866 lines
30 KiB
Python
866 lines
30 KiB
Python
#!/usr/bin/env python
|
|
#
|
|
# Copyright 2009 Facebook
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
# not use this file except in compliance with the License. You may obtain
|
|
# a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
# License for the specific language governing permissions and limitations
|
|
# under the License.
|
|
|
|
"""A simple template system that compiles templates to Python code.
|
|
|
|
Basic usage looks like::
|
|
|
|
t = template.Template("<html>{{ myvalue }}</html>")
|
|
print t.generate(myvalue="XXX")
|
|
|
|
`Loader` is a class that loads templates from a root directory and caches
|
|
the compiled templates::
|
|
|
|
loader = template.Loader("/home/btaylor")
|
|
print loader.load("test.html").generate(myvalue="XXX")
|
|
|
|
We compile all templates to raw Python. Error-reporting is currently... uh,
|
|
interesting. Syntax for the templates::
|
|
|
|
### base.html
|
|
<html>
|
|
<head>
|
|
<title>{% block title %}Default title{% end %}</title>
|
|
</head>
|
|
<body>
|
|
<ul>
|
|
{% for student in students %}
|
|
{% block student %}
|
|
<li>{{ escape(student.name) }}</li>
|
|
{% end %}
|
|
{% end %}
|
|
</ul>
|
|
</body>
|
|
</html>
|
|
|
|
### bold.html
|
|
{% extends "base.html" %}
|
|
|
|
{% block title %}A bolder title{% end %}
|
|
|
|
{% block student %}
|
|
<li><span style="bold">{{ escape(student.name) }}</span></li>
|
|
{% end %}
|
|
|
|
Unlike most other template systems, we do not put any restrictions on the
|
|
expressions you can include in your statements. ``if`` and ``for`` blocks get
|
|
translated exactly into Python, so you can do complex expressions like::
|
|
|
|
{% for student in [p for p in people if p.student and p.age > 23] %}
|
|
<li>{{ escape(student.name) }}</li>
|
|
{% end %}
|
|
|
|
Translating directly to Python means you can apply functions to expressions
|
|
easily, like the ``escape()`` function in the examples above. You can pass
|
|
functions in to your template just like any other variable
|
|
(In a `.RequestHandler`, override `.RequestHandler.get_template_namespace`)::
|
|
|
|
### Python code
|
|
def add(x, y):
|
|
return x + y
|
|
template.execute(add=add)
|
|
|
|
### The template
|
|
{{ add(1, 2) }}
|
|
|
|
We provide the functions `escape() <.xhtml_escape>`, `.url_escape()`,
|
|
`.json_encode()`, and `.squeeze()` to all templates by default.
|
|
|
|
Typical applications do not create `Template` or `Loader` instances by
|
|
hand, but instead use the `~.RequestHandler.render` and
|
|
`~.RequestHandler.render_string` methods of
|
|
`tornado.web.RequestHandler`, which load templates automatically based
|
|
on the ``template_path`` `.Application` setting.
|
|
|
|
Variable names beginning with ``_tt_`` are reserved by the template
|
|
system and should not be used by application code.
|
|
|
|
Syntax Reference
|
|
----------------
|
|
|
|
Template expressions are surrounded by double curly braces: ``{{ ... }}``.
|
|
The contents may be any python expression, which will be escaped according
|
|
to the current autoescape setting and inserted into the output. Other
|
|
template directives use ``{% %}``. These tags may be escaped as ``{{!``
|
|
and ``{%!`` if you need to include a literal ``{{`` or ``{%`` in the output.
|
|
|
|
To comment out a section so that it is omitted from the output, surround it
|
|
with ``{# ... #}``.
|
|
|
|
``{% apply *function* %}...{% end %}``
|
|
Applies a function to the output of all template code between ``apply``
|
|
and ``end``::
|
|
|
|
{% apply linkify %}{{name}} said: {{message}}{% end %}
|
|
|
|
Note that as an implementation detail apply blocks are implemented
|
|
as nested functions and thus may interact strangely with variables
|
|
set via ``{% set %}``, or the use of ``{% break %}`` or ``{% continue %}``
|
|
within loops.
