chore: Fix Streaming Callback types (#9441)

* Fix types

* Add select_streaming_callback

haystack/components/generators/azure.py

@@ -3,13 +3,13 @@
 # SPDX-License-Identifier: Apache-2.0
 
 import os
-from typing import Any, Callable, Dict, Optional
+from typing import Any, Dict, Optional
 
 from openai.lib.azure import AzureADTokenProvider, AzureOpenAI
 
 from haystack import component, default_from_dict, default_to_dict
 from haystack.components.generators import OpenAIGenerator
-from haystack.dataclasses import StreamingChunk
+from haystack.dataclasses import StreamingCallbackT
 from haystack.utils import Secret, deserialize_callable, deserialize_secrets_inplace, serialize_callable
 from haystack.utils.http_client import init_http_client
 
@@ -63,7 +63,7 @@ class AzureOpenAIGenerator(OpenAIGenerator):
         api_key: Optional[Secret] = Secret.from_env_var("AZURE_OPENAI_API_KEY", strict=False),
         azure_ad_token: Optional[Secret] = Secret.from_env_var("AZURE_OPENAI_AD_TOKEN", strict=False),
         organization: Optional[str] = None,
-        streaming_callback: Optional[Callable[[StreamingChunk], None]] = None,
+        streaming_callback: Optional[StreamingCallbackT] = None,
         system_prompt: Optional[str] = None,
         timeout: Optional[float] = None,
         max_retries: Optional[int] = None,

haystack/components/generators/chat/hugging_face_local.py

@@ -10,7 +10,7 @@ from concurrent.futures import ThreadPoolExecutor
 from typing import Any, Callable, Dict, List, Literal, Optional, Union, cast
 
 from haystack import component, default_from_dict, default_to_dict, logging
-from haystack.dataclasses import ChatMessage, StreamingChunk, ToolCall, select_streaming_callback
+from haystack.dataclasses import ChatMessage, StreamingCallbackT, ToolCall, select_streaming_callback
 from haystack.lazy_imports import LazyImport
 from haystack.tools import (
     Tool,
@@ -130,7 +130,7 @@ class HuggingFaceLocalChatGenerator:
         generation_kwargs: Optional[Dict[str, Any]] = None,
         huggingface_pipeline_kwargs: Optional[Dict[str, Any]] = None,
         stop_words: Optional[List[str]] = None,
-        streaming_callback: Optional[Callable[[StreamingChunk], None]] = None,
+        streaming_callback: Optional[StreamingCallbackT] = None,
         tools: Optional[Union[List[Tool], Toolset]] = None,
         tool_parsing_function: Optional[Callable[[str], Optional[List[ToolCall]]]] = None,
         async_executor: Optional[ThreadPoolExecutor] = None,
@@ -330,7 +330,7 @@ class HuggingFaceLocalChatGenerator:
         self,
         messages: List[ChatMessage],
         generation_kwargs: Optional[Dict[str, Any]] = None,
-        streaming_callback: Optional[Callable[[StreamingChunk], None]] = None,
+        streaming_callback: Optional[StreamingCallbackT] = None,
         tools: Optional[Union[List[Tool], Toolset]] = None,
     ):
         """
@@ -492,7 +492,7 @@ class HuggingFaceLocalChatGenerator:
         self,
         messages: List[ChatMessage],
         generation_kwargs: Optional[Dict[str, Any]] = None,
-        streaming_callback: Optional[Callable[[StreamingChunk], None]] = None,
+        streaming_callback: Optional[StreamingCallbackT] = None,
         tools: Optional[Union[List[Tool], Toolset]] = None,
     ):
         """
@@ -546,7 +546,7 @@ class HuggingFaceLocalChatGenerator:
         tokenizer: Union["PreTrainedTokenizer", "PreTrainedTokenizerFast"],
         generation_kwargs: Dict[str, Any],
         stop_words: Optional[List[str]],
-        streaming_callback: Callable[[StreamingChunk], None],
+        streaming_callback: StreamingCallbackT,
     ):
         """
         Handles async streaming generation of responses.

