prepare utils to run process preparation

client/ayon_core/addon/__init__.py

@@ -9,12 +9,17 @@ from .interfaces import (
 )
 
 from .base import (
+    ProcessPreparationError,
     AYONAddon,
     AddonsManager,
     TrayAddonsManager,
     load_addons,
 )
 
+from .utils import (
+    ensure_addons_are_process_ready,
+)
+
 
 __all__ = (
     "click_wrap",
@@ -25,8 +30,11 @@ __all__ = (
     "ITrayService",
     "IHostAddon",
 
+    "ProcessPreparationError",
     "AYONAddon",
     "AddonsManager",
     "TrayAddonsManager",
     "load_addons",
+
+    "ensure_addons_are_process_ready",
 )

client/ayon_core/addon/utils.py

@@ -0,0 +1,112 @@
+import os
+import sys
+import contextlib
+import tempfile
+import json
+from io import StringIO
+from typing import Optional
+
+from ayon_core.lib import run_ayon_launcher_process
+
+from .base import AddonsManager, ProcessContext, ProcessPreparationError
+
+
+def _handle_error(
+    process_context: ProcessContext,
+    message: str,
+    detail: Optional[str],
+):
+    """Handle error in process ready preparation.
+
+    Shows UI to inform user about the error, or prints the message
+        to stdout if running in headless mode.
+
+    Args:
+        process_context (ProcessContext): The context in which the
+            error occurred.
+        message (str): The message to show.
+        detail (Optional[str]): The detail message to show (usually
+            traceback).
+
+    """
+    if process_context.headless:
+        print(detail)
+        print(f"{10*'*'}\n{message}\n{10*'*'}")
+        return
+
+    current_dir = os.path.dirname(os.path.abspath(__file__))
+    script_path = os.path.join(current_dir, "ui", "process_ready_error.py")
+    with tempfile.NamedTemporaryFile("w", delete=False) as tmp:
+        tmp_path = tmp.name
+
+    try:
+        with open(tmp_path, "w") as stream:
+            json.dump(
+                {"message": message, "detail": detail},
+                stream
+            )
+
+        run_ayon_launcher_process(
+            "run", script_path, tmp_path
+        )
+
+    finally:
+        os.remove(tmp_path)
+
+
+def ensure_addons_are_process_ready(
+    process_context: ProcessContext,
+    addons_manager: Optional[AddonsManager] = None,
+    exit_on_failure: bool = True,
+):
+    """Ensure all enabled addons are ready to be used in the given context.
+
+    Call this method only in AYON launcher process and as first thing
+        to avoid possible clashes with preparation. For example 'QApplication'
+        should not be created.
+
+    Args:
+        process_context (ProcessContext): The context in which the
+            addons should be prepared.
+        addons_manager (Optional[AddonsManager]): The addons
+            manager to use. If not provided, a new one will be created.
+        exit_on_failure (bool, optional): If True, the process will exit
+            if an error occurs. Defaults to True.
+
+    Returns:
+        Optional[Exception]: The exception that occurred during the
+            preparation, if any.
+
+    """
+    if addons_manager is None:
+        addons_manager = AddonsManager()
+
+    exc = None
+    message = None
+    failed = False
+    use_detail = False
+    with contextlib.redirect_stdout(StringIO()) as stdout:
+        for addon in addons_manager.get_enabled_addons():
+            failed = True
+            try:
+                addon.ensure_is_process_ready(process_context)
+                failed = False
+            except ProcessPreparationError as exc:
+                message = str(exc)
+
+            except BaseException as exc:
+                message = "An unexpected error occurred."
+                use_detail = True
+
+            if failed:
+                break
+
+    if failed:
+        detail = None
+        if use_detail:
+            detail = stdout.get_value()
+
+        _handle_error(process_context, message, detail)
+        if not exit_on_failure:
+            return exc
+        sys.exit(1)