Wednesday, September 16, 2009

Richard Jones' Log: Python: Simple, elegant HTML generation

Richard Jones' Log: Python: Simple, elegant HTML generation: "

OK, I looked. I searched. I didn't find. So here you go...

from cgi import escape
class HTML(object):
   '''Easily generate HTML.

       >>> h = HTML()
       >>> p = h.p('hello, world!')
       >>> p.text('more text')
       >>> with h.table(border='1', newlines=True):
       ...     for i in range(2):
       ...         with
       ...   'helo', a='"foo"')
       ...   'there')
       >>> print h
       <p>hello, world!more text</p>
       <table border="1">
       <tr><td a=""foo"">he&lt;l&gt;lo</td><td>there</td></tr>
       <tr><td a=""foo"">he&lt;l&gt;lo</td><td>there</td></tr>

   def __init__(self, name=None, stack=None): = name
       self.content = []
       self.attrs = {}
       # insert newlines between content?
       self.newlines = False
       if stack is None:
           stack = [self]
       self.stack = stack
   def __getattr__(self, name):
       # adding a new tag or newline
       if name == 'newline':
           e = '\n'
           e = HTML(name, self.stack)
       return e
   def text(self, text):
       # adding text
   def __call__(self, *content, **kw):
       # customising a tag with content or attributes
       if content:
           self.content = map(escape, content)
       if 'newlines' in kw:
           # special-case to allow control over newlines
           self.newlines = kw.pop('newlines')
       for k in kw:
           self.attrs[k] = escape(kw[k]).replace('"', '"')
       return self
   def __enter__(self):
       # we're now adding tags to me!
       return self
   def __exit__(self, exc_type, exc_value, exc_tb):
       # we're done adding tags to me!
   def __str__(self):
       # turn me and my content into text
       join = '\n' if self.newlines else ''
       if is None:
           return join.join(map(str, self.content))
       a = ['%s="%s"'%i for i in self.attrs.items()]
       l = [] + a
       s = '<%s>%s'%(' '.join(l), join)
       if self.content:
           s += join.join(map(str, self.content))
           s += join + '</%s>'
       return s

Note that due to something playing up the &quot; in the docstring is being decoded to ' so looks incorrect. The code is correct, the display on this page is not. Hrm.

Also, look, ma! A ternary expression! My first in Python!

Did you like 'join.join'? Heh. I know...


No comments: