Add get_current() to return the current active element in a with cont…

…ext. Closes #123

dominate/_version.py

@@ -1 +1 @@
-__version__ = '2.5.2'
+__version__ = '2.6.0'

dominate/dom_tag.py

@@ -43,6 +43,7 @@
 except ImportError:
   greenlet = None
 
+
 def _get_thread_context():
   context = [threading.current_thread()]
   if greenlet:
@@ -57,11 +58,11 @@ class dom_tag(object):
                      # modified
   is_inline = False
 
-  frame = namedtuple('frame', ['tag', 'items', 'used'])
 
   def __new__(_cls, *args, **kwargs):
     '''
-    Check if bare tag is being used a a decorator.
+    Check if bare tag is being used a a decorator
+    (called with a single function arg).
     decorate the function and return
     '''
     if len(args) == 1 and isinstance(args[0], Callable) \
@@ -75,6 +76,7 @@ def f(*args, **kwargs):
       return f
     return object.__new__(_cls)
 
+
   def __init__(self, *args, **kwargs):
     '''
     Creates a new tag. Child tags should be passed as arguments and attributes
@@ -105,28 +107,35 @@ def __init__(self, *args, **kwargs):
     self._ctx = None
     self._add_to_ctx()
 
-  def _add_to_ctx(self):
-    ctx = dom_tag._with_contexts[_get_thread_context()]
-    if ctx and ctx[-1]:
-      self._ctx = ctx[-1]
-      ctx[-1].items.append(self)
 
-  # stack of (root_tag, [new_tags], set(used_tags))
+  # context manager
+  frame = namedtuple('frame', ['tag', 'items', 'used'])
+  # stack of frames
   _with_contexts = defaultdict(list)
 
+  def _add_to_ctx(self):
+    stack = dom_tag._with_contexts.get(_get_thread_context())
+    if stack:
+      self._ctx = stack[-1]
+      stack[-1].items.append(self)
+
+
   def __enter__(self):
-    ctx = dom_tag._with_contexts[_get_thread_context()]
-    ctx.append(dom_tag.frame(self, [], set()))
+    stack = dom_tag._with_contexts[_get_thread_context()]
+    stack.append(dom_tag.frame(self, [], set()))
     return self
 
+
   def __exit__(self, type, value, traceback):
-    ctx = dom_tag._with_contexts[_get_thread_context()]
-    slf, items, used = ctx[-1]
-    ctx[-1] = None
-    for item in items:
-      if item in used: continue
+    thread_id = _get_thread_context()
+    stack = dom_tag._with_contexts[thread_id]
+    frame = stack.pop()
+    for item in frame.items:
+      if item in frame.used: continue
       self.add(item)
-    ctx.pop()
+    if not stack:
+      del dom_tag._with_contexts[thread_id]
+
 
   def __call__(self, func):
     '''
@@ -146,6 +155,7 @@ def f(*args, **kwargs):
         return func(*args, **kwargs) or tag
     return f
 
+
   def set_attribute(self, key, value):
     '''
     Add or update the value of an attribute.
@@ -178,6 +188,7 @@ def setdocument(self, doc):
         if not isinstance(i, dom_tag): return
         i.setdocument(doc)
 
+
   def add(self, *args):
     '''
     Add new child tags.
@@ -192,9 +203,9 @@ def add(self, *args):
         self.children.append(obj)
 
       elif isinstance(obj, dom_tag):
-        ctx = dom_tag._with_contexts[_get_thread_context()]
-        if ctx and ctx[-1]:
-          ctx[-1].used.add(obj)
+        stack = dom_tag._with_contexts.get(_get_thread_context())
+        if stack:
+          stack[-1].used.add(obj)
         self.children.append(obj)
         obj.parent = self
         obj.setdocument(self.document)
@@ -215,18 +226,22 @@ def add(self, *args):
 
     return args
 
+
   def add_raw_string(self, s):
     self.children.append(s)
 
+
   def remove(self, obj):
     self.children.remove(obj)
 
+
   def clear(self):
     for i in self.children:
       if isinstance(i, dom_tag) and i.parent is self:
         i.parent = None
     self.children = []
 
+
   def get(self, tag=None, **kwargs):
     '''
     Recursively searches children for tags of a certain
@@ -253,6 +268,7 @@ def get(self, tag=None, **kwargs):
         results.extend(child.get(tag, **kwargs))
     return results
 
+
   def __getitem__(self, key):
     '''
     Returns the stored value of the specified attribute or child
@@ -275,32 +291,37 @@ def __getitem__(self, key):
           'child tags and attributes, respectively.')
   __getattr__ = __getitem__
 
+
   def __len__(self):
     '''
     Number of child elements.
     '''
     return len(self.children)
 
+
   def __bool__(self):
     '''
     Hack for "if x" and __len__
     '''
     return True
   __nonzero__ = __bool__
 
+
   def __iter__(self):
     '''
     Iterates over child elements.
     '''
     return self.children.__iter__()
 
+
   def __contains__(self, item):
     '''
     Checks recursively if item is in children tree.
     Accepts both a string and a class.
     '''
     return bool(self.get(item))
 
+
   def __iadd__(self, obj):
     '''
     Reflexive binary addition simply adds tag as a child.
@@ -313,10 +334,12 @@ def __unicode__(self):
     return self.render()
   __str__ = __unicode__
 
+
   def render(self, indent='  ', pretty=True, xhtml=False):
     data = self._render([], 0, indent, pretty, xhtml)
     return u''.join(data)
 
+
   def _render(self, sb, indent_level, indent_str, pretty, xhtml):
     pretty = pretty and self.is_pretty
 
