1 """

     2     Generating HTML tags

     3 """

     4 

     5 from cgi import escape

     6 

     7 def tag_attr (name, value) :

     8     return u'%s="%s"' % (name.rstrip('_'), escape(value, True))

     9 

    10 def tag_subcontent (subcontent) :

    11     if not subcontent :

    12         # skip

    13         return

    14 

    15     elif not isinstance(subcontent, basestring) and hasattr(subcontent, '__iter__') :

    16         # render each sub-item recursively

    17         for sc in subcontent :

    18             for line in tag_subcontent(sc) :

    19                 yield line

    20     

    21     else :

    22         yield subcontent

    23 

    24 def tag_content (content) :

    25     if not content:

    26         # no output

    27         return

    28     

    29     elif isinstance(content, basestring) :

    30         # escape raw vlues

    31         yield escape(unicode(content))

    32 

    33     else :

    34         # treat it as subcontent

    35         for line in tag_subcontent(content) :

    36             yield line

    37 

    38 def tag (name, *content, **attrs) :

    39     attr_stuff = " " + " ".join(tag_attr(n, v) for n, v in attrs.iteritems()) if attrs else ""

    40     

    41     if content and all(content) :

    42         # tag with content

    43         yield u"<%s%s>" % (name, attr_stuff)

    44         

    45         for c in content :

    46             for line in tag_content(c) :

    47                 yield u"\t" + line

    48 

    49         yield u"</%s>" % (name, )

    50 

    51     else :

    52         # singleton tag

    53         yield u"<%s%s />" % (name, attr_stuff)

    54 

    55 def raw (data) :

    56     yield data

    57 

    58 class TagFactory (object) :

    59     def __getattr__ (self, name) :

    60         def build_tag (*content, **attrs) :

    61             return tag(name, *content, **attrs)

    62 

    63         return build_tag

    64 

    65 tags = TagFactory()

    66 

    67 def render_lines (tags, charset=None) :

    68     for line in tag_content(tags) :

    69         if charset :

    70             yield line.encode(charset)

    71 

    72         else :

    73             yield line

    74 

    75 def render (tags, charset=None) :

    76     data = u'\n'.join(render_lines(tags))

    77 

    78     if charset :

    79         return data.encode(charset)

    80 

    81     else :

    82         return data

    83 

    84 def render_out (tags, out, charset='utf-8') :

    85     """

    86         Write the rendered tags into the given output stream using the given encoding

    87     """

    88 

    89     for line in render_lines(tags, charset) :

    90         out.write(line + '\n')

    91