added parsing code for "for item in seq recursive" and improved parser interface a bit
--HG--
branch : trunk
diff --git a/docs/cache_extension.py b/docs/cache_extension.py
index 9f324d2..ec0067b 100644
--- a/docs/cache_extension.py
+++ b/docs/cache_extension.py
@@ -27,7 +27,7 @@
# if there is a comma, the user provided a timeout. If not use
# None as second parameter.
- if parser.skip_comma():
+ if parser.stream.skip_if('comma'):
args.append(parser.parse_expression())
else:
args.append(nodes.Const(None))
diff --git a/docs/extensions.rst b/docs/extensions.rst
index f5527f7..63e9cd9 100644
--- a/docs/extensions.rst
+++ b/docs/extensions.rst
@@ -155,7 +155,7 @@
.. autoclass:: jinja2.parser.Parser
:members: parse_expression, parse_tuple, parse_assign_target,
- parse_statements, skip_colon, skip_comma, free_identifier
+ parse_statements, free_identifier
.. attribute:: filename
@@ -169,7 +169,7 @@
The current :class:`~jinja2.lexer.TokenStream`
.. autoclass:: jinja2.lexer.TokenStream
- :members: push, look, eos, skip, next, expect
+ :members: push, look, eos, skip, next, next_if, skip_if, expect
.. attribute:: current
diff --git a/docs/index.rst b/docs/index.rst
index 308563a..43f3680 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -15,6 +15,7 @@
extensions
integration
switching
+ tricks
changelog
diff --git a/docs/templates.rst b/docs/templates.rst
index d7a0f91..ea19e2d 100644
--- a/docs/templates.rst
+++ b/docs/templates.rst
@@ -281,7 +281,8 @@
this template "extends" another template. When the template system evaluates
this template, first it locates the parent. The extends tag should be the
first tag in the template. Everything before it is printed out normally and
-may cause confusion.
+may cause confusion. For details about this behavior and how to take
+advantage of it, see :ref:`null-master-fallback`.
The filename of the template depends on the template loader. For example the
:class:`FileSystemLoader` allows you to access other templates by giving the
diff --git a/docs/tricks.rst b/docs/tricks.rst
new file mode 100644
index 0000000..6029ec5
--- /dev/null
+++ b/docs/tricks.rst
@@ -0,0 +1,81 @@
+Tipps and Tricks
+================
+
+.. highlight:: html+jinja
+
+This part of the documentation shows some tipps and tricks for Jinja2
+templates.
+
+
+.. _null-master-fallback:
+
+Null-Master Fallback
+--------------------
+
+Jinja2 supports dynamic inheritance and does not distinguish between parent
+and child template as long as no `extends` tag is visited. While this leads
+to the surprising behavior that everything before the first `extends` tag
+including whitespace is printed out instead of being igored, it can be used
+for a neat trick.
+
+Usually child templates extend from one template that adds a basic HTML
+skeleton. However it's possible put the `extends` tag into an `if` tag to
+only extend from the layout template if the `standalone` variable evaluates
+to false which it does per default if it's not defined. Additionally a very
+basic skeleton is added to the file so that if it's indeed rendered with
+`standalone` set to `True` a very basic HTML skeleton is added::
+
+ {% if not standalone %}{% extends 'master.html' %}{% endif -%}
+ <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
+ <title>{% block title %}The Page Title{% endblock %}</title>
+ <link rel="stylesheet" href="style.css" type="text/css">
+ {% block body %}
+ <p>This is the page body.</p>
+ {% endblock %}
+
+
+Alternating Rows
+----------------
+
+If you want to have different styles for each row of a table or
+list you can use the `cycle` method on the `loop` object::
+
+ <ul>
+ {% for row in rows %}
+ <li class="{{ loop.cycle('odd', 'even') }}">{{ row }}</li>
+ {% endfor %}
+ </ul>
+
+`cycle` can take an unlimited amount of strings. Each time this
+tag is encountered the next item from the list is rendered.
+
+
+Highlighting Active Menu Items
+------------------------------
+
+Often you want to have a navigation bar with an active navigation
+item. This is really simple to achieve. Because assignments outside
+of `block`\s in child templates are global and executed before the layout
+template is evaluated it's possible to define the active menu item in the
+child template::
+
+ {% extends "layout.html" %}
+ {% set active_page = "index" %}
+
+The layout template can then access `active_page`. Additionally it makes
+sense to defined a default for that variable::
+
+ {% navigation_bar = [
+ ('/', 'index', 'Index'),
+ ('/downloads/', 'downloads', 'Downloads'),
+ ('/about/', 'about', 'About')
+ ] -%}
+ {% active_page = active_page|default('index') -%}
+ ...
