Document the lifespan event handler parameter#1110
Document the lifespan event handler parameter#1110graingert merged 4 commits intoKludex:masterfrom emilmelnikov:patch-1
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#799 added support for the `lifespan` parameter, but it was not reflected in the documentation.
graingert
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lifespan now takes an async context manager factory, eg an async generator function decorated with @contextlib(2).asynccontextmanager
Update docs according to changes in #1227.
docs/events.md
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| async with anyio.create_task_group() as app.tg: | ||
| try: | ||
| yield | ||
| finally: | ||
| with anyio.CancelScope(shield=True): | ||
| # release async resources |
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sorry I lead you wrong here - the TaskGroup context manager will capture any CancelledError for you
| async with anyio.create_task_group() as app.tg: | |
| try: | |
| yield | |
| finally: | |
| with anyio.CancelScope(shield=True): | |
| # release async resources | |
| async with anyio.create_task_group() as app.tg: | |
| yield | |
| # release async resources |
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I do want to somehow document that yield can now throw CancelledError
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sometimes you want to acquire/release resources inside the TaskGroup and sometimes you want to acquire/release them outside the TaskGroup and there's no specific answer as they both have different behaviours with their own pros/cons
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I'm not sure we should have the main documentation for lifespan be setting app.tg. That could be a separate topic, but I think the initial introduction to "make a lifespan" example should be as simple as possible.
@contextlib.asynccontextmanager
async def lifespan(app):
async with some_async_resource():
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I like the simple lifespan example; we can also add a link to anyio documentation on task groups and cancellation.
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Blocks #1233 |
Simplify asynccontextmanager example, and add a link to anyio docs.
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Thanks! Apologies for dragging this one off topic in my original review |
#799 added support for the
lifespanparameter, but it was not reflected in the documentation.