|
|
|
|
``{% autoescape *function* %}``
|
|
Sets the autoescape mode for the current file. This does not affect
|
|
other files, even those referenced by ``{% include %}``. Note that
|
|
autoescaping can also be configured globally, at the `.Application`
|
|
or `Loader`.::
|
|
|
|
{% autoescape xhtml_escape %}
|
|
{% autoescape None %}
|
|
|
|
``{% block *name* %}...{% end %}``
|
|
Indicates a named, replaceable block for use with ``{% extends %}``.
|
|
Blocks in the parent template will be replaced with the contents of
|
|
the same-named block in a child template.::
|
|
|
|
<!-- base.html -->
|
|
<title>{% block title %}Default title{% end %}</title>
|
|
|
|
<!-- mypage.html -->
|
|
{% extends "base.html" %}
|
|
{% block title %}My page title{% end %}
|
|
|
|
``{% comment ... %}``
|
|
A comment which will be removed from the template output. Note that
|
|
there is no ``{% end %}`` tag; the comment goes from the word ``comment``
|
|
to the closing ``%}`` tag.
|
|
|
|
``{% extends *filename* %}``
|
|
Inherit from another template. Templates that use ``extends`` should
|
|
contain one or more ``block`` tags to replace content from the parent
|
|
template. Anything in the child template not contained in a ``block``
|
|
tag will be ignored. For an example, see the ``{% block %}`` tag.
|
|
|
|
``{% for *var* in *expr* %}...{% end %}``
|
|
Same as the python ``for`` statement. ``{% break %}`` and
|
|
``{% continue %}`` may be used inside the loop.
|
|
|
|
``{% from *x* import *y* %}``
|
|
Same as the python ``import`` statement.
|
|
|
|
``{% if *condition* %}...{% elif *condition* %}...{% else %}...{% end %}``
|
|
Conditional statement - outputs the first section whose condition is
|
|
true. (The ``elif`` and ``else`` sections are optional)
|
|
|
|
``{% import *module* %}``
|
|
Same as the python ``import`` statement.
|
|
|
|
``{% include *filename* %}``
|
|
Includes another template file. The included file can see all the local
|
|
variables as if it were copied directly to the point of the ``include``
|
|
directive (the ``{% autoescape %}`` directive is an exception).
|
|
Alternately, ``{% module Template(filename, **kwargs) %}`` may be used
|
|
to include another template with an isolated namespace.
|
|
|
|
``{% module *expr* %}``
|
|
Renders a `~tornado.web.UIModule`. The output of the ``UIModule`` is
|
|
not escaped::
|
|
|
|
{% module Template("foo.html", arg=42) %}
|
|
|
|
``UIModules`` are a feature of the `tornado.web.RequestHandler`
|
|
class (and specifically its ``render`` method) and will not work
|
|
when the template system is used on its own in other contexts.
|
|
|
|
``{% raw *expr* %}``
|
|
Outputs the result of the given expression without autoescaping.
|
|
|
|
``{% set *x* = *y* %}``
|
|
Sets a local variable.
|
|
|
|
``{% try %}...{% except %}...{% else %}...{% finally %}...{% end %}``
|
|
Same as the python ``try`` statement.
|
|
|
|
``{% while *condition* %}... {% end %}``
|
|
Same as the python ``while`` statement. ``{% break %}`` and
|
|
``{% continue %}`` may be used inside the loop.
|
|
"""
|
|
|
|
from __future__ import absolute_import, division, print_function, with_statement
|
|
|
|
import datetime
|
|
import linecache
|
|
import os.path
|
|
import posixpath
|
|
import re
|
|
import threading
|
|
|
|
from tornado import escape
|
|
from tornado.log import app_log
|
|
from tornado.util import ObjectDict, exec_in, unicode_type
|
|
|
|
try:
|
|
from cStringIO import StringIO # py2
|
|
except ImportError:
|
|
from io import StringIO # py3
|
|
|
|
_DEFAULT_AUTOESCAPE = "xhtml_escape"
|
|
_UNSET = object()
|
|
|
|
|
|
class Template(object):
|
|
"""A compiled template.
|
|
|
|
We compile into Python from the given template_string. You can generate
|
|
the template from variables with generate().
|
|
"""
|
|
# note that the constructor's signature is not extracted with
|
|
# autodoc because _UNSET looks like garbage. When changing
|
|
# this signature update website/sphinx/template.rst too.
|
|
def __init__(self, template_string, name="<string>", loader=None,
|
|
compress_whitespace=None, autoescape=_UNSET):
|
|
self.name = name
|
|
if compress_whitespace is None:
|
|
compress_whitespace = name.endswith(".html") or \
|
|
name.endswith(".js")
|
|
if autoescape is not _UNSET:
|
|
self.autoescape = autoescape
|
|
elif loader:
|
|
self.autoescape = loader.autoescape
|
|
else:
|
|
self.autoescape = _DEFAULT_AUTOESCAPE
|
|
self.namespace = loader.namespace if loader else {}
|
|
reader = _TemplateReader(name, escape.native_str(template_string))
|
|
self.file = _File(self, _parse(reader, self))
|
|
self.code = self._generate_python(loader, compress_whitespace)
|
|
self.loader = loader
|
|
try:
|
|
# Under python2.5, the fake filename used here must match
|
|
# the module name used in __name__ below.
|
|
# The dont_inherit flag prevents template.py's future imports
|
|
# from being applied to the generated code.
|
|
self.compiled = compile(
|
|
escape.to_unicode(self.code),
|
|
"%s.generated.py" % self.name.replace('.', '_'),
|
|
"exec", dont_inherit=True)
|
|
except Exception:
|
|
formatted_code = _format_code(self.code).rstrip()
|
|
app_log.error("%s code:\n%s", self.name, formatted_code)
|
|
raise
|
|
|
|
def generate(self, **kwargs):
|
|
"""Generate this template with the given arguments."""
|
|
namespace = {
|
|
"escape": escape.xhtml_escape,
|
|
"xhtml_escape": escape.xhtml_escape,
|
|
"url_escape": escape.url_escape,
|
|
"json_encode": escape.json_encode,
|
|
"squeeze": escape.squeeze,
|
|
"linkify": escape.linkify,
|
|
"datetime": datetime,
|
|
"_tt_utf8": escape.utf8, # for internal use
|
|
"_tt_string_types": (unicode_type, bytes),
|
|
# __name__ and __loader__ allow the traceback mechanism to find
|
|
# the generated source code.
|
|
"__name__": self.name.replace('.', '_'),
|
|
"__loader__": ObjectDict(get_source=lambda name: self.code),
|
|
}
|
|
namespace.update(self.namespace)
|
|
namespace.update(kwargs)
|
|
exec_in(self.compiled, namespace)
|
|
execute = namespace["_tt_execute"]
|
|
# Clear the traceback module's cache of source data now that
|
|
# we've generated a new template (mainly for this module's
|
|
# unittests, where different tests reuse the same name).
|
|
linecache.clearcache()
|
|
return execute()
|
|
|
|
def _generate_python(self, loader, compress_whitespace):
|
|
buffer = StringIO()
|
|
try:
|
|
# named_blocks maps from names to _NamedBlock objects
|
|
named_blocks = {}
|
|
ancestors = self._get_ancestors(loader)
|
|
ancestors.reverse()
|
|
for ancestor in ancestors:
|
|
ancestor.find_named_blocks(loader, named_blocks)
|
|
writer = _CodeWriter(buffer, named_blocks, loader, ancestors[0].template,
|
|
compress_whitespace)
|
|
ancestors[0].generate(writer)
|
|
return buffer.getvalue()
|
|
finally:
|
|
buffer.close()
|
|
|
|
def _get_ancestors(self, loader):
|
|
ancestors = [self.file]
|
|
for chunk in self.file.body.chunks:
|
|
if isinstance(chunk, _ExtendsBlock):
|
|
if not loader:
|
|
raise ParseError("{% extends %} block found, but no "
|
|
"template loader")
|
|
template = loader.load(chunk.name, self.name)
|
|
ancestors.extend(template._get_ancestors(loader))
|
|
return ancestors
|
|
|
|
|
|
class BaseLoader(object):
|
|
"""Base class for template loaders.
|
|
|
|
You must use a template loader to use template constructs like
|
|
``{% extends %}`` and ``{% include %}``. The loader caches all
|
|
templates after they are loaded the first time.
|
|
"""
|
|
def __init__(self, autoescape=_DEFAULT_AUTOESCAPE, namespace=None):
|
|
"""``autoescape`` must be either None or a string naming a function
|
|
in the template namespace, such as "xhtml_escape".
|
|
"""
|
|
self.autoescape = autoescape
|
|
self.namespace = namespace or {}
|
|
self.templates = {}
|
|
# self.lock protects self.templates. It's a reentrant lock
|
|
# because templates may load other templates via `include` or
|
|
# `extends`. Note that thanks to the GIL this code would be safe
|
|
# even without the lock, but could lead to wasted work as multiple
|
|
# threads tried to compile the same template simultaneously.
|
|
self.lock = threading.RLock()
|
|
|
|
def reset(self):
|
|
"""Resets the cache of compiled templates."""
|
|
with self.lock:
|
|
self.templates = {}
|
|
|
|
def resolve_path(self, name, parent_path=None):
|
|
"""Converts a possibly-relative path to absolute (used internally)."""
|
|
raise NotImplementedError()
|
|
|
|
def load(self, name, parent_path=None):
|
|
"""Loads a template."""
|
|
name = self.resolve_path(name, parent_path=parent_path)
|
|
with self.lock:
|
|
if name not in self.templates:
|
|
self.templates[name] = self._create_template(name)
|
|
return self.templates[name]
|
|
|
|
def _create_template(self, name):
|
|
raise NotImplementedError()
|
|
|
|
|
|
class Loader(BaseLoader):
|
|
"""A template loader that loads from a single root directory.
|
|
"""
|
|
def __init__(self, root_directory, **kwargs):
|
|
super(Loader, self).__init__(**kwargs)
|
|
self.root = os.path.abspath(root_directory)
|
|
|
|
def resolve_path(self, name, parent_path=None):
|
|
if parent_path and not parent_path.startswith("<") and \
|
|
not parent_path.startswith("/") and \
|
|
not name.startswith("/"):
|
|
current_path = os.path.join(self.root, parent_path)
|
|
file_dir = os.path.dirname(os.path.abspath(current_path))
|
|
relative_path = os.path.abspath(os.path.join(file_dir, name))
|
|
if relative_path.startswith(self.root):
|
|
name = relative_path[len(self.root) + 1:]
|
|
return name
|
|
|
|
def _create_template(self, name):
|
|
path = os.path.join(self.root, name)
|
|
with open(path, "rb") as f:
|
|
template = Template(f.read(), name=name, loader=self)
|
|
return template
|
|
|
|
|
|
class DictLoader(BaseLoader):
|
|
"""A template loader that loads from a dictionary."""
|
|
def __init__(self, dict, **kwargs):
|
|
super(DictLoader, self).__init__(**kwargs)
|
|
self.dict = dict
|
|
|
|
def resolve_path(self, name, parent_path=None):
|
|
if parent_path and not parent_path.startswith("<") and \
|
|
not parent_path.startswith("/") and \
|
|
not name.startswith("/"):
|
|
file_dir = posixpath.dirname(parent_path)
|
|
name = posixpath.normpath(posixpath.join(file_dir, name))
|
|
return name
|
|
|
|
def _create_template(self, name):
|
|
return Template(self.dict[name], name=name, loader=self)
|
|
|
|
|
|
class _Node(object):
|
|
def each_child(self):
|
|
return ()
|
|
|
|
def generate(self, writer):
|
|
raise NotImplementedError()
|
|
|
|
def find_named_blocks(self, loader, named_blocks):
|
|
for child in self.each_child():
|
|
child.find_named_blocks(loader, named_blocks)
|
|
|
|
|
|
class _File(_Node):
|
|
def __init__(self, template, body):
|
|
self.template = template
|
|
self.body = body
|
|
self.line = 0
|
|
|
|
def generate(self, writer):
|
|
writer.write_line("def _tt_execute():", self.line)
|
|
with writer.indent():
|
|
writer.write_line("_tt_buffer = []", self.line)
|
|
writer.write_line("_tt_append = _tt_buffer.append", self.line)
|
|
self.body.generate(writer)
|
|
writer.write_line("return _tt_utf8('').join(_tt_buffer)", self.line)
|
|
|
|
def each_child(self):
|
|
return (self.body,)
|
|
|
|
|
|
class _ChunkList(_Node):
|
|
def __init__(self, chunks):
|
|
self.chunks = chunks
|
|
|
|
def generate(self, writer):
|
|
for chunk in self.chunks:
|
|
chunk.generate(writer)
|
|
|
|
def each_child(self):
|
|
return self.chunks
|
|
|
|
|
|
class _NamedBlock(_Node):
|
|
def __init__(self, name, body, template, line):
|
|
self.name = name
|
|
self.body = body
|
|
self.template = template
|
|
self.line = line
|
|
|
|
def each_child(self):
|
|
return (self.body,)
|
|
|
|
def generate(self, writer):
|
|
block = writer.named_blocks[self.name]
|
|
with writer.include(block.template, self.line):
|
|
block.body.generate(writer)
|
|
|
|
def find_named_blocks(self, loader, named_blocks):
|
|
named_blocks[self.name] = self
|
|
_Node.find_named_blocks(self, loader, named_blocks)
|
|
|
|
|
|
class _ExtendsBlock(_Node):
|
|
def __init__(self, name):
|
|
self.name = name
|
|
|
|
|
|
class _IncludeBlock(_Node):
|
|
def __init__(self, name, reader, line):
|
|
self.name = name
|
|
self.template_name = reader.name
|
|
self.line = line
|
|
|
|
def find_named_blocks(self, loader, named_blocks):
|
|
included = loader.load(self.name, self.template_name)
|
|
included.file.find_named_blocks(loader, named_blocks)
|
|
|
|
def generate(self, writer):
|
|
included = writer.loader.load(self.name, self.template_name)
|
|
with writer.include(included, self.line):
|
|
included.file.body.generate(writer)
|
|
|
|
|
|
class _ApplyBlock(_Node):
|
|
def __init__(self, method, line, body=None):
|
|
self.method = method
|
|
self.line = line
|
|
self.body = body
|
|
|
|
def each_child(self):
|
|
return (self.body,)
|
|
|
|
def generate(self, writer):
|
|
method_name = "_tt_apply%d" % writer.apply_counter
|
|
writer.apply_counter += 1
|
|
writer.write_line("def %s():" % method_name, self.line)
|
|
with writer.indent():
|
|
writer.write_line("_tt_buffer = []", self.line)
|
|
writer.write_line("_tt_append = _tt_buffer.append", self.line)
|
|
self.body.generate(writer)
|
|
writer.write_line("return _tt_utf8('').join(_tt_buffer)", self.line)
|
|
writer.write_line("_tt_append(_tt_utf8(%s(%s())))" % (
|
|
self.method, method_name), self.line)
|
|
|
|
|
|
class _ControlBlock(_Node):
|
|
def __init__(self, statement, line, body=None):
|
|
self.statement = statement
|
|
self.line = line
|
|
self.body = body
|
|
|
|
def each_child(self):
|
|
return (self.body,)
|
|
|
|
def generate(self, writer):
|
|
writer.write_line("%s:" % self.statement, self.line)
|
|
with writer.indent():
|
|
self.body.generate(writer)
|
|
# Just in case the body was empty
|
|
writer.write_line("pass", self.line)
|
|
|
|
|
|
class _IntermediateControlBlock(_Node):
|
|
def __init__(self, statement, line):
|
|
self.statement = statement
|
|
self.line = line
|
|
|
|
def generate(self, writer):
|
|
# In case the previous block was empty
|
|
writer.write_line("pass", self.line)
|
|
writer.write_line("%s:" % self.statement, self.line, writer.indent_size() - 1)
|
|
|
|
|
|
class _Statement(_Node):
|
|
def __init__(self, statement, line):
|
|
self.statement = statement
|
|
self.line = line
|
|
|
|
def generate(self, writer):
|
|
writer.write_line(self.statement, self.line)
|
|
|
|
|
|
class _Expression(_Node):
|
|
def __init__(self, expression, line, raw=False):
|
|
self.expression = expression
|
|
self.line = line
|
|
self.raw = raw
|
|
|
|
def generate(self, writer):
|
|
writer.write_line("_tt_tmp = %s" % self.expression, self.line)
|
|
writer.write_line("if isinstance(_tt_tmp, _tt_string_types):"
|
|
" _tt_tmp = _tt_utf8(_tt_tmp)", self.line)
|
|
writer.write_line("else: _tt_tmp = _tt_utf8(str(_tt_tmp))", self.line)
|
|
if not self.raw and writer.current_template.autoescape is not None:
|
|
# In python3 functions like xhtml_escape return unicode,
|
|
# so we have to convert to utf8 again.
|
|
writer.write_line("_tt_tmp = _tt_utf8(%s(_tt_tmp))" %
|
|
writer.current_template.autoescape, self.line)
|
|
writer.write_line("_tt_append(_tt_tmp)", self.line)
|
|
|
|
|
|
class _Module(_Expression):
|
|
def __init__(self, expression, line):
|
|
super(_Module, self).__init__("_tt_modules." + expression, line,
|
|
raw=True)
|
|
|
|
|
|
class _Text(_Node):
|
|
def __init__(self, value, line):
|
|
self.value = value
|
|
self.line = line
|
|
|
|
def generate(self, writer):
|
|
value = self.value
|
|
|
|
# Compress lots of white space to a single character. If the whitespace
|
|
# breaks a line, have it continue to break a line, but just with a
|
|
# single \n character
|
|
if writer.compress_whitespace and "<pre>" not in value:
|
|
value = re.sub(r"([\t ]+)", " ", value)
|
|
value = re.sub(r"(\s*\n\s*)", "\n", value)
|
|
|
|
if value:
|
|
writer.write_line('_tt_append(%r)' % escape.utf8(value), self.line)
|
|
|
|
|
|
class ParseError(Exception):
|
|
"""Raised for template syntax errors."""
|
|
pass
|
|
|
|
|
|
class _CodeWriter(object):
|
|
def __init__(self, file, named_blocks, loader, current_template,
|
|
compress_whitespace):
|
|
self.file = file
|
|
self.named_blocks = named_blocks
|
|
self.loader = loader
|
|
self.current_template = current_template
|
|
self.compress_whitespace = compress_whitespace
|
|
self.apply_counter = 0
|
|
self.include_stack = []
|
|
self._indent = 0
|
|
|
|
def indent_size(self):
|
|
return self._indent
|
|
|
|
def indent(self):
|
|
class Indenter(object):
|
|
def __enter__(_):
|
|
self._indent += 1
|
|
return self
|
|
|
|
def __exit__(_, *args):
|
|
assert self._indent > 0
|
|
self._indent -= 1
|
|
|
|
return Indenter()
|
|
|
|
def include(self, template, line):
|
|
self.include_stack.append((self.current_template, line))
|
|
self.current_template = template
|
|
|
|
class IncludeTemplate(object):
|
|
def __enter__(_):
|
|
return self
|
|
|
|
def __exit__(_, *args):
|
|
self.current_template = self.include_stack.pop()[0]
|
|
|
|
return IncludeTemplate()
|
|
|
|
def write_line(self, line, line_number, indent=None):
|
|
if indent is None:
|
|
indent = self._indent
|
|
line_comment = ' # %s:%d' % (self.current_template.name, line_number)
|
|
if self.include_stack:
|
|
ancestors = ["%s:%d" % (tmpl.name, lineno)
|
|
for (tmpl, lineno) in self.include_stack]
|
|
line_comment += ' (via %s)' % ', '.join(reversed(ancestors))
|
|
print(" " * indent + line + line_comment, file=self.file)
|
|
|
|
|
|
class _TemplateReader(object):
|
|
def __init__(self, name, text):
|
|
self.name = name
|
|
self.text = text
|
|
self.line = 1
|
|
self.pos = 0
|
|
|
|
def find(self, needle, start=0, end=None):
|
|
assert start >= 0, start
|
|
pos = self.pos
|
|
start += pos
|
|
if end is None:
|
|
index = self.text.find(needle, start)
|
|
else:
|
|
end += pos
|
|
assert end >= start
|
|
index = self.text.find(needle, start, end)
|
|
if index != -1:
|
|
index -= pos
|
|
return index
|
|
|
|
def consume(self, count=None):
|
|
if count is None:
|
|
count = len(self.text) - self.pos
|
|
newpos = self.pos + count
|
|
self.line += self.text.count("\n", self.pos, newpos)
|
|
s = self.text[self.pos:newpos]
|
|
self.pos = newpos
|
|
return s
|
|
|
|
def remaining(self):
|
|
return len(self.text) - self.pos
|
|
|
|
def __len__(self):
|
|
return self.remaining()
|
|
|
|
def __getitem__(self, key):
|
|
if type(key) is slice:
|
|
size = len(self)
|
|
start, stop, step = key.indices(size)
|
|
if start is None:
|
|
start = self.pos
|
|
else:
|
|
start += self.pos
|
|
if stop is not None:
|
|
stop += self.pos
|
|
return self.text[slice(start, stop, step)]
|
|
elif key < 0:
|
|
return self.text[key]
|
|
else:
|
|
return self.text[self.pos + key]
|
|
|
|
def __str__(self):
|
|
return self.text[self.pos:]
|
|
|
|
|
|
def _format_code(code):
|
|
lines = code.splitlines()
|
|
format = "%%%dd %%s\n" % len(repr(len(lines) + 1))
|
|
return "".join([format % (i + 1, line) for (i, line) in enumerate(lines)])
|
|
|
|
|
|
def _parse(reader, template, in_block=None, in_loop=None):
|
|
body = _ChunkList([])
|
|
while True:
|
|
# Find next template directive
|
|
curly = 0
|
|
while True:
|
|
curly = reader.find("{", curly)
|
|
if curly == -1 or curly + 1 == reader.remaining():
|
|
# EOF
|
|
if in_block:
|
|
raise ParseError("Missing {%% end %%} block for %s" %
|
|
in_block)
|
|
body.chunks.append(_Text(reader.consume(), reader.line))
|
|
return body
|
|
# If the first curly brace is not the start of a special token,
|
|
# start searching from the character after it
|
|
if reader[curly + 1] not in ("{", "%", "#"):
|
|
curly += 1
|
|
continue
|
|
# When there are more than 2 curlies in a row, use the
|
|
# innermost ones. This is useful when generating languages
|
|
# like latex where curlies are also meaningful
|
|
if (curly + 2 < reader.remaining() and
|
|
reader[curly + 1] == '{' and reader[curly + 2] == '{'):
|
|
curly += 1
|
|
continue
|
|
break
|
|
|
|
# Append any text before the special token
|
|
if curly > 0:
|
|
cons = reader.consume(curly)
|
|
body.chunks.append(_Text(cons, reader.line))
|
|
|
|
start_brace = reader.consume(2)