+ <ul id="navigation">
+ {% for href, id, caption in navigation_bar %}
+ <li{% if id == active_page %} class="active"{% endif
+ %}><a href="{{ href|e }}">{{ caption|e }}</a>/li>
+ {% endfor %}
+ </ul>
+ ...
diff --git a/jinja2/compiler.py b/jinja2/compiler.py
index 7b8366c..df1a85e 100644
--- a/jinja2/compiler.py
+++ b/jinja2/compiler.py
@@ -1175,8 +1175,8 @@
del binop, uaop
def visit_Concat(self, node, frame):
- self.write('%s((' % self.environment.autoescape and
- 'markup_join' or 'unicode_join')
+ self.write('%s((' % (self.environment.autoescape and
+ 'markup_join' or 'unicode_join'))
for arg in node.nodes:
self.visit(arg, frame)
self.write(', ')
diff --git a/jinja2/ext.py b/jinja2/ext.py
index 53b4041..aac7528 100644
--- a/jinja2/ext.py
+++ b/jinja2/ext.py
@@ -145,7 +145,7 @@
parser.stream.expect('comma')
# skip colon for python compatibility
- if parser.skip_colon():
+ if parser.stream.skip_if('colon'):
break
name = parser.stream.expect('name')
diff --git a/jinja2/lexer.py b/jinja2/lexer.py
index d950025..639b285 100644
--- a/jinja2/lexer.py
+++ b/jinja2/lexer.py
@@ -219,19 +219,27 @@
for x in xrange(n):
self.next()
- def next(self, skip_eol=True):
+ def next_if(self, expr):
+ """Perform the token test and return the token if it matched.
+ Otherwise the return value is `None`.
+ """
+ if self.current.test(expr):
+ return self.next()
+
+ def skip_if(self, expr):
+ """Like `next_if` but only returns `True` or `False`."""
+ return self.next_if(expr) is not None
+
+ def next(self):
"""Go one token ahead and return the old one"""
rv = self.current
- while 1:
- if self._pushed:
- self.current = self._pushed.popleft()
- elif self.current.type is not 'eof':
- try:
- self.current = self._next()
- except StopIteration:
- self.close()
- if not skip_eol or self.current.type is not 'eol':
- break
+ if self._pushed:
+ self.current = self._pushed.popleft()
+ elif self.current.type is not 'eof':
+ try:
+ self.current = self._next()
+ except StopIteration:
+ self.close()
return rv
def close(self):
diff --git a/jinja2/nodes.py b/jinja2/nodes.py
index 180478d..67f7559 100644
--- a/jinja2/nodes.py
+++ b/jinja2/nodes.py
@@ -273,7 +273,7 @@
For filtered nodes an expression can be stored as `test`, otherwise `None`.
"""
- fields = ('target', 'iter', 'body', 'else_', 'test')
+ fields = ('target', 'iter', 'body', 'else_', 'test', 'recursive')
class If(Stmt):
diff --git a/jinja2/parser.py b/jinja2/parser.py
index 8d23b5f..941e037 100644
--- a/jinja2/parser.py
+++ b/jinja2/parser.py
@@ -36,24 +36,12 @@
self.extensions[tag] = extension.parse
self._last_identifier = 0
- def is_tuple_end(self):
+ def is_tuple_end(self, extra_end_rules=None):
"""Are we at the end of a tuple?"""
- return self.stream.current.type in ('variable_end', 'block_end',
- 'rparen') or \
- self.stream.current.test('name:in')
-
- def skip_colon(self):
- """If there is a colon, skip it and return `True`, else `False`."""
- if self.stream.current.type is 'colon':
- self.stream.next()
+ if self.stream.current.type in ('variable_end', 'block_end', 'rparen'):
return True
- return False
-
- def skip_comma(self):
- """If there is a comma, skip it and return `True`, else `False`."""
- if self.stream.current.type is 'comma':
- self.stream.next()
- return True
+ elif extra_end_rules is not None:
+ return self.stream.current.test_any(extra_end_rules)
return False
def free_identifier(self, lineno=None):
@@ -107,7 +95,7 @@
can be set to `True` and the end token is removed.
"""
# the first token may be a colon for python compatibility
- self.skip_colon()
+ self.stream.skip_if('colon')
# in the future it would be possible to add whole code sections
# by adding some sort of end of statement token and parsing those here.
@@ -121,19 +109,21 @@
def parse_for(self):
"""Parse a for loop."""
lineno = self.stream.expect('name:for').lineno
- target = self.parse_assign_target()
+ target = self.parse_assign_target(extra_end_rules=('name:in',))
self.stream.expect('name:in')
- iter = self.parse_tuple(with_condexpr=False)
+ iter = self.parse_tuple(with_condexpr=False,
+ extra_end_rules=('name:recursive',))
test = None
- if self.stream.current.test('name:if'):
- self.stream.next()
+ if self.stream.skip_if('name:if'):
test = self.parse_expression()
+ recursive = self.stream.skip_if('name:recursive')
body = self.parse_statements(('name:endfor', 'name:else'))
if self.stream.next().value == 'endfor':
else_ = []
else:
else_ = self.parse_statements(('name:endfor',), drop_needle=True)
- return nodes.For(target, iter, body, else_, test, lineno=lineno)
+ return nodes.For(target, iter, body, else_, test,
+ recursive, lineno=lineno)
def parse_if(self):
"""Parse an if construct."""