haystack/components/generators/hugging_face_api.py

@@ -4,10 +4,10 @@
 
 from dataclasses import asdict
 from datetime import datetime
-from typing import Any, Callable, Dict, Iterable, List, Optional, Union, cast
+from typing import Any, Dict, Iterable, List, Optional, Union, cast
 
 from haystack import component, default_from_dict, default_to_dict
-from haystack.dataclasses import StreamingChunk
+from haystack.dataclasses import StreamingCallbackT, StreamingChunk, select_streaming_callback
 from haystack.lazy_imports import LazyImport
 from haystack.utils import Secret, deserialize_callable, deserialize_secrets_inplace, serialize_callable
 from haystack.utils.hf import HFGenerationAPIType, HFModelType, check_valid_model
@@ -80,7 +80,7 @@ class HuggingFaceAPIGenerator:
         token: Optional[Secret] = Secret.from_env_var(["HF_API_TOKEN", "HF_TOKEN"], strict=False),
         generation_kwargs: Optional[Dict[str, Any]] = None,
         stop_words: Optional[List[str]] = None,
-        streaming_callback: Optional[Callable[[StreamingChunk], None]] = None,
+        streaming_callback: Optional[StreamingCallbackT] = None,
     ):
         """
         Initialize the HuggingFaceAPIGenerator instance.
@@ -180,7 +180,7 @@ class HuggingFaceAPIGenerator:
     def run(
         self,
         prompt: str,
-        streaming_callback: Optional[Callable[[StreamingChunk], None]] = None,
+        streaming_callback: Optional[StreamingCallbackT] = None,
         generation_kwargs: Optional[Dict[str, Any]] = None,
     ):
         """
@@ -200,7 +200,9 @@ class HuggingFaceAPIGenerator:
         generation_kwargs = {**self.generation_kwargs, **(generation_kwargs or {})}
 
         # check if streaming_callback is passed
-        streaming_callback = streaming_callback or self.streaming_callback
+        streaming_callback = select_streaming_callback(
+            init_callback=self.streaming_callback, runtime_callback=streaming_callback, requires_async=False
+        )
 
         hf_output = self._client.text_generation(
             prompt, details=True, stream=streaming_callback is not None, **generation_kwargs
@@ -213,7 +215,7 @@ class HuggingFaceAPIGenerator:
         return self._build_non_streaming_response(cast(TextGenerationOutput, hf_output))
 
     def _stream_and_build_response(
-        self, hf_output: Iterable["TextGenerationStreamOutput"], streaming_callback: Callable[[StreamingChunk], None]
+        self, hf_output: Iterable["TextGenerationStreamOutput"], streaming_callback: StreamingCallbackT
     ):
         chunks: List[StreamingChunk] = []
         first_chunk_time = None

haystack/components/generators/hugging_face_local.py

@@ -2,10 +2,10 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-from typing import Any, Callable, Dict, List, Literal, Optional, cast
+from typing import Any, Dict, List, Literal, Optional, cast
 
 from haystack import component, default_from_dict, default_to_dict, logging
-from haystack.dataclasses import StreamingChunk
+from haystack.dataclasses import StreamingCallbackT, select_streaming_callback
 from haystack.lazy_imports import LazyImport
 from haystack.utils import (
     ComponentDevice,
@@ -63,7 +63,7 @@ class HuggingFaceLocalGenerator:
         generation_kwargs: Optional[Dict[str, Any]] = None,
         huggingface_pipeline_kwargs: Optional[Dict[str, Any]] = None,
         stop_words: Optional[List[str]] = None,
-        streaming_callback: Optional[Callable[[StreamingChunk], None]] = None,
+        streaming_callback: Optional[StreamingCallbackT] = None,
     ):
         """
         Creates an instance of a HuggingFaceLocalGenerator.
@@ -210,7 +210,7 @@ class HuggingFaceLocalGenerator:
     def run(
         self,
         prompt: str,
-        streaming_callback: Optional[Callable[[StreamingChunk], None]] = None,
+        streaming_callback: Optional[StreamingCallbackT] = None,
         generation_kwargs: Optional[Dict[str, Any]] = None,
     ):
         """
@@ -239,7 +239,9 @@ class HuggingFaceLocalGenerator:
         updated_generation_kwargs = {**self.generation_kwargs, **(generation_kwargs or {})}
 
