http://b"/></a>').__repr__(1) == '<a xmlns="http://a"><b xmlns="http://b"></b></a>'
  
if __name__ == '__main__': unittest()