@@ -214,8 +204,7 @@
'underscores can not be '
'imported', target.lineno,
self.filename)
- if self.stream.current.test('name:as'):
- self.stream.next()
+ if self.stream.skip_if('name:as'):
alias = self.parse_assign_target(name_only=True)
node.names.append((target.name, alias.name))
else:
@@ -226,8 +215,7 @@
break
if not hasattr(node, 'with_context'):
node.with_context = False
- if self.stream.current.type is 'comma':
- self.stream.next()
+ self.stream.skip_if('comma')
return node
def parse_signature(self, node):
@@ -238,8 +226,7 @@
if args:
self.stream.expect('comma')
arg = self.parse_assign_target(name_only=True)
- if self.stream.current.type is 'assign':
- self.stream.next()
+ if self.stream.skip_if('assign'):
defaults.append(self.parse_expression())
args.append(arg)
self.stream.expect('rparen')
@@ -283,19 +270,22 @@
node.nodes.append(self.parse_expression())
return node
- def parse_assign_target(self, with_tuple=True, name_only=False):
+ def parse_assign_target(self, with_tuple=True, name_only=False,
+ extra_end_rules=None):
"""Parse an assignment target. As Jinja2 allows assignments to
tuples, this function can parse all allowed assignment targets. Per
default assignments to tuples are parsed, that can be disable however
by setting `with_tuple` to `False`. If only assignments to names are
- wanted `name_only` can be set to `True`.
+ wanted `name_only` can be set to `True`. The `extra_end_rules`
+ parameter is forwarded to the tuple parsing function.
"""
if name_only:
token = self.stream.expect('name')
target = nodes.Name(token.value, 'store', lineno=token.lineno)
else:
if with_tuple:
- target = self.parse_tuple(simplified=True)
+ target = self.parse_tuple(simplified=True,
+ extra_end_rules=extra_end_rules)
else:
target = self.parse_primary(with_postfix=False)
target.set_ctx('store')
@@ -317,8 +307,7 @@
def parse_condexpr(self):
lineno = self.stream.current.lineno
expr1 = self.parse_or()
- while self.stream.current.test('name:if'):
- self.stream.next()
+ while self.stream.skip_if('name:if'):
expr2 = self.parse_or()
self.stream.expect('name:else')
expr3 = self.parse_condexpr()
@@ -329,8 +318,7 @@
def parse_or(self):
lineno = self.stream.current.lineno
left = self.parse_and()
- while self.stream.current.test('name:or'):
- self.stream.next()
+ while self.stream.skip_if('name:or'):
right = self.parse_and()
left = nodes.Or(left, right, lineno=lineno)
lineno = self.stream.current.lineno
@@ -339,8 +327,7 @@
def parse_and(self):
lineno = self.stream.current.lineno
left = self.parse_compare()
- while self.stream.current.test('name:and'):
- self.stream.next()
+ while self.stream.skip_if('name:and'):
right = self.parse_compare()
left = nodes.And(left, right, lineno=lineno)
lineno = self.stream.current.lineno
@@ -355,8 +342,7 @@
if token_type in _compare_operators:
self.stream.next()
ops.append(nodes.Operand(token_type, self.parse_add()))
- elif self.stream.current.test('name:in'):
- self.stream.next()
+ elif self.stream.skip_if('name:in'):
ops.append(nodes.Operand('in', self.parse_add()))
elif self.stream.current.test('name:not') and \
self.stream.look().test('name:in'):
@@ -495,7 +481,8 @@
node = self.parse_postfix(node)
return node
- def parse_tuple(self, simplified=False, with_condexpr=True):
+ def parse_tuple(self, simplified=False, with_condexpr=True,
+ extra_end_rules=None):
"""Works like `parse_expression` but if multiple expressions are
delimited by a comma a :class:`~jinja2.nodes.Tuple` node is created.
This method could also return a regular expression instead of a tuple
@@ -504,6 +491,11 @@
The default parsing mode is a full tuple. If `simplified` is `True`
only names and literals are parsed. The `no_condexpr` parameter is
forwarded to :meth:`parse_expression`.
+
+ Because tuples do not require delimiters and may end in a bogus comma
+ an extra hint is needed that marks the end of a tuple. For example
+ for loops support tuples between `for` and `in`. In that case the
+ `extra_end_rules` is set to ``['name:in']``.
"""
lineno = self.stream.current.lineno
if simplified:
@@ -517,7 +509,7 @@
while 1:
if args:
self.stream.expect('comma')
- if self.is_tuple_end():
+ if self.is_tuple_end(extra_end_rules):
break
args.append(parse())
if self.stream.current.type is 'comma':