Upgrade streamlit as a dev dep to 1.12.0 and fix imports (#1005)

* Upgrade streamlit as a dev dep to 1.12.0 and fix imports

* Update CHANGELOG.md

* Fix to use packaging.version for version comparison

* Fix import

* Fix import

* Add a test matrix item

* Fix initialization of SessionInfo in a test

.github/workflows/main.yml

@@ -29,12 +29,15 @@ jobs:
             streamlit-version: 1.0.0
           - python-version: 3.9
             streamlit-version: 1.4.0
-          # Test with streamlit <1.6.0 and >=1.6.0. See https://github.com/whitphx/streamlit-webrtc/issues/709
+          # Test with streamlit >=1.6.0. See https://github.com/whitphx/streamlit-webrtc/issues/709
           - python-version: 3.9
             streamlit-version: 1.6.0
-          # Test with streamlit <1.8.0 and >=1.8.0. See https://github.com/whitphx/streamlit-webrtc/issues/759
+          # Test with streamlit >=1.8.0. See https://github.com/whitphx/streamlit-webrtc/issues/759
           - python-version: 3.9
             streamlit-version: 1.8.0
+          # Test with streamlit >=1.12.0. See https://github.com/whitphx/streamlit-webrtc/issues/1004
+          - python-version: 3.9
+            streamlit-version: 1.12.0
 
     steps:
     - uses: actions/checkout@v3

CHANGELOG.md

@@ -3,6 +3,9 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+### Fix
+- Escape-hatch to access the running Streamlit server object for the new web server design with streamlit>=1.12.0, #1005.
+
 ## [0.42.0] - 2022-07-02
 
 ### Fix

pyproject.toml

@@ -16,6 +16,7 @@ python = ">=3.7,<3.11"
 streamlit = ">=0.84.1"
 aiortc = "^1.1.2"
 typing_extensions = { version = ">=3.7.4,<5.0.0", python = "<3.8" }
+packaging = ">=20.0"
 
 [tool.poetry.dev-dependencies]
 black = "^21.12b0"

streamlit_webrtc/eventloop.py

@@ -2,12 +2,17 @@
 import contextlib
 from typing import Union
 
-from streamlit.server.server import Server
 from tornado.platform.asyncio import BaseAsyncIOLoop
 
+from .server import _is_modern_architecture, get_current_server
+
 
 def get_server_event_loop() -> asyncio.AbstractEventLoop:
-    current_server = Server.get_current()
+    current_server = get_current_server()
+
+    if _is_modern_architecture():
+        return current_server._eventloop
+
     ioloop = current_server._ioloop
 
     # `ioloop` is expected to be of type `BaseAsyncIOLoop`,

streamlit_webrtc/relay.py

@@ -1,13 +1,13 @@
 from aiortc.contrib.media import MediaRelay
-from streamlit.server.server import Server
 
 from .eventloop import get_server_event_loop, loop_context
+from .server import get_current_server
 
 _SERVER_GLOBAL_RELAY_ATTR_NAME_ = "streamlit-webrtc-global-relay"
 
 
 def get_global_relay() -> MediaRelay:
-    server = Server.get_current()
+    server = get_current_server()
 
     if hasattr(server, _SERVER_GLOBAL_RELAY_ATTR_NAME_):
         return getattr(server, _SERVER_GLOBAL_RELAY_ATTR_NAME_)

streamlit_webrtc/server.py

@@ -0,0 +1,67 @@
+import logging
+
+import streamlit as st
+from packaging import version
+
+logger = logging.getLogger(__name__)
+
+_server = None
+
+VERSION_1_12_0 = version.parse("1.12.0")
+
+
+def _is_modern_architecture() -> bool:
+    """Returns if the imported streamlit package version is >=1.12.0.
+    It is because since that version, streamlit has changed its internal architecture
+    making `web` and `runtime` submodules to which some files have been moved
+    decoupling the web server-related files and the core runtime,
+    e.g. https://github.com/streamlit/streamlit/pull/4956.
+
+    During this a huge refactoring, `Server._singleton` and
+    its accessor `Server.get_current()` have been removed
+    (https://github.com/streamlit/streamlit/pull/4966)
+    that we have been using as a server-wide global object,
+    so we have to change the way to access it.
+    """
+    return version.parse(st.__version__) >= VERSION_1_12_0
+
+
+def get_current_server():
+    global _server
+    if _server:
+        return _server
+
+    if _is_modern_architecture():
+        logger.debug(
+            "The running Streamlit version is gte 1.12.0. "
+            "Try to get the server instance"
+        )
+
+        import gc
+
+        from streamlit.web.server.server import Server
+
+        servers = [obj for obj in gc.get_objects() if isinstance(obj, Server)]
+
+        if len(servers) == 0:
+            raise RuntimeError("Unexpectedly no server exists")
+        if len(servers) > 1:
+            logger.warning(
+                "Unexpectedly multiple server instances exist. Use the first one."
+            )
+
+        _server = servers[0]
+    else:
+        logger.debug(
+            "The running Streamlit version is less than 1.12.0. "
+            "Call Server.get_current()"
+        )
+        try:
+            from streamlit.web.server.server import Server
+        except ModuleNotFoundError:
+            # streamlit < 1.12.0
+            from streamlit.server.server import Server
+
+        _server = Server.get_current()
+
+    return _server

