[Sommaire] [Imprimer]

   1  # Portal transform for images with captions
   2  #
   3  # We want to be able to support captions in images.
   4  # The easiest way to do this is to define a Portal Transform which is
   5  # applied to the HTML body text on output.
   6  #
   7  # The transform finds all the embedded images, and replaces them with
   8  # an appropriate chunk of HTML to include the caption.
   9  #
  10  from Products.CMFCore.utils import getToolByName
  11  from Products.PortalTransforms.interfaces import itransform
  12  from DocumentTemplate.DT_Util import html_quote
  13  from DocumentTemplate.DT_Var import newline_to_br
  14  import re
  15  
  16  __revision__ = '$Id$'
  17  
  18  # IMAGE_PATTERN matches an image tag on its own, or an image tag
  19  # enclosed in a simple <p> or <div>. In the latter case we strip out
  20  # the enclosing tag since we are going to insert our own.
  21  PATIMG = '\\<img[^>]+class=[^=>]*captioned[^>]+\\>'
  22  PATA = '(?:\\<a[^>]*\\>'+PATIMG+'\\</a\\>)' + '|' + PATIMG
  23  PAT0 = '('+PATA+')'
  24  PAT1 = '<(?:p|div)[^>]*>'+PAT0 + '</(?:p|div)>' + '|' + PAT0
  25  IMAGE_PATTERN = re.compile(PAT1, re.IGNORECASE)
  26  
  27  # Regex to match stupid IE attributes. In IE generated HTML an
  28  # attribute may not be enclosed by quotes if it doesn't contain
  29  # certain punctuation.
  30  ATTR_VALUE = '=(?:"?)(?P<%s>(?<=")[^"]*|[^ \/>]*)'
  31  ATTR_CLASS = ATTR_VALUE % 'class'
  32  ATTR_WIDTH = ATTR_VALUE % 'width'
  33  
  34  ATTR_PATTERN = re.compile('''
  35      (?P<tag>\<
  36       ( class%s
  37       | src="resolveuid/(?P<src>([^/"#? ]*))
  38       | width%s
  39       | .
  40       )*\>
  41      )''' % (ATTR_CLASS, ATTR_WIDTH), re.VERBOSE)
  42  
  43  CLASS_PATTERN = re.compile('\s*class=("[^"]*captioned[^"]*"|[^" \/>]+)')
  44  IMAGE_TEMPLATE = '''\
  45  <div class="%(class)s" style="width:%(width)spx;">
  46   <div style="width:%(width)spx;">
  47    %(tag)s
  48   </div>
  49   <div class="image-caption">
  50    %(caption)s
  51   </div>
  52  </div>
  53  '''
  54  
  55  UID_PATTERN = re.compile('(?P<tag><(?:a|img) [^>]*(?:src|href)=")(?P<url>[^"]*resolveuid/(?P<uid>[^"#? ]*))')
  56  
  57  class HTMLToCaptioned:
  58      """Transform which adds captions to images embedded in HTML"""
  59      __implements__ = itransform
  60      __name__ = "html_to_captioned"
  61      inputs = ('text/html',)
  62      output = "text/x-html-captioned"
  63      
  64      def __init__(self, name=None):
  65          self.config_metadata = {
  66              'inputs' : ('list', 'Inputs', 'Input(s) MIME type. Change with care.'),
  67              }
  68          if name:
  69              self.__name__ = name
  70  
  71      def name(self):
  72          return self.__name__
  73  
  74      def __getattr__(self, attr):
  75          if attr == 'inputs':
  76              return self.config['inputs']
  77          if attr == 'output':
  78              return self.config['output']
  79          raise AttributeError(attr)
  80  
  81      def convert(self, data, idata, filename=None, **kwargs):
  82          """convert the data, store the result in idata and return that
  83          optional argument filename may give the original file name of received data
  84          additional arguments given to engine's convert, convertTo or __call__ are
  85          passed back to the transform
  86          
  87          The object on which the translation was invoked is available as context
  88          (default: None)
  89          """
  90          context = kwargs.get('context', None)
  91          if context:
  92              at_tool = context.archetype_tool
  93  
  94          if context and at_tool:        
  95              def replaceImage(match):
  96                  tag = match.group(1) or match.group(2)
  97                  attrs = ATTR_PATTERN.match(tag)
  98                  src = attrs.group('src')
  99                  klass = attrs.group('class')
 100                  width = attrs.group('width')
 101                  if src:
 102                      d = attrs.groupdict()
 103                      target = at_tool.reference_catalog.lookupObject(src)
 104                      if target:
 105                          d['caption'] = newline_to_br(target.Description())
 106                          d['tag'] = CLASS_PATTERN.sub('', d['tag'])
 107                          if not width:
 108                              d['width'] = target.getWidth()
 109  
 110                          return IMAGE_TEMPLATE % d
 111                  return match.group(0) # No change
 112  
 113              html = IMAGE_PATTERN.sub(replaceImage, data)
 114  
 115              # Replace urls that use UIDs with human friendly urls.
 116              def replaceUids(match):
 117                  tag = match.group('tag')
 118                  uid = match.group('uid')
 119                  target = at_tool.reference_catalog.lookupObject(uid)
 120                  if target:
 121                      return tag + target.absolute_url()
 122                  return match.group(0)
 123  
 124              html = UID_PATTERN.sub(replaceUids, html)
 125              
 126              idata.setData(html)
 127              return idata
 128  
 129          # No context to use for replacements, so don't bother trying.
 130          return data
 131  
 132  def register():
 133      return HTMLToCaptioned()
 134  
 135  def initialize():
 136      engine = getToolByName(portal, 'portal_transforms')
 137      engine.registerTransform(register())