|
|
line = reader.line
|
|
|
|
# Template directives may be escaped as "{{!" or "{%!".
|
|
# In this case output the braces and consume the "!".
|
|
# This is especially useful in conjunction with jquery templates,
|
|
# which also use double braces.
|
|
if reader.remaining() and reader[0] == "!":
|
|
reader.consume(1)
|
|
body.chunks.append(_Text(start_brace, line))
|
|
continue
|
|
|
|
# Comment
|
|
if start_brace == "{#":
|
|
end = reader.find("#}")
|
|
if end == -1:
|
|
raise ParseError("Missing end expression #} on line %d" % line)
|
|
contents = reader.consume(end).strip()
|
|
reader.consume(2)
|
|
continue
|
|
|
|
# Expression
|
|
if start_brace == "{{":
|
|
end = reader.find("}}")
|
|
if end == -1:
|
|
raise ParseError("Missing end expression }} on line %d" % line)
|
|
contents = reader.consume(end).strip()
|
|
reader.consume(2)
|
|
if not contents:
|
|
raise ParseError("Empty expression on line %d" % line)
|
|
body.chunks.append(_Expression(contents, line))
|
|
continue
|
|
|
|
# Block
|
|
assert start_brace == "{%", start_brace
|
|
end = reader.find("%}")
|
|
if end == -1:
|
|
raise ParseError("Missing end block %%} on line %d" % line)
|
|
contents = reader.consume(end).strip()
|
|
reader.consume(2)
|
|
if not contents:
|
|
raise ParseError("Empty block tag ({%% %%}) on line %d" % line)
|
|
|
|
operator, space, suffix = contents.partition(" ")
|
|
suffix = suffix.strip()
|
|
|
|
# Intermediate ("else", "elif", etc) blocks
|
|
intermediate_blocks = {
|
|
"else": set(["if", "for", "while", "try"]),
|
|
"elif": set(["if"]),
|
|
"except": set(["try"]),
|
|
"finally": set(["try"]),
|
|
}
|
|
allowed_parents = intermediate_blocks.get(operator)
|
|
if allowed_parents is not None:
|
|
if not in_block:
|
|
raise ParseError("%s outside %s block" %
|
|
(operator, allowed_parents))
|
|
if in_block not in allowed_parents:
|
|
raise ParseError("%s block cannot be attached to %s block" % (operator, in_block))
|
|
body.chunks.append(_IntermediateControlBlock(contents, line))
|
|
continue
|
|
|
|
# End tag
|
|
elif operator == "end":
|
|
if not in_block:
|
|
raise ParseError("Extra {%% end %%} block on line %d" % line)
|
|
return body
|
|
|
|
elif operator in ("extends", "include", "set", "import", "from",
|
|
"comment", "autoescape", "raw", "module"):
|
|
if operator == "comment":
|
|
continue
|
|
if operator == "extends":
|
|
suffix = suffix.strip('"').strip("'")
|
|
if not suffix:
|
|
raise ParseError("extends missing file path on line %d" % line)
|
|
block = _ExtendsBlock(suffix)
|
|
elif operator in ("import", "from"):
|
|
if not suffix:
|
|
raise ParseError("import missing statement on line %d" % line)
|
|
block = _Statement(contents, line)
|
|
elif operator == "include":
|
|
suffix = suffix.strip('"').strip("'")
|
|
if not suffix:
|
|
raise ParseError("include missing file path on line %d" % line)
|
|
block = _IncludeBlock(suffix, reader, line)
|
|
elif operator == "set":
|
|
if not suffix:
|
|
raise ParseError("set missing statement on line %d" % line)
|
|
block = _Statement(suffix, line)
|
|
elif operator == "autoescape":
|
|
fn = suffix.strip()
|
|
if fn == "None":
|
|
fn = None
|
|
template.autoescape = fn
|
|
continue
|
|
elif operator == "raw":
|
|
block = _Expression(suffix, line, raw=True)
|
|
elif operator == "module":
|
|
block = _Module(suffix, line)
|
|
body.chunks.append(block)
|
|
continue
|
|
|
|
elif operator in ("apply", "block", "try", "if", "for", "while"):
|
|
# parse inner body recursively
|
|
if operator in ("for", "while"):
|
|
block_body = _parse(reader, template, operator, operator)
|
|
elif operator == "apply":
|
|
# apply creates a nested function so syntactically it's not
|
|
# in the loop.
|
|
block_body = _parse(reader, template, operator, None)
|
|
else:
|
|
block_body = _parse(reader, template, operator, in_loop)
|
|
|
|
if operator == "apply":
|
|
if not suffix:
|
|
raise ParseError("apply missing method name on line %d" % line)
|
|
block = _ApplyBlock(suffix, line, block_body)
|
|
elif operator == "block":
|
|
if not suffix:
|
|
raise ParseError("block missing name on line %d" % line)
|
|
block = _NamedBlock(suffix, block_body, template, line)
|
|
else:
|
|
block = _ControlBlock(contents, line, block_body)
|
|
body.chunks.append(block)
|
|
continue
|
|
|
|
elif operator in ("break", "continue"):
|
|
if not in_loop:
|
|
raise ParseError("%s outside %s block" % (operator, set(["for", "while"])))
|
|
body.chunks.append(_Statement(contents, line))
|
|
continue
|
|
|
|
else:
|
|
raise ParseError("unknown operator: %r" % operator)
|