# -*- coding: utf-8 -*-
"""The code for async support. Importing this patches Jinja on supported
Python versions.
"""
import asyncio
import inspect
from functools import update_wrapper
from markupsafe import Markup
from .environment import TemplateModule
from .runtime import LoopContext
from .utils import concat
from .utils import internalcode
from .utils import missing
async def concat_async(async_gen):
rv = []
async def collect():
async for event in async_gen:
rv.append(event)
await collect()
return concat(rv)
async def generate_async(self, *args, **kwargs):
vars = dict(*args, **kwargs)
try:
async for event in self.root_render_func(self.new_context(vars)):
yield event
except Exception:
yield self.environment.handle_exception()
def wrap_generate_func(original_generate):
def _convert_generator(self, loop, args, kwargs):
async_gen = self.generate_async(*args, **kwargs)
try:
while 1:
yield loop.run_until_complete(async_gen.__anext__())
except StopAsyncIteration:
pass
def generate(self, *args, **kwargs):
if not self.environment.is_async:
return original_generate(self, *args, **kwargs)
return _convert_generator(self, asyncio.get_event_loop(), args, kwargs)
return update_wrapper(generate, original_generate)
async def render_async(self, *args, **kwargs):
if not self.environment.is_async:
raise RuntimeError("The environment was not created with async mode enabled.")
vars = dict(*args, **kwargs)
ctx = self.new_context(vars)
try:
return await concat_async(self.root_render_func(ctx))
except Exception:
return self.environment.handle_exception()
def wrap_render_func(original_render):
def render(self, *args, **kwargs):
if not self.environment.is_async:
return original_render(self, *args, **kwargs)
loop = asyncio.get_event_loop()
return loop.run_until_complete(self.render_async(*args, **kwargs))
return update_wrapper(render, original_render)
def wrap_block_reference_call(original_call):
@internalcode
async def async_call(self):
rv = await concat_async(self._stack[self._depth](self._context))
if self._context.eval_ctx.autoescape:
rv = Markup(rv)
return rv
@internalcode
def __call__(self):
if not self._context.environment.is_async:
return original_call(self)
return async_call(self)
return update_wrapper(__call__, original_call)
def wrap_macro_invoke(original_invoke):
@internalcode
async def async_invoke(self, arguments, autoescape):
rv = await self._func(*arguments)
if autoescape:
rv = Markup(rv)
return rv
@internalcode
def _invoke(self, arguments, autoescape):
if not self._environment.is_async:
return original_invoke(self, arguments, autoescape)
return async_invoke(self, arguments, autoescape)
return update_wrapper(_invoke, original_invoke)
@internalcode
async def get_default_module_async(self):
if self._module is not None:
return self._module
self._module = rv = await self.make_module_async()
return rv
def wrap_default_module(original_default_module):
@internalcode
def _get_default_module(self):
if self.environment.is_async:
raise RuntimeError("Template module attribute is unavailable in async mode")
return original_default_module(self)
return _get_default_module
async def make_module_async(self, vars=None, shared=False, locals=None):
context = self.new_context(vars, shared, locals)
body_stream = []
async for item in self.root_render_func(context):
body_stream.append(item)
return TemplateModule(self, context, body_stream)
def patch_template():
from . import Template
Template.generate = wrap_generate_func(Template.generate)
Template.generate_async = update_wrapper(generate_async, Template.generate_async)
Template.render_async = update_wrapper(render_async, Template.render_async)
Template.render = wrap_render_func(Template.render)
Template._get_default_module = wrap_default_module(Template._get_default_module)
Template._get_default_module_async = get_default_module_async
Template.make_module_async = update_wrapper(
make_module_async, Template.make_module_async
)
def patch_runtime():
from .runtime import BlockReference, Macro
BlockReference.__call__ = wrap_block_reference_call(BlockReference.__call__)
Macro._invoke = wrap_macro_invoke(Macro._invoke)
def patch_filters():
from .filters import FILTERS
from .asyncfilters import ASYNC_FILTERS
FILTERS.update(ASYNC_FILTERS)
def patch_all():
patch_template()
patch_runtime()
patch_filters()
async def auto_await(value):
if inspect.isawaitable(value):
return await value
return value
async def auto_aiter(iterable):
if hasattr(iterable, "__aiter__"):
async for item in iterable:
yield item
return
for item in iterable:
yield item
class AsyncLoopContext(LoopContext):
_to_iterator = staticmethod(auto_aiter)
@property
async def length(self):
if self._length is not None:
return self._length
try:
self._length = len(self._iterable)
except TypeError:
iterable = [x async for x in self._iterator]
self._iterator = self._to_iterator(iterable)
self._length = len(iterable) + self.index + (self._after is not missing)
return self._length
@property
async def revindex0(self):
return await self.length - self.index
@property
async def revindex(self):
return await self.length - self.index0
async def _peek_next(self):
if self._after is not missing:
return self._after
try:
self._after = await self._iterator.__anext__()
except StopAsyncIteration:
self._after = missing
return self._after
@property
async def last(self):
return await self._peek_next() is missing
@property
async def nextitem(self):
rv = await self._peek_next()
if rv is missing:
return self._undefined("there is no next item")
return rv
def __aiter__(self):
return self
async def __anext__(self):
if self._after is not missing:
rv = self._after
self._after = missing
else:
rv = await self._iterator.__anext__()
self.index0 += 1
self._before = self._current
self._current = rv
return rv, self
async def make_async_loop_context(iterable, undefined, recurse=None, depth0=0):
import warnings
warnings.warn(
"This template must be recompiled with at least Jinja 2.11, or"
" it will fail in 3.0.",
DeprecationWarning,
stacklevel=2,
)
return AsyncLoopContext(iterable, undefined, recurse, depth0)
patch_all()