@@ -365,6 +388,7 @@ def _render_children(self, sb, indent_level, indent_str, pretty, xhtml):
 
     return inline
 
+
   def __repr__(self):
     name = '%s.%s' % (self.__module__, type(self).__name__)
 
@@ -432,18 +456,30 @@ def clean_pair(cls, attribute, value):
     return (attribute, value)
 
 
+_get_current_none = object()
+def get_current(default=_get_current_none):
+  '''
+  get the current tag being used as a with context or decorated function.
+  if no context is active, raises ValueError, or returns the default, if provided
+  '''
+  h = _get_thread_context()
+  ctx = dom_tag._with_contexts.get(h, None)
+  if ctx:
+    return ctx[-1].tag
+  if default is _get_current_none:
+    raise ValueError('no current context')
+  return default
+
+
 def attr(*args, **kwargs):
   '''
   Set attributes on the current active tag context
   '''
-  ctx = dom_tag._with_contexts[_get_thread_context()]
-  if ctx and ctx[-1]:
-    dicts = args + (kwargs,)
-    for d in dicts:
-      for attr, value in d.items():
-        ctx[-1].tag.set_attribute(*dom_tag.clean_pair(attr, value))
-  else:
-    raise ValueError('not in a tag context')
+  c = get_current()
+  dicts = args + (kwargs,)
+  for d in dicts:
+    for attr, value in d.items():
+      c.set_attribute(*dom_tag.clean_pair(attr, value))
 
 
 # escape() is used in render

dominate/tags.py

@@ -18,7 +18,7 @@
 Public License along with Dominate.  If not, see
 <http://www.gnu.org/licenses/>.
 '''
-from .dom_tag  import dom_tag, attr
+from .dom_tag  import dom_tag, attr, get_current
 from .dom1core import dom1core
 
 try:

dominate/util.py

@@ -21,8 +21,8 @@
 '''
 
 import re
-from .dom_tag import dom_tag
 
+from .dom_tag import dom_tag
 
 try:
   basestring = basestring

tests/test_dominate.py

@@ -0,0 +1,18 @@
+import pytest
+
+import dominate
+from dominate import tags
+from dominate import util
+
+def test_version():
+  import dominate
+  version = '2.6.0'
+  assert dominate.version == version
+  assert dominate.__version__ == version
+
+
+def test_context():
+  id1 = dominate.dom_tag._get_thread_context()
+  id2 = dominate.dom_tag._get_thread_context()
+  assert id1 == id2
+

tests/test_html.py

@@ -1,3 +1,4 @@
+import dominate
 from dominate.tags import *
 import pytest
 
@@ -6,12 +7,6 @@
 except NameError:
   xrange = range
 
-def test_version():
-  import dominate
-  version = '2.5.2'
-  assert dominate.version == version
-  assert dominate.__version__ == version
-
 
 def test_arguments():
   assert html(body(h1('Hello, pyy!'))).render() == \
@@ -29,7 +24,7 @@ def test_kwargs():
     cls="mydiv",
     data_name='foo',
     onclick='alert(1);').render() == \
-'''<div checked="checked" class="mydiv" data-name="foo" id="4" onclick="alert(1);"></div>'''
+  '''<div checked="checked" class="mydiv" data-name="foo" id="4" onclick="alert(1);"></div>'''
 
 
 def test_repr():
@@ -77,15 +72,15 @@ def test_iadd():
 </ul>'''
 
 
-# copy rest of examples here
-
-
 def test_context_manager():
+  other = div()
   h = ul()
   with h:
     li('One')
     li('Two')
     li('Three')
+    # added to other, so not added to h
+    other += li('Four')
 
   assert h.render() == \
 '''<ul>
@@ -186,6 +181,22 @@ def test_escape():
 <pre>&lt;&gt;</pre>'''
 
 
+def test_get_context():
+  with pytest.raises(ValueError):
+    d = get_current()
+
+  d = get_current(None)
+  assert d is None
+
+  with div() as d1:
+    d2 = span()
+    with d2:
+      d2p = get_current()
+    d1p = get_current()
+  assert d1 is d1p
+  assert d2 is d2p
+
+
 def test_attributes():
   d = div()
   d['id'] = 'foo'
@@ -248,6 +259,14 @@ def test_comment():
   assert d.render() == '<!--Hi there-->'
   assert div(d).render() == '<div>\n  <!--Hi there-->\n</div>'
 
+  d = comment('Hi ie user', condition='IE 6')
+  assert d.render() == '<!--[if IE 6]>Hi ie user<![endif]-->'
+
+  d = comment(div('Hi non-ie user'), condition='!IE', downlevel='revealed')
+  assert d.render() == '''<![if !IE]>
+<div>Hi non-ie user</div>
+<![endif]>'''
+
 
 def test_boolean_attributes():
   assert input_(type="checkbox", checked=True).render() == \

tests/test_utils.py

@@ -1,6 +1,9 @@
+import pytest
+
 from dominate.tags import *
 from dominate import util
 
+
 def test_include():
   import os
   try:
@@ -18,6 +21,7 @@ def test_include():
     except:
       pass
 
+
 def test_system():
   d = div()
   d += util.system('echo Hello World')
@@ -27,6 +31,7 @@ def test_system():
 def test_unescape():
   assert util.unescape('&amp;&lt;&gt;&#32;') == '&<> '
 
+
 def test_url():
   assert util.url_escape('hi there?') == 'hi%20there%3F'
-  assert util.url_unescape('hi%20there%3f') == 'hi there?'
+  assert util.url_unescape('hi%20there%3f') == 'hi there?'