         # check if streaming_callback is passed
-        streaming_callback = streaming_callback or self.streaming_callback
+        streaming_callback = select_streaming_callback(
+            init_callback=self.streaming_callback, runtime_callback=streaming_callback, requires_async=False
+        )
 
         if streaming_callback:
             num_responses = updated_generation_kwargs.get("num_return_sequences", 1)

haystack/components/generators/openai.py

@@ -4,13 +4,13 @@
 
 import os
 from datetime import datetime
-from typing import Any, Callable, Dict, List, Optional, Union
+from typing import Any, Dict, List, Optional, Union
 
 from openai import OpenAI, Stream
 from openai.types.chat import ChatCompletion, ChatCompletionChunk
 
 from haystack import component, default_from_dict, default_to_dict, logging
-from haystack.dataclasses import ChatMessage, StreamingChunk
+from haystack.dataclasses import ChatMessage, StreamingCallbackT, StreamingChunk, select_streaming_callback
 from haystack.utils import Secret, deserialize_callable, deserialize_secrets_inplace, serialize_callable
 from haystack.utils.http_client import init_http_client
 
@@ -54,7 +54,7 @@ class OpenAIGenerator:
         self,
         api_key: Secret = Secret.from_env_var("OPENAI_API_KEY"),
         model: str = "gpt-4o-mini",
-        streaming_callback: Optional[Callable[[StreamingChunk], None]] = None,
+        streaming_callback: Optional[StreamingCallbackT] = None,
         api_base_url: Optional[str] = None,
         organization: Optional[str] = None,
         system_prompt: Optional[str] = None,
@@ -178,7 +178,7 @@ class OpenAIGenerator:
         self,
         prompt: str,
         system_prompt: Optional[str] = None,
-        streaming_callback: Optional[Callable[[StreamingChunk], None]] = None,
+        streaming_callback: Optional[StreamingCallbackT] = None,
         generation_kwargs: Optional[Dict[str, Any]] = None,
     ):
         """
@@ -211,7 +211,9 @@ class OpenAIGenerator:
         generation_kwargs = {**self.generation_kwargs, **(generation_kwargs or {})}
 
         # check if streaming_callback is passed
-        streaming_callback = streaming_callback or self.streaming_callback
+        streaming_callback = select_streaming_callback(
+            init_callback=self.streaming_callback, runtime_callback=streaming_callback, requires_async=False
+        )
 
         # adapt ChatMessage(s) to the format expected by the OpenAI API
         openai_formatted_messages = [message.to_openai_dict_format() for message in messages]

haystack/utils/hf.py

@@ -4,10 +4,10 @@
 
 import copy
 from enum import Enum
-from typing import Any, Callable, Dict, List, Optional, Union
+from typing import Any, Dict, List, Optional, Union
 
 from haystack import logging
-from haystack.dataclasses import ChatMessage, StreamingChunk
+from haystack.dataclasses import ChatMessage, StreamingCallbackT, StreamingChunk
 from haystack.lazy_imports import LazyImport
 from haystack.utils.auth import Secret
 from haystack.utils.device import ComponentDevice
@@ -349,7 +349,7 @@ with LazyImport(message="Run 'pip install \"transformers[torch]\"'") as transfor
         Streaming handler for HuggingFaceLocalGenerator and HuggingFaceLocalChatGenerator.
 
         Note: This is a helper class for HuggingFaceLocalGenerator & HuggingFaceLocalChatGenerator enabling streaming
-        of generated text via Haystack Callable[StreamingChunk, None] callbacks.
+        of generated text via Haystack StreamingCallbackT callbacks.
 
         Do not use this class directly.
         """
@@ -357,7 +357,7 @@ with LazyImport(message="Run 'pip install \"transformers[torch]\"'") as transfor
         def __init__(
             self,
             tokenizer: Union[PreTrainedTokenizer, PreTrainedTokenizerFast],
-            stream_handler: Callable[[StreamingChunk], None],
+            stream_handler: StreamingCallbackT,
             stop_words: Optional[List[str]] = None,
         ):
             super().__init__(tokenizer=tokenizer, skip_prompt=True)  # type: ignore