class Template(DirectiveFactory):
"""Abstract template base class.
This class implements most of the template processing model, but does not
specify the syntax of templates.
"""
EXEC = StreamEventKind('EXEC')
"""Stream event kind representing a Python code suite to execute."""
EXPR = StreamEventKind('EXPR')
"""Stream event kind representing a Python expression."""
INCLUDE = StreamEventKind('INCLUDE')
"""Stream event kind representing the inclusion of another template."""
SUB = StreamEventKind('SUB')
"""Stream event kind representing a nested stream to which one or more
directives should be applied.
"""
serializer = None
_number_conv = unicode # function used to convert numbers to event data
def __init__(self, source, filepath=None, filename=None, loader=None,
encoding=None, lookup='strict', allow_exec=True):
"""Initialize a template from either a string, a file-like object, or
an already parsed markup stream.
:param source: a string, file-like object, or markup stream to read the
template from
:param filepath: the absolute path to the template file
:param filename: the path to the template file relative to the search
path
:param loader: the `TemplateLoader` to use for loading included
templates
:param encoding: the encoding of the `source`
:param lookup: the variable lookup mechanism; either "strict" (the
default), "lenient", or a custom lookup class
:param allow_exec: whether Python code blocks in templates should be
allowed
:note: Changed in 0.5: Added the `allow_exec` argument
"""
self.filepath = filepath or filename
self.filename = filename
self.loader = loader
self.lookup = lookup
self.allow_exec = allow_exec
self._init_filters()
self._prepared = False
if isinstance(source, basestring):
source = StringIO(source)
else:
source = source
try:
self._stream = self._parse(source, encoding)
except ParseError, e:
raise TemplateSyntaxError(e.msg, self.filepath, e.lineno, e.offset)
class EmptyTagFilter(object):
"""Combines `START` and `STOP` events into `EMPTY` events for elements that
have no contents.
"""
EMPTY = StreamEventKind('EMPTY')
def __call__(self, stream):
prev = (None, None, None)
for ev in stream:
if prev[0] is START:
if ev[0] is END:
prev = EMPTY, prev[1], prev[2]
yield prev
continue
else:
yield prev
if ev[0] is not START:
yield ev
prev = ev
class Template(DirectiveFactory):
"""Abstract template base class.
This class implements most of the template processing model, but does not
specify the syntax of templates.
"""
EXEC = StreamEventKind('EXEC')
"""Stream event kind representing a Python code suite to execute."""
EXPR = StreamEventKind('EXPR')
"""Stream event kind representing a Python expression."""
INCLUDE = StreamEventKind('INCLUDE')
"""Stream event kind representing the inclusion of another template."""
SUB = StreamEventKind('SUB')
"""Stream event kind representing a nested stream to which one or more
directives should be applied.
"""
serializer = None
_number_conv = str # function used to convert numbers to event data
def __init__(self,
source,
filepath=None,
filename=None,
loader=None,
encoding=None,
lookup='strict',
allow_exec=True):
"""Initialize a template from either a string, a file-like object, or
an already parsed markup stream.
:param source: a string, file-like object, or markup stream to read the
template from
:param filepath: the absolute path to the template file
:param filename: the path to the template file relative to the search
path
:param loader: the `TemplateLoader` to use for loading included
templates
:param encoding: the encoding of the `source`
:param lookup: the variable lookup mechanism; either "strict" (the
default), "lenient", or a custom lookup class
:param allow_exec: whether Python code blocks in templates should be
allowed
:note: Changed in 0.5: Added the `allow_exec` argument
"""
self.filepath = filepath or filename
self.filename = filename
self.loader = loader
self.lookup = lookup
self.allow_exec = allow_exec
self._init_filters()
self._init_loader()
self._prepared = False
if not isinstance(source, Stream) and not hasattr(source, 'read'):
if isinstance(source, str):
source = StringIO(source)
else:
source = BytesIO(source)
try:
self._stream = self._parse(source, encoding)
except ParseError as e:
raise TemplateSyntaxError(e.msg, self.filepath, e.lineno, e.offset)
def __getstate__(self):
state = self.__dict__.copy()
state['filters'] = []
return state
def __setstate__(self, state):
self.__dict__ = state
self._init_filters()
def __repr__(self):
return '<%s "%s">' % (type(self).__name__, self.filename)
def _init_filters(self):
self.filters = [self._flatten, self._include]
def _init_loader(self):
if self.loader is None:
from genshi.template.loader import TemplateLoader
if self.filename:
if self.filepath != self.filename:
basedir = os.path.normpath(
self.filepath)[:-len(os.path.normpath(self.filename))]
else:
basedir = os.path.dirname(self.filename)
else:
basedir = '.'
self.loader = TemplateLoader([os.path.abspath(basedir)])
@property
def stream(self):
if not self._prepared:
self._prepare_self()
return self._stream
def _parse(self, source, encoding):
"""Parse the template.
The parsing stage parses the template and constructs a list of
directives that will be executed in the render stage. The input is
split up into literal output (text that does not depend on the context
data) and directives or expressions.
:param source: a file-like object containing the XML source of the
template, or an XML event stream
:param encoding: the encoding of the `source`
"""
raise NotImplementedError
def _prepare_self(self, inlined=None):
if not self._prepared:
self._stream = list(self._prepare(self._stream, inlined))
self._prepared = True
def _prepare(self, stream, inlined):
"""Call the `attach` method of every directive found in the template.