streamlit_webrtc/session_info.py

@@ -1,20 +1,28 @@
 from typing import Optional
 
-from streamlit.server.server import SessionInfo
+try:
+    from streamlit.web.server.server import SessionInfo
+except ModuleNotFoundError:
+    # streamlit < 1.12.0
+    from streamlit.server.server import SessionInfo  # type: ignore
 
 try:
-    from streamlit.scriptrunner import get_script_run_ctx
+    from streamlit.runtime.scriptrunner import get_script_run_ctx
 except ModuleNotFoundError:
-    # streamlit < 1.8
+    # streamlit < 1.12.0
     try:
-        from streamlit.script_run_context import get_script_run_ctx  # type: ignore
+        from streamlit.scriptrunner import get_script_run_ctx  # type: ignore
     except ModuleNotFoundError:
-        # streamlit < 1.4
-        from streamlit.report_thread import (  # type: ignore
-            get_report_ctx as get_script_run_ctx,
-        )
+        # streamlit < 1.8
+        try:
+            from streamlit.script_run_context import get_script_run_ctx  # type: ignore
+        except ModuleNotFoundError:
+            # streamlit < 1.4
+            from streamlit.report_thread import (  # type: ignore
+                get_report_ctx as get_script_run_ctx,
+            )
 
-from streamlit.server.server import Server
+from .server import get_current_server
 
 # Ref: https://gist.github.com/tvst/036da038ab3e999a64497f42de966a92
 
@@ -28,7 +36,7 @@ def get_session_id() -> str:
 
 
 def get_this_session_info() -> Optional[SessionInfo]:
-    current_server = Server.get_current()
+    current_server = get_current_server()
 
     # The original implementation of SessionState (https://gist.github.com/tvst/036da038ab3e999a64497f42de966a92) has a problem    # noqa: E501
     # as referred to in https://gist.github.com/tvst/036da038ab3e999a64497f42de966a92#gistcomment-3484515,                         # noqa: E501

streamlit_webrtc/shutdown.py

@@ -4,13 +4,17 @@
 from typing import Callable, Union
 
 try:
-    from streamlit.app_session import AppSession, AppSessionState
+    from streamlit.runtime.app_session import AppSession, AppSessionState
 except ModuleNotFoundError:
-    # streamlit < 1.4
-    from streamlit.report_session import (  # type: ignore
-        ReportSession as AppSession,
-        ReportSessionState as AppSessionState,
-    )
+    # streamlit < 1.12.0
+    try:
+        from streamlit.app_session import AppSession, AppSessionState  # type: ignore
+    except ModuleNotFoundError:
+        # streamlit < 1.4
+        from streamlit.report_session import (  # type: ignore
+            ReportSession as AppSession,
+            ReportSessionState as AppSessionState,
+        )
 
 from .session_info import get_this_session_info
 

tests/session_info_test.py

@@ -1,10 +1,12 @@
 from unittest.mock import Mock
 
-from streamlit.server.server import SessionInfo
-
-from streamlit_webrtc.session_info import get_script_run_count
+from streamlit_webrtc.server import _is_modern_architecture
+from streamlit_webrtc.session_info import SessionInfo, get_script_run_count
 
 
 def test_get_script_run_count():
-    session_info = SessionInfo(ws=Mock(), session=Mock())
+    if _is_modern_architecture():
+        session_info = SessionInfo(client=Mock(), session=Mock())
+    else:
+        session_info = SessionInfo(ws=Mock(), session=Mock())
     assert get_script_run_count(session_info) == 0