:param stream: the event stream of the template
"""
from genshi.template.loader import TemplateNotFound
if inlined is None:
inlined = set((self.filepath, ))
for kind, data, pos in stream:
if kind is SUB:
directives = []
substream = data[1]
for _, cls, value, namespaces, pos in sorted(data[0]):
directive, substream = cls.attach(self, substream, value,
namespaces, pos)
if directive:
directives.append(directive)
substream = self._prepare(substream, inlined)
if directives:
yield kind, (directives, list(substream)), pos
else:
for event in substream:
yield event
else:
if kind is INCLUDE:
href, cls, fallback = data
tmpl_inlined = False
if (isinstance(href, str)
and not getattr(self.loader, 'auto_reload', True)):
# If the path to the included template is static, and
# auto-reloading is disabled on the template loader,
# the template is inlined into the stream provided it
# is not already in the stack of templates being
# processed.
tmpl = None
try:
tmpl = self.loader.load(href,
relative_to=pos[0],
cls=cls or self.__class__)
except TemplateNotFound:
if fallback is None:
raise
if tmpl is not None:
if tmpl.filepath not in inlined:
inlined.add(tmpl.filepath)
tmpl._prepare_self(inlined)
for event in tmpl.stream:
yield event
inlined.discard(tmpl.filepath)
tmpl_inlined = True
else:
for event in self._prepare(fallback, inlined):
yield event
tmpl_inlined = True
if tmpl_inlined:
continue
if fallback:
# Otherwise the include is performed at run time
data = href, cls, list(self._prepare(
fallback, inlined))
yield kind, data, pos
else:
yield kind, data, pos
def generate(self, *args, **kwargs):
"""Apply the template to the given context data.
Any keyword arguments are made available to the template as context
data.
Only one positional argument is accepted: if it is provided, it must be
an instance of the `Context` class, and keyword arguments are ignored.
This calling style is used for internal processing.
:return: a markup event stream representing the result of applying
the template to the context data.
"""
vars = {}
if args:
assert len(args) == 1
ctxt = args[0]
if ctxt is None:
ctxt = Context(**kwargs)
else:
vars = kwargs
assert isinstance(ctxt, Context)
else:
ctxt = Context(**kwargs)
stream = self.stream
for filter_ in self.filters:
stream = filter_(iter(stream), ctxt, **vars)
return Stream(stream, self.serializer)
def _flatten(self, stream, ctxt, **vars):
number_conv = self._number_conv
stack = []
push = stack.append
pop = stack.pop
stream = iter(stream)
while 1:
for kind, data, pos in stream:
if kind is START and data[1]:
# Attributes may still contain expressions in start tags at
# this point, so do some evaluation
tag, attrs = data
new_attrs = []
for name, value in attrs:
if type(value
) is list: # this is an interpolated string
values = [
event[1] for event in self._flatten(
value, ctxt, **vars)
if event[0] is TEXT and event[1] is not None
]
if not values:
continue
value = ''.join(values)
new_attrs.append((name, value))
yield kind, (tag, Attrs(new_attrs)), pos
elif kind is EXPR:
result = _eval_expr(data, ctxt, vars)
if result is not None:
# First check for a string, otherwise the iterable test
# below succeeds, and the string will be chopped up into
# individual characters
if isinstance(result, str):
yield TEXT, result, pos
elif isinstance(result, (int, float)):
yield TEXT, number_conv(result), pos
elif hasattr(result, '__iter__'):
push(stream)
stream = _ensure(result)
break
else:
yield TEXT, str(result), pos
elif kind is SUB:
# This event is a list of directives and a list of nested
# events to which those directives should be applied
push(stream)
stream = _apply_directives(data[1], data[0], ctxt, vars)
break
elif kind is EXEC:
_exec_suite(data, ctxt, vars)
else:
yield kind, data, pos
else:
if not stack:
break
stream = pop()
def _include(self, stream, ctxt, **vars):
"""Internal stream filter that performs inclusion of external
template files.
"""
from genshi.template.loader import TemplateNotFound
for event in stream:
if event[0] is INCLUDE:
href, cls, fallback = event[1]
if not isinstance(href, str):
parts = []
for subkind, subdata, subpos in self._flatten(
href, ctxt, **vars):
if subkind is TEXT:
parts.append(subdata)
href = ''.join([x for x in parts if x is not None])
try:
tmpl = self.loader.load(href,
relative_to=event[2][0],
cls=cls or self.__class__)
for event in tmpl.generate(ctxt, **vars):
yield event
except TemplateNotFound:
if fallback is None:
raise
for filter_ in self.filters:
fallback = filter_(iter(fallback), ctxt, **vars)
for event in fallback:
yield event
else:
yield event
from types import FunctionType
from genshi.core import Attrs, Namespace, QName, START, END, TEXT, \
XML_NAMESPACE, _ensure, StreamEventKind
from genshi.template.eval import _ast
from genshi.template.base import DirectiveFactory, EXPR, SUB, _apply_directives
from genshi.template.directives import Directive, StripDirective
from genshi.template.markup import MarkupTemplate, EXEC
from genshi.compat import IS_PYTHON2
__all__ = ['Translator', 'extract']
__docformat__ = 'restructuredtext en'
I18N_NAMESPACE = Namespace('http://genshi.edgewall.org/i18n')
MSGBUF = StreamEventKind('MSGBUF')
SUB_START = StreamEventKind('SUB_START')
SUB_END = StreamEventKind('SUB_END')
GETTEXT_FUNCTIONS = ('_', 'gettext', 'ngettext', 'dgettext', 'dngettext',
'ugettext', 'ungettext')
class I18NDirective(Directive):
"""Simple interface for i18n directives to support messages extraction."""
def __call__(self, stream, directives, ctxt, **vars):
return _apply_directives(stream, directives, ctxt, vars)
class ExtractableI18NDirective(I18NDirective):
"""Simple interface for directives to support messages extraction."""